symbolic calculations added

src/main/java/org/solovyev/android/calculator/CalculatorActivity.java

@@ -92,6 +92,13 @@ public class CalculatorActivity extends Activity implements FontSizeAdjuster, Sh
 		((DragButton) findViewById(R.id.leftButton)).setOnDragListener(toPositionOnDragListener);
 		dpclRegister.addListener(toPositionOnDragListener);
 
+		final DragButton equalsButton = (DragButton) findViewById(R.id.equalsButton);
+		if (equalsButton != null) {
+			final SimpleOnDragListener evalOnDragListener = new SimpleOnDragListener(new EvalDragProcessor(calculatorModel), dragPreferences);
+			equalsButton.setOnDragListener(evalOnDragListener);
+			dpclRegister.addListener(evalOnDragListener);
+		}
+
 		CalculatorEngine.instance.reset(this, preferences);
 
 		preferences.registerOnSharedPreferenceChangeListener(this);
@@ -389,10 +396,7 @@ public class CalculatorActivity extends Activity implements FontSizeAdjuster, Sh
 		}
 
 		calculatorModel = CalculatorModel.instance.init(this, preferences, CalculatorEngine.instance);
-
 		AndroidMessageRegistry.instance.init(this);
-
-		this.calculatorModel.evaluate();
 	}
 
 	@Override

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

@@ -12,6 +12,7 @@ import android.util.AttributeSet;
 import android.util.Log;
 import android.widget.TextView;
 import org.jetbrains.annotations.NotNull;
+import org.solovyev.android.calculator.jscl.JsclOperation;
 import org.solovyev.android.calculator.model.ParseException;
 import org.solovyev.android.calculator.model.TextProcessor;
 
@@ -24,6 +25,9 @@ public class CalculatorDisplay extends TextView {
 
 	private boolean valid = true;
 
+	@NotNull
+	private JsclOperation jsclOperation = JsclOperation.numeric;
+
 	@NotNull
 	private final static TextProcessor<TextHighlighter.Result> textHighlighter = new TextHighlighter(Color.WHITE, true);
 
@@ -47,6 +51,15 @@ public class CalculatorDisplay extends TextView {
 		this.valid = valid;
 	}
 
+	public void setJsclOperation(@NotNull JsclOperation jsclOperation) {
+		this.jsclOperation = jsclOperation;
+	}
+
+	@NotNull
+	public JsclOperation getJsclOperation() {
+		return jsclOperation;
+	}
+
 	@Override
 	public void setText(CharSequence text, BufferType type) {
 		super.setText(text, type);

src/main/java/org/solovyev/android/calculator/CalculatorDisplayHistoryState.java

@@ -6,7 +6,7 @@
 package org.solovyev.android.calculator;
 
 import org.jetbrains.annotations.NotNull;
-import org.jetbrains.annotations.Nullable;
+import org.solovyev.android.calculator.jscl.JsclOperation;
 
 /**
  * User: serso
@@ -18,45 +18,49 @@ public class CalculatorDisplayHistoryState {
 	private boolean valid = true;
 
 	@NotNull
-	private final EditorHistoryState editorHistoryState;
+	private EditorHistoryState editorHistoryState;
 
-	public CalculatorDisplayHistoryState() {
-		this.editorHistoryState = new EditorHistoryState();
+	@NotNull
+	private JsclOperation jsclOperation;
+
+	private CalculatorDisplayHistoryState() {
 	}
 
-	public CalculatorDisplayHistoryState(boolean valid) {
-		this.editorHistoryState = new EditorHistoryState();
-		this.valid = valid;
-	}
+	@NotNull
+	public static CalculatorDisplayHistoryState newInstance(@NotNull CalculatorDisplay display) {
+		final CalculatorDisplayHistoryState result = new CalculatorDisplayHistoryState();
 
-	public CalculatorDisplayHistoryState(int cursorPosition, @Nullable String text, boolean valid) {
-		this.editorHistoryState = new EditorHistoryState(cursorPosition, text);
-		this.valid = valid;
+		result.editorHistoryState = EditorHistoryState.newInstance(display);
+		result.valid = display.isValid();
+		result.jsclOperation = display.getJsclOperation();
+
+		return result;
 	}
 
 	public boolean isValid() {
 		return valid;
 	}
 
-	public void setValid(boolean valid) {
-		this.valid = valid;
-	}
-
 	@NotNull
 	public EditorHistoryState getEditorHistoryState() {
 		return editorHistoryState;
 	}
 
