KeyboardUi

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

@@ -117,9 +117,8 @@ public class ActivityUi extends BaseUi {
 
         activity.setContentView(layoutId);
 
-        final View root = activity.findViewById(R.id.main_layout);
+        final View root = activity.findViewById(R.id.main);
         if (root != null) {
-            processButtons(activity, root);
             fixFonts(root);
             addHelpInfo(activity, root);
         }
@@ -291,60 +290,62 @@ public class ActivityUi extends BaseUi {
     }
 
     private void addHelpInfo(@Nonnull Activity activity, @Nonnull View root) {
-        if (App.isMonkeyRunner(activity)) {
+        if (!App.isMonkeyRunner(activity)) {
-            if (root instanceof ViewGroup) {
+            return;
-                final TextView helperTextView = new TextView(activity);
-
-                final DisplayMetrics dm = new DisplayMetrics();
-                activity.getWindowManager().getDefaultDisplay().getMetrics(dm);
-
-                helperTextView.setTextSize(15);
-                helperTextView.setTextColor(Color.WHITE);
-
-                final Configuration c = activity.getResources().getConfiguration();
-
-                final StringBuilder helpText = new StringBuilder();
-                helpText.append("Size: ");
-                if (Views.isLayoutSizeAtLeast(Configuration.SCREENLAYOUT_SIZE_XLARGE, c)) {
-                    helpText.append("xlarge");
-                } else if (Views.isLayoutSizeAtLeast(Configuration.SCREENLAYOUT_SIZE_LARGE, c)) {
-                    helpText.append("large");
-                } else if (Views.isLayoutSizeAtLeast(Configuration.SCREENLAYOUT_SIZE_NORMAL, c)) {
-                    helpText.append("normal");
-                } else if (Views.isLayoutSizeAtLeast(Configuration.SCREENLAYOUT_SIZE_SMALL, c)) {
-                    helpText.append("small");
-                } else {
-                    helpText.append("unknown");
-                }
-
-                helpText.append(" (").append(dm.widthPixels).append("x").append(dm.heightPixels).append(")");
-
-                helpText.append(" Density: ");
-                switch (dm.densityDpi) {
-                    case DisplayMetrics.DENSITY_LOW:
-                        helpText.append("ldpi");
-                        break;
-                    case DisplayMetrics.DENSITY_MEDIUM:
-                        helpText.append("mdpi");
-                        break;
-                    case DisplayMetrics.DENSITY_HIGH:
-                        helpText.append("hdpi");
-                        break;
-                    case DisplayMetrics.DENSITY_XHIGH:
-                        helpText.append("xhdpi");
-                        break;
-                    case DisplayMetrics.DENSITY_TV:
-                        helpText.append("tv");
-                        break;
-                }
-
-                helpText.append(" (").append(dm.densityDpi).append(")");
-
-                helperTextView.setText(helpText);
-
-                ((ViewGroup) root).addView(helperTextView, new ViewGroup.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT));
-            }
         }
+        if (!(root instanceof ViewGroup)) {
+            return;
+        }
+        final TextView helperTextView = new TextView(activity);
+
+        final DisplayMetrics dm = new DisplayMetrics();
+        activity.getWindowManager().getDefaultDisplay().getMetrics(dm);
+
+        helperTextView.setTextSize(15);
+        helperTextView.setTextColor(Color.WHITE);
+
+        final Configuration c = activity.getResources().getConfiguration();
+
+        final StringBuilder helpText = new StringBuilder();
+        helpText.append("Size: ");
+        if (Views.isLayoutSizeAtLeast(Configuration.SCREENLAYOUT_SIZE_XLARGE, c)) {
+            helpText.append("xlarge");
+        } else if (Views.isLayoutSizeAtLeast(Configuration.SCREENLAYOUT_SIZE_LARGE, c)) {
+            helpText.append("large");
+        } else if (Views.isLayoutSizeAtLeast(Configuration.SCREENLAYOUT_SIZE_NORMAL, c)) {
+            helpText.append("normal");
+        } else if (Views.isLayoutSizeAtLeast(Configuration.SCREENLAYOUT_SIZE_SMALL, c)) {
+            helpText.append("small");
+        } else {
+            helpText.append("unknown");
+        }
+
+        helpText.append(" (").append(dm.widthPixels).append("x").append(dm.heightPixels).append(")");
+
+        helpText.append(" Density: ");
+        switch (dm.densityDpi) {
+            case DisplayMetrics.DENSITY_LOW:
+                helpText.append("ldpi");
+                break;
+            case DisplayMetrics.DENSITY_MEDIUM:
+                helpText.append("mdpi");
+                break;
+            case DisplayMetrics.DENSITY_HIGH:
+                helpText.append("hdpi");
+                break;
+            case DisplayMetrics.DENSITY_XHIGH:
+                helpText.append("xhdpi");
+                break;
+            case DisplayMetrics.DENSITY_TV:
+                helpText.append("tv");
+                break;
+        }
+
+        helpText.append(" (").append(dm.densityDpi).append(")");
+
+        helperTextView.setText(helpText);
+
+        ((ViewGroup) root).addView(helperTextView, new ViewGroup.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT));
     }
 
     public void onStop(@Nonnull Activity activity) {

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

@@ -22,70 +22,61 @@
 
 package org.solovyev.android.calculator;
 
-import android.app.Activity;
 import jscl.NumeralBase;
+import org.solovyev.android.calculator.keyboard.KeyboardUi;
 import org.solovyev.android.calculator.units.CalculatorNumeralBase;
 import org.solovyev.android.views.dragbutton.DirectionDragButton;
 import org.solovyev.android.views.dragbutton.DragDirection;
 
 import javax.annotation.Nonnull;
-import java.util.ArrayList;
-import java.util.Arrays;
-import java.util.List;
 
-/**
- * User: serso
- * Date: 4/21/12
- * Time: 8:00 PM
- */
 public enum AndroidNumeralBase {
 
     bin(CalculatorNumeralBase.bin) {
-        @Nonnull
         @Override
-        public List<Integer> getButtonIds() {
+        public void toggleButtons(boolean show, @Nonnull KeyboardUi ui) {
-            return Arrays.asList(R.id.cpp_button_0, R.id.cpp_button_1);
+            toggleButton(show, ui.button0);
+            toggleButton(show, ui.button1);
         }
     },
 
     oct(CalculatorNumeralBase.oct) {
-        @Nonnull
         @Override
-        public List<Integer> getButtonIds() {
+        public void toggleButtons(boolean show, @Nonnull KeyboardUi ui) {
-            final List<Integer> result = new ArrayList<Integer>(bin.getButtonIds());
+            bin.toggleButtons(show, ui);
-            result.addAll(Arrays.asList(R.id.cpp_button_2, R.id.cpp_button_3, R.id.cpp_button_4, R.id.cpp_button_5, R.id.cpp_button_6, R.id.cpp_button_7));
+            toggleButton(show, ui.button2);
-            return result;
+            toggleButton(show, ui.button3);
+            toggleButton(show, ui.button4);
+            toggleButton(show, ui.button5);
+            toggleButton(show, ui.button6);
+            toggleButton(show, ui.button7);
         }
     },
 
     dec(CalculatorNumeralBase.dec) {
-        @Nonnull
         @Override
-        public List<Integer> getButtonIds() {
+        public void toggleButtons(boolean show, @Nonnull KeyboardUi ui) {
-            final List<Integer> result = new ArrayList<Integer>(oct.getButtonIds());
+            oct.toggleButtons(show, ui);
-            result.addAll(Arrays.asList(R.id.cpp_button_8, R.id.cpp_button_9));
+            toggleButton(show, ui.button8);
-            return result;
+            toggleButton(show, ui.button9);
         }
     },
 
     hex(CalculatorNumeralBase.hex) {
-
-        @Nonnull
-        private List<Integer> specialHexButtonIds = Arrays.asList(R.id.cpp_button_1, R.id.cpp_button_2, R.id.cpp_button_3, R.id.cpp_button_4, R.id.cpp_button_5, R.id.cpp_button_6);
-
-        @Nonnull
         @Override
-        public List<Integer> getButtonIds() {
+        public void toggleButtons(boolean show, @Nonnull KeyboardUi ui) {
-            return dec.getButtonIds();
+            dec.toggleButtons(show, ui);
+            toggleLeftButton(show, ui.button1);
+            toggleLeftButton(show, ui.button2);
+            toggleLeftButton(show, ui.button3);
+            toggleLeftButton(show, ui.button4);
+            toggleLeftButton(show, ui.button5);
+            toggleLeftButton(show, ui.button6);
         }
 
-        @Override
+        protected final void toggleLeftButton(boolean show, @Nonnull DirectionDragButton button) {
-        protected void toggleButton(boolean show, @Nonnull DirectionDragButton button) {
+            button.showDirectionText(show, DragDirection.left);
-            super.toggleButton(show, button);
+            button.invalidate();
-            if (specialHexButtonIds.contains(button.getId())) {
-                button.showDirectionText(show, DragDirection.left);
-                button.invalidate();
-            }
         }
     };
 
@@ -107,19 +98,9 @@ public enum AndroidNumeralBase {
         throw new IllegalArgumentException(nb + " is not supported numeral base!");
     }
 
-    @Nonnull
+    public abstract void toggleButtons(boolean show, @Nonnull KeyboardUi ui);
-    public abstract List<Integer> getButtonIds();
 
-    public void toggleButtons(boolean show, @Nonnull Activity activity) {
+    protected final void toggleButton(boolean show, @Nonnull DirectionDragButton button) {
-        for (Integer buttonId : getButtonIds()) {
-            final DirectionDragButton button = (DirectionDragButton) activity.findViewById(buttonId);
-            if (button != null) {
-                toggleButton(show, button);
-            }
-        }
-    }
-
-    protected void toggleButton(boolean show, @Nonnull DirectionDragButton button) {
         button.setShowText(show);
         button.invalidate();
     }

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

@@ -27,7 +27,6 @@ import android.content.Context;
 import android.content.SharedPreferences;
 import android.content.pm.PackageManager;
 import android.content.res.Configuration;
-import android.graphics.Typeface;
 import android.os.Build;
 import android.preference.PreferenceManager;
 import android.support.annotation.NonNull;
@@ -47,13 +46,11 @@ import org.solovyev.android.calculator.language.Languages;
 import org.solovyev.android.calculator.onscreen.CalculatorOnscreenService;
 import org.solovyev.android.calculator.view.ScreenMetrics;
 import org.solovyev.android.calculator.wizard.CalculatorWizards;
-import org.solovyev.android.checkout.*;
 import org.solovyev.android.wizard.Wizards;
 import org.solovyev.common.JPredicate;
 
 import javax.annotation.Nonnull;
 import javax.annotation.Nullable;
-import java.util.Arrays;
 import java.util.Collection;
 import java.util.List;
 import java.util.concurrent.Executor;
@@ -91,8 +88,6 @@ public final class App {
     private static volatile Ga ga;
     @Nullable
     private static Boolean lg = null;
-    @Nullable
-    private static Typeface typeFace;
     @Nonnull
     private static volatile ScreenMetrics screenMetrics;
     @Nonnull
@@ -228,15 +223,6 @@ public final class App {
         return spannable;
     }
 
-    @Nonnull
-    public static Typeface getTypeFace() {
-        Check.isMainThread();
-        if (typeFace == null) {
-            typeFace = Typeface.createFromAsset(application.getAssets(), "fonts/Roboto-Regular.ttf");
-        }
-        return typeFace;
-    }
-
     public static boolean isMonkeyRunner(@Nonnull Context context) {
         // NOTE: this code is only for monkeyrunner
         return context.checkCallingOrSelfPermission(android.Manifest.permission.DISABLE_KEYGUARD) == PackageManager.PERMISSION_GRANTED;
@@ -322,6 +308,11 @@ public final class App {
         return null;
     }
 
+    @NonNull
+    public static CalculatorApplication cast(@NonNull Fragment fragment) {
+        return cast(fragment.getActivity());
+    }
+
     @NonNull
     public static CalculatorApplication cast(@NonNull Context context) {
         if (context instanceof CalculatorApplication) {

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

@@ -7,6 +7,7 @@ import org.solovyev.android.calculator.functions.EditFunctionFragment;
 import org.solovyev.android.calculator.functions.FunctionsFragment;
 import org.solovyev.android.calculator.history.BaseHistoryFragment;
 import org.solovyev.android.calculator.history.EditHistoryFragment;
+import org.solovyev.android.calculator.keyboard.BaseKeyboardUi;
 import org.solovyev.android.calculator.onscreen.CalculatorOnscreenService;
 import org.solovyev.android.calculator.operators.OperatorsFragment;
 import org.solovyev.android.calculator.preferences.PreferencesActivity;
@@ -40,4 +41,5 @@ public interface AppComponent {
     void inject(KeyboardFragment fragment);
     void inject(PurchaseDialogActivity activity);
     void inject(PreferencesActivity activity);
+    void inject(BaseKeyboardUi ui);
 }

