Refactor

app/src/main/java/org/solovyev/android/calculator/AndroidCalculator.java

@@ -27,7 +27,7 @@ import android.content.SharedPreferences;
 import android.preference.PreferenceManager;
 import jscl.NumeralBase;
 import jscl.math.Generic;
-import org.solovyev.android.calculator.history.CalculatorHistoryState;
+import org.solovyev.android.calculator.history.HistoryState;
 import org.solovyev.android.calculator.jscl.JsclOperation;
 import org.solovyev.common.history.HistoryAction;
 import org.solovyev.common.msg.Message;
@@ -156,12 +156,12 @@ public class AndroidCalculator implements Calculator, CalculatorEventListener, S
 
     @Override
     @Nonnull
-    public CalculatorHistoryState getCurrentHistoryState() {
+    public HistoryState getCurrentHistoryState() {
         return calculator.getCurrentHistoryState();
     }
 
     @Override
-    public void setCurrentHistoryState(@Nonnull CalculatorHistoryState editorHistoryState) {
+    public void setCurrentHistoryState(@Nonnull HistoryState editorHistoryState) {
         calculator.setCurrentHistoryState(editorHistoryState);
     }
 

app/src/main/java/org/solovyev/android/calculator/AndroidCalculatorDisplayView.java

@@ -68,7 +68,7 @@ public class AndroidCalculatorDisplayView extends AutoResizeTextView implements
     @Nonnull
     private final Handler uiHandler = new Handler();
     @Nonnull
-    private volatile CalculatorDisplayViewState state = CalculatorDisplayViewStateImpl.newDefaultInstance();
+    private volatile DisplayState state = DisplayState.empty();
     private volatile boolean initialized = false;
 
 	/*
@@ -109,14 +109,14 @@ public class AndroidCalculatorDisplayView extends AutoResizeTextView implements
 
     @Nonnull
     @Override
-    public CalculatorDisplayViewState getState() {
+    public DisplayState getState() {
         synchronized (lock) {
             return this.state;
         }
     }
 
     @Override
-    public void setState(@Nonnull final CalculatorDisplayViewState state) {
+    public void setState(@Nonnull final DisplayState state) {
 
         uiHandler.post(new Runnable() {
             @Override

app/src/main/java/org/solovyev/android/calculator/BaseUi.java

@@ -40,13 +40,12 @@ import org.solovyev.android.views.dragbutton.DragButton;
 import org.solovyev.android.views.dragbutton.DragDirection;
 import org.solovyev.android.views.dragbutton.DragListener;
 import org.solovyev.android.views.dragbutton.SimpleDragListener;
-import org.solovyev.android.calculator.history.CalculatorHistoryState;
+import org.solovyev.android.calculator.history.HistoryState;
 import org.solovyev.android.calculator.history.HistoryDragProcessor;
 import org.solovyev.android.calculator.view.AngleUnitsButton;
 import org.solovyev.android.calculator.view.LongClickEraser;
 import org.solovyev.android.calculator.view.NumeralBasesButton;
 import org.solovyev.android.calculator.view.ViewsCache;
-import org.solovyev.common.math.Point2d;
 
 import java.util.ArrayList;
 import java.util.List;
@@ -166,7 +165,7 @@ public abstract class BaseUi implements SharedPreferences.OnSharedPreferenceChan
         final ViewsCache views = ViewsCache.forView(root);
         setOnDragListeners(views, activity);
 
-        HistoryDragProcessor<CalculatorHistoryState> historyDragProcessor = new HistoryDragProcessor<>(getCalculator());
+        HistoryDragProcessor<HistoryState> historyDragProcessor = new HistoryDragProcessor<>(getCalculator());
         final DragListener historyDragListener = newDragListener(historyDragProcessor, activity);
         final DragButton historyButton = getButton(views, R.id.cpp_button_history);
         if (historyButton != null) {

app/src/main/java/org/solovyev/android/calculator/Calculator.java

@@ -22,7 +22,7 @@
 
 package org.solovyev.android.calculator;
 
-import org.solovyev.android.calculator.history.CalculatorHistoryState;
+import org.solovyev.android.calculator.history.HistoryState;
 import org.solovyev.android.calculator.jscl.JsclOperation;
 import org.solovyev.common.history.HistoryControl;
 
@@ -37,7 +37,7 @@ import jscl.math.Generic;
  * Date: 20.09.12
  * Time: 16:38
  */
-public interface Calculator extends CalculatorEventContainer, HistoryControl<CalculatorHistoryState> {
+public interface Calculator extends CalculatorEventContainer, HistoryControl<HistoryState> {
 
     void init();
 

app/src/main/java/org/solovyev/android/calculator/CalculatorActivityLauncher.java

@@ -130,7 +130,7 @@ public final class CalculatorActivityLauncher implements CalculatorEventListener
 
     public static void tryCreateVar(@Nonnull final Context context) {
         final CalculatorDisplay display = Locator.getInstance().getDisplay();
-        final CalculatorDisplayViewState viewState = display.getViewState();
+        final DisplayState viewState = display.getViewState();
         if (viewState.isValid()) {
             final String varValue = viewState.getText();
             if (!Strings.isEmpty(varValue)) {
@@ -156,7 +156,7 @@ public final class CalculatorActivityLauncher implements CalculatorEventListener
 
     public static void tryCreateFunction(@Nonnull final Context context) {
         final CalculatorDisplay display = Locator.getInstance().getDisplay();
-        final CalculatorDisplayViewState viewState = display.getViewState();
+        final DisplayState viewState = display.getViewState();
 
         if (viewState.isValid()) {
             final String functionValue = viewState.getText();
@@ -180,7 +180,7 @@ public final class CalculatorActivityLauncher implements CalculatorEventListener
     public static void tryPlot() {
         final CalculatorPlotter plotter = Locator.getInstance().getPlotter();
         final CalculatorDisplay display = Locator.getInstance().getDisplay();
-        final CalculatorDisplayViewState viewState = display.getViewState();
+        final DisplayState viewState = display.getViewState();
 
         if (viewState.isValid()) {
             final String functionValue = viewState.getText();

app/src/main/java/org/solovyev/android/calculator/CalculatorConversionEventData.java

@@ -36,7 +36,7 @@ public interface CalculatorConversionEventData extends CalculatorEventData {
 
     // display state on the moment of conversion
     @Nonnull
-    CalculatorDisplayViewState getDisplayState();
+    DisplayState getDisplayState();
 
     @Nonnull
     NumeralBase getFromNumeralBase();

app/src/main/java/org/solovyev/android/calculator/CalculatorConversionEventDataImpl.java

@@ -47,7 +47,7 @@ public class CalculatorConversionEventDataImpl implements CalculatorConversionEv
     private Generic value;
 
     @Nonnull
-    private CalculatorDisplayViewState displayState;
+    private DisplayState displayState;
 
     private CalculatorConversionEventDataImpl() {
     }
@@ -57,7 +57,7 @@ public class CalculatorConversionEventDataImpl implements CalculatorConversionEv
                                                             @Nonnull Generic value,
                                                             @Nonnull NumeralBase from,
                                                             @Nonnull NumeralBase to,
-                                                            @Nonnull CalculatorDisplayViewState displayViewState) {
+                                                            @Nonnull DisplayState displayViewState) {
         final CalculatorConversionEventDataImpl result = new CalculatorConversionEventDataImpl();
 
         result.calculatorEventData = calculatorEventData;
@@ -102,7 +102,7 @@ public class CalculatorConversionEventDataImpl implements CalculatorConversionEv
 
     @Nonnull
     @Override
-    public CalculatorDisplayViewState getDisplayState() {
+    public DisplayState getDisplayState() {
         return this.displayState;
     }
 

app/src/main/java/org/solovyev/android/calculator/CalculatorDisplay.java

@@ -40,9 +40,9 @@ public interface CalculatorDisplay extends CalculatorEventListener {
     void setView(@Nonnull CalculatorDisplayView view);
 
     @Nonnull
-    CalculatorDisplayViewState getViewState();
+    DisplayState getViewState();
 
-    void setViewState(@Nonnull CalculatorDisplayViewState viewState);
+    void setViewState(@Nonnull DisplayState viewState);
 
     @Nonnull
     CalculatorEventData getLastEventData();

app/src/main/java/org/solovyev/android/calculator/CalculatorDisplayChangeEventData.java

@@ -27,5 +27,5 @@ package org.solovyev.android.calculator;
  * Date: 9/21/12
  * Time: 9:49 PM
  */
-public interface CalculatorDisplayChangeEventData extends Change<CalculatorDisplayViewState> {
+public interface CalculatorDisplayChangeEventData extends Change<DisplayState> {
 }

app/src/main/java/org/solovyev/android/calculator/CalculatorDisplayChangeEventDataImpl.java

@@ -32,25 +32,25 @@ import javax.annotation.Nonnull;
 public class CalculatorDisplayChangeEventDataImpl implements CalculatorDisplayChangeEventData {
 
     @Nonnull
-    private final CalculatorDisplayViewState oldState;
+    private final DisplayState oldState;
 
     @Nonnull
-    private final CalculatorDisplayViewState newState;
+    private final DisplayState newState;
 
-    public CalculatorDisplayChangeEventDataImpl(@Nonnull CalculatorDisplayViewState oldState, @Nonnull CalculatorDisplayViewState newState) {
+    public CalculatorDisplayChangeEventDataImpl(@Nonnull DisplayState oldState, @Nonnull DisplayState newState) {
         this.oldState = oldState;
         this.newState = newState;
     }
 
     @Nonnull
     @Override
-    public CalculatorDisplayViewState getOldValue() {
+    public DisplayState getOldValue() {
         return this.oldState;
     }
 
     @Nonnull
     @Override
-    public CalculatorDisplayViewState getNewValue() {
+    public DisplayState getNewValue() {
         return this.newState;
     }
 }

app/src/main/java/org/solovyev/android/calculator/CalculatorDisplayImpl.java

@@ -32,11 +32,6 @@ import static org.solovyev.android.calculator.CalculatorEventType.conversion_fai
 import static org.solovyev.android.calculator.CalculatorEventType.conversion_result;
 import static org.solovyev.android.calculator.CalculatorEventType.display_state_changed;
 
-/**
- * User: serso
- * Date: 9/20/12
- * Time: 8:24 PM
- */
 public class CalculatorDisplayImpl implements CalculatorDisplay {
 
     @Nonnull
@@ -48,7 +43,7 @@ public class CalculatorDisplayImpl implements CalculatorDisplay {
     @Nullable
     private CalculatorDisplayView view;
     @Nonnull
-    private CalculatorDisplayViewState viewState = CalculatorDisplayViewStateImpl.newDefaultInstance();
+    private DisplayState viewState = DisplayState.empty();
 
     public CalculatorDisplayImpl(@Nonnull Calculator calculator) {
         this.calculator = calculator;
@@ -81,22 +76,22 @@ public class CalculatorDisplayImpl implements CalculatorDisplay {
 
     @Nonnull
     @Override
-    public CalculatorDisplayViewState getViewState() {
+    public DisplayState getViewState() {
         return this.viewState;
     }
 
     @Override
-    public void setViewState(@Nonnull CalculatorDisplayViewState newViewState) {
+    public void setViewState(@Nonnull DisplayState newViewState) {
         synchronized (viewLock) {
-            final CalculatorDisplayViewState oldViewState = setViewState0(newViewState);
+            final DisplayState oldViewState = setViewState0(newViewState);
 
             this.calculator.fireCalculatorEvent(display_state_changed, new CalculatorDisplayChangeEventDataImpl(oldViewState, newViewState));
         }
     }
 
-    private void setViewStateForSequence(@Nonnull CalculatorDisplayViewState newViewState, @Nonnull Long sequenceId) {
+    private void setViewStateForSequence(@Nonnull DisplayState newViewState, @Nonnull Long sequenceId) {
         synchronized (viewLock) {
-            final CalculatorDisplayViewState oldViewState = setViewState0(newViewState);
+            final DisplayState oldViewState = setViewState0(newViewState);
 
             this.calculator.fireCalculatorEvent(display_state_changed, new CalculatorDisplayChangeEventDataImpl(oldViewState, newViewState), sequenceId);
         }
@@ -104,8 +99,8 @@ public class CalculatorDisplayImpl implements CalculatorDisplay {
 
     // must be synchronized with viewLock
     @Nonnull
-    private CalculatorDisplayViewState setViewState0(@Nonnull CalculatorDisplayViewState newViewState) {
+    private DisplayState setViewState0(@Nonnull DisplayState newViewState) {
-        final CalculatorDisplayViewState oldViewState = this.viewState;
+        final DisplayState oldViewState = this.viewState;
 
         this.viewState = newViewState;
         if (this.view != null) {
@@ -152,7 +147,7 @@ public class CalculatorDisplayImpl implements CalculatorDisplay {
 
     private void processConversationFailed(@Nonnull CalculatorConversionEventData calculatorEventData,
                                            @Nonnull ConversionFailure data) {
-        this.setViewStateForSequence(CalculatorDisplayViewStateImpl.newErrorState(calculatorEventData.getDisplayState().getOperation(), CalculatorMessages.getBundle().getString(CalculatorMessages.syntax_error)), calculatorEventData.getSequenceId());
+        this.setViewStateForSequence(DisplayState.createError(calculatorEventData.getDisplayState().getOperation(), CalculatorMessages.getBundle().getString(CalculatorMessages.syntax_error)), calculatorEventData.getSequenceId());
 
     }
 
@@ -172,18 +167,18 @@ public class CalculatorDisplayImpl implements CalculatorDisplay {
             }
         }
 
-        this.setViewStateForSequence(CalculatorDisplayViewStateImpl.newErrorState(calculatorEventData.getOperation(), errorMessage), calculatorEventData.getSequenceId());
+        this.setViewStateForSequence(DisplayState.createError(calculatorEventData.getOperation(), errorMessage), calculatorEventData.getSequenceId());
     }
 
     private void processCalculationCancelled(@Nonnull CalculatorEvaluationEventData calculatorEventData) {
         final String errorMessage = CalculatorMessages.getBundle().getString(CalculatorMessages.syntax_error);
 
-        this.setViewStateForSequence(CalculatorDisplayViewStateImpl.newErrorState(calculatorEventData.getOperation(), errorMessage), calculatorEventData.getSequenceId());
+        this.setViewStateForSequence(DisplayState.createError(calculatorEventData.getOperation(), errorMessage), calculatorEventData.getSequenceId());
     }
 
     private void processCalculationResult(@Nonnull CalculatorEvaluationEventData calculatorEventData, @Nonnull CalculatorOutput data) {
         final String stringResult = data.getStringResult();
-        this.setViewStateForSequence(CalculatorDisplayViewStateImpl.newValidState(calculatorEventData.getOperation(), data.getResult(), stringResult, 0), calculatorEventData.getSequenceId());
+        this.setViewStateForSequence(DisplayState.createValid(calculatorEventData.getOperation(), data.getResult(), stringResult, 0), calculatorEventData.getSequenceId());
     }
 
     private void processConversationResult(@Nonnull CalculatorConversionEventData calculatorEventData, @Nonnull String result) {
@@ -192,7 +187,7 @@ public class CalculatorDisplayImpl implements CalculatorDisplay {
             result = calculatorEventData.getToNumeralBase().getJsclPrefix() + result;
         }
 