+	@NotNull
+	public JsclOperation getJsclOperation() {
+		return jsclOperation;
+	}
+
 	@Override
 	public boolean equals(Object o) {
 		if (this == o) return true;
-		if (!(o instanceof CalculatorDisplayHistoryState)) return false;
+		if (o == null || getClass() != o.getClass()) return false;
 
 		CalculatorDisplayHistoryState that = (CalculatorDisplayHistoryState) o;
 
 		if (valid != that.valid) return false;
-		if (editorHistoryState != null ? !editorHistoryState.equals(that.editorHistoryState) : that.editorHistoryState != null)
-			return false;
+		if (!editorHistoryState.equals(that.editorHistoryState)) return false;
+		if (jsclOperation != that.jsclOperation) return false;
 
 		return true;
 	}
@@ -64,7 +68,8 @@ public class CalculatorDisplayHistoryState {
 	@Override
 	public int hashCode() {
 		int result = (valid ? 1 : 0);
-		result = 31 * result + (editorHistoryState != null ? editorHistoryState.hashCode() : 0);
+		result = 31 * result + editorHistoryState.hashCode();
+		result = 31 * result + jsclOperation.hashCode();
 		return result;
 	}
 
@@ -72,6 +77,7 @@ public class CalculatorDisplayHistoryState {
 	public String toString() {
 		return "CalculatorDisplayHistoryState{" +
 				"valid=" + valid +
+				"jsclOperation=" + jsclOperation +
 				", editorHistoryState=" + editorHistoryState +
 				'}';
 	}

src/main/java/org/solovyev/android/calculator/CalculatorEngineControl.java

@@ -0,0 +1,19 @@
+/*
+ * Copyright (c) 2009-2011. Created by serso aka se.solovyev.
+ * For more information, please, contact se.solovyev@gmail.com
+ * or visit http://se.solovyev.org
+ */
+
+package org.solovyev.android.calculator;
+
+/**
+ * User: serso
+ * Date: 10/24/11
+ * Time: 9:55 PM
+ */
+public interface CalculatorEngineControl {
+
+	void evaluate();
+
+	void simplify();
+}

src/main/java/org/solovyev/android/calculator/CalculatorHistoryActivity.java

@@ -12,6 +12,7 @@ import android.os.Bundle;
 import android.view.*;
 import android.widget.*;
 import org.jetbrains.annotations.NotNull;
+import org.solovyev.android.calculator.jscl.JsclOperation;
 import org.solovyev.common.utils.Filter;
 import org.solovyev.common.utils.FilterRule;
 import org.solovyev.common.utils.FilterRulesChain;
@@ -53,14 +54,16 @@ public class CalculatorHistoryActivity extends ListActivity {
 									final int position,
 									final long id) {
 
+				final CalculatorHistoryState historyState = (CalculatorHistoryState) parent.getItemAtPosition(position);
+
 				CalculatorModel.instance.doTextOperation(new CalculatorModel.TextOperation() {
 					@Override
 					public void doOperation(@NotNull EditText editor) {
-						final EditorHistoryState editorState = ((CalculatorHistoryState) parent.getItemAtPosition(position)).getEditorState();
+						final EditorHistoryState editorState = historyState.getEditorState();
 						editor.setText(editorState.getText());
 						editor.setSelection(editorState.getCursorPosition());
 					}
-				}, false);
+				}, false, historyState.getDisplayState().getJsclOperation(), true);
 
 				CalculatorModel.instance.setCursorOnEnd();
 
@@ -108,10 +111,15 @@ public class CalculatorHistoryActivity extends ListActivity {
 			time.setText(new SimpleDateFormat().format(state.getTime()));
 
 			final TextView editor = (TextView) result.findViewById(R.id.history_item);
-			editor.setText(state.getEditorState().getText() + "=" + state.getDisplayState().getEditorHistoryState().getText());
+			editor.setText(state.getEditorState().getText() + getIdentitySign(state.getDisplayState().getJsclOperation()) + state.getDisplayState().getEditorHistoryState().getText());
 
 			return result;
 		}
+
+		@NotNull
+		private String getIdentitySign(@NotNull JsclOperation jsclOperation) {
+			return jsclOperation == JsclOperation.simplify ? "≡" : "=";
+		}
 	}
 