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

@@ -2,6 +2,7 @@ package org.solovyev.android.calculator;
 
 import android.app.Application;
 import android.content.SharedPreferences;
+import android.graphics.Typeface;
 import android.os.Handler;
 import android.os.Looper;
 import android.preference.PreferenceManager;
@@ -139,6 +140,12 @@ public class AppModule {
         return Products.create().add(ProductTypes.IN_APP, Collections.singletonList("ad_free"));
     }
 
+    @Singleton
+    @Provides
+    Typeface provideTypeface() {
+        return Typeface.createFromAsset(application.getAssets(), "fonts/Roboto-Regular.ttf");
+    }
+
     private static class AppBus extends Bus {
 
         @NonNull

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

@@ -110,6 +110,6 @@ public class BaseActivity extends AppCompatActivity {
         final Bundle arguments = new Bundle(1);
         arguments.putString(BaseEntitiesFragment.ARG_CATEGORY, category.name());
         final String fragmentTag = tab.subTag(category.name());
-        ui.addTab(this, fragmentTag, tab.type, arguments, title, R.id.main_layout);
+        ui.addTab(this, fragmentTag, tab.type, arguments, title, R.id.main);
     }
 }

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

@@ -27,7 +27,7 @@ public abstract class BaseFragment extends Fragment {
 
     @Nonnull
     protected final FragmentUi createUi(@Nonnull FragmentTab tab) {
-        return new FragmentUi(tab.layout, tab.title, false);
+        return new FragmentUi(tab.layout, tab.title);
     }
 
     protected void inject(@Nonnull AppComponent component) {
@@ -35,36 +35,32 @@ public abstract class BaseFragment extends Fragment {
 
     @Override
     public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
-        return ui.onCreateView(this, inflater, container);
+        final View view = ui.onCreateView(inflater, container);
-    }
+        ui.onCreateView(this, view);
-
+        return view;
-    @Override
-    public void onViewCreated(View root, Bundle savedInstanceState) {
-        super.onViewCreated(root, savedInstanceState);
-        ui.onViewCreated(this, root);
     }
 
     @Override
     public void onResume() {
         super.onResume();
-        ui.onResume(this);
+        ui.onResume();
     }
 
     @Override
     public void onPause() {
-        ui.onPause(this);
+        ui.onPause();
         super.onPause();
     }
 
     @Override
     public void onDestroyView() {
-        ui.onDestroyView(this);
+        ui.onDestroyView();
         super.onDestroyView();
     }
 
     @Override
     public void onDestroy() {
-        ui.onDestroy(this);
+        ui.onDestroy();
         super.onDestroy();
     }
 

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

@@ -26,42 +26,18 @@ import android.app.Activity;
 import android.app.KeyguardManager;
 import android.content.Context;
 import android.content.SharedPreferences;
-import android.graphics.PointF;
 import android.graphics.Typeface;
-import android.preference.PreferenceManager;
-import android.util.Log;
-import android.view.MotionEvent;
 import android.view.View;
 import android.widget.TextView;
-
 import org.solovyev.android.Views;
-import org.solovyev.android.calculator.buttons.CppButtons;
 import org.solovyev.android.calculator.history.History;
-import org.solovyev.android.calculator.history.HistoryDragProcessor;
-import org.solovyev.android.calculator.view.*;
-import org.solovyev.android.views.dragbutton.DirectionDragButton;
-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 java.util.ArrayList;
-import java.util.List;
 
 import javax.annotation.Nonnull;
-import javax.annotation.Nullable;
 import javax.inject.Inject;
 
 import static org.solovyev.android.calculator.App.cast;
-import static org.solovyev.android.calculator.Preferences.Gui.Layout.simple;
-import static org.solovyev.android.calculator.Preferences.Gui.Layout.simple_mobile;
-import static org.solovyev.android.calculator.Engine.Preferences.angleUnit;
-import static org.solovyev.android.calculator.Engine.Preferences.numeralBase;
 
-public abstract class BaseUi implements SharedPreferences.OnSharedPreferenceChangeListener {
+public abstract class BaseUi {
-
-    @Nonnull
-    private static final List<Integer> viewIds = new ArrayList<>(200);
 
     @Nonnull
     protected Preferences.Gui.Layout layout;
@@ -69,52 +45,10 @@ public abstract class BaseUi implements SharedPreferences.OnSharedPreferenceChan
     @Nonnull
     protected Preferences.Gui.Theme theme;
 
-    @Nonnull
-    private String logTag = "CalculatorActivity";
-
-    @Nullable
-    private AngleUnitsButton angleUnitsButton;
-
-    @Nullable
-    private NumeralBasesButton clearButton;
-
     protected BaseUi() {
     }
 
     protected BaseUi(@Nonnull String logTag) {
-        this.logTag = logTag;
-    }
-
-    @Nonnull
-    private static List<Integer> getViewIds() {
-        if (viewIds.isEmpty()) {
-            viewIds.add(R.id.wizard_dragbutton);
-            viewIds.add(R.id.cpp_button_vars);
-            viewIds.add(R.id.cpp_button_round_brackets);
-            viewIds.add(R.id.cpp_button_right);
-            viewIds.add(R.id.cpp_button_plus);
-            viewIds.add(R.id.cpp_button_operators);
-            viewIds.add(R.id.cpp_button_multiplication);
-            viewIds.add(R.id.cpp_button_subtraction);
-            viewIds.add(R.id.cpp_button_left);
-            viewIds.add(R.id.cpp_button_history);
-            viewIds.add(R.id.cpp_button_functions);
-            viewIds.add(R.id.cpp_button_equals);
-            viewIds.add(R.id.cpp_button_period);
-            viewIds.add(R.id.cpp_button_division);
-            viewIds.add(R.id.cpp_button_9);
-            viewIds.add(R.id.cpp_button_8);
-            viewIds.add(R.id.cpp_button_7);
-            viewIds.add(R.id.cpp_button_6);
-            viewIds.add(R.id.cpp_button_5);
-            viewIds.add(R.id.cpp_button_4);
-            viewIds.add(R.id.cpp_button_3);
-            viewIds.add(R.id.cpp_button_2);
-            viewIds.add(R.id.cpp_button_1);
-            viewIds.add(R.id.cpp_button_0);
-            viewIds.add(R.id.cpp_button_clear);
-        }
-        return viewIds;
     }
 
     @Inject
@@ -131,6 +65,8 @@ public abstract class BaseUi implements SharedPreferences.OnSharedPreferenceChan
     PreferredPreferences preferredPreferences;
     @Inject
     ActivityLauncher launcher;
+    @Inject
+    Typeface typeface;
 
     protected void onCreate(@Nonnull Activity activity) {
         inject(cast(activity.getApplication()).getComponent());
@@ -138,8 +74,6 @@ public abstract class BaseUi implements SharedPreferences.OnSharedPreferenceChan
         layout = Preferences.Gui.layout.getPreferenceNoError(preferences);
         theme = Preferences.Gui.theme.getPreferenceNoError(preferences);
 
-        preferences.registerOnSharedPreferenceChangeListener(this);
-
         // let's disable locking of screen for monkeyrunner
         if (App.isMonkeyRunner(activity)) {
             final KeyguardManager km = (KeyguardManager) activity.getSystemService(Context.KEYGUARD_SERVICE);
@@ -157,179 +91,25 @@ public abstract class BaseUi implements SharedPreferences.OnSharedPreferenceChan
         return theme;
     }
 
-    public void logError(@Nonnull String message) {
-        Log.e(logTag, message);
-    }
-
     public void onDestroy(@Nonnull Activity activity) {
-        final SharedPreferences preferences = PreferenceManager.getDefaultSharedPreferences(activity);
-
-        preferences.unregisterOnSharedPreferenceChangeListener(this);
     }
 
     protected void fixFonts(@Nonnull View root) {
         // some devices ship own fonts which causes issues with rendering. Let's use our own font for all text views
-        final Typeface typeFace = App.getTypeFace();
         Views.processViewsOfType(root, TextView.class, new Views.ViewProcessor<TextView>() {
             @Override
             public void process(@Nonnull TextView view) {
-                int style = Typeface.NORMAL;
+                setFont(view, typeface);
-                final Typeface oldTypeface = view.getTypeface();
-                if (oldTypeface != null) {
-                    style = oldTypeface.getStyle();
-                }
-                view.setTypeface(typeFace, style);
             }
         });
     }
 
-    public void processButtons(@Nonnull final Activity activity, @Nonnull View root) {
+    public static void setFont(@Nonnull TextView view, @Nonnull Typeface newTypeface) {
-        final SharedPreferences preferences = PreferenceManager.getDefaultSharedPreferences(activity);
+        final Typeface oldTypeface = view.getTypeface();
-
+        if (oldTypeface == newTypeface) {
-        final ViewsCache views = ViewsCache.forView(root);
+            return;
-        setOnDragListeners(views, activity);
-
-        HistoryDragProcessor historyDragProcessor = new HistoryDragProcessor(history);
-        final DragListener historyDragListener = newDragListener(historyDragProcessor, activity);
-        final DragButton historyButton = getButton(views, R.id.cpp_button_history);
-        if (historyButton != null) {
-            historyButton.setOnDragListener(historyDragListener);
-        }
-
-        final DragButton minusButton = getButton(views, R.id.cpp_button_subtraction);
-        if (minusButton != null) {
-            minusButton.setOnDragListener(newDragListener(new OperatorsDragProcessor(), activity));
-        }
-
-        final DragListener toPositionDragListener = new SimpleDragListener(new CursorDragProcessor(editor), activity);
-
-        final DragButton rightButton = getButton(views, R.id.cpp_button_right);
-        if (rightButton != null) {
-            rightButton.setOnDragListener(toPositionDragListener);
-        }
-
-        final DragButton leftButton = getButton(views, R.id.cpp_button_left);
-        if (leftButton != null) {
-            leftButton.setOnDragListener(toPositionDragListener);
-        }
-
-        final DragButton equalsButton = getButton(views, R.id.cpp_button_equals);
-        if (equalsButton != null) {
-            equalsButton.setOnDragListener(newDragListener(new EqualsDragProcessor(calculator), activity));
-        }
-
-        angleUnitsButton = getButton(views, R.id.cpp_button_6);
-        if (angleUnitsButton != null) {
-            angleUnitsButton.setOnDragListener(newDragListener(new CppButtons.AngleUnitsChanger(activity, keyboard, preferredPreferences), activity));
-        }
-
-        final View eraseButton = getButton(views, R.id.cpp_button_erase);
-        if (eraseButton != null) {
-            EditorLongClickEraser.attachTo(eraseButton);
-        }
-
-        clearButton = getButton(views, R.id.cpp_button_clear);
-        if (clearButton != null) {
-            clearButton.setOnDragListener(newDragListener(new CppButtons.NumeralBasesChanger(activity, preferredPreferences), activity));
-        }
-
-        final DragButton varsButton = getButton(views, R.id.cpp_button_vars);
-        if (varsButton != null) {
-            varsButton.setOnDragListener(newDragListener(new CppButtons.VarsDragProcessor(activity), activity));
-        }
-
-        final DragButton functionsButton = getButton(views, R.id.cpp_button_functions);
-        if (functionsButton != null) {
-            functionsButton.setOnDragListener(newDragListener(new CppButtons.FunctionsDragProcessor(activity), activity));
-        }
-
-        final DragButton roundBracketsButton = getButton(views, R.id.cpp_button_round_brackets);
-        if (roundBracketsButton != null) {
-            roundBracketsButton.setOnDragListener(newDragListener(new CppButtons.RoundBracketsDragProcessor(keyboard), activity));
-        }
-
-        if (layout == simple || layout == simple_mobile) {
-            toggleButtonDirectionText(views, R.id.cpp_button_1, false, DragDirection.up, DragDirection.down);
-            toggleButtonDirectionText(views, R.id.cpp_button_2, false, DragDirection.up, DragDirection.down);
-            toggleButtonDirectionText(views, R.id.cpp_button_3, false, DragDirection.up, DragDirection.down);
-
-            toggleButtonDirectionText(views, R.id.cpp_button_6, false, DragDirection.up, DragDirection.down);
-            toggleButtonDirectionText(views, R.id.cpp_button_7, false, DragDirection.left, DragDirection.up, DragDirection.down);
-            toggleButtonDirectionText(views, R.id.cpp_button_8, false, DragDirection.left, DragDirection.up, DragDirection.down);
-
-            toggleButtonDirectionText(views, R.id.cpp_button_clear, false, DragDirection.left, DragDirection.up, DragDirection.down);
-
-            toggleButtonDirectionText(views, R.id.cpp_button_4, false, DragDirection.down);
-            toggleButtonDirectionText(views, R.id.cpp_button_5, false, DragDirection.down);
-
-            toggleButtonDirectionText(views, R.id.cpp_button_9, false, DragDirection.left);
-
-            toggleButtonDirectionText(views, R.id.cpp_button_multiplication, false, DragDirection.left);
-            toggleButtonDirectionText(views, R.id.cpp_button_plus, false, DragDirection.down, DragDirection.up);
-        }
-
-        CppButtons.fixButtonsTextSize(theme, layout, root);
-        CppButtons.toggleEqualsButton(preferences, activity);
-        CppButtons.initMultiplicationButton(root);
-        NumeralBaseButtons.toggleNumericDigits(activity, preferences);
-
-        new ButtonOnClickListener(keyboard).attachToViews(views);
-    }
-
-    private void setOnDragListeners(@Nonnull ViewsCache views, @Nonnull Context context) {
-        final DragListener dragListener = newDragListener(new DigitButtonDragProcessor(keyboard), context);
-
-        final List<Integer> viewIds = getViewIds();
-        for (Integer viewId : viewIds) {
-            final View view = views.findViewById(viewId);
-            if (view instanceof DragButton) {
-                ((DragButton) view).setOnDragListener(dragListener);
-            }
-        }
-    }
-
-    @Nonnull
-    private SimpleDragListener newDragListener(@Nonnull SimpleDragListener.DragProcessor dragProcessor, @Nonnull Context context) {
-        return new SimpleDragListener(dragProcessor, context);
-    }
-
-    private void toggleButtonDirectionText(@Nonnull ViewsCache views, int id, boolean showDirectionText, @Nonnull DragDirection... dragDirections) {
-        final View v = getButton(views, id);
-        if (v instanceof DirectionDragButton) {
-            final DirectionDragButton button = (DirectionDragButton) v;
-            for (DragDirection dragDirection : dragDirections) {
-                button.showDirectionText(showDirectionText, dragDirection);
-            }
-        }
-    }
-
-    @Nullable
-    private <V extends View> V getButton(@Nonnull ViewsCache views, int buttonId) {
-        //noinspection unchecked
-        return (V) views.findViewById(buttonId);
-    }
-
-    @Override
-    public void onSharedPreferenceChanged(SharedPreferences preferences, String key) {
-        if (angleUnit.isSameKey(key) || numeralBase.isSameKey(key)) {
-            if (angleUnitsButton != null) {
-                angleUnitsButton.setAngleUnit(angleUnit.getPreference(preferences));
-            }
-
-            if (clearButton != null) {
-                clearButton.setNumeralBase(numeralBase.getPreference(preferences));
-            }
-        }
-    }
-
-    private class OperatorsDragProcessor implements SimpleDragListener.DragProcessor {
-        @Override
-        public boolean processDragEvent(@Nonnull DragDirection dragDirection, @Nonnull DragButton dragButton, @Nonnull PointF startPoint, @Nonnull MotionEvent motionEvent) {
-            if (dragDirection == DragDirection.down) {
-                launcher.showOperators();
-                return true;
-            }
-            return false;
         }
+        final int style = oldTypeface != null ? oldTypeface.getStyle() : Typeface.NORMAL;
+        view.setTypeface(newTypeface, style);
     }
 }