-        final CalculatorDisplayViewState displayState = calculatorEventData.getDisplayState();
+        final DisplayState displayState = calculatorEventData.getDisplayState();
-        this.setViewStateForSequence(CalculatorDisplayViewStateImpl.newValidState(displayState.getOperation(), displayState.getResult(), result, 0), calculatorEventData.getSequenceId());
+        this.setViewStateForSequence(DisplayState.createValid(displayState.getOperation(), displayState.getResult(), result, 0), calculatorEventData.getSequenceId());
     }
 }

app/src/main/java/org/solovyev/android/calculator/CalculatorDisplayMenuItem.java

@@ -38,18 +38,18 @@ import jscl.math.Generic;
  * Date: 21.09.12
  * Time: 10:55
  */
-public enum CalculatorDisplayMenuItem implements LabeledMenuItem<CalculatorDisplayViewState> {
+public enum CalculatorDisplayMenuItem implements LabeledMenuItem<DisplayState> {
 
     copy(R.string.c_copy) {
         @Override
-        public void onClick(@Nonnull CalculatorDisplayViewState data, @Nonnull Context context) {
+        public void onClick(@Nonnull DisplayState data, @Nonnull Context context) {
             Locator.getInstance().getKeyboard().copyButtonPressed();
         }
     },
 
     convert_to_bin(R.string.convert_to_bin) {
         @Override
-        public void onClick(@Nonnull CalculatorDisplayViewState data, @Nonnull Context context) {
+        public void onClick(@Nonnull DisplayState data, @Nonnull Context context) {
             ConversionMenuItem.convert_to_bin.onClick(data, context);
         }
 
@@ -61,7 +61,7 @@ public enum CalculatorDisplayMenuItem implements LabeledMenuItem<CalculatorDispl
 
     convert_to_dec(R.string.convert_to_dec) {
         @Override
-        public void onClick(@Nonnull CalculatorDisplayViewState data, @Nonnull Context context) {
+        public void onClick(@Nonnull DisplayState data, @Nonnull Context context) {
             ConversionMenuItem.convert_to_dec.onClick(data, context);
         }
 
@@ -73,7 +73,7 @@ public enum CalculatorDisplayMenuItem implements LabeledMenuItem<CalculatorDispl
 
     convert_to_hex(R.string.convert_to_hex) {
         @Override
-        public void onClick(@Nonnull CalculatorDisplayViewState data, @Nonnull Context context) {
+        public void onClick(@Nonnull DisplayState data, @Nonnull Context context) {
             ConversionMenuItem.convert_to_hex.onClick(data, context);
         }
 
@@ -85,7 +85,7 @@ public enum CalculatorDisplayMenuItem implements LabeledMenuItem<CalculatorDispl
 
     convert(R.string.c_convert) {
         @Override
-        public void onClick(@Nonnull CalculatorDisplayViewState data, @Nonnull Context context) {
+        public void onClick(@Nonnull DisplayState data, @Nonnull Context context) {
             final Generic result = data.getResult();
             if (result != null) {
                 new NumeralBaseConverterDialog(result.toString()).show(context);
@@ -100,7 +100,7 @@ public enum CalculatorDisplayMenuItem implements LabeledMenuItem<CalculatorDispl
 
     plot(R.string.c_plot) {
         @Override
-        public void onClick(@Nonnull CalculatorDisplayViewState data, @Nonnull Context context) {
+        public void onClick(@Nonnull DisplayState data, @Nonnull Context context) {
             final Generic expression = data.getResult();
             if (expression == null) throw new AssertionError();
 
@@ -121,7 +121,7 @@ public enum CalculatorDisplayMenuItem implements LabeledMenuItem<CalculatorDispl
         this.captionId = captionId;
     }
 
-    public final boolean isItemVisible(@Nonnull CalculatorDisplayViewState displayViewState) {
+    public final boolean isItemVisible(@Nonnull DisplayState displayViewState) {
         //noinspection ConstantConditions
         return displayViewState.isValid() && displayViewState.getResult() != null && isItemVisibleFor(displayViewState.getResult(), displayViewState.getOperation());
     }

app/src/main/java/org/solovyev/android/calculator/CalculatorDisplayOnClickListener.java

@@ -52,7 +52,7 @@ public class CalculatorDisplayOnClickListener implements View.OnClickListener {
         if (v instanceof CalculatorDisplayView) {
             final CalculatorDisplay cd = Locator.getInstance().getDisplay();
 
-            final CalculatorDisplayViewState displayViewState = cd.getViewState();
+            final DisplayState displayViewState = cd.getViewState();
 
             if (displayViewState.isValid()) {
                 final List<CalculatorDisplayMenuItem> filteredMenuItems = new ArrayList<CalculatorDisplayMenuItem>(CalculatorDisplayMenuItem.values().length);

app/src/main/java/org/solovyev/android/calculator/CalculatorDisplayView.java

@@ -32,7 +32,7 @@ import javax.annotation.Nonnull;
 public interface CalculatorDisplayView {
 
     @Nonnull
-    CalculatorDisplayViewState getState();
+    DisplayState getState();
 
-    void setState(@Nonnull CalculatorDisplayViewState state);
+    void setState(@Nonnull DisplayState state);
 }

app/src/main/java/org/solovyev/android/calculator/CalculatorDisplayViewState.java

@@ -1,59 +0,0 @@
-/*
- * Copyright 2013 serso aka se.solovyev
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *    http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- *
- * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
- * Contact details
- *
- * Email: se.solovyev@gmail.com
- * Site:  http://se.solovyev.org
- */
-
-package org.solovyev.android.calculator;
-
-import org.solovyev.android.calculator.jscl.JsclOperation;
-
-import java.io.Serializable;
-
-import javax.annotation.Nonnull;
-import javax.annotation.Nullable;
-
-import jscl.math.Generic;
-
-/**
- * User: serso
- * Date: 9/20/12
- * Time: 9:50 PM
- */
-public interface CalculatorDisplayViewState extends Serializable {
-
-    @Nonnull
-    String getText();
-
-    int getSelection();
-
-    @Nullable
-    Generic getResult();
-
-    boolean isValid();
-
-    @Nullable
-    String getErrorMessage();
-
-    @Nonnull
-    JsclOperation getOperation();
-
-    @Nullable
-    String getStringResult();
-}

app/src/main/java/org/solovyev/android/calculator/CalculatorEditor.java

@@ -1,117 +0,0 @@
-/*
- * Copyright 2013 serso aka se.solovyev
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *    http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- *
- * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
- * Contact details
- *
- * Email: se.solovyev@gmail.com
- * Site:  http://se.solovyev.org
- */
-
-package org.solovyev.android.calculator;
-
-import org.solovyev.common.gui.CursorControl;
-
-import javax.annotation.Nonnull;
-
-/**
- * User: Solovyev_S
- * Date: 21.09.12
- * Time: 11:47
- */
-public interface CalculatorEditor extends CalculatorEventListener {
-
-    @Nonnull
-    String TAG = CalculatorEditor.class.getSimpleName();
-
-    void setView(@Nonnull EditorView view);
-
-    void clearView(@Nonnull EditorView view);
-
-    @Nonnull
-    EditorState getViewState();
-
-    void setViewState(@Nonnull EditorState viewState);
-
-    // updates state of view (view.setState())
-    void updateViewState();
-
-	/*
-    **********************************************************************
-	*
-	*                           CURSOR CONTROL
-	*
-	**********************************************************************
-	*/
-
-    /**
-     * Method sets the cursor to the beginning
-     */
-    @Nonnull
-    EditorState setCursorOnStart();
-
-    /**
-     * Method sets the cursor to the end
-     */
-    @Nonnull
-    EditorState setCursorOnEnd();
-
-    /**
-     * Method moves cursor to the left of current position
-     */
-    @Nonnull
-    EditorState moveCursorLeft();
-
-    /**
-     * Method moves cursor to the right of current position
-     */
-    @Nonnull
-    EditorState moveCursorRight();
-
-    @Nonnull
-    CursorControl asCursorControl();
-
-
-    /*
-    **********************************************************************
-    *
-    *                           EDITOR OPERATIONS
-    *
-    **********************************************************************
-    */
-    @Nonnull
-    EditorState erase();
-
-    @Nonnull
-    EditorState clear();
-
-    @Nonnull
-    EditorState setText(@Nonnull String text);
-
-    @Nonnull
-    EditorState setText(@Nonnull String text, int selection);
-
-    @Nonnull
-    EditorState insert(@Nonnull String text);
-
-    @Nonnull
-    EditorState insert(@Nonnull String text, int selectionOffset);
-
-    @Nonnull
-    EditorState moveSelection(int offset);
-
-    @Nonnull
-    EditorState setSelection(int selection);
-}

app/src/main/java/org/solovyev/android/calculator/CalculatorEditorImpl.java

@@ -1,356 +0,0 @@
-/*
- * Copyright 2013 serso aka se.solovyev
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *    http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- *
- * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
- * Contact details
- *
- * Email: se.solovyev@gmail.com
- * Site:  http://se.solovyev.org
- */
-
-package org.solovyev.android.calculator;
-
-import org.solovyev.android.calculator.history.CalculatorHistoryState;
-import org.solovyev.android.calculator.history.EditorHistoryState;
-import org.solovyev.android.calculator.text.TextProcessor;
-import org.solovyev.android.calculator.text.TextProcessorEditorResult;
-import org.solovyev.common.gui.CursorControl;
-import org.solovyev.common.text.Strings;
-
-import javax.annotation.Nonnull;
-import javax.annotation.Nullable;
-
-import static java.lang.Math.min;
-import static org.solovyev.android.calculator.CalculatorEditorChangeEventData.newChangeEventData;
-import static org.solovyev.android.calculator.CalculatorEventType.editor_state_changed;
-import static org.solovyev.android.calculator.CalculatorEventType.editor_state_changed_light;
-
-/**
- * User: Solovyev_S
- * Date: 21.09.12
- * Time: 11:53
- */
-public class CalculatorEditorImpl implements CalculatorEditor {
-
-    @Nonnull
-    private final Object viewLock = new Object();
-    @Nonnull
-    private final Calculator calculator;
-    @Nonnull
-    private final CalculatorEventHolder lastEventHolder;
-    @Nonnull
-    private final CursorControlAdapter cursorControlAdapter = new CursorControlAdapter(this);
-    @Nullable
-    private final TextProcessor<TextProcessorEditorResult, String> textProcessor;
-    @Nullable
-    private EditorView view;
-    @Nonnull
-    private EditorState lastViewState = EditorState.empty();
-
-    public CalculatorEditorImpl(@Nonnull Calculator calculator, @Nullable TextProcessor<TextProcessorEditorResult, String> textProcessor) {
-        this.calculator = calculator;
-        this.textProcessor = textProcessor;
-        this.calculator.addCalculatorEventListener(this);
-        this.lastEventHolder = new CalculatorEventHolder(CalculatorUtils.createFirstEventDataId());
-    }
-
-    public static int clamp(int selection, @Nonnull CharSequence text) {
-        return clamp(selection, text.length());
-    }
-
-    public static int clamp(int selection, int max) {
-        return min(Math.max(selection, 0), max);
-    }
-
-    @Override
-    public void setView(@Nonnull EditorView view) {
-        synchronized (viewLock) {
-            this.view = view;
-            this.view.setState(lastViewState);
-        }
-    }
-
-    @Override
-    public void clearView(@Nonnull EditorView view) {
-        synchronized (viewLock) {
-            if (this.view == view) {
-                this.view = null;
-            }
-        }
-    }
-
-    @Nonnull
-    @Override
-    public EditorState getViewState() {
-        return lastViewState;
-    }
-
-    @Override
-    public void setViewState(@Nonnull EditorState newViewState) {
-        setViewState(newViewState, true);
-    }
-
-    @Override
-    public void updateViewState() {
-        setViewState(this.lastViewState, false);
-    }
-
-    private void setViewState(@Nonnull EditorState newViewState, boolean majorChanges) {
-        if (textProcessor != null) {
-            try {
-                final TextProcessorEditorResult result = textProcessor.process(newViewState.getText());
-                newViewState = EditorState.create(result.getCharSequence(), newViewState.getSelection() + result.getOffset());
-            } catch (CalculatorParseException e) {
-                Locator.getInstance().getLogger().error(TAG, e.getMessage(), e);
-            }
-        }
-        synchronized (viewLock) {
-            final EditorState oldViewState = this.lastViewState;
-
-            this.lastViewState = newViewState;
-            if (this.view != null) {
-                this.view.setState(newViewState);
-            }
-
-            fireStateChangedEvent(majorChanges, oldViewState, newViewState);
-        }
-    }
-
-	/*
-    **********************************************************************
-	*
-	*                           SELECTION
-	*
-	**********************************************************************
-	*/
-
-    private void fireStateChangedEvent(boolean majorChanges, @Nonnull EditorState oldViewState, @Nonnull EditorState newViewState) {
-        if (!Thread.holdsLock(viewLock)) throw new AssertionError();
-
-        if (majorChanges) {
-            calculator.fireCalculatorEvent(editor_state_changed, newChangeEventData(oldViewState, newViewState));
-        } else {
-            calculator.fireCalculatorEvent(editor_state_changed_light, newChangeEventData(oldViewState, newViewState));
-        }
-    }
-
-    @Override
-    public void onCalculatorEvent(@Nonnull CalculatorEventData calculatorEventData,
-                                  @Nonnull CalculatorEventType calculatorEventType,
-                                  @Nullable Object data) {
-        final CalculatorEventHolder.Result result = lastEventHolder.apply(calculatorEventData);
-
-        if (result.isNewAfter()) {
-            switch (calculatorEventType) {
-                case use_history_state:
-                    final CalculatorHistoryState calculatorHistoryState = (CalculatorHistoryState) data;
-                    final EditorHistoryState editorState = calculatorHistoryState.getEditorState();
-                    this.setText(Strings.getNotEmpty(editorState.getText(), ""), editorState.getCursorPosition());
-                    break;
-            }
-        }
-    }
-
-    @Nonnull
-    private EditorState newSelectionViewState(int newSelection) {
-        if (this.lastViewState.getSelection() != newSelection) {
-            final EditorState result = EditorState.newSelection(this.lastViewState, newSelection);
-            setViewState(result, false);
-            return result;
-        } else {
-            return this.lastViewState;
-        }
-    }
-
-    @Nonnull
-    public EditorState setCursorOnStart() {
-        synchronized (viewLock) {
-            return newSelectionViewState(0);
-        }
-    }
-
-    @Nonnull
-    public EditorState setCursorOnEnd() {
-        synchronized (viewLock) {
-            return newSelectionViewState(this.lastViewState.getText().length());
-        }
-    }
-
-    @Nonnull
-    public EditorState moveCursorLeft() {
-        synchronized (viewLock) {
-            if (this.lastViewState.getSelection() > 0) {
-                return newSelectionViewState(this.lastViewState.getSelection() - 1);
-            } else {
-                return this.lastViewState;
-            }
-        }
-    }
-
-	/*
-	**********************************************************************
-	*
-	*                           EDITOR ACTIONS
-	*
-	**********************************************************************
-	*/
-
-    @Nonnull
-    public EditorState moveCursorRight() {
-        synchronized (viewLock) {
-            if (this.lastViewState.getSelection() < this.lastViewState.getText().length()) {
-                return newSelectionViewState(this.lastViewState.getSelection() + 1);
-            } else {
-                return this.lastViewState;
-            }
-        }
-    }
-
-    @Nonnull
-    @Override
-    public CursorControl asCursorControl() {
-        return cursorControlAdapter;
-    }
-
-    @Nonnull
-    @Override
-    public EditorState erase() {
-        synchronized (viewLock) {
-            int selection = this.lastViewState.getSelection();
-            final String text = this.lastViewState.getText();
-            if (selection > 0 && text.length() > 0 && selection <= text.length()) {
-                final StringBuilder newText = new StringBuilder(text.length() - 1);
-                newText.append(text.substring(0, selection - 1)).append(text.substring(selection, text.length()));
-
-                final EditorState result = EditorState.create(newText.toString(), selection - 1);
-                setViewState(result);
-                return result;
-            } else {
-                return this.lastViewState;
-            }
-        }
-    }
-
-    @Nonnull
-    @Override
-    public EditorState clear() {
-        synchronized (viewLock) {
-            return setText("");
-        }
-    }
-
-    @Nonnull
-    @Override
-    public EditorState setText(@Nonnull String text) {
-        synchronized (viewLock) {
-            final EditorState result = EditorState.create(text, text.length());
-            setViewState(result);
-            return result;
-        }
-    }
-
-    @Nonnull
-    @Override
-    public EditorState setText(@Nonnull String text, int selection) {
-        synchronized (viewLock) {
-            selection = clamp(selection, text);
-
-            final EditorState result = EditorState.create(text, selection);
-            setViewState(result);
-            return result;
-        }
-    }
-
-    @Nonnull
-    @Override
-    public EditorState insert(@Nonnull String text) {
-        synchronized (viewLock) {
-            return insert(text, 0);
-        }
-    }
-
-    @Nonnull
-    @Override
-    public EditorState insert(@Nonnull String text, int selectionOffset) {
-        synchronized (viewLock) {
-            final String oldText = lastViewState.getText();
-            final int selection = clamp(lastViewState.getSelection(), oldText);
-
-            int newTextLength = text.length() + oldText.length();
-            final StringBuilder newText = new StringBuilder(newTextLength);
-
-            newText.append(oldText.substring(0, selection));
-            newText.append(text);
-            newText.append(oldText.substring(selection));
-
-            int newSelection = clamp(text.length() + selection + selectionOffset, newTextLength);
-            final EditorState result = EditorState.create(newText.toString(), newSelection);
-            setViewState(result);
-            return result;
-        }
-    }
-
-    @Nonnull
-    @Override
-    public EditorState moveSelection(int offset) {
-        synchronized (viewLock) {
-            int selection = this.lastViewState.getSelection() + offset;
-
-            return setSelection(selection);
-        }
-    }
-
-    @Nonnull
-    @Override
-    public EditorState setSelection(int selection) {
-        synchronized (viewLock) {
-            selection = clamp(selection, this.lastViewState.getText());
-
-            final EditorState result = EditorState.newSelection(this.lastViewState, selection);
-            setViewState(result, false);
-            return result;
-        }
-    }
-
-    private static final class CursorControlAdapter implements CursorControl {
-
-        @Nonnull
-        private final CalculatorEditor calculatorEditor;
-
-        private CursorControlAdapter(@Nonnull CalculatorEditor calculatorEditor) {
-            this.calculatorEditor = calculatorEditor;
-        }
-
-        @Override
-        public void setCursorOnStart() {
-            this.calculatorEditor.setCursorOnStart();
-        }
-
-        @Override
-        public void setCursorOnEnd() {
-            this.calculatorEditor.setCursorOnEnd();
-        }
-
-        @Override
-        public void moveCursorLeft() {
-            this.calculatorEditor.moveCursorLeft();
-        }
-
-        @Override
-        public void moveCursorRight() {
-            this.calculatorEditor.moveCursorRight();
-        }
-    }
-}