 	@Override

src/main/java/org/solovyev/android/calculator/CalculatorModel.java

@@ -34,7 +34,7 @@ import org.solovyev.common.utils.history.HistoryAction;
  * Date: 9/12/11
  * Time: 11:15 PM
  */
-public enum CalculatorModel implements CursorControl, HistoryControl<CalculatorHistoryState> {
+public enum CalculatorModel implements CursorControl, HistoryControl<CalculatorHistoryState>, CalculatorEngineControl {
 
 	instance;
 
@@ -51,6 +51,7 @@ public enum CalculatorModel implements CursorControl, HistoryControl<CalculatorH
 	private CalculatorEngine calculatorEngine;
 
 	public CalculatorModel init(@NotNull final Activity activity, @NotNull SharedPreferences preferences, @NotNull CalculatorEngine calculator) {
+		Log.d(this.getClass().getName(), "CalculatorModel initialization with activity: " + activity);
 		this.calculatorEngine = calculator;
 
 		this.editor = (CalculatorEditor) activity.findViewById(R.id.calculatorEditor);
@@ -119,24 +120,29 @@ public enum CalculatorModel implements CursorControl, HistoryControl<CalculatorH
 	}
 
 	public void doTextOperation(@NotNull TextOperation operation, boolean delayEvaluate) {
+		doTextOperation(operation, delayEvaluate, JsclOperation.numeric, false);
+	}
+
+	public void doTextOperation(@NotNull TextOperation operation, boolean delayEvaluate, @NotNull JsclOperation jsclOperation, boolean forceEval) {
 		final String editorStateBefore = this.editor.getText().toString();
 
+		Log.d(CalculatorModel.class.getName(), "Editor state changed before '" + editorStateBefore + "'");
 		operation.doOperation(this.editor);
 		//Log.d(CalculatorModel.class.getName(), "Doing text operation" + StringUtils.fromStackTrace(Thread.currentThread().getStackTrace()));
 
 		final String editorStateAfter = this.editor.getText().toString();
-		if (!editorStateBefore.equals(editorStateAfter)) {
+		if (forceEval ||!editorStateBefore.equals(editorStateAfter)) {
 
 			editor.redraw();
 
-			evaluate(delayEvaluate, editorStateAfter);
+			evaluate(delayEvaluate, editorStateAfter, jsclOperation);
 		}
 	}
 
 	@NotNull
 	private final static MutableObject<Runnable> pendingOperation = new MutableObject<Runnable>();
 
-	private void evaluate(boolean delayEvaluate, @NotNull final String expression) {
+	private void evaluate(boolean delayEvaluate, @NotNull final String expression, @NotNull final JsclOperation operation) {
 		final CalculatorHistoryState historyState = getCurrentHistoryState();
 
 		pendingOperation.setObject(new Runnable() {
@@ -147,7 +153,7 @@ public enum CalculatorModel implements CursorControl, HistoryControl<CalculatorH
 					//lock all operations with history
 					if (pendingOperation.getObject() == this) {
 						// actually nothing shall be logged while text operations are done
-						evaluate(expression);
+						evaluate(expression, operation);
 
 						historyState.setDisplayState(getCurrentHistoryState().getDisplayState());
 
@@ -166,19 +172,27 @@ public enum CalculatorModel implements CursorControl, HistoryControl<CalculatorH
 		}
 	}
 
+	@Override
 	public void evaluate() {
-   		evaluate(false, this.editor.getText().toString());
+   		evaluate(false, this.editor.getText().toString(), JsclOperation.numeric);
 	}
 