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

@@ -1,125 +0,0 @@
-package org.solovyev.android.calculator;
-
-import android.support.annotation.IdRes;
-import android.view.HapticFeedbackConstants;
-import android.view.View;
-import android.widget.Button;
-
-import org.solovyev.android.calculator.buttons.CppSpecialButton;
-import org.solovyev.android.calculator.view.ViewsCache;
-
-import javax.annotation.Nonnull;
-
-final class ButtonOnClickListener implements View.OnClickListener {
-
-    @Nonnull
-    private final Keyboard keyboard;
-
-    ButtonOnClickListener(@Nonnull Keyboard keyboard) {
-        this.keyboard = keyboard;
-    }
-
-    @Override
-    public void onClick(View v) {
-        switch (v.getId()) {
-            case R.id.cpp_button_0:
-            case R.id.cpp_button_1:
-            case R.id.cpp_button_2:
-            case R.id.cpp_button_3:
-            case R.id.cpp_button_4:
-            case R.id.cpp_button_5:
-            case R.id.cpp_button_6:
-            case R.id.cpp_button_7:
-            case R.id.cpp_button_8:
-            case R.id.cpp_button_9:
-            case R.id.cpp_button_division:
-            case R.id.cpp_button_period:
-            case R.id.cpp_button_left:
-            case R.id.cpp_button_subtraction:
-            case R.id.cpp_button_multiplication:
-            case R.id.cpp_button_plus:
-            case R.id.cpp_button_right:
-            case R.id.cpp_button_round_brackets:
-                onClick(v, ((Button) v).getText().toString());
-                break;
-            case R.id.cpp_button_clear:
-                onClick(v, CppSpecialButton.clear);
-                break;
-            case R.id.cpp_button_functions:
-                onClick(v, CppSpecialButton.functions);
-                break;
-            case R.id.cpp_button_history:
-                onClick(v, CppSpecialButton.history);
-                break;
-            case R.id.cpp_button_erase:
-                onClick(v, CppSpecialButton.erase);
-                break;
-            case R.id.cpp_button_paste:
-                onClick(v, CppSpecialButton.paste);
-                break;
-            case R.id.cpp_button_copy:
-                onClick(v, CppSpecialButton.copy);
-                break;
-            case R.id.cpp_button_like:
-                onClick(v, CppSpecialButton.like);
-                break;
-            case R.id.cpp_button_operators:
-                onClick(v, CppSpecialButton.operators);
-                break;
-            case R.id.cpp_button_vars:
-                onClick(v, CppSpecialButton.vars);
-                break;
-            case R.id.cpp_button_equals:
-                onClick(v, CppSpecialButton.equals);
-                break;
-        }
-    }
-
-    private void onClick(@Nonnull View v, @Nonnull CppSpecialButton b) {
-        onClick(v, b.action);
-    }
-
-    private void onClick(@Nonnull View v, @Nonnull String s) {
-        if (keyboard.buttonPressed(s)) {
-            v.performHapticFeedback(HapticFeedbackConstants.VIRTUAL_KEY);
-        }
-    }
-
-    public void attachToViews(@Nonnull ViewsCache views) {
-        attachToView(views, R.id.cpp_button_0);
-        attachToView(views, R.id.cpp_button_1);
-        attachToView(views, R.id.cpp_button_2);
-        attachToView(views, R.id.cpp_button_3);
-        attachToView(views, R.id.cpp_button_4);
-        attachToView(views, R.id.cpp_button_5);
-        attachToView(views, R.id.cpp_button_6);
-        attachToView(views, R.id.cpp_button_7);
-        attachToView(views, R.id.cpp_button_8);
-        attachToView(views, R.id.cpp_button_9);
-        attachToView(views, R.id.cpp_button_division);
-        attachToView(views, R.id.cpp_button_period);
-        attachToView(views, R.id.cpp_button_left);
-        attachToView(views, R.id.cpp_button_subtraction);
-        attachToView(views, R.id.cpp_button_multiplication);
-        attachToView(views, R.id.cpp_button_plus);
-        attachToView(views, R.id.cpp_button_right);
-        attachToView(views, R.id.cpp_button_round_brackets);
-        attachToView(views, R.id.cpp_button_clear);
-        attachToView(views, R.id.cpp_button_functions);
-        attachToView(views, R.id.cpp_button_history);
-        attachToView(views, R.id.cpp_button_erase);
-        attachToView(views, R.id.cpp_button_paste);
-        attachToView(views, R.id.cpp_button_copy);
-        attachToView(views, R.id.cpp_button_like);
-        attachToView(views, R.id.cpp_button_operators);
-        attachToView(views, R.id.cpp_button_vars);
-        attachToView(views, R.id.cpp_button_equals);
-    }
-
-    private void attachToView(@Nonnull ViewsCache views, @IdRes int viewId) {
-        final View view = views.findViewById(viewId);
-        if (view != null) {
-            view.setOnClickListener(this);
-        }
-    }
-}

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

@@ -34,9 +34,12 @@ import android.support.v7.app.ActionBar;
 import android.text.method.LinkMovementMethod;
 import android.view.*;
 import android.widget.TextView;
+import butterknife.Bind;
+import butterknife.ButterKnife;
 import org.solovyev.android.Activities;
 import org.solovyev.android.Android;
 import org.solovyev.android.calculator.history.History;
+import org.solovyev.android.calculator.keyboard.PartialKeyboardUi;
 import org.solovyev.android.calculator.wizard.CalculatorWizards;
 import org.solovyev.android.fragments.FragmentUtils;
 import org.solovyev.android.prefs.Preference;
@@ -59,13 +62,22 @@ public class CalculatorActivity extends BaseActivity implements SharedPreference
 
     @Nonnull
     public static final String TAG = CalculatorActivity.class.getSimpleName();
-
-    private boolean useBackAsPrev;
-    
     @Inject
     PreferredPreferences preferredPreferences;
     @Inject
+    SharedPreferences preferences;
+    @Inject
     Keyboard keyboard;
+    @Inject
+    PartialKeyboardUi partialKeyboardUi;
+    @Inject
+    History history;
+    @Inject
+    ActivityLauncher launcher;
+    @Nullable
+    @Bind(R.id.partial_keyboard)
+    View partialKeyboard;
+    private boolean useBackAsPrev;
 
     public CalculatorActivity() {
         super(0, TAG);
@@ -140,15 +152,6 @@ public class CalculatorActivity extends BaseActivity implements SharedPreference
         return result;
     }
 
-    @Inject
-    History history;
-
-    @Inject
-    ActivityLauncher launcher;
-
-    /**
-     * Called when the activity is first created.
-     */
     @Override
     public void onCreate(@Nullable Bundle savedInstanceState) {
         final SharedPreferences preferences = PreferenceManager.getDefaultSharedPreferences(this);
@@ -172,10 +175,15 @@ public class CalculatorActivity extends BaseActivity implements SharedPreference
                 actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_STANDARD);
             }
         }
+        ButterKnife.bind(this);
 
-        FragmentUtils.createFragment(this, EditorFragment.class, R.id.editorContainer, "editor");
+        FragmentUtils.createFragment(this, EditorFragment.class, R.id.editor, "editor");
-        FragmentUtils.createFragment(this, DisplayFragment.class, R.id.displayContainer, "display");
+        FragmentUtils.createFragment(this, DisplayFragment.class, R.id.display, "display");
-        FragmentUtils.createFragment(this, KeyboardFragment.class, R.id.keyboardContainer, "keyboard");
+        FragmentUtils.createFragment(this, KeyboardFragment.class, R.id.keyboard, "keyboard");
+
+        if (partialKeyboard != null) {
+            partialKeyboardUi.onCreateView(this, partialKeyboard);
+        }
 
         this.useBackAsPrev = Preferences.Gui.usePrevAsBack.getPreference(preferences);
         if (savedInstanceState == null) {
@@ -226,7 +234,6 @@ public class CalculatorActivity extends BaseActivity implements SharedPreference
         super.onResume();
         launcher.setActivity(this);
 
-        final SharedPreferences preferences = PreferenceManager.getDefaultSharedPreferences(this);
         final Preferences.Gui.Layout newLayout = Preferences.Gui.layout.getPreference(preferences);
         if (newLayout != ui.getLayout()) {
             Activities.restartActivity(this);
@@ -248,8 +255,10 @@ public class CalculatorActivity extends BaseActivity implements SharedPreference
 
     @Override
     protected void onDestroy() {
-        PreferenceManager.getDefaultSharedPreferences(this).unregisterOnSharedPreferenceChangeListener(this);
+        preferences.unregisterOnSharedPreferenceChangeListener(this);
-
+        if (partialKeyboard != null) {
+            partialKeyboardUi.onDestroyView();
+        }
         super.onDestroy();
     }
 

app/src/main/java/org/solovyev/android/calculator/CursorDragProcessor.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 android.graphics.PointF;
-import android.view.MotionEvent;
-
-import org.solovyev.android.views.dragbutton.DirectionDragButton;
-import org.solovyev.android.views.dragbutton.DragButton;
-import org.solovyev.android.views.dragbutton.DragDirection;
-import org.solovyev.android.views.dragbutton.SimpleDragListener;
-
-import javax.annotation.Nonnull;
-
-public class CursorDragProcessor implements SimpleDragListener.DragProcessor {
-
-    @Nonnull
-    private final Editor editor;
-
-    public CursorDragProcessor(@Nonnull Editor editor) {
-        this.editor = editor;
-    }
-
-    @Override
-    public boolean processDragEvent(@Nonnull DragDirection dragDirection, @Nonnull DragButton dragButton, @Nonnull PointF startPoint, @Nonnull MotionEvent motionEvent) {
-        if (dragButton instanceof DirectionDragButton) {
-            final String text = ((DirectionDragButton) dragButton).getText(dragDirection);
-            if ("◁◁".equals(text)) {
-                editor.setCursorOnStart();
-                return true;
-            } else if ("▷▷".equals(text)) {
-                editor.setCursorOnEnd();
-                return true;
-            }
-        }
-
-        return false;
-    }
-}