app/src/main/java/org/solovyev/android/calculator/CalculatorImpl.java

@@ -31,7 +31,7 @@ import jscl.math.function.IConstant;
 import jscl.math.operator.Operator;
 import jscl.text.ParseInterruptedException;
 import org.solovyev.android.calculator.history.CalculatorHistory;
-import org.solovyev.android.calculator.history.CalculatorHistoryState;
+import org.solovyev.android.calculator.history.HistoryState;
 import org.solovyev.android.calculator.jscl.JsclOperation;
 import org.solovyev.android.calculator.model.Var;
 import org.solovyev.android.calculator.text.TextProcessor;
@@ -173,21 +173,21 @@ public class CalculatorImpl implements Calculator, CalculatorEventListener {
 
     @Override
     public void evaluate() {
-        final  EditorState viewState = getEditor().getViewState();
+        final  EditorState viewState = getEditor().getState();
         final CalculatorEventData eventData = fireCalculatorEvent(CalculatorEventType.manual_calculation_requested, viewState);
         this.evaluate(JsclOperation.numeric, viewState.getText(), eventData.getSequenceId());
     }
 
     @Override
     public void evaluate(@Nonnull Long sequenceId) {
-        final  EditorState viewState = getEditor().getViewState();
+        final  EditorState viewState = getEditor().getState();
         fireCalculatorEvent(CalculatorEventType.manual_calculation_requested, viewState, sequenceId);
         this.evaluate(JsclOperation.numeric, viewState.getText(), sequenceId);
     }
 
     @Override
     public void simplify() {
-        final  EditorState viewState = getEditor().getViewState();
+        final  EditorState viewState = getEditor().getState();
         final CalculatorEventData eventData = fireCalculatorEvent(CalculatorEventType.manual_calculation_requested, viewState);
         this.evaluate(JsclOperation.simplify, viewState.getText(), eventData.getSequenceId());
     }
@@ -250,7 +250,7 @@ public class CalculatorImpl implements Calculator, CalculatorEventListener {
                                                                  @Nonnull Generic value,
                                                                  @Nonnull NumeralBase from,
                                                                  @Nonnull NumeralBase to,
-                                                                 @Nonnull CalculatorDisplayViewState displayViewState) {
+                                                                 @Nonnull DisplayState displayViewState) {
         return CalculatorConversionEventDataImpl.newInstance(nextEventData(sequenceId), value, from, to, displayViewState);
     }
 
@@ -393,7 +393,7 @@ public class CalculatorImpl implements Calculator, CalculatorEventListener {
                                        @Nonnull final NumeralBase to) {
         final CalculatorEventData eventDataId = nextEventData();
 
-        final CalculatorDisplayViewState displayViewState = Locator.getInstance().getDisplay().getViewState();
+        final DisplayState displayViewState = Locator.getInstance().getDisplay().getViewState();
         final NumeralBase from = Locator.getInstance().getEngine().getNumeralBase();
 
         calculationsExecutor.execute(new Runnable() {
@@ -562,7 +562,7 @@ public class CalculatorImpl implements Calculator, CalculatorEventListener {
     }
 
     private void onDisplayStateChanged(@Nonnull CalculatorDisplayChangeEventData displayChangeEventData) {
-        final CalculatorDisplayViewState newState = displayChangeEventData.getNewValue();
+        final DisplayState newState = displayChangeEventData.getNewValue();
         if (newState.isValid()) {
             final String result = newState.getStringResult();
             if (!Strings.isEmpty(result)) {
@@ -597,7 +597,7 @@ public class CalculatorImpl implements Calculator, CalculatorEventListener {
     public void doHistoryAction(@Nonnull HistoryAction historyAction) {
         final CalculatorHistory history = Locator.getInstance().getHistory();
         if (history.isActionAvailable(historyAction)) {
-            final CalculatorHistoryState newState = history.doAction(historyAction, getCurrentHistoryState());
+            final HistoryState newState = history.doAction(historyAction, getCurrentHistoryState());
             if (newState != null) {
                 setCurrentHistoryState(newState);
             }
@@ -606,12 +606,12 @@ public class CalculatorImpl implements Calculator, CalculatorEventListener {
 
     @Nonnull
     @Override
-    public CalculatorHistoryState getCurrentHistoryState() {
+    public HistoryState getCurrentHistoryState() {
-        return CalculatorHistoryState.newInstance(getEditor(), getDisplay());
+        return HistoryState.create(getEditor(), getDisplay());
     }
 
     @Override
-    public void setCurrentHistoryState(@Nonnull CalculatorHistoryState editorHistoryState) {
+    public void setCurrentHistoryState(@Nonnull HistoryState editorHistoryState) {
         editorHistoryState.setValuesFromHistory(getEditor(), getDisplay());
     }
 
@@ -624,7 +624,7 @@ public class CalculatorImpl implements Calculator, CalculatorEventListener {
 	*/
 
     @Nonnull
-    private CalculatorEditor getEditor() {
+    private Editor getEditor() {
         return Locator.getInstance().getEditor();
     }
 

app/src/main/java/org/solovyev/android/calculator/CalculatorKeyboardImpl.java

@@ -83,7 +83,7 @@ public class CalculatorKeyboardImpl implements CalculatorKeyboard {
             }
         }
 
-        final CalculatorEditor editor = Locator.getInstance().getEditor();
+        final Editor editor = Locator.getInstance().getEditor();
         editor.insert(textToBeInserted.toString(), cursorPositionOffset);
     }
 
@@ -110,8 +110,8 @@ public class CalculatorKeyboardImpl implements CalculatorKeyboard {
 
     @Override
     public void roundBracketsButtonPressed() {
-        final CalculatorEditor editor = Locator.getInstance().getEditor();
+        final Editor editor = Locator.getInstance().getEditor();
-         EditorState viewState = editor.getViewState();
+         EditorState viewState = editor.getState();
 
         final int cursorPosition = viewState.getSelection();
         final String oldText = viewState.getText();
@@ -139,7 +139,7 @@ public class CalculatorKeyboardImpl implements CalculatorKeyboard {
 
     @Override
     public void copyButtonPressed() {
-        final CalculatorDisplayViewState displayViewState = Locator.getInstance().getDisplay().getViewState();
+        final DisplayState displayViewState = Locator.getInstance().getDisplay().getViewState();
         if (displayViewState.isValid()) {
             final CharSequence text = displayViewState.getText();
             if (!Strings.isEmpty(text)) {

app/src/main/java/org/solovyev/android/calculator/CalculatorLocator.java

@@ -58,7 +58,7 @@ public interface CalculatorLocator {
     CalculatorDisplay getDisplay();
 
     @Nonnull
-    CalculatorEditor getEditor();
+    Editor getEditor();
 
     @Nonnull
     CalculatorKeyboard getKeyboard();

app/src/main/java/org/solovyev/android/calculator/CalculatorSpecialButton.java

@@ -115,7 +115,7 @@ public enum CalculatorSpecialButton {
                 return;
             }
 
-            final CalculatorDisplayViewState displayViewState = Locator.getInstance().getDisplay().getViewState();
+            final DisplayState displayViewState = Locator.getInstance().getDisplay().getViewState();
             if (displayViewState.isValid()) {
                 final CharSequence text = displayViewState.getText();
                 if (!Strings.isEmpty(text)) {

app/src/main/java/org/solovyev/android/calculator/ConversionMenuItem.java

@@ -37,7 +37,7 @@ import jscl.math.Generic;
  * Date: 9/21/12
  * Time: 12:11 AM
  */
-enum ConversionMenuItem implements AMenuItem<CalculatorDisplayViewState> {
+enum ConversionMenuItem implements AMenuItem<DisplayState> {
 
     convert_to_bin(NumeralBase.bin),
     convert_to_dec(NumeralBase.dec),
@@ -67,7 +67,7 @@ enum ConversionMenuItem implements AMenuItem<CalculatorDisplayViewState> {
     }
 
     @Override
-    public void onClick(@Nonnull CalculatorDisplayViewState data, @Nonnull Context context) {
+    public void onClick(@Nonnull DisplayState data, @Nonnull Context context) {
         final Generic result = data.getResult();
 
         if (result != null) {

app/src/main/java/org/solovyev/android/calculator/DisplayState.java

@@ -25,25 +25,14 @@ package org.solovyev.android.calculator;
 import org.solovyev.android.calculator.jscl.JsclOperation;
 import org.solovyev.common.text.Strings;
 
+import java.io.Serializable;
+
 import javax.annotation.Nonnull;
 import javax.annotation.Nullable;
 
 import jscl.math.Generic;
 
-/**
+public class DisplayState implements Serializable {
- * User: serso
- * Date: 9/20/12
- * Time: 9:50 PM
- */
-public class CalculatorDisplayViewStateImpl implements CalculatorDisplayViewState {
-
-	/*
-    **********************************************************************
-	*
-	*                           FIELDS
-	*
-	**********************************************************************
-	*/
 
     @Nonnull
     private JsclOperation operation = JsclOperation.numeric;
@@ -61,26 +50,18 @@ public class CalculatorDisplayViewStateImpl implements CalculatorDisplayViewStat
 
     private int selection = 0;
 
-	/*
+    private DisplayState() {
-	**********************************************************************
-	*
-	*                           CONSTRUCTORS
-	*
-	**********************************************************************
-	*/
-
-    private CalculatorDisplayViewStateImpl() {
     }
 
     @Nonnull
-    public static CalculatorDisplayViewState newDefaultInstance() {
+    public static DisplayState empty() {
-        return new CalculatorDisplayViewStateImpl();
+        return new DisplayState();
     }
 
     @Nonnull
-    public static CalculatorDisplayViewState newErrorState(@Nonnull JsclOperation operation,
+    public static DisplayState createError(@Nonnull JsclOperation operation,
                                            @Nonnull String errorMessage) {
-        final CalculatorDisplayViewStateImpl calculatorDisplayState = new CalculatorDisplayViewStateImpl();
+        final DisplayState calculatorDisplayState = new DisplayState();
         calculatorDisplayState.valid = false;
         calculatorDisplayState.errorMessage = errorMessage;
         calculatorDisplayState.operation = operation;
@@ -88,11 +69,11 @@ public class CalculatorDisplayViewStateImpl implements CalculatorDisplayViewStat
     }
 
     @Nonnull
-    public static CalculatorDisplayViewState newValidState(@Nonnull JsclOperation operation,
+    public static DisplayState createValid(@Nonnull JsclOperation operation,
                                            @Nullable Generic result,
                                            @Nonnull String stringResult,
                                            int selection) {
-        final CalculatorDisplayViewStateImpl calculatorDisplayState = new CalculatorDisplayViewStateImpl();
+        final DisplayState calculatorDisplayState = new DisplayState();
         calculatorDisplayState.valid = true;
         calculatorDisplayState.result = result;
         calculatorDisplayState.stringResult = stringResult;
@@ -102,50 +83,35 @@ public class CalculatorDisplayViewStateImpl implements CalculatorDisplayViewStat
         return calculatorDisplayState;
     }
 
-	/*
-	**********************************************************************
-	*
-	*                           METHODS
-	*
-	**********************************************************************
-	*/
-
     @Nonnull
-    @Override
     public String getText() {
         return Strings.getNotEmpty(isValid() ? stringResult : errorMessage, "");
     }
 
-    @Override
     public int getSelection() {
         return selection;
     }
 
     @Nullable
-    @Override
     public Generic getResult() {
         return this.result;
     }
 
-    @Override
     public boolean isValid() {
         return this.valid;
     }
 
     @Nullable
-    @Override
     public String getErrorMessage() {
         return this.errorMessage;
     }
 
-    @Override
     @Nullable
     public String getStringResult() {
         return stringResult;
     }
 
