Choose theme wizard step

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

@@ -86,6 +86,7 @@ public class ActivityUi extends BaseUi {
 		final View root = activity.findViewById(R.id.main_layout);
 		if (root != null) {
 			processButtons(activity, root);
+			fixFonts(root);
 			addHelpInfo(activity, root);
 		}
 	}

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

@@ -47,8 +47,6 @@ import org.solovyev.common.math.Point2d;
 
 import javax.annotation.Nonnull;
 import javax.annotation.Nullable;
-import java.lang.reflect.Field;
-import java.lang.reflect.Modifier;
 import java.util.ArrayList;
 import java.util.List;
 
@@ -68,26 +66,26 @@ public abstract class BaseUi implements SharedPreferences.OnSharedPreferenceChan
 	private static final List<Integer> viewIds = new ArrayList<Integer>(200);
 
 	@Nonnull
-	private Preferences.Gui.Layout layout;
+	protected Preferences.Gui.Layout layout;
 
 	@Nonnull
-	private Preferences.Gui.Theme theme;
+	protected Preferences.Gui.Theme theme;
-
-	@Nullable
-	private Vibrator vibrator;
-
-	@Nonnull
-	private final JListeners<DragPreferencesChangeListener> dpclRegister = Listeners.newHardRefListeners();
 
 	@Nonnull
 	private String logTag = "CalculatorActivity";
 
+	@Nullable
+	private Vibrator vibrator;
+
 	@Nullable
 	private AngleUnitsButton angleUnitsButton;
 
 	@Nullable
 	private NumeralBasesButton clearButton;
 
+	@Nonnull
+	private final JListeners<DragPreferencesChangeListener> dpclRegister = Listeners.newHardRefListeners();
+
 	protected BaseUi() {
 	}
 
@@ -119,6 +117,28 @@ public abstract class BaseUi implements SharedPreferences.OnSharedPreferenceChan
 		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 = CalculatorApplication.getInstance().getTypeFace();
+		Views.processViewsOfType(root, TextView.class, new Views.ViewProcessor<TextView>() {
+			@Override
+			public void process(@Nonnull TextView view) {
+				int style = Typeface.NORMAL;
+				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) {
 		dpclRegister.removeListeners();
 
@@ -211,24 +231,32 @@ public abstract class BaseUi implements SharedPreferences.OnSharedPreferenceChan
 			toggleButtonDirectionText(views, R.id.cpp_button_plus, false, DragDirection.down, DragDirection.up);
 		}
 
-		CalculatorButtons.processButtons(theme, layout, root);
+		CalculatorButtons.fixButtonsTextSize(theme, layout, root);
 		CalculatorButtons.toggleEqualsButton(preferences, activity);
 		CalculatorButtons.initMultiplicationButton(root);
 		NumeralBaseButtons.toggleNumericDigits(activity, preferences);
 
-		// some devices ship own fonts which causes issues with rendering. Let's use our own font for all text views
+		new ButtonOnClickListener().attachToViews(views);
-		final Typeface typeFace = CalculatorApplication.getInstance().getTypeFace();
-		Views.processViewsOfType(root, TextView.class, new Views.ViewProcessor<TextView>() {
-			@Override
-			public void process(@Nonnull TextView view) {
-				int style = Typeface.NORMAL;
-				final Typeface oldTypeface = view.getTypeface();
-				if (oldTypeface != null) {
-					style = oldTypeface.getStyle();
 	}
-				view.setTypeface(typeFace, style);
+
+	private void setOnDragListeners(@Nonnull ViewsCache views, @Nonnull SimpleDragListener.Preferences dragPreferences, @Nonnull SharedPreferences preferences) {
+		final DragListener dragListener = new DragListenerVibrator(newOnDragListener(new DigitButtonDragProcessor(getKeyboard()), dragPreferences), vibrator, preferences);
+
+		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 newOnDragListener(@Nonnull SimpleDragListener.DragProcessor dragProcessor,
+												 @Nonnull SimpleDragListener.Preferences dragPreferences) {
+		final SimpleDragListener onDragListener = new SimpleDragListener(dragProcessor, dragPreferences);
+		dpclRegister.addListener(onDragListener);
+		return onDragListener;
 	}
 
 	private void toggleButtonDirectionText(@Nonnull ViewsCache views, int id, boolean showDirectionText, @Nonnull DragDirection... dragDirections) {
@@ -246,32 +274,34 @@ public abstract class BaseUi implements SharedPreferences.OnSharedPreferenceChan
 		return Locator.getInstance().getCalculator();
 	}
 