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

@@ -77,7 +77,7 @@ public class EditorFragment extends BaseFragment {
     @Override
     public void onDestroyView() {
         editor.clearView(editorView);
-        ui.onDestroyView(this);
+        ui.onDestroyView();
         super.onDestroyView();
     }
 

app/src/main/java/org/solovyev/android/calculator/EqualsDragProcessor.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 android.graphics.PointF;
-import android.view.MotionEvent;
-
-import org.solovyev.android.views.dragbutton.DirectionDragButton;
-import org.solovyev.android.views.dragbutton.DragButton;
-import org.solovyev.android.views.dragbutton.DragDirection;
-import org.solovyev.android.views.dragbutton.SimpleDragListener;
-
-import javax.annotation.Nonnull;
-
-public class EqualsDragProcessor implements SimpleDragListener.DragProcessor {
-
-    @Nonnull
-    private final Calculator calculator;
-
-    public EqualsDragProcessor(@Nonnull Calculator calculator) {
-        this.calculator = calculator;
-    }
-
-    @Override
-    public boolean processDragEvent(@Nonnull DragDirection direction, @Nonnull DragButton button, @Nonnull PointF startPoint, @Nonnull MotionEvent motionEvent) {
-        if (direction == DragDirection.down) {
-            ActivityLauncher.tryPlot();
-            return true;
-        } else if (button instanceof DirectionDragButton) {
-            final String text = ((DirectionDragButton) button).getText(direction);
-            if ("≡".equals(text)) {
-                calculator.simplify();
-                return true;
-            }
-        }
-
-        return false;
-    }
-}

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

@@ -23,11 +23,12 @@
 package org.solovyev.android.calculator;
 
 import android.support.v4.app.Fragment;
-import android.support.v4.app.FragmentActivity;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
 import android.widget.TextView;
+import butterknife.Bind;
+import butterknife.ButterKnife;
 import org.solovyev.android.checkout.CppCheckout;
 import org.solovyev.android.checkout.Inventory;
 import org.solovyev.android.checkout.ProductTypes;
@@ -37,92 +38,56 @@ import javax.annotation.Nullable;
 import javax.inject.Inject;
 import java.util.Locale;
 
-public class FragmentUi extends BaseUi {
+import static org.solovyev.android.calculator.App.cast;
 
-    @Nullable
+public class FragmentUi {
-    private AdView adView;
+    private final int layoutId;
-
+    private final int titleId;
-    private int layoutId;
-
-    private int titleResId = -1;
-
-    private boolean listenersOnCreate = true;
 
     @Nullable
     private Boolean adFree = null;
 
     @Inject
     CppCheckout checkout;
+    @Nullable
+    @Bind(R.id.fragment_title)
+    TextView fragmentTitle;
+    @Nullable
+    @Bind(R.id.admob)
+    AdView adView;
 
     public FragmentUi(int layoutId) {
-        this.layoutId = layoutId;
+        this(layoutId, View.NO_ID);
     }
 
-    public FragmentUi(int layoutId, int titleResId) {
+    public FragmentUi(int layoutId, int titleId) {
         this.layoutId = layoutId;
-        this.titleResId = titleResId;
+        this.titleId = titleId;
-    }
-
-    public FragmentUi(int layoutId, int titleResId, boolean listenersOnCreate) {
-        this.layoutId = layoutId;
-        this.titleResId = titleResId;
-        this.listenersOnCreate = listenersOnCreate;
     }
 
     public boolean isPane(@Nonnull Fragment fragment) {
         return fragment.getActivity() instanceof CalculatorActivity;
     }
 
-    public void setPaneTitle(@Nonnull Fragment fragment, int titleResId) {
-        final TextView fragmentTitle = (TextView) fragment.getView().findViewById(R.id.fragment_title);
-        if (fragmentTitle != null) {
-            if (!isPane(fragment)) {
-                fragmentTitle.setVisibility(View.GONE);
-            } else {
-                fragmentTitle.setText(fragment.getString(titleResId).toUpperCase(Locale.getDefault()));
-            }
-        }
-    }
-
     public void onCreate(@Nonnull Fragment fragment) {
-        final FragmentActivity activity = fragment.getActivity();
+        cast(fragment).getComponent().inject(this);
-        super.onCreate(activity);
-
-        if (listenersOnCreate) {
-            if (fragment instanceof CalculatorEventListener) {
-                Locator.getInstance().getCalculator().addCalculatorEventListener((CalculatorEventListener) fragment);
-            }
-        }
-
         checkout.start();
     }
 
-    @Override
+    public void onResume() {
-    protected void inject(@Nonnull AppComponent component) {
-        super.inject(component);
-        component.inject(this);
-    }
-
-    public void onResume(@Nonnull Fragment fragment) {
         if (adView != null) {
             adView.resume();
         }
-        if (!listenersOnCreate) {
-            if (fragment instanceof CalculatorEventListener) {
-                Locator.getInstance().getCalculator().addCalculatorEventListener((CalculatorEventListener) fragment);
-            }
-        }
-
         checkout.loadInventory().whenLoaded(new Inventory.Listener() {
             @Override
             public void onLoaded(@Nonnull Inventory.Products products) {
                 adFree = products.get(ProductTypes.IN_APP).isPurchased("ad_free");
-                updateAdViewState();
+                updateAdView();
             }
         });
     }
 
-    private void updateAdViewState() {
+    private void updateAdView() {
         if (adFree == null || adView == null) {
             return;
         }
@@ -134,62 +99,44 @@ public class FragmentUi extends BaseUi {
         }
     }
 
-    public void onPause(@Nonnull Fragment fragment) {
+    public void onPause() {
         adFree = null;
         if (adView != null) {
             adView.pause();
         }
-        if (!listenersOnCreate) {
-            if (fragment instanceof CalculatorEventListener) {
-                Locator.getInstance().getCalculator().removeCalculatorEventListener((CalculatorEventListener) fragment);
-            }
-        }
     }
 
-    public void onViewCreated(@Nonnull Fragment fragment, @Nonnull View root) {
+    public void onCreateView(@Nonnull Fragment fragment, @Nonnull View root) {
-        adView = (AdView) root.findViewById(R.id.ad);
+        ButterKnife.bind(this, root);
-        final ViewGroup mainFragmentLayout = (ViewGroup) root.findViewById(R.id.main_fragment_layout);
-
         if (fragment instanceof DisplayFragment || fragment instanceof EditorFragment || fragment instanceof KeyboardFragment) {
             // no ads in those fragments
-        } else {
+        } else if (adView != null) {
-            if (adView != null) {
+            updateAdView();
-                updateAdViewState();
+        }
-            } else if (mainFragmentLayout != null) {
+
+        if (titleId != View.NO_ID && fragmentTitle != null) {
+            if (isPane(fragment)) {
+                fragmentTitle.setText(fragment.getString(titleId).toUpperCase(Locale.getDefault()));
+            } else {
+                fragmentTitle.setVisibility(View.GONE);
             }
         }
-
-        if (fragment instanceof KeyboardFragment) {
-            processButtons(fragment.getActivity(), root);
-        }
-        fixFonts(root);
-
-        if (titleResId >= 0) {
-            this.setPaneTitle(fragment, titleResId);
-        }
     }
 
-    public void onDestroy(@Nonnull Fragment fragment) {
+    public void onDestroy() {
-        if (listenersOnCreate) {
-            if (fragment instanceof CalculatorEventListener) {
-                Locator.getInstance().getCalculator().removeCalculatorEventListener((CalculatorEventListener) fragment);
-            }
-        }
-
         checkout.stop();
-
-        super.onDestroy(fragment.getActivity());
     }
 
     @Nonnull
-    public View onCreateView(@Nonnull Fragment fragment, @Nonnull LayoutInflater inflater, @Nullable ViewGroup container) {
+    public View onCreateView(@Nonnull LayoutInflater inflater, @Nullable ViewGroup container) {
         return inflater.inflate(layoutId, container, false);
     }
 
-    public void onDestroyView(@Nonnull Fragment fragment) {
+    public void onDestroyView() {
-        if (adView != null) {
+        if (adView == null) {
-            adView.destroy();
+            return;
-            adView = null;
         }
+        adView.destroy();
+        adView = null;
     }
 }

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

@@ -27,36 +27,19 @@ import android.os.Bundle;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
-import android.widget.Button;
-import butterknife.Bind;
 import butterknife.ButterKnife;
-import org.solovyev.android.calculator.buttons.CppButtons;
+import org.solovyev.android.Check;
+import org.solovyev.android.calculator.keyboard.KeyboardUi;
 
 import javax.annotation.Nonnull;
-import javax.annotation.Nullable;
 import javax.inject.Inject;
 
-import static org.solovyev.android.calculator.Engine.Preferences.multiplicationSign;
+public class KeyboardFragment extends BaseFragment {
-import static org.solovyev.android.calculator.Engine.Preferences.numeralBase;
-import static org.solovyev.android.calculator.NumeralBaseButtons.toggleNumericDigits;
-import static org.solovyev.android.calculator.Preferences.Gui.hideNumeralBaseDigits;
-import static org.solovyev.android.calculator.Preferences.Gui.showEqualsButton;
-
-public class KeyboardFragment extends BaseFragment implements SharedPreferences.OnSharedPreferenceChangeListener {
 
     @Inject
     SharedPreferences preferences;
-    @Bind(R.id.cpp_button_multiplication)
+    @Inject
-    Button multiplicationButton;
+    KeyboardUi keyboardUi;
-    @Nullable
-    @Bind(R.id.cpp_button_equals)
-    Button equalsButton;
-
-    @Override
-    public void onCreate(Bundle savedInstanceState) {
-        super.onCreate(savedInstanceState);
-        preferences.registerOnSharedPreferenceChangeListener(this);
-    }
 
     @Override
     protected void inject(@Nonnull AppComponent component) {
@@ -68,6 +51,8 @@ public class KeyboardFragment extends BaseFragment implements SharedPreferences.
     public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
         final View view = super.onCreateView(inflater, container, savedInstanceState);
         ButterKnife.bind(this, view);
+        Check.isNotNull(view);
+        keyboardUi.onCreateView(getActivity(), view);
         return view;
     }
 
@@ -83,24 +68,9 @@ public class KeyboardFragment extends BaseFragment implements SharedPreferences.
     }
 
     @Override
-    public void onDestroy() {
+    public void onDestroyView() {
-        preferences.unregisterOnSharedPreferenceChangeListener(this);
+        keyboardUi.onDestroyView();
-        super.onDestroy();
+        super.onDestroyView();
-    }
-
-    @Override
-    public void onSharedPreferenceChanged(SharedPreferences preferences, String key) {
-        if (numeralBase.isSameKey(key) || hideNumeralBaseDigits.isSameKey(key)) {
-            toggleNumericDigits(this.getActivity(), preferences);
-        }
-
-        if (equalsButton != null && showEqualsButton.isSameKey(key)) {
-            CppButtons.toggleEqualsButton(preferences, getActivity(), equalsButton);
-        }
-
-        if (multiplicationSign.isSameKey(key)) {
-            multiplicationButton.setText(Engine.Preferences.multiplicationSign.getPreference(preferences));
-        }
     }
 }
 

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

@@ -1,56 +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 android.app.Activity;
-import android.content.SharedPreferences;
-import jscl.NumeralBase;
-
-import javax.annotation.Nonnull;
-
-import static jscl.NumeralBase.hex;
-import static org.solovyev.android.calculator.Engine.Preferences.numeralBase;
-import static org.solovyev.android.calculator.Preferences.Gui.hideNumeralBaseDigits;
-
-public class NumeralBaseButtons {
-
-    public static void toggleNumericDigits(@Nonnull Activity activity, @Nonnull NumeralBase currentNumeralBase) {
-        for (NumeralBase numeralBase : NumeralBase.values()) {
-            if (currentNumeralBase != numeralBase) {
-                AndroidNumeralBase.valueOf(numeralBase).toggleButtons(false, activity);
-            }
-        }
-
-        AndroidNumeralBase.valueOf(currentNumeralBase).toggleButtons(true, activity);
-    }
-
-    public static void toggleNumericDigits(@Nonnull Activity activity, @Nonnull SharedPreferences preferences) {
-        if (hideNumeralBaseDigits.getPreference(preferences)) {
-            final NumeralBase nb = numeralBase.getPreference(preferences);
-            toggleNumericDigits(activity, nb);
-        } else {
-            // set HEX to show all digits
-            AndroidNumeralBase.valueOf(hex).toggleButtons(true, activity);
-        }
-    }
-}

app/src/main/java/org/solovyev/android/calculator/about/AboutActivity.java

@@ -41,7 +41,7 @@ public class AboutActivity extends EmptyActivity {
     public void onCreate(@Nullable Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
 