     @Nonnull
-    @Override
     public JsclOperation getOperation() {
         return this.operation;
     }

app/src/main/java/org/solovyev/android/calculator/Editor.java

@@ -0,0 +1,265 @@
+/*
+ * Copyright 2013 serso aka se.solovyev
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ * Contact details
+ *
+ * Email: se.solovyev@gmail.com
+ * Site:  http://se.solovyev.org
+ */
+
+package org.solovyev.android.calculator;
+
+import org.solovyev.android.Check;
+import org.solovyev.android.calculator.history.HistoryState;
+import org.solovyev.android.calculator.history.EditorHistoryState;
+import org.solovyev.android.calculator.text.TextProcessor;
+import org.solovyev.android.calculator.text.TextProcessorEditorResult;
+import org.solovyev.common.text.Strings;
+
+import javax.annotation.Nonnull;
+import javax.annotation.Nullable;
+
+import static java.lang.Math.min;
+import static org.solovyev.android.calculator.CalculatorEditorChangeEventData.newChangeEventData;
+import static org.solovyev.android.calculator.CalculatorEventType.editor_state_changed;
+import static org.solovyev.android.calculator.CalculatorEventType.editor_state_changed_light;
+
+public class Editor implements CalculatorEventListener {
+
+    private static final String TAG = App.subTag("Editor");
+
+    @Nonnull
+    private final Calculator calculator;
+    @Nonnull
+    private final CalculatorEventHolder lastEventHolder;
+    @Nullable
+    private final TextProcessor<TextProcessorEditorResult, String> textProcessor;
+    @Nullable
+    private EditorView view;
+    @Nonnull
+    private EditorState state = EditorState.empty();
+
+    public Editor(@Nonnull Calculator calculator, @Nullable TextProcessor<TextProcessorEditorResult, String> textProcessor) {
+        this.calculator = calculator;
+        this.textProcessor = textProcessor;
+        this.calculator.addCalculatorEventListener(this);
+        this.lastEventHolder = new CalculatorEventHolder(CalculatorUtils.createFirstEventDataId());
+    }
+
+    public static int clamp(int selection, @Nonnull CharSequence text) {
+        return clamp(selection, text.length());
+    }
+
+    public static int clamp(int selection, int max) {
+        return min(Math.max(selection, 0), max);
+    }
+
+    public void setView(@Nonnull EditorView view) {
+        Check.isMainThread();
+        this.view = view;
+        this.view.setState(state);
+    }
+
+    public void clearView(@Nonnull EditorView view) {
+        Check.isMainThread();
+        if (this.view == view) {
+            this.view = null;
+        }
+    }
+
+    @Nonnull
+    public EditorState getState() {
+        return state;
+    }
+
+    public void setState(@Nonnull EditorState state) {
+        setState(state, true);
+    }
+
+    private void setState(@Nonnull EditorState newState, boolean majorChanges) {
+        Check.isMainThread();
+        if (textProcessor != null) {
+            try {
+                final TextProcessorEditorResult result = textProcessor.process(newState.getText());
+                newState = EditorState.create(result.getCharSequence(), newState.getSelection() + result.getOffset());
+            } catch (CalculatorParseException e) {
+                Locator.getInstance().getLogger().error(TAG, e.getMessage(), e);
+            }
+        }
+        final EditorState oldState = state;
+        state = newState;
+        if (view != null) {
+            view.setState(newState);
+        }
+        fireStateChangedEvent(majorChanges, oldState, newState);
+    }
+
+    private void fireStateChangedEvent(boolean majorChanges, @Nonnull EditorState oldViewState, @Nonnull EditorState newViewState) {
+        Check.isMainThread();
+
+        if (majorChanges) {
+            calculator.fireCalculatorEvent(editor_state_changed, newChangeEventData(oldViewState, newViewState));
+        } else {
+            calculator.fireCalculatorEvent(editor_state_changed_light, newChangeEventData(oldViewState, newViewState));
+        }
+    }
+
+    @Override
+    public void onCalculatorEvent(@Nonnull CalculatorEventData evenData,
+                                  @Nonnull CalculatorEventType eventType,
+                                  @Nullable Object data) {
+        Check.isMainThread();
+        final CalculatorEventHolder.Result result = lastEventHolder.apply(evenData);
+
+        if (result.isNewAfter()) {
+            switch (eventType) {
+                case use_history_state:
+                    final HistoryState historyState = (HistoryState) data;
+                    final EditorHistoryState editorState = historyState.getEditorState();
+                    this.setText(Strings.getNotEmpty(editorState.getText(), ""), editorState.getCursorPosition());
+                    break;
+            }
+        }
+    }
+
+    @Nonnull
+    private EditorState newSelectionViewState(int newSelection) {
+        Check.isMainThread();
+        if (state.getSelection() != newSelection) {
+            final EditorState result = EditorState.newSelection(state, newSelection);
+            setState(result, false);
+            return result;
+        } else {
+            return state;
+        }
+    }
+
+    @Nonnull
+    public EditorState setCursorOnStart() {
+        Check.isMainThread();
+        return newSelectionViewState(0);
+    }
+
+    @Nonnull
+    public EditorState setCursorOnEnd() {
+        Check.isMainThread();
+        return newSelectionViewState(state.getText().length());
+    }
+
+    @Nonnull
+    public EditorState moveCursorLeft() {
+        Check.isMainThread();
+        if (state.getSelection() > 0) {
+            return newSelectionViewState(state.getSelection() - 1);
+        } else {
+            return state;
+        }
+    }
+
+    @Nonnull
+    public EditorState moveCursorRight() {
+        Check.isMainThread();
+        if (state.getSelection() < state.getText().length()) {
+            return newSelectionViewState(state.getSelection() + 1);
+        } else {
+            return state;
+        }
+    }
+
+    @Nonnull
+    public EditorState erase() {
+        Check.isMainThread();
+        int selection = state.getSelection();
+        final String text = state.getText();
+        if (selection > 0 && text.length() > 0 && selection <= text.length()) {
+            final StringBuilder newText = new StringBuilder(text.length() - 1);
+            newText.append(text.substring(0, selection - 1)).append(text.substring(selection, text.length()));
+
+            final EditorState result = EditorState.create(newText.toString(), selection - 1);
+            setState(result);
+            return result;
+        } else {
+            return state;
+        }
+    }
+
+    @Nonnull
+    public EditorState clear() {
+        Check.isMainThread();
+        return setText("");
+    }
+
+    @Nonnull
+    public EditorState setText(@Nonnull String text) {
+        Check.isMainThread();
+        final EditorState result = EditorState.create(text, text.length());
+        setState(result);
+        return result;
+    }
+
+    @Nonnull
+    public EditorState setText(@Nonnull String text, int selection) {
+        Check.isMainThread();
+        selection = clamp(selection, text);
+
+        final EditorState result = EditorState.create(text, selection);
+        setState(result);
+        return result;
+    }
+
+    @Nonnull
+    public EditorState insert(@Nonnull String text) {
+        Check.isMainThread();
+        return insert(text, 0);
+    }
+
+    @Nonnull
+    public EditorState insert(@Nonnull String text, int selectionOffset) {
+        Check.isMainThread();
+        final String oldText = state.getText();
+        final int selection = clamp(state.getSelection(), oldText);
+
+        int newTextLength = text.length() + oldText.length();
+        final StringBuilder newText = new StringBuilder(newTextLength);
+
+        newText.append(oldText.substring(0, selection));
+        newText.append(text);
+        newText.append(oldText.substring(selection));
+
+        int newSelection = clamp(text.length() + selection + selectionOffset, newTextLength);
+        final EditorState result = EditorState.create(newText.toString(), newSelection);
+        setState(result);
+        return result;
+    }
+
+    @Nonnull
+    public EditorState moveSelection(int offset) {
+        Check.isMainThread();
+        int selection = state.getSelection() + offset;
+        return setSelection(selection);
+    }
+
+    @Nonnull
+    public EditorState setSelection(int selection) {
+        Check.isMainThread();
+        selection = clamp(selection, state.getText());
+
+        final EditorState result = EditorState.newSelection(state, selection);
+        setState(result, false);
+        return result;
+    }
+
+}

app/src/main/java/org/solovyev/android/calculator/EditorView.java

@@ -31,22 +31,23 @@ import android.util.AttributeSet;
 import android.util.Log;
 import android.view.ContextMenu;
 import android.widget.EditText;
+
 import org.solovyev.android.Check;
 import org.solovyev.android.calculator.onscreen.CalculatorOnscreenService;
 
+import java.lang.reflect.Method;
+
 import javax.annotation.Nonnull;
 import javax.annotation.Nullable;
-import java.lang.reflect.Method;
 
 public class EditorView extends EditText {
 
     @Nonnull
     private static final String TAG = App.subTag("EditorView");
 
-    private boolean initialized;
+    private boolean reportChanges;
     @Nullable
     private Method setShowSoftInputOnFocusMethod;
-    private boolean externalChange;
 
     public EditorView(Context context) {
         super(context);
@@ -70,10 +71,10 @@ public class EditorView extends EditText {
     }
 
     private void init() {
-        Check.isTrue(!initialized);
         addTextChangedListener(new MyTextWatcher());
         setShowSoftInputOnFocusCompat(false);
-        initialized = true;
+        // changes should only be reported after the view has been set up completely, i.e. now
+        reportChanges = true;
     }
 
     @Override
@@ -85,24 +86,25 @@ public class EditorView extends EditText {
     public void setState(@Nonnull final EditorState state) {
         Check.isMainThread();
         try {
-            externalChange = true;
+            // we don't want to be notified about changes we make ourselves
+            reportChanges = false;
             if (App.getTheme().light && getContext() instanceof CalculatorOnscreenService) {
                 // don't need formatting
                 setText(state.getText());
             } else {
                 setText(state.getTextAsCharSequence(), BufferType.EDITABLE);
             }
-            final int selection = CalculatorEditorImpl.clamp(state.getSelection(), length());
+            final int selection = Editor.clamp(state.getSelection(), length());
             setSelection(selection);
         } finally {
-            externalChange = false;
+            reportChanges = true;
         }
     }
 
     @Override
     protected void onSelectionChanged(int start, int end) {
         Check.isMainThread();
-        if (!initialized || externalChange) {
+        if (!reportChanges) {
             return;
         }
         // external text change => need to notify editor
@@ -147,7 +149,7 @@ public class EditorView extends EditText {
 
         @Override
         public void afterTextChanged(Editable s) {
-            if (!initialized || externalChange) {
+            if (!reportChanges) {
                 return;
             }
             // external text change => need to notify editor

app/src/main/java/org/solovyev/android/calculator/Locator.java

@@ -44,7 +44,7 @@ public class Locator implements CalculatorLocator {
     @Nonnull
     private Calculator calculator;
     @Nonnull
-    private CalculatorEditor calculatorEditor;
+    private Editor editor;
     @Nonnull
     private CalculatorDisplay calculatorDisplay;
     @Nonnull
@@ -92,7 +92,7 @@ public class Locator implements CalculatorLocator {
         this.calculatorPreferenceService = preferenceService;
         this.calculatorPlotter = plotter;
 
-        calculatorEditor = new CalculatorEditorImpl(this.calculator, editorTextProcessor);
+        editor = new Editor(this.calculator, editorTextProcessor);
         calculatorDisplay = new CalculatorDisplayImpl(this.calculator);
         calculatorKeyboard = keyboard;
     }
@@ -117,8 +117,8 @@ public class Locator implements CalculatorLocator {
 
     @Nonnull
     @Override
-    public CalculatorEditor getEditor() {
+    public Editor getEditor() {
-        return calculatorEditor;
+        return editor;
     }
 
     @Override

app/src/main/java/org/solovyev/android/calculator/function/FunctionEditDialogFragment.java

@@ -36,11 +36,11 @@ import android.view.ViewGroup;
 import android.widget.EditText;
 
 import org.solovyev.android.calculator.App;
-import org.solovyev.android.calculator.CalculatorDisplayViewState;
 import org.solovyev.android.calculator.CalculatorEventData;
 import org.solovyev.android.calculator.CalculatorEventListener;
 import org.solovyev.android.calculator.CalculatorEventType;
 import org.solovyev.android.calculator.CalculatorUtils;
+import org.solovyev.android.calculator.DisplayState;
 import org.solovyev.android.calculator.Locator;
 import org.solovyev.android.calculator.R;
 import org.solovyev.android.calculator.math.edit.CalculatorFunctionsActivity;
@@ -308,7 +308,7 @@ public class FunctionEditDialogFragment extends DialogFragment implements Calcul
         }
 
         @Nonnull
-        public static Input newFromDisplay(@Nonnull CalculatorDisplayViewState viewState) {
+        public static Input newFromDisplay(@Nonnull DisplayState viewState) {
             final Input result = new Input();
 
             result.content = viewState.getText();

app/src/main/java/org/solovyev/android/calculator/history/AndroidCalculatorHistory.java

@@ -80,7 +80,7 @@ public class AndroidCalculatorHistory implements CalculatorHistory {
         save();
     }
 
-    public void removeSavedHistory(@Nonnull CalculatorHistoryState historyState) {
+    public void removeSavedHistory(@Nonnull HistoryState historyState) {
         historyState.setSaved(false);
         calculatorHistory.removeSavedHistory(historyState);
         save();
@@ -92,7 +92,7 @@ public class AndroidCalculatorHistory implements CalculatorHistory {
     }
 
     @Override
-    public CalculatorHistoryState getLastHistoryState() {
+    public HistoryState getLastHistoryState() {
         return calculatorHistory.getLastHistoryState();
     }
 
@@ -102,7 +102,7 @@ public class AndroidCalculatorHistory implements CalculatorHistory {
     }
 
     @Override
-    public CalculatorHistoryState undo(@Nullable CalculatorHistoryState currentState) {
+    public HistoryState undo(@Nullable HistoryState currentState) {
         return calculatorHistory.undo(currentState);
     }
 
@@ -112,7 +112,7 @@ public class AndroidCalculatorHistory implements CalculatorHistory {
     }
 
     @Override
-    public CalculatorHistoryState redo(@Nullable CalculatorHistoryState currentState) {
+    public HistoryState redo(@Nullable HistoryState currentState) {
         return calculatorHistory.redo(currentState);
     }
 
@@ -122,24 +122,24 @@ public class AndroidCalculatorHistory implements CalculatorHistory {
     }
 
     @Override
-    public CalculatorHistoryState doAction(@Nonnull HistoryAction historyAction, @Nullable CalculatorHistoryState currentState) {
+    public HistoryState doAction(@Nonnull HistoryAction historyAction, @Nullable HistoryState currentState) {
         return calculatorHistory.doAction(historyAction, currentState);
     }
 
     @Override
-    public void addState(@Nullable CalculatorHistoryState currentState) {
+    public void addState(@Nullable HistoryState currentState) {
         calculatorHistory.addState(currentState);
     }
 
     @Nonnull
     @Override
-    public List<CalculatorHistoryState> getStates() {
+    public List<HistoryState> getStates() {
         return calculatorHistory.getStates();
     }
 
     @Nonnull
     @Override
-    public List<CalculatorHistoryState> getStates(boolean includeIntermediateStates) {
+    public List<HistoryState> getStates(boolean includeIntermediateStates) {
         return calculatorHistory.getStates(includeIntermediateStates);
     }
 
@@ -149,12 +149,12 @@ public class AndroidCalculatorHistory implements CalculatorHistory {
     }
 