-	private void evaluate(@Nullable final String expression) {
+	@Override
+	public void simplify() {
+   		evaluate(false, this.editor.getText().toString(), JsclOperation.simplify);
+	}
+
+	private void evaluate(@Nullable final String expression, @NotNull JsclOperation operation) {
 		if (!StringUtils.isEmpty(expression)) {
 			try {
-				Log.d(CalculatorModel.class.getName(), "Trying to evaluate: " + expression /*+ StringUtils.fromStackTrace(Thread.currentThread().getStackTrace())*/);
-				display.setText(calculatorEngine.evaluate(JsclOperation.numeric, expression));
+				Log.d(CalculatorModel.class.getName(), "Trying to evaluate '" + operation + "': " + expression /*+ StringUtils.fromStackTrace(Thread.currentThread().getStackTrace())*/);
+				final CalculatorEngine.Result result = calculatorEngine.evaluate(operation, expression);
+				display.setText(result.getResult());
+				display.setJsclOperation(result.getUserOperation());
 			} catch (EvalError e) {
-				handleEvaluationException(expression, display, e);
+				handleEvaluationException(expression, display, operation, e);
 			} catch (ParseException e) {
-				handleEvaluationException(expression, display, e);
+				handleEvaluationException(expression, display, operation, e);
 			}
 		} else {
 			this.display.setText("");
@@ -187,9 +201,13 @@ public enum CalculatorModel implements CursorControl, HistoryControl<CalculatorH
 		this.display.redraw();
 	}
 
-	private void handleEvaluationException(@NotNull String expression, @NotNull CalculatorDisplay localDisplay, @NotNull Exception e) {
+	private void handleEvaluationException(@NotNull String expression,
+										   @NotNull CalculatorDisplay localDisplay,
+										   @NotNull JsclOperation operation,
+										   @NotNull Exception e) {
 		Log.d(CalculatorModel.class.getName(), "Evaluation failed for : " + expression + ". Error message: " + e.getMessage());
 		localDisplay.setText(R.string.c_syntax_error);
+		localDisplay.setJsclOperation(operation);
 		localDisplay.setValid(false);
 	}
 
@@ -268,6 +286,7 @@ public enum CalculatorModel implements CursorControl, HistoryControl<CalculatorH
 	private void setValuesFromHistory(@NotNull CalculatorDisplay display, CalculatorDisplayHistoryState editorHistoryState) {
 		setValuesFromHistory(display, editorHistoryState.getEditorHistoryState());
 		display.setValid(editorHistoryState.isValid());
+		display.setJsclOperation(editorHistoryState.getJsclOperation());
 	}
 
 	private void setValuesFromHistory(@NotNull TextView editText, EditorHistoryState editorHistoryState) {
@@ -286,22 +305,11 @@ public enum CalculatorModel implements CursorControl, HistoryControl<CalculatorH
 	}
 
 	private EditorHistoryState getEditorHistoryState(@NotNull TextView textView) {
-		final EditorHistoryState result = new EditorHistoryState();
-
-		result.setText(String.valueOf(textView.getText()));
-		result.setCursorPosition(textView.getSelectionStart());
-
-		return result;
+		return EditorHistoryState.newInstance(textView);
 	}
 
 	private CalculatorDisplayHistoryState getCalculatorDisplayHistoryState(@NotNull CalculatorDisplay display) {
-		final CalculatorDisplayHistoryState result = new CalculatorDisplayHistoryState();
-
-		result.getEditorHistoryState().setText(String.valueOf(display.getText()));
-		result.getEditorHistoryState().setCursorPosition(display.getSelectionStart());
-		result.setValid(display.isValid());
-
-		return result;
+		return CalculatorDisplayHistoryState.newInstance(display);
 	}
 
 	@NotNull

src/main/java/org/solovyev/android/calculator/CursorDragProcessor.java

@@ -36,8 +36,10 @@ public class CursorDragProcessor implements SimpleOnDragListener.DragProcessor{
 			String text = ((DirectionDragButton) dragButton).getText(dragDirection);
 			if ("◀◀".equals(text)) {
 				cursorControl.setCursorOnStart();
+				result = true;
 			} else if ("▶▶".equals(text)) {
 				cursorControl.setCursorOnEnd();
+				result = true;
 			}
 		}
 

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

@@ -5,25 +5,29 @@
 
 package org.solovyev.android.calculator;
 