-        getUi().addTab(this, FragmentTab.about, null, R.id.main_layout);
+        getUi().addTab(this, FragmentTab.about, null, R.id.main);
-        getUi().addTab(this, FragmentTab.release_notes, null, R.id.main_layout);
+        getUi().addTab(this, FragmentTab.release_notes, null, R.id.main);
     }
 }

app/src/main/java/org/solovyev/android/calculator/about/AboutFragment.java

@@ -31,6 +31,7 @@ import android.widget.ImageView;
 import android.widget.TextView;
 import butterknife.Bind;
 import butterknife.ButterKnife;
+import org.solovyev.android.calculator.App;
 import org.solovyev.android.calculator.BaseFragment;
 import org.solovyev.android.calculator.FragmentUi;
 import org.solovyev.android.calculator.R;
@@ -62,7 +63,7 @@ public class AboutFragment extends BaseFragment {
     public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
         final View view = super.onCreateView(inflater, container, savedInstanceState);
         ButterKnife.bind(this, view);
-        if (ui.getTheme().light) {
+        if (App.getTheme().light) {
             imageView.setImageResource(R.drawable.logo_wizard_light);
         }
         textView.setMovementMethod(LinkMovementMethod.getInstance());

app/src/main/java/org/solovyev/android/calculator/buttons/CppButtons.java

@@ -1,268 +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.buttons;
-
-import android.app.Activity;
-import android.content.Context;
-import android.content.SharedPreferences;
-import android.content.res.Configuration;
-import android.graphics.PointF;
-import android.preference.PreferenceManager;
-import android.util.Log;
-import android.util.TypedValue;
-import android.view.MotionEvent;
-import android.view.View;
-import android.widget.Button;
-import jscl.AngleUnit;
-import jscl.NumeralBase;
-import org.solovyev.android.Views;
-import org.solovyev.android.calculator.*;
-import org.solovyev.android.calculator.view.AngleUnitsButton;
-import org.solovyev.android.calculator.view.NumeralBasesButton;
-import org.solovyev.android.calculator.view.ScreenMetrics;
-import org.solovyev.android.views.dragbutton.DragButton;
-import org.solovyev.android.views.dragbutton.DragDirection;
-import org.solovyev.android.views.dragbutton.SimpleDragListener;
-
-import javax.annotation.Nonnull;
-import javax.annotation.Nullable;
-
-public final class CppButtons {
-
-    private CppButtons() {
-    }
-
-
-    public static void fixButtonsTextSize(@Nonnull Preferences.Gui.Theme theme,
-                                          @Nonnull Preferences.Gui.Layout layout,
-                                          @Nonnull View root) {
-        if (!layout.optimized) {
-
-            final ScreenMetrics metrics = App.getScreenMetrics();
-            final boolean portrait = metrics.isInPortraitMode();
-            final int buttonsCount = portrait ? 5 : 4;
-            final int buttonsWeight = portrait ? (2 + 1 + buttonsCount) : (2 + buttonsCount);
-            final int buttonSize = metrics.getHeightPxs() / buttonsWeight;
-            final int textSize = 5 * buttonSize / 12;
-
-            Views.processViewsOfType(root, DragButton.class, new Views.ViewProcessor<DragButton>() {
-                @Override
-                public void process(@Nonnull DragButton button) {
-                    button.setTextSize(TypedValue.COMPLEX_UNIT_PX, textSize);
-                }
-            });
-        }
-    }
-
-    public static void initMultiplicationButton(@Nonnull View root) {
-        final View multiplicationButton = root.findViewById(R.id.cpp_button_multiplication);
-        if (multiplicationButton instanceof Button) {
-            ((Button) multiplicationButton).setText(Locator.getInstance().getEngine().getMultiplicationSign());
-        }
-    }
-
-
-    public static void toggleEqualsButton(@Nullable SharedPreferences preferences,
-                                          @Nonnull Activity activity) {
-        preferences = preferences == null ? PreferenceManager.getDefaultSharedPreferences(activity) : preferences;
-        final DragButton equalsButton = (DragButton) activity.findViewById(R.id.cpp_button_equals);
-        if(equalsButton == null) {
-            return;
-        }
-
-        toggleEqualsButton(preferences, activity, equalsButton);
-    }
-
-    public static void toggleEqualsButton(@Nonnull SharedPreferences preferences, @Nonnull Activity activity, @Nonnull Button button) {
-        final boolean large = App.isLargeScreen() && Preferences.Gui.getLayout(preferences).optimized;
-        if (large) {
-            return;
-        }
-        if (Views.getScreenOrientation(activity) != Configuration.ORIENTATION_PORTRAIT && Preferences.Gui.autoOrientation.getPreference(preferences)) {
-            return;
-        }
-
-        if (Preferences.Gui.showEqualsButton.getPreference(preferences)) {
-            button.setVisibility(View.VISIBLE);
-        } else {
-            button.setVisibility(View.GONE);
-        }
-    }
-
-    public static class RoundBracketsDragProcessor implements SimpleDragListener.DragProcessor {
-
-        @Nonnull
-        private final Keyboard keyboard;
-        @Nonnull
-        private final DigitButtonDragProcessor upDownProcessor;
-
-        public RoundBracketsDragProcessor(@Nonnull Keyboard keyboard) {
-            this.keyboard = keyboard;
-            this.upDownProcessor = new DigitButtonDragProcessor(keyboard);
-        }
-
-        @Override
-        public boolean processDragEvent(@Nonnull DragDirection direction, @Nonnull DragButton button, @Nonnull PointF startPoint, @Nonnull MotionEvent motionEvent) {
-            if (direction == DragDirection.left) {
-                keyboard.roundBracketsButtonPressed();
-                return true;
-            }
-
-            return upDownProcessor.processDragEvent(direction, button, startPoint, motionEvent);
-        }
-    }
-
-    public static class VarsDragProcessor implements SimpleDragListener.DragProcessor {
-
-        @Nonnull
-        private Context context;
-
-        public VarsDragProcessor(@Nonnull Context context) {
-            this.context = context;
-        }
-
-        @Override
-        public boolean processDragEvent(@Nonnull DragDirection dragDirection,
-                                        @Nonnull DragButton dragButton,
-                                        @Nonnull PointF startPoint,
-                                        @Nonnull MotionEvent motionEvent) {
-            if (dragDirection == DragDirection.up) {
-                Locator.getInstance().getCalculator().fireCalculatorEvent(CalculatorEventType.show_create_var_dialog, null, context);
-                return true;
-            }
-
-            return false;
-        }
-    }
-
-    public static class AngleUnitsChanger implements SimpleDragListener.DragProcessor {
-
-        @Nonnull
-        private final DigitButtonDragProcessor processor;
-
-        @Nonnull
-        private final Context context;
-        @Nonnull
-        private final PreferredPreferences preferredPreferences;
-
-        public AngleUnitsChanger(@Nonnull Context context, @Nonnull Keyboard keyboard, @Nonnull PreferredPreferences preferredPreferences) {
-            this.context = context;
-            this.preferredPreferences = preferredPreferences;
-            this.processor = new DigitButtonDragProcessor(keyboard);
-        }
-
-        @Override
-        public boolean processDragEvent(@Nonnull DragDirection dragDirection,
-                                        @Nonnull DragButton dragButton,
-                                        @Nonnull PointF startPoint,
-                                        @Nonnull MotionEvent motionEvent) {
-            if (dragButton instanceof AngleUnitsButton) {
-                if (dragDirection != DragDirection.left) {
-                    final String directionText = ((AngleUnitsButton) dragButton).getText(dragDirection);
-                    if (directionText != null) {
-                        try {
-
-                            final AngleUnit angleUnits = AngleUnit.valueOf(directionText);
-
-                            final SharedPreferences preferences = PreferenceManager.getDefaultSharedPreferences(context);
-
-                            final AngleUnit oldAngleUnits = Engine.Preferences.angleUnit.getPreference(preferences);
-                            if (oldAngleUnits != angleUnits) {
-                                preferredPreferences.setAngleUnits(angleUnits);
-                            }
-                        } catch (IllegalArgumentException e) {
-                            Log.d(this.getClass().getName(), "Unsupported angle units: " + directionText);
-                        }
-                        return true;
-                    }
-                } else if (dragDirection == DragDirection.left) {
-                    return processor.processDragEvent(dragDirection, dragButton, startPoint, motionEvent);
-                }
-            }
-
-            return false;
-        }
-    }
-
-    public static class NumeralBasesChanger implements SimpleDragListener.DragProcessor {
-
-        @Nonnull
-        private final Context context;
-        @Nonnull
-        private final PreferredPreferences preferredPreferences;
-
-        public NumeralBasesChanger(@Nonnull Context context, @Nonnull PreferredPreferences preferredPreferences) {
-            this.context = context;
-            this.preferredPreferences = preferredPreferences;
-        }
-
-        @Override
-        public boolean processDragEvent(@Nonnull DragDirection dragDirection,
-                                        @Nonnull DragButton dragButton,
-                                        @Nonnull PointF startPoint,
-                                        @Nonnull MotionEvent motionEvent) {
-            if (dragButton instanceof NumeralBasesButton) {
-                final String directionText = ((NumeralBasesButton) dragButton).getText(dragDirection);
-                if (directionText != null) {
-                    try {
-                        final NumeralBase numeralBase = NumeralBase.valueOf(directionText);
-
-                        final SharedPreferences preferences = PreferenceManager.getDefaultSharedPreferences(context);
-
-                        final NumeralBase oldNumeralBase = Engine.Preferences.numeralBase.getPreference(preferences);
-                        if (oldNumeralBase != numeralBase) {
-                            preferredPreferences.setNumeralBase(numeralBase);
-                        }
-                    } catch (IllegalArgumentException e) {
-                        Log.d(this.getClass().getName(), "Unsupported numeral base: " + directionText);
-                    }
-                    return true;
-                }
-            }
-
-            return false;
-        }
-    }
-
-    public static class FunctionsDragProcessor implements SimpleDragListener.DragProcessor {
-
-        @Nonnull
-        private Context context;
-
-        public FunctionsDragProcessor(@Nonnull Context context) {
-            this.context = context;
-        }
-
-        @Override
-        public boolean processDragEvent(@Nonnull DragDirection dragDirection,
-                                        @Nonnull DragButton dragButton,
-                                        @Nonnull PointF startPoint,
-                                        @Nonnull MotionEvent motionEvent) {
-            if (dragDirection == DragDirection.up) {
-                Locator.getInstance().getCalculator().fireCalculatorEvent(CalculatorEventType.show_create_function_dialog, null, context);
-                return true;
-            }
-            return false;
-        }
-    }
-}

app/src/main/java/org/solovyev/android/calculator/entities/BaseEntitiesFragment.java

@@ -83,7 +83,7 @@ public abstract class BaseEntitiesFragment<E extends MathEntity> extends BaseFra
 
     @Override
     public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
-        final View view = ui.onCreateView(this, inflater, container);
+        final View view = ui.onCreateView(inflater, container);
         ButterKnife.bind(this, view);
         final Context context = inflater.getContext();
         adapter = new EntitiesAdapter(context, TextUtils.isEmpty(category) ? getEntities() : getEntities(category));

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

@@ -117,7 +117,7 @@ public abstract class BaseHistoryFragment extends BaseFragment {
     }
 
     private void showClearHistoryDialog() {
-        new AlertDialog.Builder(getActivity(), ui.getTheme().alertDialogTheme)
+        new AlertDialog.Builder(getActivity(), App.getTheme().alertDialogTheme)
                 .setTitle(R.string.cpp_clear_history_title)
                 .setMessage(R.string.cpp_clear_history_message)
                 .setPositiveButton(R.string.cpp_clear_history, new DialogInterface.OnClickListener() {

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

@@ -42,7 +42,7 @@ public class HistoryActivity extends BaseActivity {
     public void onCreate(@Nullable Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
 
-        ui.addTab(this, history, null, R.id.main_layout);
+        ui.addTab(this, history, null, R.id.main);
-        ui.addTab(this, saved_history, null, R.id.main_layout);
+        ui.addTab(this, saved_history, null, R.id.main);
     }
 }