     @Nonnull
-    public List<CalculatorHistoryState> getSavedHistory() {
+    public List<HistoryState> getSavedHistory() {
         return calculatorHistory.getSavedHistory();
     }
 
     @Nonnull
-    public CalculatorHistoryState addSavedState(@Nonnull CalculatorHistoryState historyState) {
+    public HistoryState addSavedState(@Nonnull HistoryState historyState) {
         return calculatorHistory.addSavedState(historyState);
     }
 

app/src/main/java/org/solovyev/android/calculator/history/BaseHistoryFragment.java

@@ -88,9 +88,9 @@ public abstract class BaseHistoryFragment extends ListFragment implements Calcul
 	**********************************************************************
 	*/
 
-    public static final Comparator<CalculatorHistoryState> COMPARATOR = new Comparator<CalculatorHistoryState>() {
+    public static final Comparator<HistoryState> COMPARATOR = new Comparator<HistoryState>() {
         @Override
-        public int compare(CalculatorHistoryState state1, CalculatorHistoryState state2) {
+        public int compare(HistoryState state1, HistoryState state2) {
             if (state1.isSaved() == state2.isSaved()) {
                 long l = state2.getTime() - state1.getTime();
                 return l > 0l ? 1 : (l < 0l ? -1 : 0);
@@ -137,15 +137,15 @@ public abstract class BaseHistoryFragment extends ListFragment implements Calcul
         ui = CalculatorApplication.getInstance().createFragmentHelper(fragmentType.getDefaultLayoutId(), fragmentType.getDefaultTitleResId(), false);
     }
 
-    public static boolean isAlreadySaved(@Nonnull CalculatorHistoryState historyState) {
+    public static boolean isAlreadySaved(@Nonnull HistoryState historyState) {
         if (historyState.isSaved()) throw new AssertionError();
 
         boolean result = false;
         try {
             historyState.setSaved(true);
-            if (Collections.contains(historyState, Locator.getInstance().getHistory().getSavedHistory(), new Equalizer<CalculatorHistoryState>() {
+            if (Collections.contains(historyState, Locator.getInstance().getHistory().getSavedHistory(), new Equalizer<HistoryState>() {
                 @Override
-                public boolean areEqual(@Nullable CalculatorHistoryState first, @Nullable CalculatorHistoryState second) {
+                public boolean areEqual(@Nullable HistoryState first, @Nullable HistoryState second) {
                     return first != null && second != null &&
                             first.getTime() == second.getTime() &&
                             first.getDisplayState().equals(second.getDisplayState()) &&
@@ -160,13 +160,13 @@ public abstract class BaseHistoryFragment extends ListFragment implements Calcul
         return result;
     }
 
-    public static void useHistoryItem(@Nonnull final CalculatorHistoryState historyState) {
+    public static void useHistoryItem(@Nonnull final HistoryState historyState) {
         App.getVibrator().vibrate();
         Locator.getInstance().getCalculator().fireCalculatorEvent(CalculatorEventType.use_history_state, historyState);
     }
 
     @Nonnull
-    public static String getHistoryText(@Nonnull CalculatorHistoryState state) {
+    public static String getHistoryText(@Nonnull HistoryState state) {
         final StringBuilder result = new StringBuilder();
         result.append(state.getEditorState().getText());
         result.append(getIdentitySign(state.getDisplayState().getJsclOperation()));
@@ -211,7 +211,7 @@ public abstract class BaseHistoryFragment extends ListFragment implements Calcul
 
         ui.onViewCreated(this, root);
 
-        adapter = new HistoryArrayAdapter(this.getActivity(), getItemLayoutId(), org.solovyev.android.calculator.R.id.history_item, new ArrayList<CalculatorHistoryState>(), showDatetime);
+        adapter = new HistoryArrayAdapter(this.getActivity(), getItemLayoutId(), org.solovyev.android.calculator.R.id.history_item, new ArrayList<HistoryState>(), showDatetime);
         setListAdapter(adapter);
 
         final ListView lv = getListView();
@@ -232,14 +232,14 @@ public abstract class BaseHistoryFragment extends ListFragment implements Calcul
                                     final int position,
                                     final long id) {
 
-                useHistoryItem((CalculatorHistoryState) parent.getItemAtPosition(position));
+                useHistoryItem((HistoryState) parent.getItemAtPosition(position));
             }
         });
 
         lv.setOnItemLongClickListener(new AdapterView.OnItemLongClickListener() {
             @Override
             public boolean onItemLongClick(AdapterView<?> parent, View view, final int position, long id) {
-                final CalculatorHistoryState historyState = (CalculatorHistoryState) parent.getItemAtPosition(position);
+                final HistoryState historyState = (HistoryState) parent.getItemAtPosition(position);
 
                 final FragmentActivity activity = getActivity();
 
@@ -309,13 +309,13 @@ public abstract class BaseHistoryFragment extends ListFragment implements Calcul
     protected abstract int getItemLayoutId();
 
     private void updateAdapter() {
-        final List<CalculatorHistoryState> historyList = getHistoryList();
+        final List<HistoryState> historyList = getHistoryList();
 
-        final ArrayAdapter<CalculatorHistoryState> adapter = getAdapter();
+        final ArrayAdapter<HistoryState> adapter = getAdapter();
         try {
             adapter.setNotifyOnChange(false);
             adapter.clear();
-            for (CalculatorHistoryState historyState : historyList) {
+            for (HistoryState historyState : historyList) {
                 adapter.add(historyState);
             }
         } finally {
@@ -326,26 +326,26 @@ public abstract class BaseHistoryFragment extends ListFragment implements Calcul
     }
 
     @Nonnull
-    private List<CalculatorHistoryState> getHistoryList() {
+    private List<HistoryState> getHistoryList() {
-        final List<CalculatorHistoryState> calculatorHistoryStates = getHistoryItems();
+        final List<HistoryState> historyStates = getHistoryItems();
 
-        java.util.Collections.sort(calculatorHistoryStates, COMPARATOR);
+        java.util.Collections.sort(historyStates, COMPARATOR);
 
-        final FilterRulesChain<CalculatorHistoryState> filterRulesChain = new FilterRulesChain<>();
+        final FilterRulesChain<HistoryState> filterRulesChain = new FilterRulesChain<>();
-        filterRulesChain.addFilterRule(new JPredicate<CalculatorHistoryState>() {
+        filterRulesChain.addFilterRule(new JPredicate<HistoryState>() {
             @Override
-            public boolean apply(CalculatorHistoryState object) {
+            public boolean apply(HistoryState object) {
                 return object == null || Strings.isEmpty(object.getEditorState().getText());
             }
         });
 
-        new Filter<>(filterRulesChain).filter(calculatorHistoryStates.iterator());
+        new Filter<>(filterRulesChain).filter(historyStates.iterator());
 
-        return calculatorHistoryStates;
+        return historyStates;
     }
 
     @Nonnull
-    protected abstract List<CalculatorHistoryState> getHistoryItems();
+    protected abstract List<HistoryState> getHistoryItems();
 
     protected abstract void clearHistory();
 

app/src/main/java/org/solovyev/android/calculator/history/BaseHistoryState.java

@@ -29,12 +29,7 @@ import java.util.Date;
 
 import javax.annotation.Nullable;
 
-/**
+public class BaseHistoryState implements Cloneable {
- * User: serso
- * Date: 10/15/11
- * Time: 1:45 PM
- */
-public class AbstractHistoryState implements Cloneable {
 
     @Element
     private long time = new Date().getTime();
@@ -82,16 +77,13 @@ public class AbstractHistoryState implements Cloneable {
         this.saved = saved;
     }
 
+    @SuppressWarnings("CloneDoesntDeclareCloneNotSupportedException")
     @Override
-    protected AbstractHistoryState clone() {
+    protected BaseHistoryState clone() {
-        AbstractHistoryState clone;
-
         try {
-            clone = (AbstractHistoryState) super.clone();
+            return (BaseHistoryState) super.clone();
         } catch (CloneNotSupportedException e) {
             throw new UnsupportedOperationException(e);
         }
-
-        return clone;
     }
 }

app/src/main/java/org/solovyev/android/calculator/history/CalculatorHistory.java

@@ -34,7 +34,7 @@ import javax.annotation.Nonnull;
  * Date: 20.09.12
  * Time: 16:11
  */
-public interface CalculatorHistory extends HistoryHelper<CalculatorHistoryState>, CalculatorEventListener {
+public interface CalculatorHistory extends HistoryHelper<HistoryState>, CalculatorEventListener {
 
     void load();
 
@@ -46,18 +46,18 @@ public interface CalculatorHistory extends HistoryHelper<CalculatorHistoryState>
 
     void clearSavedHistory();
 
-    void removeSavedHistory(@Nonnull CalculatorHistoryState historyState);
+    void removeSavedHistory(@Nonnull HistoryState historyState);
 
     @Nonnull
-    List<CalculatorHistoryState> getSavedHistory();
+    List<HistoryState> getSavedHistory();
 
     @Nonnull
-    CalculatorHistoryState addSavedState(@Nonnull CalculatorHistoryState historyState);
+    HistoryState addSavedState(@Nonnull HistoryState historyState);
 
     @Nonnull
-    List<CalculatorHistoryState> getStates();
+    List<HistoryState> getStates();
 
     @Nonnull
-    List<CalculatorHistoryState> getStates(boolean includeIntermediateStates);
+    List<HistoryState> getStates(boolean includeIntermediateStates);
 
 }

app/src/main/java/org/solovyev/android/calculator/history/CalculatorHistoryImpl.java

@@ -47,10 +47,10 @@ public class CalculatorHistoryImpl implements CalculatorHistory {
     private final AtomicInteger counter = new AtomicInteger(0);
 
     @Nonnull
-    private final HistoryHelper<CalculatorHistoryState> history = SimpleHistoryHelper.newInstance();
+    private final HistoryHelper<HistoryState> history = SimpleHistoryHelper.newInstance();
 
     @Nonnull
-    private final List<CalculatorHistoryState> savedHistory = new ArrayList<CalculatorHistoryState>();
+    private final List<HistoryState> savedHistory = new ArrayList<HistoryState>();
 
     @Nonnull
     private final CalculatorEventHolder lastEventData = new CalculatorEventHolder(CalculatorUtils.createFirstEventDataId());
@@ -70,7 +70,7 @@ public class CalculatorHistoryImpl implements CalculatorHistory {
     }
 
     @Override
-    public CalculatorHistoryState getLastHistoryState() {
+    public HistoryState getLastHistoryState() {
         synchronized (history) {
             return this.history.getLastHistoryState();
         }
@@ -84,7 +84,7 @@ public class CalculatorHistoryImpl implements CalculatorHistory {
     }
 
     @Override
-    public CalculatorHistoryState undo(@Nullable CalculatorHistoryState currentState) {
+    public HistoryState undo(@Nullable HistoryState currentState) {
         synchronized (history) {
             return history.undo(currentState);
         }
@@ -96,7 +96,7 @@ public class CalculatorHistoryImpl implements CalculatorHistory {
     }
 
     @Override
-    public CalculatorHistoryState redo(@Nullable CalculatorHistoryState currentState) {
+    public HistoryState redo(@Nullable HistoryState currentState) {
         synchronized (history) {
             return history.redo(currentState);
         }
@@ -110,14 +110,14 @@ public class CalculatorHistoryImpl implements CalculatorHistory {
     }
 
     @Override
-    public CalculatorHistoryState doAction(@Nonnull HistoryAction historyAction, @Nullable CalculatorHistoryState currentState) {
+    public HistoryState doAction(@Nonnull HistoryAction historyAction, @Nullable HistoryState currentState) {
         synchronized (history) {
             return history.doAction(historyAction, currentState);
         }
     }
 
     @Override
-    public void addState(@Nullable CalculatorHistoryState currentState) {
+    public void addState(@Nullable HistoryState currentState) {
         synchronized (history) {
             history.addState(currentState);
             Locator.getInstance().getCalculator().fireCalculatorEvent(CalculatorEventType.history_state_added, currentState);
@@ -126,7 +126,7 @@ public class CalculatorHistoryImpl implements CalculatorHistory {
 
     @Nonnull
     @Override
-    public List<CalculatorHistoryState> getStates() {
+    public List<HistoryState> getStates() {
         synchronized (history) {
             return history.getStates();
         }
@@ -134,17 +134,17 @@ public class CalculatorHistoryImpl implements CalculatorHistory {
 
     @Nonnull
     @Override
-    public List<CalculatorHistoryState> getStates(boolean includeIntermediateStates) {
+    public List<HistoryState> getStates(boolean includeIntermediateStates) {
         synchronized (history) {
             if (includeIntermediateStates) {
                 return getStates();
             } else {
-                final List<CalculatorHistoryState> states = getStates();
+                final List<HistoryState> states = getStates();
 
-                final List<CalculatorHistoryState> result = new LinkedList<CalculatorHistoryState>();
+                final List<HistoryState> result = new LinkedList<HistoryState>();
 
-                CalculatorHistoryState laterState = null;
+                HistoryState laterState = null;
-                for (CalculatorHistoryState state : org.solovyev.common.collections.Collections.reversed(states)) {
+                for (HistoryState state : org.solovyev.common.collections.Collections.reversed(states)) {
                     if (laterState != null) {
                         final String laterEditorText = laterState.getEditorState().getText();
                         final String editorText = state.getEditorState().getText();
@@ -187,17 +187,17 @@ public class CalculatorHistoryImpl implements CalculatorHistory {
 
     @Override
     @Nonnull
-    public List<CalculatorHistoryState> getSavedHistory() {
+    public List<HistoryState> getSavedHistory() {
         return Collections.unmodifiableList(savedHistory);
     }
 
     @Override
     @Nonnull
-    public CalculatorHistoryState addSavedState(@Nonnull CalculatorHistoryState historyState) {
+    public HistoryState addSavedState(@Nonnull HistoryState historyState) {
         if (historyState.isSaved()) {
             return historyState;
         } else {
-            final CalculatorHistoryState savedState = historyState.clone();
+            final HistoryState savedState = historyState.clone();
 
             savedState.setId(counter.incrementAndGet());
             savedState.setSaved(true);
@@ -223,7 +223,7 @@ public class CalculatorHistoryImpl implements CalculatorHistory {
         clearSavedHistory();
 
         HistoryUtils.fromXml(xml, this.savedHistory);
-        for (CalculatorHistoryState historyState : savedHistory) {
+        for (HistoryState historyState : savedHistory) {
             historyState.setSaved(true);
             historyState.setId(counter.incrementAndGet());
         }
@@ -240,7 +240,7 @@ public class CalculatorHistoryImpl implements CalculatorHistory {
     }
 
     @Override
-    public void removeSavedHistory(@Nonnull CalculatorHistoryState historyState) {
+    public void removeSavedHistory(@Nonnull HistoryState historyState) {
         this.savedHistory.remove(historyState);
     }
 
@@ -266,8 +266,8 @@ public class CalculatorHistoryImpl implements CalculatorHistory {
                             if (lastEditorViewState != null) {
                                 final EditorState editorViewState = lastEditorViewState;
                                 final CalculatorDisplayChangeEventData displayChangeData = (CalculatorDisplayChangeEventData) data;
-                                final CalculatorDisplayViewState displayViewState = displayChangeData.getNewValue();
+                                final DisplayState displayViewState = displayChangeData.getNewValue();
-                                addState(CalculatorHistoryState.newInstance(editorViewState, displayViewState));
+                                addState(HistoryState.create(editorViewState, displayViewState));
                             }
                         } else {
                             lastEditorViewState = null;

app/src/main/java/org/solovyev/android/calculator/history/DisplayHistoryState.java