+import android.widget.TextView;
+import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
 public class EditorHistoryState {
-	
+
 	private int cursorPosition;
-	
+
 	@Nullable
 	private String text;
-	
-	public EditorHistoryState() {
-	}
-	
-	public EditorHistoryState( int cursorPosition, @Nullable String text ) {
-		this.cursorPosition = cursorPosition;
-		this.text = text;
+
+	private EditorHistoryState() {
 	}
 
-	public void setText(@Nullable String text) {
-		this.text = text;
+
+	@NotNull
+	public static EditorHistoryState newInstance(@NotNull TextView textView) {
+		final EditorHistoryState result = new EditorHistoryState();
+
+		result.text = String.valueOf(textView.getText());
+		result.cursorPosition = textView.getSelectionStart();
+
+		return result;
 	}
 
 	@Nullable
@@ -31,10 +35,6 @@ public class EditorHistoryState {
 		return text;
 	}
 
-	public void setCursorPosition(int cursorPosition) {
-		this.cursorPosition = cursorPosition;
-	}
-
 	public int getCursorPosition() {
 		return cursorPosition;
 	}

src/main/java/org/solovyev/android/calculator/EvalDragProcessor.java

@@ -0,0 +1,44 @@
+/*
+ * Copyright (c) 2009-2011. Created by serso aka se.solovyev.
+ * For more information, please, contact se.solovyev@gmail.com
+ * or visit http://se.solovyev.org
+ */
+
+package org.solovyev.android.calculator;
+
+import android.view.MotionEvent;
+import org.jetbrains.annotations.NotNull;
+import org.solovyev.android.view.widgets.DirectionDragButton;
+import org.solovyev.android.view.widgets.DragButton;
+import org.solovyev.android.view.widgets.DragDirection;
+import org.solovyev.android.view.widgets.SimpleOnDragListener;
+import org.solovyev.common.utils.Point2d;
+
+/**
+ * User: serso
+ * Date: 10/24/11
+ * Time: 9:52 PM
+ */
+public class EvalDragProcessor implements SimpleOnDragListener.DragProcessor {
+	@NotNull
+	private final CalculatorEngineControl calculatorControl;
+
+	public EvalDragProcessor(@NotNull CalculatorEngineControl calculatorControl) {
+		this.calculatorControl = calculatorControl;
+	}
+
+	@Override
+	public boolean processDragEvent(@NotNull DragDirection dragDirection, @NotNull DragButton dragButton, @NotNull Point2d startPoint2d, @NotNull MotionEvent motionEvent) {
+		boolean result = false;
+
+		if (dragButton instanceof DirectionDragButton) {
+			String text = ((DirectionDragButton) dragButton).getText(dragDirection);
+			if ("≡".equals(text)) {
+				calculatorControl.simplify();
+				result = true;
+			}
+		}
+
+		return result;
+	}
+}

src/main/java/org/solovyev/android/calculator/model/CalculatorEngine.java

@@ -98,12 +98,35 @@ public enum CalculatorEngine {
 		}
 	}
 
-	public String evaluate(@NotNull JsclOperation operation,
+	public static class Result {
+		@NotNull
+		private String result;
+
+		@NotNull
+		private JsclOperation userOperation;
+
+		public Result(@NotNull String result, @NotNull JsclOperation userOperation) {
+			this.result = result;
+			this.userOperation = userOperation;
+		}
+
+		@NotNull
+		public String getResult() {
+			return result;
+		}
+
+		@NotNull
+		public JsclOperation getUserOperation() {
+			return userOperation;
+		}
+	}
+
+	public Result evaluate(@NotNull JsclOperation operation,
 						   @NotNull String expression) throws EvalError, ParseException {
 		return evaluate(operation, expression, null);
 	}
 
-	public String evaluate(@NotNull JsclOperation operation,
+	public Result evaluate(@NotNull JsclOperation operation,
 						   @NotNull String expression,
 						   @Nullable MessageRegistry<AndroidMessage> mr) throws EvalError, ParseException {
 		synchronized (lock) {
@@ -190,7 +213,7 @@ public enum CalculatorEngine {
 				throw new ParseException("Too long calculation for: " + jsclExpression);
 			}
 
-			return operation.getFromProcessor().process(result);
+			return new Result(operation.getFromProcessor().process(result), operation);
 		}
 	}