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

@@ -1,55 +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.history;
-
-import android.graphics.PointF;
-import android.view.MotionEvent;
-
-import org.solovyev.android.views.dragbutton.DragButton;
-import org.solovyev.android.views.dragbutton.DragDirection;
-import org.solovyev.android.views.dragbutton.SimpleDragListener;
-
-import javax.annotation.Nonnull;
-
-public class HistoryDragProcessor implements SimpleDragListener.DragProcessor {
-
-    @Nonnull
-    private final History history;
-
-    public HistoryDragProcessor(@Nonnull History history) {
-        this.history = history;
-    }
-
-    @Override
-    public boolean processDragEvent(@Nonnull DragDirection direction, @Nonnull DragButton button, @Nonnull PointF startPoint, @Nonnull MotionEvent motionEvent) {
-        switch (direction) {
-            case up:
-                history.undo();
-                return true;
-            case down:
-                history.redo();
-                return true;
-        }
-        return false;
-    }
-}

app/src/main/java/org/solovyev/android/calculator/keyboard/BaseKeyboardUi.java

@@ -0,0 +1,123 @@
+package org.solovyev.android.calculator.keyboard;
+
+import android.app.Activity;
+import android.app.Application;
+import android.content.SharedPreferences;
+import android.content.res.Configuration;
+import android.graphics.Typeface;
+import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
+import android.util.TypedValue;
+import android.view.HapticFeedbackConstants;
+import android.view.View;
+import org.solovyev.android.Views;
+import org.solovyev.android.calculator.*;
+import org.solovyev.android.calculator.buttons.CppSpecialButton;
+import org.solovyev.android.calculator.view.ScreenMetrics;
+import org.solovyev.android.views.dragbutton.DirectionDragButton;
+import org.solovyev.android.views.dragbutton.DragDirection;
+import org.solovyev.android.views.dragbutton.SimpleDragListener;
+
+import javax.annotation.Nonnull;
+import javax.inject.Inject;
+
+import static org.solovyev.android.calculator.App.cast;
+import static org.solovyev.android.calculator.App.getScreenMetrics;
+import static org.solovyev.android.calculator.Preferences.Gui.Layout.simple;
+import static org.solovyev.android.calculator.Preferences.Gui.Layout.simple_mobile;
+
+public abstract class BaseKeyboardUi implements SharedPreferences.OnSharedPreferenceChangeListener, SimpleDragListener.DragProcessor, View.OnClickListener {
+
+    @NonNull
+    protected final SimpleDragListener listener;
+    @Inject
+    SharedPreferences preferences;
+    @Inject
+    Typeface typeface;
+    @Inject
+    Keyboard keyboard;
+    @Inject
+    Editor editor;
+    @Inject
+    Calculator calculator;
+    @Inject
+    PreferredPreferences preferredPreferences;
+    protected int orientation = Configuration.ORIENTATION_PORTRAIT;
+    private int textSize;
+    private Preferences.Gui.Layout layout;
+
+    public BaseKeyboardUi(@NonNull Application application) {
+        listener = new SimpleDragListener(this, application);
+    }
+
+    public void onCreateView(@Nonnull Activity activity, @Nonnull View view) {
+        cast(activity.getApplication()).getComponent().inject(this);
+        preferences.registerOnSharedPreferenceChangeListener(this);
+
+        orientation = Views.getScreenOrientation(activity);
+        layout = Preferences.Gui.layout.getPreferenceNoError(preferences);
+        textSize = layout.optimized ? 0 : calculateTextSize();
+    }
+
+    protected final void prepareButton(@Nullable View button) {
+        if (button == null) {
+            return;
+        }
+        button.setOnClickListener(this);
+    }
+
+    protected final void prepareButton(@Nullable DirectionDragButton button) {
+        if (button == null) {
+            return;
+        }
+        prepareButton((View) button);
+        button.setOnDragListener(listener);
+        BaseUi.setFont(button, typeface);
+        if (textSize > 0) {
+            button.setTextSize(TypedValue.COMPLEX_UNIT_PX, textSize);
+        }
+    }
+
+    protected final void hideText(@Nullable DirectionDragButton button, @Nonnull DragDirection... directions) {
+        if (button == null) {
+            return;
+        }
+        for (DragDirection direction : directions) {
+            hideText(button, direction);
+        }
+    }
+
+    protected final void hideText(@Nullable DirectionDragButton button, @Nonnull DragDirection direction) {
+        if (button == null) {
+            return;
+        }
+        button.showDirectionText(false, direction);
+    }
+
+    public void onDestroyView() {
+        preferences.unregisterOnSharedPreferenceChangeListener(this);
+    }
+
+    public static int calculateTextSize() {
+        final ScreenMetrics metrics = getScreenMetrics();
+        final boolean portrait = metrics.isInPortraitMode();
+        final int buttonsCount = portrait ? 5 : 4;
+        final int buttonsWeight = portrait ? (2 + 1 + buttonsCount) : (2 + buttonsCount);
+        final int buttonSize = metrics.getHeightPxs() / buttonsWeight;
+        return 5 * buttonSize / 12;
+    }
+
+    protected boolean isSimpleLayout() {
+        return layout == simple || layout == simple_mobile;
+    }
+
+    protected final void onClick(@Nonnull View v, @Nonnull String s) {
+        if (keyboard.buttonPressed(s)) {
+            v.performHapticFeedback(HapticFeedbackConstants.VIRTUAL_KEY);
+        }
+    }
+
+    protected final void onClick(@Nonnull View v, @Nonnull CppSpecialButton b) {
+        onClick(v, b.action);
+    }
+}

app/src/main/java/org/solovyev/android/calculator/keyboard/KeyboardUi.java

@@ -0,0 +1,296 @@
+package org.solovyev.android.calculator.keyboard;
+
+import android.app.Activity;
+import android.app.Application;
+import android.content.SharedPreferences;
+import android.graphics.PointF;
+import android.support.annotation.Nullable;
+import android.text.TextUtils;
+import android.util.Log;
+import android.view.MotionEvent;
+import android.view.View;
+import android.widget.Button;
+import android.widget.ImageButton;
+import butterknife.Bind;
+import butterknife.ButterKnife;
+import jscl.AngleUnit;
+import jscl.NumeralBase;
+import org.solovyev.android.calculator.*;
+import org.solovyev.android.calculator.buttons.CppSpecialButton;
+import org.solovyev.android.calculator.history.History;
+import org.solovyev.android.calculator.view.AngleUnitsButton;
+import org.solovyev.android.views.dragbutton.DirectionDragButton;
+import org.solovyev.android.views.dragbutton.DragButton;
+import org.solovyev.android.views.dragbutton.DragDirection;
+
+import javax.annotation.Nonnull;
+import javax.inject.Inject;
+
+import static jscl.NumeralBase.hex;
+import static org.solovyev.android.calculator.Engine.Preferences.*;
+import static org.solovyev.android.calculator.Preferences.Gui.hideNumeralBaseDigits;
+import static org.solovyev.android.views.dragbutton.DragDirection.*;
+
+public class KeyboardUi extends BaseKeyboardUi {
+
+    @Bind(R.id.cpp_button_0)
+    public DirectionDragButton button0;
+    @Bind(R.id.cpp_button_1)
+    public DirectionDragButton button1;
+    @Bind(R.id.cpp_button_2)
+    public DirectionDragButton button2;
+    @Bind(R.id.cpp_button_3)
+    public DirectionDragButton button3;
+    @Bind(R.id.cpp_button_4)
+    public DirectionDragButton button4;
+    @Bind(R.id.cpp_button_5)
+    public DirectionDragButton button5;
+    @Bind(R.id.cpp_button_6)
+    public AngleUnitsButton button6;
+    @Bind(R.id.cpp_button_7)
+    public DirectionDragButton button7;
+    @Bind(R.id.cpp_button_8)
+    public DirectionDragButton button8;
+    @Bind(R.id.cpp_button_9)
+    public DirectionDragButton button9;
+    @Inject
+    History history;
+    @Inject
+    ActivityLauncher launcher;
+    @Inject
+    Engine engine;
+    @Inject
+    PartialKeyboardUi partialUi;
+    @Bind(R.id.cpp_button_vars)
+    DirectionDragButton variablesButton;
+    @Nullable
+    @Bind(R.id.cpp_button_operators)
+    DirectionDragButton operatorsButton;
+    @Bind(R.id.cpp_button_functions)
+    DirectionDragButton functionsButton;
+    @Bind(R.id.cpp_button_history)
+    DirectionDragButton historyButton;
+    @Bind(R.id.cpp_button_multiplication)
+    DirectionDragButton multiplicationButton;
+    @Bind(R.id.cpp_button_plus)
+    DirectionDragButton plusButton;
+    @Bind(R.id.cpp_button_subtraction)
+    DirectionDragButton subtractionButton;
+    @Bind(R.id.cpp_button_division)
+    DirectionDragButton divisionButton;
+    @Bind(R.id.cpp_button_period)
+    DirectionDragButton periodButton;
+    @Bind(R.id.cpp_button_round_brackets)
+    DirectionDragButton bracketsButton;
+    @Bind(R.id.cpp_button_copy)
+    ImageButton copyButton;
+    @Bind(R.id.cpp_button_paste)
+    ImageButton pasteButton;
+    @Nullable
+    @Bind(R.id.cpp_button_like)
+    ImageButton likeButton;
+
+    @Inject
+    public KeyboardUi(@Nonnull Application application) {
+        super(application);
+    }
+
+    public void toggleNumericDigits() {
+        if (hideNumeralBaseDigits.getPreference(preferences)) {
+            toggleNumericDigits(numeralBase.getPreference(preferences));
+        } else {
+            // set HEX to show all digits
+            AndroidNumeralBase.valueOf(hex).toggleButtons(true, this);
+        }
+    }
+
+    public void toggleNumericDigits(@Nonnull NumeralBase currentNumeralBase) {
+        for (NumeralBase numeralBase : NumeralBase.values()) {
+            if (currentNumeralBase != numeralBase) {
+                AndroidNumeralBase.valueOf(numeralBase).toggleButtons(false, this);
+            }
+        }
+
+        AndroidNumeralBase.valueOf(currentNumeralBase).toggleButtons(true, this);
+    }
+
+    public void onCreateView(@Nonnull Activity activity, @Nonnull View view) {
+        super.onCreateView(activity, view);
+        partialUi.onCreateView(activity, view);
+        ButterKnife.bind(this, view);
+
+        prepareButton(variablesButton);
+        prepareButton(operatorsButton);
+        prepareButton(functionsButton);
+        prepareButton(historyButton);
+
+        prepareButton(multiplicationButton);
+        prepareButton(plusButton);
+        prepareButton(subtractionButton);
+        prepareButton(divisionButton);
+
+        prepareButton(periodButton);
+        prepareButton(bracketsButton);
+
+        prepareButton(button0);
+        prepareButton(button1);
+        prepareButton(button2);
+        prepareButton(button3);
+        prepareButton(button4);
+        prepareButton(button5);
+        prepareButton(button6);
+        prepareButton(button7);
+        prepareButton(button8);
+        prepareButton(button9);
+
+        prepareButton(copyButton);
+        prepareButton(pasteButton);
+        prepareButton(likeButton);
+
+        if (isSimpleLayout()) {
+            hideText(button1, up, down);
+            hideText(button2, up, down);
+            hideText(button3, up, down);
+            hideText(button4, down);
+            hideText(button5, down);
+            hideText(button6, up, down);
+            hideText(button7, left, up, down);
+            hideText(button8, left, up, down);
+            hideText(button9, left);
+            hideText(multiplicationButton, left);
+            hideText(plusButton, up, down);
+        }
+        multiplicationButton.setText(engine.getMultiplicationSign());
+        toggleNumericDigits();
+    }
+
+    @Override
+    public void onDestroyView() {
+        partialUi.onDestroyView();
+        super.onDestroyView();
+    }
+
+    @Override
+    public void onSharedPreferenceChanged(SharedPreferences preferences, String key) {
+        if (angleUnit.isSameKey(key)) {
+            button6.setAngleUnit(angleUnit.getPreference(preferences));
+        }
+        if (numeralBase.isSameKey(key) || hideNumeralBaseDigits.isSameKey(key)) {
+            toggleNumericDigits();
+        }
+        if (multiplicationSign.isSameKey(key)) {
+            multiplicationButton.setText(multiplicationSign.getPreference(preferences));
+        }
+    }
+
+    @Override
+    public void onClick(View v) {
+        switch (v.getId()) {
+            case R.id.cpp_button_0:
+            case R.id.cpp_button_1:
+            case R.id.cpp_button_2:
+            case R.id.cpp_button_3:
+            case R.id.cpp_button_4:
+            case R.id.cpp_button_5:
+            case R.id.cpp_button_6:
+            case R.id.cpp_button_7:
+            case R.id.cpp_button_8:
+            case R.id.cpp_button_9:
+            case R.id.cpp_button_division:
+            case R.id.cpp_button_period:
+            case R.id.cpp_button_subtraction:
+            case R.id.cpp_button_multiplication:
+            case R.id.cpp_button_plus:
+            case R.id.cpp_button_round_brackets:
+                onClick(v, ((Button) v).getText().toString());
+                break;
+            case R.id.cpp_button_functions:
+                onClick(v, CppSpecialButton.functions);
+                break;
+            case R.id.cpp_button_history:
+                onClick(v, CppSpecialButton.history);
+                break;
+            case R.id.cpp_button_paste:
+                onClick(v, CppSpecialButton.paste);
+                break;
+            case R.id.cpp_button_copy:
+                onClick(v, CppSpecialButton.copy);
+                break;
+            case R.id.cpp_button_like:
+                onClick(v, CppSpecialButton.like);
+                break;
+            case R.id.cpp_button_operators:
+                onClick(v, CppSpecialButton.operators);
+                break;
+            case R.id.cpp_button_vars:
+                onClick(v, CppSpecialButton.vars);
+                break;
+        }
+    }
+
+    @Override
+    public boolean processDragEvent(@Nonnull DragDirection direction, @Nonnull DragButton button, @Nonnull PointF point, @Nonnull MotionEvent event) {
+        switch (button.getId()) {
+            case R.id.cpp_button_vars:
+                calculator.fireCalculatorEvent(CalculatorEventType.show_create_var_dialog, null);
+                return true;
+            case R.id.cpp_button_functions:
+                if (direction == up) {
+                    calculator.fireCalculatorEvent(CalculatorEventType.show_create_function_dialog, null);
+                    return true;
+                }
+                return false;
+            case R.id.cpp_button_history:
+                if (direction == up) {
+                    history.undo();
+                    return true;
+                } else if (direction == down) {
+                    history.redo();
+                    return true;
+                }
+                return false;
+            case R.id.cpp_button_subtraction:
+                if (direction == down) {
+                    launcher.showOperators();
+                    return true;
+                }
+                return false;
+            case R.id.cpp_button_6:
+                return processAngleUnitsButton(direction, (DirectionDragButton) button);
+            case R.id.cpp_button_round_brackets:
+                if (direction == left) {
+                    keyboard.roundBracketsButtonPressed();
+                    return true;
+                }
+                return processDefault(direction, button);
+            default:
+                return processDefault(direction, button);
+        }
+    }
+
+    private boolean processAngleUnitsButton(@Nonnull DragDirection direction, @Nonnull DirectionDragButton button) {
+        if (direction == DragDirection.left) {
+            return processDefault(direction, button);
+        }
+        final String text = button.getText(direction);
+        if (TextUtils.isEmpty(text)) {
+            return processDefault(direction, button);
+        }
+        try {
+            final AngleUnit newAngleUnits = AngleUnit.valueOf(text);
+            final AngleUnit oldAngleUnits = Engine.Preferences.angleUnit.getPreference(preferences);
+            if (oldAngleUnits != newAngleUnits) {
+                preferredPreferences.setAngleUnits(newAngleUnits);
+                return true;
+            }
+        } catch (IllegalArgumentException e) {
+            Log.d(this.getClass().getName(), "Unsupported angle units: " + text);
+        }
+        return false;
+    }
+
+    private boolean processDefault(@Nonnull DragDirection direction, @Nonnull DragButton button) {
+        final String text = ((DirectionDragButton) button).getText(direction);
+        return keyboard.buttonPressed(text);
+    }
+}