@@ -26,8 +26,7 @@ import org.simpleframework.xml.Element;
 import org.simpleframework.xml.Root;
 import org.simpleframework.xml.Transient;
 import org.solovyev.android.calculator.CalculatorDisplay;
-import org.solovyev.android.calculator.CalculatorDisplayViewState;
+import org.solovyev.android.calculator.DisplayState;
-import org.solovyev.android.calculator.CalculatorDisplayViewStateImpl;
 import org.solovyev.android.calculator.jscl.JsclOperation;
 import org.solovyev.common.text.Strings;
 
@@ -43,7 +42,7 @@ import jscl.math.Generic;
  */
 
 @Root
-public class CalculatorDisplayHistoryState implements Cloneable {
+public class DisplayHistoryState implements Cloneable {
 
     @Transient
     private boolean valid = true;
@@ -64,15 +63,15 @@ public class CalculatorDisplayHistoryState implements Cloneable {
     @Nullable
     private Generic genericResult;
 
-    private CalculatorDisplayHistoryState() {
+    private DisplayHistoryState() {
         // for xml
     }
 
     @Nonnull
-    public static CalculatorDisplayHistoryState newInstance(@Nonnull CalculatorDisplayViewState viewState) {
+    public static DisplayHistoryState newInstance(@Nonnull DisplayState viewState) {
-        final CalculatorDisplayHistoryState result = new CalculatorDisplayHistoryState();
+        final DisplayHistoryState result = new DisplayHistoryState();
 
-        result.editorState = EditorHistoryState.newInstance(viewState);
+        result.editorState = EditorHistoryState.create(viewState);
 
         result.valid = viewState.isValid();
         result.jsclOperation = viewState.getOperation();
@@ -84,9 +83,9 @@ public class CalculatorDisplayHistoryState implements Cloneable {
 
     public void setValuesFromHistory(@Nonnull CalculatorDisplay display) {
         if (this.isValid()) {
-            display.setViewState(CalculatorDisplayViewStateImpl.newValidState(this.getJsclOperation(), this.getGenericResult(), Strings.getNotEmpty(this.getEditorState().getText(), ""), this.getEditorState().getCursorPosition()));
+            display.setViewState(DisplayState.createValid(this.getJsclOperation(), this.getGenericResult(), Strings.getNotEmpty(this.getEditorState().getText(), ""), this.getEditorState().getCursorPosition()));
         } else {
-            display.setViewState(CalculatorDisplayViewStateImpl.newErrorState(this.getJsclOperation(), Strings.getNotEmpty(this.getErrorMessage(), "")));
+            display.setViewState(DisplayState.createError(this.getJsclOperation(), Strings.getNotEmpty(this.getErrorMessage(), "")));
         }
     }
 
@@ -121,7 +120,7 @@ public class CalculatorDisplayHistoryState implements Cloneable {
         if (this == o) return true;
         if (o == null || getClass() != o.getClass()) return false;
 
-        CalculatorDisplayHistoryState that = (CalculatorDisplayHistoryState) o;
+        DisplayHistoryState that = (DisplayHistoryState) o;
 
         if (!editorState.equals(that.editorState)) return false;
         if (jsclOperation != that.jsclOperation) return false;
@@ -147,9 +146,9 @@ public class CalculatorDisplayHistoryState implements Cloneable {
     }
 
     @Override
-    protected CalculatorDisplayHistoryState clone() {
+    protected DisplayHistoryState clone() {
         try {
-            final CalculatorDisplayHistoryState clone = (CalculatorDisplayHistoryState) super.clone();
+            final DisplayHistoryState clone = (DisplayHistoryState) super.clone();
 
             clone.editorState = this.editorState.clone();
 

app/src/main/java/org/solovyev/android/calculator/history/EditorHistoryState.java

@@ -24,8 +24,8 @@ package org.solovyev.android.calculator.history;
 
 import org.simpleframework.xml.Element;
 import org.simpleframework.xml.Root;
-import org.solovyev.android.calculator.CalculatorDisplayViewState;
+import org.solovyev.android.calculator.DisplayState;
-import org.solovyev.android.calculator.CalculatorEditor;
+import org.solovyev.android.calculator.Editor;
 import org.solovyev.android.calculator.EditorState;
 import org.solovyev.common.text.Strings;
 
@@ -47,17 +47,17 @@ public class EditorHistoryState implements Cloneable {
     }
 
     @Nonnull
-    public static EditorHistoryState newInstance(@Nonnull EditorState viewState) {
+    public static EditorHistoryState create(@Nonnull EditorState state) {
         final EditorHistoryState result = new EditorHistoryState();
 
-        result.text = String.valueOf(viewState.getText());
+        result.text = String.valueOf(state.getText());
-        result.cursorPosition = viewState.getSelection();
+        result.cursorPosition = state.getSelection();
 
         return result;
     }
 
     @Nonnull
-    public static EditorHistoryState newInstance(@Nonnull CalculatorDisplayViewState viewState) {
+    public static EditorHistoryState create(@Nonnull DisplayState viewState) {
         final EditorHistoryState result = new EditorHistoryState();
 
         result.text = viewState.getText();
@@ -66,7 +66,7 @@ public class EditorHistoryState implements Cloneable {
         return result;
     }
 
-    public void setValuesFromHistory(@Nonnull CalculatorEditor editor) {
+    public void setValuesFromHistory(@Nonnull Editor editor) {
         editor.setText(Strings.getNotEmpty(this.getText(), ""));
         editor.setSelection(this.getCursorPosition());
     }

app/src/main/java/org/solovyev/android/calculator/history/History.java

@@ -37,13 +37,13 @@ import java.util.List;
 @Root
 public class History {
 
-    @ElementList(type = CalculatorHistoryState.class)
+    @ElementList(type = HistoryState.class)
-    private List<CalculatorHistoryState> historyItems = new ArrayList<CalculatorHistoryState>();
+    private List<HistoryState> historyItems = new ArrayList<HistoryState>();
 
     public History() {
     }
 
-    public List<CalculatorHistoryState> getHistoryItems() {
+    public List<HistoryState> getHistoryItems() {
         return historyItems;
     }
 }

app/src/main/java/org/solovyev/android/calculator/history/HistoryArrayAdapter.java

@@ -47,12 +47,12 @@ import static org.solovyev.android.calculator.history.BaseHistoryFragment.isAlre
  * Date: 12/18/11
  * Time: 7:39 PM
  */
-public class HistoryArrayAdapter extends ArrayAdapter<CalculatorHistoryState> {
+public class HistoryArrayAdapter extends ArrayAdapter<HistoryState> {
 
     private static final int DATETIME_FORMAT = DateUtils.FORMAT_SHOW_TIME | DateUtils.FORMAT_SHOW_DATE | DateUtils.FORMAT_ABBREV_MONTH | DateUtils.FORMAT_ABBREV_TIME;
     private boolean showDatetime;
 
-    HistoryArrayAdapter(Context context, int resource, int textViewResourceId, @Nonnull List<CalculatorHistoryState> historyList, boolean showDatetime) {
+    HistoryArrayAdapter(Context context, int resource, int textViewResourceId, @Nonnull List<HistoryState> historyList, boolean showDatetime) {
         super(context, resource, textViewResourceId, historyList);
         this.showDatetime = showDatetime;
     }
@@ -61,7 +61,7 @@ public class HistoryArrayAdapter extends ArrayAdapter<CalculatorHistoryState> {
     public View getView(int position, View convertView, ViewGroup parent) {
         final ViewGroup result = (ViewGroup) super.getView(position, convertView, parent);
 
-        final CalculatorHistoryState state = getItem(position);
+        final HistoryState state = getItem(position);
 
         final TextView time = (TextView) result.findViewById(R.id.history_time);
         if (showDatetime) {

app/src/main/java/org/solovyev/android/calculator/history/HistoryFragment.java

@@ -48,11 +48,11 @@ public class HistoryFragment extends BaseHistoryFragment {
 
     @Nonnull
     @Override
-    protected List<CalculatorHistoryState> getHistoryItems() {
+    protected List<HistoryState> getHistoryItems() {
         final SharedPreferences preferences = PreferenceManager.getDefaultSharedPreferences(getActivity());
         final boolean showIntermediateCalculations = Preferences.History.showIntermediateCalculations.getPreference(preferences);
-        final List<CalculatorHistoryState> historyStates = Locator.getInstance().getHistory().getStates(showIntermediateCalculations);
+        final List<HistoryState> historyStates = Locator.getInstance().getHistory().getStates(showIntermediateCalculations);
-        return new ArrayList<CalculatorHistoryState>(historyStates);
+        return new ArrayList<HistoryState>(historyStates);
     }
 
     @Override

app/src/main/java/org/solovyev/android/calculator/history/HistoryItemMenuData.java

@@ -34,23 +34,23 @@ import javax.annotation.Nonnull;
 public class HistoryItemMenuData {
 
     @Nonnull
-    private final ArrayAdapter<CalculatorHistoryState> adapter;
+    private final ArrayAdapter<HistoryState> adapter;
 
     @Nonnull
-    private final CalculatorHistoryState historyState;
+    private final HistoryState historyState;
 
-    public HistoryItemMenuData(@Nonnull CalculatorHistoryState historyState, ArrayAdapter<CalculatorHistoryState> adapter) {
+    public HistoryItemMenuData(@Nonnull HistoryState historyState, ArrayAdapter<HistoryState> adapter) {
         this.historyState = historyState;
         this.adapter = adapter;
     }
 
     @Nonnull
-    public CalculatorHistoryState getHistoryState() {
+    public HistoryState getHistoryState() {
         return historyState;
     }
 
     @Nonnull
-    public ArrayAdapter<CalculatorHistoryState> getAdapter() {
+    public ArrayAdapter<HistoryState> getAdapter() {
         return adapter;
     }
 }

app/src/main/java/org/solovyev/android/calculator/history/HistoryItemMenuItem.java

@@ -57,8 +57,8 @@ public enum HistoryItemMenuItem implements LabeledMenuItem<HistoryItemMenuData>
     copy_expression(R.string.c_copy_expression) {
         @Override
         public void onClick(@Nonnull HistoryItemMenuData data, @Nonnull Context context) {
-            final CalculatorHistoryState calculatorHistoryState = data.getHistoryState();
+            final HistoryState historyState = data.getHistoryState();
-            final String text = calculatorHistoryState.getEditorState().getText();
+            final String text = historyState.getEditorState().getText();
             if (!Strings.isEmpty(text)) {
                 final ClipboardManager clipboard = (ClipboardManager) context.getSystemService(Activity.CLIPBOARD_SERVICE);
                 clipboard.setText(text);
@@ -70,8 +70,8 @@ public enum HistoryItemMenuItem implements LabeledMenuItem<HistoryItemMenuData>
     copy_result(R.string.c_copy_result) {
         @Override
         public void onClick(@Nonnull HistoryItemMenuData data, @Nonnull Context context) {
-            final CalculatorHistoryState calculatorHistoryState = data.getHistoryState();
+            final HistoryState historyState = data.getHistoryState();
-            final String text = calculatorHistoryState.getDisplayState().getEditorState().getText();
+            final String text = historyState.getDisplayState().getEditorState().getText();
             if (!Strings.isEmpty(text)) {
                 final ClipboardManager clipboard = (ClipboardManager) context.getSystemService(Activity.CLIPBOARD_SERVICE);
                 clipboard.setText(text);
@@ -83,7 +83,7 @@ public enum HistoryItemMenuItem implements LabeledMenuItem<HistoryItemMenuData>
     save(R.string.c_save) {
         @Override
         public void onClick(@Nonnull final HistoryItemMenuData data, @Nonnull final Context context) {
-            final CalculatorHistoryState historyState = data.getHistoryState();
+            final HistoryState historyState = data.getHistoryState();
             if (!historyState.isSaved()) {
                 createEditHistoryDialog(data, context, true);
             } else {
@@ -95,7 +95,7 @@ public enum HistoryItemMenuItem implements LabeledMenuItem<HistoryItemMenuData>
     edit(R.string.c_edit) {
         @Override
         public void onClick(@Nonnull final HistoryItemMenuData data, @Nonnull final Context context) {
-            final CalculatorHistoryState historyState = data.getHistoryState();
+            final HistoryState historyState = data.getHistoryState();
             if (historyState.isSaved()) {
                 createEditHistoryDialog(data, context, false);
             } else {
@@ -107,7 +107,7 @@ public enum HistoryItemMenuItem implements LabeledMenuItem<HistoryItemMenuData>
     remove(R.string.c_remove) {
         @Override
         public void onClick(@Nonnull HistoryItemMenuData data, @Nonnull Context context) {
-            final CalculatorHistoryState historyState = data.getHistoryState();
+            final HistoryState historyState = data.getHistoryState();
             if (historyState.isSaved()) {
                 data.getAdapter().remove(historyState);
                 Locator.getInstance().getHistory().removeSavedHistory(historyState);
@@ -124,7 +124,7 @@ public enum HistoryItemMenuItem implements LabeledMenuItem<HistoryItemMenuData>
     }
 
     private static void createEditHistoryDialog(@Nonnull final HistoryItemMenuData data, @Nonnull final Context context, final boolean save) {
-        final CalculatorHistoryState historyState = data.getHistoryState();
+        final HistoryState historyState = data.getHistoryState();
 
         final LayoutInflater layoutInflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
         final View editView = layoutInflater.inflate(R.layout.history_edit, null);
@@ -142,7 +142,7 @@ public enum HistoryItemMenuItem implements LabeledMenuItem<HistoryItemMenuData>
                     @Override
                     public void onClick(DialogInterface dialog, int which) {
                         if (save) {
-                            final CalculatorHistoryState savedHistoryItem = Locator.getInstance().getHistory().addSavedState(historyState);
+                            final HistoryState savedHistoryItem = Locator.getInstance().getHistory().addSavedState(historyState);
                             savedHistoryItem.setComment(comment.getText().toString());
                             Locator.getInstance().getHistory().save();
                             // we don't need to add element to the adapter as adapter of another activity must be updated and not this

app/src/main/java/org/solovyev/android/calculator/history/HistoryState.java

@@ -25,20 +25,14 @@ package org.solovyev.android.calculator.history;
 import org.simpleframework.xml.Element;
 import org.simpleframework.xml.Root;
 import org.solovyev.android.calculator.CalculatorDisplay;
-import org.solovyev.android.calculator.CalculatorDisplayViewState;
+import org.solovyev.android.calculator.DisplayState;
-import org.solovyev.android.calculator.CalculatorEditor;
+import org.solovyev.android.calculator.Editor;
 import org.solovyev.android.calculator.EditorState;
 
 import javax.annotation.Nonnull;
 
-/**
- * User: serso
- * Date: 9/11/11
- * Time: 12:16 AM
- */
-
 @Root
-public class CalculatorHistoryState extends AbstractHistoryState {
+public class HistoryState extends BaseHistoryState {
 
     @Element
     @Nonnull
@@ -46,35 +40,28 @@ public class CalculatorHistoryState extends AbstractHistoryState {
 
     @Element
     @Nonnull
-    private CalculatorDisplayHistoryState displayState;
+    private DisplayHistoryState displayState;
 
-    private CalculatorHistoryState() {
+    private HistoryState() {
         // for xml
     }
 
-    private CalculatorHistoryState(@Nonnull EditorHistoryState editorState,
+    private HistoryState(@Nonnull EditorHistoryState editorState,
-                                   @Nonnull CalculatorDisplayHistoryState displayState) {
+                         @Nonnull DisplayHistoryState displayState) {
         this.editorState = editorState;
         this.displayState = displayState;
     }
 
     @Nonnull
-    public static CalculatorHistoryState newInstance(@Nonnull CalculatorEditor editor,
+    public static HistoryState create(@Nonnull Editor editor,
                                       @Nonnull CalculatorDisplay display) {
-        final EditorState editorViewState = editor.getViewState();
+        return create(editor.getState(), display.getViewState());
-        final CalculatorDisplayViewState displayViewState = display.getViewState();
-
-        return newInstance(editorViewState, displayViewState);
     }
 
     @Nonnull
-    public static CalculatorHistoryState newInstance(@Nonnull EditorState editorViewState,
+    public static HistoryState create(@Nonnull EditorState editorState,
-                                                     @Nonnull CalculatorDisplayViewState displayViewState) {
+                                      @Nonnull DisplayState displayState) {
-        final EditorHistoryState editorHistoryState = EditorHistoryState.newInstance(editorViewState);
+        return new HistoryState(EditorHistoryState.create(editorState), DisplayHistoryState.newInstance(displayState));
-
-        final CalculatorDisplayHistoryState displayHistoryState = CalculatorDisplayHistoryState.newInstance(displayViewState);
-
-        return new CalculatorHistoryState(editorHistoryState, displayHistoryState);
     }
 
     @Nonnull
@@ -82,22 +69,14 @@ public class CalculatorHistoryState extends AbstractHistoryState {
         return editorState;
     }
 
-    public void setEditorState(@Nonnull EditorHistoryState editorState) {
-        this.editorState = editorState;
-    }
-
     @Nonnull
-    public CalculatorDisplayHistoryState getDisplayState() {
+    public DisplayHistoryState getDisplayState() {
         return displayState;
     }
 
-    public void setDisplayState(@Nonnull CalculatorDisplayHistoryState displayState) {
-        this.displayState = displayState;
-    }
-
     @Override
     public String toString() {
-        return "CalculatorHistoryState{" +
+        return "HistoryState{" +
                 "editorState=" + editorState +
                 ", displayState=" + displayState +
                 '}';
@@ -108,7 +87,7 @@ public class CalculatorHistoryState extends AbstractHistoryState {
         if (this == o) return true;
         if (o == null || getClass() != o.getClass()) return false;
 
-        CalculatorHistoryState that = (CalculatorHistoryState) o;
+        HistoryState that = (HistoryState) o;
 
         if (this.isSaved() != that.isSaved()) return false;
         if (this.getId() != that.getId()) return false;
@@ -127,18 +106,18 @@ public class CalculatorHistoryState extends AbstractHistoryState {
         return result;
     }
 
-    public void setValuesFromHistory(@Nonnull CalculatorEditor editor, @Nonnull CalculatorDisplay display) {
+    public void setValuesFromHistory(@Nonnull Editor editor, @Nonnull CalculatorDisplay display) {
         this.getEditorState().setValuesFromHistory(editor);
         this.getDisplayState().setValuesFromHistory(display);
     }
 
     @Override
-    protected CalculatorHistoryState clone() {
+    protected HistoryState clone() {
-        final CalculatorHistoryState clone = (CalculatorHistoryState) super.clone();
+        final HistoryState that = (HistoryState) super.clone();
 
-        clone.editorState = this.editorState.clone();
+        that.editorState = this.editorState.clone();
-        clone.displayState = this.displayState.clone();
+        that.displayState = this.displayState.clone();
 
-        return clone;
+        return that;
     }
 }

app/src/main/java/org/solovyev/android/calculator/history/HistoryUtils.java

@@ -43,12 +43,12 @@ class HistoryUtils {
         throw new AssertionError();
     }
 
-    public static void fromXml(@Nullable String xml, @Nonnull List<CalculatorHistoryState> historyItems) {
+    public static void fromXml(@Nullable String xml, @Nonnull List<HistoryState> historyItems) {
         if (xml != null) {
             final Serializer serializer = new Persister();
             try {
                 final History history = serializer.read(History.class, xml);
-                for (CalculatorHistoryState historyItem : history.getHistoryItems()) {
+                for (HistoryState historyItem : history.getHistoryItems()) {
                     historyItems.add(historyItem);
                 }
             } catch (Exception e) {
@@ -58,9 +58,9 @@ class HistoryUtils {
     }
 
     @Nonnull
-    public static String toXml(@Nonnull List<CalculatorHistoryState> historyItems) {
+    public static String toXml(@Nonnull List<HistoryState> historyItems) {
         final History history = new History();
-        for (CalculatorHistoryState historyState : historyItems) {
+        for (HistoryState historyState : historyItems) {
             if (historyState.isSaved()) {
                 history.getHistoryItems().add(historyState);
             }

app/src/main/java/org/solovyev/android/calculator/history/SavedHistoryFragment.java

@@ -44,8 +44,8 @@ public class SavedHistoryFragment extends BaseHistoryFragment {
 
     @Nonnull
     @Override
-    protected List<CalculatorHistoryState> getHistoryItems() {
+    protected List<HistoryState> getHistoryItems() {
-        return new ArrayList<CalculatorHistoryState>(Locator.getInstance().getHistory().getSavedHistory());
+        return new ArrayList<HistoryState>(Locator.getInstance().getHistory().getSavedHistory());
     }
 
     @Override

app/src/main/java/org/solovyev/android/calculator/onscreen/CalculatorOnscreenService.java

@@ -122,7 +122,7 @@ public class CalculatorOnscreenService extends Service implements OnscreenViewLi
             view.show();
 
             startCalculatorListening();
-            view.updateEditorState(Locator.getInstance().getEditor().getViewState());
+            view.updateEditorState(Locator.getInstance().getEditor().getState());
             view.updateDisplayState(Locator.getInstance().getDisplay().getViewState());
 
             viewCreated = true;

app/src/main/java/org/solovyev/android/calculator/onscreen/CalculatorOnscreenView.java

@@ -180,7 +180,7 @@ public class CalculatorOnscreenView {
         }
     }
 
-    public void updateDisplayState(@Nonnull CalculatorDisplayViewState displayState) {
+    public void updateDisplayState(@Nonnull DisplayState displayState) {
         checkInit();
         displayView.setState(displayState);
     }

app/src/main/java/org/solovyev/android/calculator/view/LongClickEraser.java

@@ -5,7 +5,7 @@ import android.view.MotionEvent;
 import android.view.View;
 
 import org.solovyev.android.calculator.Calculator;
-import org.solovyev.android.calculator.CalculatorEditor;
+import org.solovyev.android.calculator.Editor;
 import org.solovyev.android.calculator.EditorState;
 import org.solovyev.android.calculator.Locator;
 
@@ -22,7 +22,7 @@ public final class LongClickEraser implements View.OnTouchListener {
     private final GestureDetector gestureDetector;
 
     @Nonnull
-    private final CalculatorEditor editor = Locator.getInstance().getEditor();
+    private final Editor editor = Locator.getInstance().getEditor();
 
     @Nonnull
     private final Calculator calculator = Locator.getInstance().getCalculator();

app/src/main/java/org/solovyev/android/calculator/widget/CalculatorWidget.java

@@ -107,8 +107,8 @@ public class CalculatorWidget extends AppWidgetProvider {
     private void updateWidget(@Nonnull Context context,
                               @Nonnull AppWidgetManager manager,
                               @Nonnull int[] widgetIds) {
-        final  EditorState editorState = Locator.getInstance().getEditor().getViewState();
+        final  EditorState editorState = Locator.getInstance().getEditor().getState();
-        final CalculatorDisplayViewState displayState = Locator.getInstance().getDisplay().getViewState();
+        final DisplayState displayState = Locator.getInstance().getDisplay().getViewState();
 
         final Resources resources = context.getResources();
         final SimpleTheme theme = App.getWidgetTheme().resolveThemeFor(App.getTheme());
@@ -195,7 +195,7 @@ public class CalculatorWidget extends AppWidgetProvider {
         }
     }
 
-    private void updateDisplayState(@Nonnull Context context, @Nonnull RemoteViews views, @Nonnull CalculatorDisplayViewState displayState, @Nonnull SimpleTheme theme) {
+    private void updateDisplayState(@Nonnull Context context, @Nonnull RemoteViews views, @Nonnull DisplayState displayState, @Nonnull SimpleTheme theme) {
         final boolean error = !displayState.isValid();
         if (!error) {
             views.setTextViewText(R.id.calculator_display, displayState.getText());

app/src/test/java/org/solovyev/android/calculator/AndroidEditorViewTest.java

@@ -47,7 +47,7 @@ import java.util.concurrent.atomic.AtomicBoolean;
 
 @Config(constants = BuildConfig.class, sdk = Build.VERSION_CODES.LOLLIPOP)
 @RunWith(value = RobolectricGradleTestRunner.class)
-public class AndroidCalculatorEditorViewTest {
+public class AndroidEditorViewTest {
 
     @BeforeClass
     public static void staticSetUp() throws Exception {

app/src/test/java/org/solovyev/android/calculator/CalculatorDisplayViewStateImplTest.java

@@ -36,11 +36,11 @@ public class CalculatorDisplayViewStateImplTest {
 
     @Test
     public void testSerializable() throws Exception {
-        CalculatorTestUtils.testSerialization(CalculatorDisplayViewStateImpl.newValidState(JsclOperation.numeric, null, "test", 3));
+        CalculatorTestUtils.testSerialization(DisplayState.createValid(JsclOperation.numeric, null, "test", 3));
-        CalculatorTestUtils.testSerialization(CalculatorDisplayViewStateImpl.newValidState(JsclOperation.numeric, Expression.valueOf("3"), "test", 3));
+        CalculatorTestUtils.testSerialization(DisplayState.createValid(JsclOperation.numeric, Expression.valueOf("3"), "test", 3));
-        CalculatorTestUtils.testSerialization(CalculatorDisplayViewStateImpl.newValidState(JsclOperation.simplify, Expression.valueOf("3+3"), "test", 3));
+        CalculatorTestUtils.testSerialization(DisplayState.createValid(JsclOperation.simplify, Expression.valueOf("3+3"), "test", 3));
-        CalculatorTestUtils.testSerialization(CalculatorDisplayViewStateImpl.newDefaultInstance());
+        CalculatorTestUtils.testSerialization(DisplayState.empty());
-        CalculatorTestUtils.testSerialization(CalculatorDisplayViewStateImpl.newErrorState(JsclOperation.numeric, "ertert"));
+        CalculatorTestUtils.testSerialization(DisplayState.createError(JsclOperation.numeric, "ertert"));
     }
 
 }

app/src/test/java/org/solovyev/android/calculator/CalculatorTestUtils.java

@@ -76,7 +76,6 @@ public class CalculatorTestUtils {
 
     public static void initViews(@Nonnull Context context) {
         final EditorView editor = new EditorView(context);
-        editor.init();
         Locator.getInstance().getEditor().setView(editor);
 
         final AndroidCalculatorDisplayView display = new AndroidCalculatorDisplayView(context);
@@ -105,7 +104,7 @@ public class CalculatorTestUtils {
     public static void assertEval(@Nonnull String expected, @Nonnull String expression, @Nonnull JsclOperation operation) {
         final Calculator calculator = Locator.getInstance().getCalculator();
 
-        Locator.getInstance().getDisplay().setViewState(CalculatorDisplayViewStateImpl.newDefaultInstance());
+        Locator.getInstance().getDisplay().setViewState(DisplayState.empty());
 
         final CountDownLatch latch = new CountDownLatch(1);
         final TestCalculatorEventListener calculatorEventListener = new TestCalculatorEventListener(latch);
@@ -161,7 +160,7 @@ public class CalculatorTestUtils {
     public static void assertError(@Nonnull String expression, @Nonnull JsclOperation operation) {
         final Calculator calculator = Locator.getInstance().getCalculator();
 
-        Locator.getInstance().getDisplay().setViewState(CalculatorDisplayViewStateImpl.newDefaultInstance());
+        Locator.getInstance().getDisplay().setViewState(DisplayState.empty());
 
         final CountDownLatch latch = new CountDownLatch(1);
         final TestCalculatorEventListener calculatorEventListener = new TestCalculatorEventListener(latch);
@@ -190,7 +189,7 @@ public class CalculatorTestUtils {
         @Nullable
         private CalculatorEventData calculatorEventData;
         @Nullable
-        private volatile CalculatorDisplayViewState result = null;
+        private volatile DisplayState result = null;
 
         public TestCalculatorEventListener(@Nonnull CountDownLatch latch) {
             this.latch = latch;
@@ -230,7 +229,7 @@ public class CalculatorTestUtils {
         }
 
         @Nullable
-        public CalculatorDisplayViewState getResult() {
+        public DisplayState getResult() {
             return result;
         }
     }

app/src/test/java/org/solovyev/android/calculator/EditorTest.java

@@ -33,198 +33,198 @@ import javax.annotation.Nonnull;
  * Date: 21.09.12
  * Time: 12:44
  */
-public class CalculatorEditorImplTest extends AbstractCalculatorTest {
+public class EditorTest extends AbstractCalculatorTest {
 
     @Nonnull
-    private CalculatorEditor calculatorEditor;
+    private Editor editor;
 
     @Before
     public void setUp() throws Exception {
         super.setUp();
-        this.calculatorEditor = new CalculatorEditorImpl(Locator.getInstance().getCalculator(), null);
+        this.editor = new Editor(Locator.getInstance().getCalculator(), null);
     }
 
     @Test
     public void testInsert() throws Exception {
-        CalculatorEditorViewState viewState = this.calculatorEditor.getViewState();
+        EditorState viewState = this.editor.getState();
 
         Assert.assertEquals("", viewState.getText());
         Assert.assertEquals(0, viewState.getSelection());
 
-        viewState = this.calculatorEditor.insert("");
+        viewState = this.editor.insert("");
 
         Assert.assertEquals("", viewState.getText());
         Assert.assertEquals(0, viewState.getSelection());
 
-        viewState = this.calculatorEditor.insert("test");
+        viewState = this.editor.insert("test");
 
         Assert.assertEquals("test", viewState.getText());
         Assert.assertEquals(4, viewState.getSelection());
 
-        viewState = this.calculatorEditor.insert("test");
+        viewState = this.editor.insert("test");
         Assert.assertEquals("testtest", viewState.getText());
         Assert.assertEquals(8, viewState.getSelection());
 
-        viewState = this.calculatorEditor.insert("");
+        viewState = this.editor.insert("");
         Assert.assertEquals("testtest", viewState.getText());
         Assert.assertEquals(8, viewState.getSelection());
 
-        viewState = this.calculatorEditor.insert("1234567890");
+        viewState = this.editor.insert("1234567890");
         Assert.assertEquals("testtest1234567890", viewState.getText());
         Assert.assertEquals(18, viewState.getSelection());
 
-        viewState = this.calculatorEditor.moveCursorLeft();
+        viewState = this.editor.moveCursorLeft();
-        viewState = this.calculatorEditor.insert("9");
+        viewState = this.editor.insert("9");
         Assert.assertEquals("testtest12345678990", viewState.getText());
         Assert.assertEquals(18, viewState.getSelection());
 