app/src/main/java/org/solovyev/android/calculator/keyboard/PartialKeyboardUi.java

@@ -0,0 +1,165 @@
+package org.solovyev.android.calculator.keyboard;
+
+import android.app.Activity;
+import android.app.Application;
+import android.content.SharedPreferences;
+import android.content.res.Configuration;
+import android.graphics.PointF;
+import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
+import android.text.TextUtils;
+import android.util.Log;
+import android.view.MotionEvent;
+import android.view.View;
+import android.widget.Button;
+import android.widget.ImageButton;
+import butterknife.Bind;
+import butterknife.ButterKnife;
+import jscl.NumeralBase;
+import org.solovyev.android.calculator.*;
+import org.solovyev.android.calculator.buttons.CppSpecialButton;
+import org.solovyev.android.calculator.view.EditorLongClickEraser;
+import org.solovyev.android.calculator.view.NumeralBasesButton;
+import org.solovyev.android.views.dragbutton.DirectionDragButton;
+import org.solovyev.android.views.dragbutton.DragButton;
+import org.solovyev.android.views.dragbutton.DragDirection;
+
+import javax.annotation.Nonnull;
+import javax.inject.Inject;
+
+import static org.solovyev.android.calculator.Engine.Preferences.numeralBase;
+import static org.solovyev.android.calculator.Preferences.Gui.showEqualsButton;
+import static org.solovyev.android.views.dragbutton.DragDirection.*;
+
+public class PartialKeyboardUi extends BaseKeyboardUi {
+
+    @Nullable
+    @Bind(R.id.cpp_button_right)
+    DirectionDragButton rightButton;
+    @Nullable
+    @Bind(R.id.cpp_button_left)
+    DirectionDragButton leftButton;
+    @Nullable
+    @Bind(R.id.cpp_button_clear)
+    NumeralBasesButton clearButton;
+    @Nullable
+    @Bind(R.id.cpp_button_erase)
+    ImageButton eraseButton;
+    @Nullable
+    @Bind(R.id.cpp_button_equals)
+    DirectionDragButton equalsButton;
+
+    @Inject
+    public PartialKeyboardUi(@NonNull Application application) {
+        super(application);
+    }
+
+    @Override
+    public void onCreateView(@Nonnull Activity activity, @Nonnull View view) {
+        super.onCreateView(activity, view);
+        ButterKnife.bind(this, view);
+        prepareButton(rightButton);
+        prepareButton(leftButton);
+        prepareButton(equalsButton);
+        prepareButton(clearButton);
+        prepareButton(eraseButton);
+        if (eraseButton != null) {
+            EditorLongClickEraser.attachTo(eraseButton);
+        }
+        if (isSimpleLayout()) {
+            hideText(clearButton, left, up, down);
+        }
+        toggleEqualsButton();
+    }
+
+    public void toggleEqualsButton() {
+        if (equalsButton == null) {
+            return;
+        }
+        final boolean large = App.isLargeScreen() && Preferences.Gui.getLayout(preferences).optimized;
+        if (large) {
+            return;
+        }
+        if (orientation != Configuration.ORIENTATION_PORTRAIT && Preferences.Gui.autoOrientation.getPreference(preferences)) {
+            return;
+        }
+
+        if (Preferences.Gui.showEqualsButton.getPreference(preferences)) {
+            equalsButton.setVisibility(View.VISIBLE);
+        } else {
+            equalsButton.setVisibility(View.GONE);
+        }
+    }
+
+    @Override
+    public void onSharedPreferenceChanged(SharedPreferences preferences, String key) {
+        if (clearButton != null && numeralBase.isSameKey(key)) {
+            clearButton.setNumeralBase(numeralBase.getPreference(preferences));
+        }
+        if (equalsButton != null && showEqualsButton.isSameKey(key)) {
+            toggleEqualsButton();
+        }
+    }
+
+    @Override
+    public boolean processDragEvent(@Nonnull DragDirection direction, @Nonnull DragButton button, @Nonnull PointF point, @Nonnull MotionEvent event) {
+        switch (button.getId()) {
+            case R.id.cpp_button_right:
+                editor.setCursorOnEnd();
+                return true;
+            case R.id.cpp_button_left:
+                editor.setCursorOnStart();
+                return true;
+            case R.id.cpp_button_equals:
+                if (direction == down) {
+                    ActivityLauncher.tryPlot();
+                    return true;
+                } else if (direction == up) {
+                    calculator.simplify();
+                    return true;
+                }
+
+                return false;
+            case R.id.cpp_button_clear:
+                return processNumeralBaseButton(direction, (DirectionDragButton) button);
+        }
+        return false;
+    }
+
+    @Override
+    public void onClick(View v) {
+        switch (v.getId()) {
+            case R.id.cpp_button_left:
+            case R.id.cpp_button_right:
+                onClick(v, ((Button) v).getText().toString());
+                break;
+            case R.id.cpp_button_clear:
+                onClick(v, CppSpecialButton.clear);
+                break;
+            case R.id.cpp_button_erase:
+                onClick(v, CppSpecialButton.erase);
+                break;
+            case R.id.cpp_button_equals:
+                onClick(v, CppSpecialButton.equals);
+                break;
+        }
+    }
+
+    private boolean processNumeralBaseButton(@Nonnull DragDirection direction, @Nonnull DirectionDragButton button) {
+        final String text = button.getText(direction);
+        if (TextUtils.isEmpty(text)) {
+            return false;
+        }
+        try {
+            final NumeralBase newNumeralBase = NumeralBase.valueOf(text);
+            final NumeralBase oldNumeralBase = Engine.Preferences.numeralBase.getPreference(preferences);
+            if (oldNumeralBase != newNumeralBase) {
+                preferredPreferences.setNumeralBase(newNumeralBase);
+                return true;
+            }
+        } catch (IllegalArgumentException e) {
+            Log.d(this.getClass().getName(), "Unsupported numeral base: " + text);
+        }
+        return false;
+    }
+}

app/src/main/java/org/solovyev/android/calculator/matrix/CalculatorMatrixActivity.java

@@ -42,6 +42,6 @@ public class CalculatorMatrixActivity extends EmptyActivity {
         super.onCreate(savedInstanceState);
 
         getSupportActionBar().setNavigationMode(NAVIGATION_MODE_STANDARD);
-        getUi().setFragment(this, FragmentTab.matrix_edit, null, R.id.main_layout);
+        getUi().setFragment(this, FragmentTab.matrix_edit, null, R.id.main);
     }
 }

app/src/main/java/org/solovyev/android/calculator/preferences/PreferencesActivity.java

@@ -86,7 +86,7 @@ public class PreferencesActivity extends BaseActivity implements SharedPreferenc
         if (savedInstanceState == null) {
             final int preference = intent.getIntExtra(EXTRA_PREFERENCE, R.xml.preferences);
             getSupportFragmentManager().beginTransaction()
-                    .add(R.id.main_layout, PreferencesFragment.create(preference, R.layout.fragment_preferences))
+                    .add(R.id.main, PreferencesFragment.create(preference, R.layout.fragment_preferences))
                     .commit();
         }
 

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

@@ -23,24 +23,17 @@
 package org.solovyev.android.calculator.view;
 
 import android.content.Context;
-import android.content.res.Resources;
 import android.graphics.Paint;
+import android.support.v4.content.ContextCompat;
 import android.text.TextPaint;
 import android.util.AttributeSet;
-
+import jscl.AngleUnit;
 import org.solovyev.android.calculator.Locator;
 import org.solovyev.android.calculator.R;
 import org.solovyev.android.views.dragbutton.DirectionDragButton;
 
 import javax.annotation.Nonnull;
 
-import jscl.AngleUnit;
-
-/**
- * User: serso
- * Date: 11/22/11
- * Time: 2:42 PM
- */
 public class AngleUnitsButton extends DirectionDragButton {
 
     @Nonnull
@@ -66,14 +59,10 @@ public class AngleUnitsButton extends DirectionDragButton {
     }
 
     int getDirectionTextColor(@Nonnull String directionText) {
-        final int color;
-        final Resources resources = getResources();
         if (isCurrentAngleUnits(directionText)) {
-            color = resources.getColor(R.color.cpp_selected_angle_unit_text);
+            return ContextCompat.getColor(getContext(), R.color.cpp_selected_angle_unit_text);
-        } else {
-            color = resources.getColor(R.color.cpp_text);
         }
-        return color;
+        return ContextCompat.getColor(getContext(), R.color.cpp_text);
     }
 
     boolean isCurrentAngleUnits(@Nonnull String directionText) {

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

@@ -24,22 +24,16 @@ package org.solovyev.android.calculator.view;
 
 import android.content.Context;
 import android.graphics.Paint;
+import android.support.v4.content.ContextCompat;
 import android.text.TextPaint;
 import android.util.AttributeSet;
-
+import jscl.NumeralBase;
 import org.solovyev.android.calculator.Locator;
 import org.solovyev.android.calculator.R;
 import org.solovyev.android.views.dragbutton.DirectionDragButton;
 
 import javax.annotation.Nonnull;
 
-import jscl.NumeralBase;
-
-/**
- * User: serso
- * Date: 12/8/11
- * Time: 2:22 AM
- */
 public class NumeralBasesButton extends DirectionDragButton {
 