-        viewState = this.calculatorEditor.setCursorOnStart();
+        viewState = this.editor.setCursorOnStart();
-        viewState = this.calculatorEditor.insert("9");
+        viewState = this.editor.insert("9");
         Assert.assertEquals("9testtest12345678990", viewState.getText());
         Assert.assertEquals(1, viewState.getSelection());
 
-        viewState = this.calculatorEditor.erase();
+        viewState = this.editor.erase();
-        viewState = this.calculatorEditor.insert("9");
+        viewState = this.editor.insert("9");
         Assert.assertEquals("9testtest12345678990", viewState.getText());
         Assert.assertEquals(1, viewState.getSelection());
 
-        viewState = this.calculatorEditor.insert("öäü");
+        viewState = this.editor.insert("öäü");
         Assert.assertEquals("9öäütesttest12345678990", viewState.getText());
 
-        this.calculatorEditor.setCursorOnEnd();
+        this.editor.setCursorOnEnd();
-        viewState = this.calculatorEditor.insert("öäü");
+        viewState = this.editor.insert("öäü");
         Assert.assertEquals("9öäütesttest12345678990öäü", viewState.getText());
     }
 
     @Test
     public void testErase() throws Exception {
-        this.calculatorEditor.setText("");
+        this.editor.setText("");
-        this.calculatorEditor.erase();
+        this.editor.erase();
 
-        Assert.assertEquals("", this.calculatorEditor.getViewState().getText());
+        Assert.assertEquals("", this.editor.getState().getText());
 
-        this.calculatorEditor.setText("test");
+        this.editor.setText("test");
-        this.calculatorEditor.erase();
+        this.editor.erase();
-        Assert.assertEquals("tes", this.calculatorEditor.getViewState().getText());
+        Assert.assertEquals("tes", this.editor.getState().getText());
 
-        this.calculatorEditor.erase();
+        this.editor.erase();
-        Assert.assertEquals("te", this.calculatorEditor.getViewState().getText());
+        Assert.assertEquals("te", this.editor.getState().getText());
 
-        this.calculatorEditor.erase();
+        this.editor.erase();
-        Assert.assertEquals("t", this.calculatorEditor.getViewState().getText());
+        Assert.assertEquals("t", this.editor.getState().getText());
 
-        this.calculatorEditor.erase();
+        this.editor.erase();
-        Assert.assertEquals("", this.calculatorEditor.getViewState().getText());
+        Assert.assertEquals("", this.editor.getState().getText());
 
-        this.calculatorEditor.erase();
+        this.editor.erase();
-        Assert.assertEquals("", this.calculatorEditor.getViewState().getText());
+        Assert.assertEquals("", this.editor.getState().getText());
 
-        this.calculatorEditor.setText("1234");
+        this.editor.setText("1234");
-        this.calculatorEditor.moveCursorLeft();
+        this.editor.moveCursorLeft();
-        this.calculatorEditor.erase();
+        this.editor.erase();
-        Assert.assertEquals("124", this.calculatorEditor.getViewState().getText());
+        Assert.assertEquals("124", this.editor.getState().getText());
 
-        this.calculatorEditor.erase();
+        this.editor.erase();
-        Assert.assertEquals("14", this.calculatorEditor.getViewState().getText());
+        Assert.assertEquals("14", this.editor.getState().getText());
 
-        this.calculatorEditor.erase();
+        this.editor.erase();
-        Assert.assertEquals("4", this.calculatorEditor.getViewState().getText());
+        Assert.assertEquals("4", this.editor.getState().getText());
 
-        this.calculatorEditor.setText("1");
+        this.editor.setText("1");
-        this.calculatorEditor.moveCursorLeft();
+        this.editor.moveCursorLeft();
-        this.calculatorEditor.erase();
+        this.editor.erase();
-        Assert.assertEquals("1", this.calculatorEditor.getViewState().getText());
+        Assert.assertEquals("1", this.editor.getState().getText());
     }
 
     @Test
     public void testMoveSelection() throws Exception {
-        this.calculatorEditor.setText("");
+        this.editor.setText("");
 
-        CalculatorEditorViewState viewState = this.calculatorEditor.moveSelection(0);
+        EditorState viewState = this.editor.moveSelection(0);
         Assert.assertEquals(0, viewState.getSelection());
 
-        viewState = this.calculatorEditor.moveSelection(2);
+        viewState = this.editor.moveSelection(2);
         Assert.assertEquals(0, viewState.getSelection());
 
-        viewState = this.calculatorEditor.moveSelection(100);
+        viewState = this.editor.moveSelection(100);
         Assert.assertEquals(0, viewState.getSelection());
 
-        viewState = this.calculatorEditor.moveSelection(-3);
+        viewState = this.editor.moveSelection(-3);
         Assert.assertEquals(0, viewState.getSelection());
 
-        viewState = this.calculatorEditor.moveSelection(-100);
+        viewState = this.editor.moveSelection(-100);
         Assert.assertEquals(0, viewState.getSelection());
 
-        viewState = this.calculatorEditor.setText("0123456789");
+        viewState = this.editor.setText("0123456789");
 
-        viewState = this.calculatorEditor.moveSelection(0);
+        viewState = this.editor.moveSelection(0);
         Assert.assertEquals(10, viewState.getSelection());
 
-        viewState = this.calculatorEditor.moveSelection(1);
+        viewState = this.editor.moveSelection(1);
         Assert.assertEquals(10, viewState.getSelection());
 
-        viewState = this.calculatorEditor.moveSelection(-2);
+        viewState = this.editor.moveSelection(-2);
         Assert.assertEquals(8, viewState.getSelection());
 
-        viewState = this.calculatorEditor.moveSelection(1);
+        viewState = this.editor.moveSelection(1);
         Assert.assertEquals(9, viewState.getSelection());
 
-        viewState = this.calculatorEditor.moveSelection(-9);
+        viewState = this.editor.moveSelection(-9);
         Assert.assertEquals(0, viewState.getSelection());
 
-        viewState = this.calculatorEditor.moveSelection(-10);
+        viewState = this.editor.moveSelection(-10);
         Assert.assertEquals(0, viewState.getSelection());
 
-        viewState = this.calculatorEditor.moveSelection(2);
+        viewState = this.editor.moveSelection(2);
         Assert.assertEquals(2, viewState.getSelection());
 
-        viewState = this.calculatorEditor.moveSelection(2);
+        viewState = this.editor.moveSelection(2);
         Assert.assertEquals(4, viewState.getSelection());
 
-        viewState = this.calculatorEditor.moveSelection(-6);
+        viewState = this.editor.moveSelection(-6);
         Assert.assertEquals(0, viewState.getSelection());
     }
 
     @Test
     public void testSetText() throws Exception {
-        CalculatorEditorViewState viewState = this.calculatorEditor.setText("test");
+        EditorState viewState = this.editor.setText("test");
 
         Assert.assertEquals("test", viewState.getText());
         Assert.assertEquals(4, viewState.getSelection());
 
-        viewState = this.calculatorEditor.setText("testtest");
+        viewState = this.editor.setText("testtest");
         Assert.assertEquals("testtest", viewState.getText());
         Assert.assertEquals(8, viewState.getSelection());
 
-        viewState = this.calculatorEditor.setText("");
+        viewState = this.editor.setText("");
         Assert.assertEquals("", viewState.getText());
         Assert.assertEquals(0, viewState.getSelection());
 
-        viewState = this.calculatorEditor.setText("testtest", 0);
+        viewState = this.editor.setText("testtest", 0);
         Assert.assertEquals("testtest", viewState.getText());
         Assert.assertEquals(0, viewState.getSelection());
 
-        viewState = this.calculatorEditor.setText("testtest", 2);
+        viewState = this.editor.setText("testtest", 2);
         Assert.assertEquals("testtest", viewState.getText());
         Assert.assertEquals(2, viewState.getSelection());
 
-        viewState = this.calculatorEditor.setText("", 0);
+        viewState = this.editor.setText("", 0);
         Assert.assertEquals("", viewState.getText());
         Assert.assertEquals(0, viewState.getSelection());
 
-        viewState = this.calculatorEditor.setText("", 3);
+        viewState = this.editor.setText("", 3);
         Assert.assertEquals("", viewState.getText());
         Assert.assertEquals(0, viewState.getSelection());
 
-        viewState = this.calculatorEditor.setText("", -3);
+        viewState = this.editor.setText("", -3);
         Assert.assertEquals("", viewState.getText());
         Assert.assertEquals(0, viewState.getSelection());
 
-        viewState = this.calculatorEditor.setText("test");
+        viewState = this.editor.setText("test");
         Assert.assertEquals("test", viewState.getText());
         Assert.assertEquals(4, viewState.getSelection());
 
-        viewState = this.calculatorEditor.setText("", 2);
+        viewState = this.editor.setText("", 2);
         Assert.assertEquals("", viewState.getText());
         Assert.assertEquals(0, viewState.getSelection());
     }

app/src/test/java/org/solovyev/android/calculator/history/CalculatorHistoryImplTest.java

@@ -25,7 +25,7 @@ package org.solovyev.android.calculator.history;
 import org.junit.Assert;
 import org.junit.BeforeClass;
 import org.junit.Test;
-import org.solovyev.android.calculator.CalculatorDisplayViewStateImpl;
+import org.solovyev.android.calculator.DisplayState;
 import org.solovyev.android.calculator.EditorState;
 import org.solovyev.android.calculator.CalculatorTestUtils;
 import org.solovyev.android.calculator.Locator;
@@ -64,13 +64,13 @@ public class CalculatorHistoryImplTest {
         addState(calculatorHistory, "2354");
         addState(calculatorHistory, "23547");
 
-        final List<CalculatorHistoryState> states = calculatorHistory.getStates(false);
+        final List<HistoryState> states = calculatorHistory.getStates(false);
         Assert.assertEquals(2, states.size());
         Assert.assertEquals("23547", states.get(1).getEditorState().getText());
         Assert.assertEquals("123+3", states.get(0).getEditorState().getText());
     }
 
     private void addState(@Nonnull CalculatorHistory calculatorHistory, @Nonnull String text) {
-        calculatorHistory.addState(CalculatorHistoryState.newInstance(EditorState.create(text, 3), CalculatorDisplayViewStateImpl.newDefaultInstance()));
+        calculatorHistory.addState(HistoryState.create(EditorState.create(text, 3), DisplayState.empty()));
     }
 }

app/src/test/java/org/solovyev/android/calculator/history/HistoryUtilsTest.java

@@ -24,8 +24,7 @@ package org.solovyev.android.calculator.history;
 
 import org.junit.Assert;
 import org.junit.Test;
-import org.solovyev.android.calculator.CalculatorDisplayViewState;
+import org.solovyev.android.calculator.DisplayState;
-import org.solovyev.android.calculator.CalculatorDisplayViewStateImpl;
 import org.solovyev.android.calculator.EditorState;
 import org.solovyev.android.calculator.jscl.JsclOperation;
 import org.solovyev.common.Objects;
@@ -137,13 +136,13 @@ public class HistoryUtilsTest {
     public void testToXml() throws Exception {
         final Date date = new Date(100000000);
 
-        HistoryHelper<CalculatorHistoryState> history = SimpleHistoryHelper.newInstance();
+        HistoryHelper<HistoryState> history = SimpleHistoryHelper.newInstance();
 
-        CalculatorDisplayViewState calculatorDisplay = CalculatorDisplayViewStateImpl.newErrorState(JsclOperation.simplify, "Error");
+        DisplayState calculatorDisplay = DisplayState.createError(JsclOperation.simplify, "Error");
 
         CalculatorEditorViewState calculatorEditor = EditorState.create("1+1", 3);
 
-        CalculatorHistoryState state = CalculatorHistoryState.newInstance(calculatorEditor, calculatorDisplay);
+        HistoryState state = HistoryState.newInstance(calculatorEditor, calculatorDisplay);
         state.setTime(date.getTime());
         history.addState(state);
 
@@ -154,29 +153,29 @@ public class HistoryUtilsTest {
 
         assertEquals(toXml1, HistoryUtils.toXml(history.getStates()));
 
-        calculatorDisplay = CalculatorDisplayViewStateImpl.newValidState(JsclOperation.numeric, null, "5/6", 3);
+        calculatorDisplay = DisplayState.createValid(JsclOperation.numeric, null, "5/6", 3);
 
         calculatorEditor = EditorState.create("5/6", 2);
 
-        state = CalculatorHistoryState.newInstance(calculatorEditor, calculatorDisplay);
+        state = HistoryState.newInstance(calculatorEditor, calculatorDisplay);
         state.setSaved(true);
         state.setTime(date.getTime());
         history.addState(state);
 
-        calculatorDisplay = CalculatorDisplayViewStateImpl.newErrorState(JsclOperation.elementary, "Error");
+        calculatorDisplay = DisplayState.createError(JsclOperation.elementary, "Error");
 
         calculatorEditor = EditorState.create("", 1);
 
-        state = CalculatorHistoryState.newInstance(calculatorEditor, calculatorDisplay);
+        state = HistoryState.newInstance(calculatorEditor, calculatorDisplay);
         state.setSaved(true);
         state.setTime(date.getTime());
         history.addState(state);
 
-        calculatorDisplay = CalculatorDisplayViewStateImpl.newValidState(JsclOperation.numeric, null, "4+5/35sin(41)+dfdsfsdfs", 1);
+        calculatorDisplay = DisplayState.createValid(JsclOperation.numeric, null, "4+5/35sin(41)+dfdsfsdfs", 1);
 
         calculatorEditor = EditorState.create("4+5/35sin(41)+dfdsfsdfs", 0);
 
-        state = CalculatorHistoryState.newInstance(calculatorEditor, calculatorDisplay);
+        state = HistoryState.newInstance(calculatorEditor, calculatorDisplay);
         state.setSaved(true);
         state.setTime(date.getTime());
         history.addState(state);
@@ -184,23 +183,23 @@ public class HistoryUtilsTest {
         String xml = HistoryUtils.toXml(history.getStates());
         assertEquals(toXml2, xml);
 
-        final List<CalculatorHistoryState> fromXml = new ArrayList<CalculatorHistoryState>();
+        final List<HistoryState> fromXml = new ArrayList<HistoryState>();
-        final HistoryHelper<CalculatorHistoryState> historyFromXml = SimpleHistoryHelper.newInstance();
+        final HistoryHelper<HistoryState> historyFromXml = SimpleHistoryHelper.newInstance();
         HistoryUtils.fromXml(xml, fromXml);
-        for (CalculatorHistoryState historyState : fromXml) {
+        for (HistoryState historyState : fromXml) {
             historyFromXml.addState(historyState);
         }
 
         assertEquals(history.getStates().size(), historyFromXml.getStates().size());
 
-        for (CalculatorHistoryState historyState : history.getStates()) {
+        for (HistoryState historyState : history.getStates()) {
             historyState.setId(0);
             historyState.setSaved(true);
         }
-        for (CalculatorHistoryState historyState : historyFromXml.getStates()) {
+        for (HistoryState historyState : historyFromXml.getStates()) {
             historyState.setId(0);
             historyState.setSaved(true);
         }
-        Assert.assertTrue(Objects.areEqual(history.getStates(), historyFromXml.getStates(), new CollectionEqualizer<CalculatorHistoryState>(null)));
+        Assert.assertTrue(Objects.areEqual(history.getStates(), historyFromXml.getStates(), new CollectionEqualizer<HistoryState>(null)));
     }
 }