     @Nonnull
@@ -65,13 +59,10 @@ public class NumeralBasesButton extends DirectionDragButton {
     }
 
     int getDirectionTextColor(@Nonnull String directionText) {
-        final int color;
         if (isCurrentNumberBase(directionText)) {
-            color = getResources().getColor(R.color.cpp_selected_angle_unit_text);
+            return ContextCompat.getColor(getContext(), R.color.cpp_selected_angle_unit_text);
-        } else {
-            color = getResources().getColor(R.color.cpp_text);
         }
-        return color;
+        return ContextCompat.getColor(getContext(), R.color.cpp_text);
     }
 
     boolean isCurrentNumberBase(@Nonnull String directionText) {

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

@@ -1,95 +0,0 @@
-package org.solovyev.android.calculator.view;
-
-import android.app.Activity;
-import android.support.v4.app.Fragment;
-import android.util.SparseArray;
-import android.view.View;
-
-import javax.annotation.Nonnull;
-
-public abstract class ViewsCache {
-
-    @Nonnull
-    private final SparseArray<View> cache = new SparseArray<View>();
-
-    protected ViewsCache() {
-    }
-
-    @Nonnull
-    public static ViewsCache forActivity(@Nonnull Activity activity) {
-        return new ActivityViewsCache(activity);
-    }
-
-    @Nonnull
-    public static ViewsCache forFragment(@Nonnull Fragment fragment) {
-        return new FragmentViewsCache(fragment);
-    }
-
-    @Nonnull
-    public static ViewsCache forView(@Nonnull View view) {
-        return new ViewViewsCache(view);
-    }
-
-    public final View findViewById(int id) {
-        View view = cache.get(id);
-        if (view == null) {
-            view = lookupViewById(id);
-            if (view != null) {
-                cache.append(id, view);
-            }
-        }
-        return view;
-    }
-
-    public final void clear() {
-        cache.clear();
-    }
-
-    protected abstract View lookupViewById(int id);
-
-    private static final class FragmentViewsCache extends ViewsCache {
-
-        @Nonnull
-        private final Fragment fragment;
-
-        private FragmentViewsCache(@Nonnull Fragment fragment) {
-            this.fragment = fragment;
-        }
-
-        @Override
-        protected View lookupViewById(int id) {
-            final View view = fragment.getView();
-            return view != null ? view.findViewById(id) : null;
-        }
-    }
-
-    private static final class ViewViewsCache extends ViewsCache {
-
-        @Nonnull
-        private final View view;
-
-        private ViewViewsCache(@Nonnull View view) {
-            this.view = view;
-        }
-
-        @Override
-        protected View lookupViewById(int id) {
-            return view.findViewById(id);
-        }
-    }
-
-    private static final class ActivityViewsCache extends ViewsCache {
-
-        @Nonnull
-        private final Activity activity;
-
-        private ActivityViewsCache(@Nonnull Activity activity) {
-            this.activity = activity;
-        }
-
-        @Override
-        protected View lookupViewById(int id) {
-            return activity.findViewById(id);
-        }
-    }
-}

app/src/main/res/layout-land/main_calculator.xml

@@ -22,7 +22,7 @@
   ~ Site:  http://se.solovyev.org
   -->
 <LinearLayout xmlns:a="http://schemas.android.com/apk/res/android"
-    a:id="@+id/main_layout"
+    a:id="@+id/main"
     style="@style/CppMain"
     a:orientation="vertical">
 

app/src/main/res/layout-land/main_calculator_mobile.xml

@@ -22,7 +22,7 @@
   ~ Site:  http://se.solovyev.org
   -->
 <LinearLayout xmlns:a="http://schemas.android.com/apk/res/android"
-    a:id="@+id/main_layout"
+    a:id="@+id/main"
     style="@style/CppMain"
     a:orientation="vertical">
 

app/src/main/res/layout-land/main_first_pane.xml

@@ -28,13 +28,14 @@
     a:orientation="vertical">
 
     <LinearLayout
-        a:id="@+id/editorContainer"
+        a:id="@+id/editor"
         a:layout_width="match_parent"
         a:layout_height="0dp"
         a:layout_weight="2"
         a:orientation="horizontal" />
 
     <LinearLayout
+        a:id="@+id/partial_keyboard"
         a:layout_width="match_parent"
         a:layout_height="0dp"
         a:layout_weight="1"
@@ -54,7 +55,7 @@
             a:layout_weight="1" />
 
         <FrameLayout
-            a:id="@+id/displayContainer"
+            a:id="@+id/display"
             a:layout_width="0dp"
             a:layout_height="match_parent"
             a:layout_weight="4"
@@ -75,7 +76,7 @@
     </LinearLayout>
 
     <LinearLayout
-        a:id="@+id/keyboardContainer"
+        a:id="@+id/keyboard"
         a:layout_width="match_parent"
         a:layout_height="0dp"
         a:layout_weight="3"

app/src/main/res/layout-land/main_first_pane_mobile.xml

@@ -28,13 +28,14 @@
     a:orientation="vertical">
 
     <LinearLayout
-        a:id="@+id/editorContainer"
+        a:id="@+id/editor"
         a:layout_width="match_parent"
         a:layout_height="0dp"
         a:layout_weight="2"
         a:orientation="horizontal" />
 
     <LinearLayout
+        a:id="@+id/partial_keyboard"
         a:layout_width="match_parent"
         a:layout_height="0dp"
         a:layout_weight="1"
@@ -53,7 +54,7 @@
             a:layout_weight="1" />
 
         <FrameLayout
-            a:id="@+id/displayContainer"
+            a:id="@+id/display"
             a:layout_width="0dp"
             a:layout_height="match_parent"
             a:layout_weight="4" />
@@ -73,7 +74,7 @@
     </LinearLayout>
 
     <LinearLayout
-        a:id="@+id/keyboardContainer"
+        a:id="@+id/keyboard"
         a:layout_width="match_parent"
         a:layout_height="0dp"
         a:layout_weight="3"

app/src/main/res/layout-large-land/main_calculator.xml

@@ -23,7 +23,7 @@
   -->
 <LinearLayout
     xmlns:a="http://schemas.android.com/apk/res/android"
-    a:id="@+id/main_layout"
+    a:id="@+id/main"
     style="@style/CppMain.Multipane"
     a:orientation="vertical">
 
@@ -43,14 +43,14 @@
             a:orientation="vertical">
 
             <LinearLayout
-                a:id="@+id/editorContainer"
+                a:id="@+id/editor"
                 style="@style/CppPane.Multipane.Left"
                 a:layout_width="match_parent"
                 a:layout_height="0dp"
                 a:layout_weight="1" />
 
             <FrameLayout
-                a:id="@+id/displayContainer"
+                a:id="@+id/display"
                 style="@style/CppPane.Multipane.Left"
                 a:layout_width="match_parent"
                 a:layout_height="0dp"
@@ -69,7 +69,7 @@
     </LinearLayout>
 
     <LinearLayout
-        a:id="@+id/keyboardContainer"
+        a:id="@+id/keyboard"
         style="@style/CppPane.Transparent.Bottom"
         a:layout_width="match_parent"
         a:layout_height="0dp"

app/src/main/res/layout-large/main_calculator.xml

@@ -23,7 +23,7 @@
   -->
 <LinearLayout
     xmlns:a="http://schemas.android.com/apk/res/android"
-    a:id="@+id/main_layout"
+    a:id="@+id/main"
     style="@style/CppMain.Multipane"
     a:orientation="vertical">
 
@@ -43,14 +43,14 @@
             a:orientation="vertical">
 
             <LinearLayout
-                a:id="@+id/editorContainer"
+                a:id="@+id/editor"
                 style="@style/CppPane.Multipane.Left"
                 a:layout_width="match_parent"
                 a:layout_height="0dp"
                 a:layout_weight="3" />
 
             <FrameLayout
-                a:id="@+id/displayContainer"
+                a:id="@+id/display"
                 style="@style/CppPane.Multipane.Left"
                 a:layout_width="match_parent"
                 a:layout_height="0dp"
@@ -69,7 +69,7 @@
     </LinearLayout>
 
     <LinearLayout
-        a:id="@+id/keyboardContainer"
+        a:id="@+id/keyboard"
         style="@style/CppPane.Transparent.Bottom"
         a:layout_width="match_parent"
         a:layout_height="0dp"

app/src/main/res/layout-xlarge-land/main_calculator.xml

@@ -23,7 +23,7 @@
   -->
 <LinearLayout
     xmlns:a="http://schemas.android.com/apk/res/android"
-    a:id="@+id/main_layout"
+    a:id="@+id/main"
     style="@style/CppMain.Multipane"
     a:orientation="vertical">
 
@@ -43,7 +43,7 @@
             a:orientation="vertical">
 
             <LinearLayout
-                a:id="@+id/editorContainer"
+                a:id="@+id/editor"
                 style="@style/CppPane.Multipane.Left"
                 a:layout_width="match_parent"
                 a:layout_height="0dp"
@@ -51,7 +51,7 @@
                 a:orientation="horizontal" />
 
             <FrameLayout
-                a:id="@+id/displayContainer"
+                a:id="@+id/display"
                 style="@style/CppPane.Multipane.Left"
                 a:layout_width="match_parent"
                 a:layout_height="0dp"
@@ -70,7 +70,7 @@
     </LinearLayout>
 
     <LinearLayout
-        a:id="@+id/keyboardContainer"
+        a:id="@+id/keyboard"
         style="@style/CppPane.Transparent.Bottom"
         a:layout_width="match_parent"
         a:layout_height="0dp"

app/src/main/res/layout-xlarge/main_calculator.xml

@@ -23,7 +23,7 @@
   -->
 <LinearLayout
     xmlns:a="http://schemas.android.com/apk/res/android"
-    a:id="@+id/main_layout"
+    a:id="@+id/main"
     style="@style/CppMain.Multipane"
     a:orientation="vertical">
 
@@ -43,14 +43,14 @@
             a:orientation="vertical">
 
             <LinearLayout
-                a:id="@+id/editorContainer"
+                a:id="@+id/editor"
                 style="@style/CppPane.Multipane.Left"
                 a:layout_width="match_parent"
                 a:layout_height="0dp"
                 a:layout_weight="4" />
 
             <FrameLayout
-                a:id="@+id/displayContainer"
+                a:id="@+id/display"
                 style="@style/CppPane.Multipane.Left"
                 a:layout_width="match_parent"
                 a:layout_height="0dp"
@@ -69,7 +69,7 @@
     </LinearLayout>
 
     <LinearLayout
-        a:id="@+id/keyboardContainer"
+        a:id="@+id/keyboard"
         style="@style/CppPane.Transparent.Bottom"
         a:layout_width="match_parent"
         a:layout_height="0dp"

app/src/main/res/layout/main_calculator.xml

@@ -24,20 +24,21 @@
 
 <LinearLayout
     xmlns:a="http://schemas.android.com/apk/res/android"
-    a:id="@+id/main_layout"
+    a:id="@+id/main"
     style="@style/CppMain"
     a:layout_width="match_parent"
     a:layout_height="match_parent"
     a:orientation="vertical">
 
     <LinearLayout
-        a:id="@+id/editorContainer"
+        a:id="@+id/editor"
         a:layout_width="match_parent"
         a:layout_height="0dp"
         a:layout_weight="2"
         a:orientation="horizontal" />
 
     <LinearLayout
+        a:id="@+id/partial_keyboard"
         a:layout_width="match_parent"
         a:layout_height="0dp"
         a:layout_weight="1"
@@ -50,7 +51,7 @@
             a:layout_weight="1" />
 
         <FrameLayout
-            a:id="@+id/displayContainer"
+            a:id="@+id/display"
             a:layout_width="0dp"
             a:layout_height="match_parent"
             a:layout_weight="4" />
@@ -58,7 +59,7 @@
     </LinearLayout>
 
     <LinearLayout
-        a:id="@+id/keyboardContainer"
+        a:id="@+id/keyboard"
         a:layout_width="match_parent"
         a:layout_height="0dp"
         a:layout_weight="5"

app/src/main/res/layout/main_calculator_mobile.xml

@@ -24,20 +24,21 @@
 
 <LinearLayout
     xmlns:a="http://schemas.android.com/apk/res/android"
-    a:id="@+id/main_layout"
+    a:id="@+id/main"
     style="@style/CppMain"
     a:layout_width="match_parent"
     a:layout_height="match_parent"
     a:orientation="vertical">
 
     <LinearLayout
-        a:id="@+id/editorContainer"
+        a:id="@+id/editor"
         a:layout_width="match_parent"
         a:layout_height="0dp"
         a:layout_weight="2"
         a:orientation="horizontal" />
 
     <LinearLayout
+        a:id="@+id/partial_keyboard"
         a:layout_width="match_parent"
         a:layout_height="0dp"
         a:layout_weight="1"
@@ -50,7 +51,7 @@
             a:layout_weight="1" />
 
         <FrameLayout
-            a:id="@+id/displayContainer"
+            a:id="@+id/display"
             a:layout_width="0dp"
             a:layout_height="match_parent"
             a:layout_weight="4"
@@ -59,7 +60,7 @@
     </LinearLayout>
 
     <LinearLayout
-        a:id="@+id/keyboardContainer"
+        a:id="@+id/keyboard"
         a:layout_width="match_parent"
         a:layout_height="0dp"
         a:layout_weight="5"

app/src/main/res/layout/main_empty.xml

@@ -24,7 +24,7 @@
 
 <LinearLayout
     xmlns:a="http://schemas.android.com/apk/res/android"
-    a:id="@+id/main_layout"
+    a:id="@+id/main"
     style="@style/CppMain"
     a:orientation="vertical">