-
-	private void setOnDragListeners(@Nonnull ViewsCache views, @Nonnull SimpleDragListener.Preferences dragPreferences, @Nonnull SharedPreferences preferences) {
-		final DragListener dragListener = new DragListenerVibrator(newOnDragListener(new DigitButtonDragProcessor(getKeyboard()), dragPreferences), vibrator, preferences);
-
-		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 static List<Integer> getViewIds() {
 		if (viewIds.isEmpty()) {
-			for (Field field : R.id.class.getDeclaredFields()) {
+			viewIds.add(R.id.wizard_dragbutton);
-				int modifiers = field.getModifiers();
+			viewIds.add(R.id.cpp_button_vars);
-				if (Modifier.isFinal(modifiers) && Modifier.isStatic(modifiers)) {
+			viewIds.add(R.id.cpp_button_round_brackets);
-					try {
+			viewIds.add(R.id.cpp_button_right);
-						viewIds.add(field.getInt(R.id.class));
+			viewIds.add(R.id.cpp_button_plus);
-					} catch (IllegalAccessException e) {
+			viewIds.add(R.id.cpp_button_operators);
-						Log.e(R.id.class.getName(), e.getMessage());
+			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;
 	}
@@ -286,23 +316,8 @@ public abstract class BaseUi implements SharedPreferences.OnSharedPreferenceChan
 		return (T) views.findViewById(buttonId);
 	}
 
-	@Nonnull
-	private SimpleDragListener newOnDragListener(@Nonnull SimpleDragListener.DragProcessor dragProcessor,
-												   @Nonnull SimpleDragListener.Preferences dragPreferences) {
-		final SimpleDragListener onDragListener = new SimpleDragListener(dragProcessor, dragPreferences);
-		dpclRegister.addListener(onDragListener);
-		return onDragListener;
-	}
-
 	@Override
 	public void onSharedPreferenceChanged(SharedPreferences preferences, String key) {
-		if (key.startsWith("org.solovyev.android.calculator.DragButtonCalibrationActivity")) {
-			final SimpleDragListener.Preferences dragPreferences = SimpleDragListener.getPreferences(preferences, CalculatorApplication.getInstance());
-			for (DragPreferencesChangeListener dragPreferencesChangeListener : dpclRegister.getListeners()) {
-				dragPreferencesChangeListener.onDragPreferencesChange(dragPreferences);
-			}
-		}
-
 		if (angleUnit.isSameKey(key) || numeralBase.isSameKey(key)) {
 			if (angleUnitsButton != null) {
 				angleUnitsButton.setAngleUnit(angleUnit.getPreference(preferences));
@@ -313,10 +328,4 @@ public abstract class BaseUi implements SharedPreferences.OnSharedPreferenceChan
 			}
 		}
 	}
-
-	public void onDestroy(@Nonnull Activity activity) {
-		final SharedPreferences preferences = PreferenceManager.getDefaultSharedPreferences(activity);
-
-		preferences.unregisterOnSharedPreferenceChangeListener(this);
-	}
 }

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

@@ -0,0 +1,113 @@
+package org.solovyev.android.calculator;
+
+import android.support.annotation.IdRes;
+import android.view.View;
+import android.widget.Button;
+import org.solovyev.android.calculator.view.ViewsCache;
+
+import javax.annotation.Nonnull;
+
+final class ButtonOnClickListener implements View.OnClickListener {
+
+	@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(((Button) v).getText().toString());
+				break;
+			case R.id.cpp_button_clear:
+				onClick(CalculatorSpecialButton.clear);
+				break;
+			case R.id.cpp_button_functions:
+				onClick(CalculatorSpecialButton.functions);
+				break;
+			case R.id.cpp_button_history:
+				onClick(CalculatorSpecialButton.history);
+				break;
+			case R.id.cpp_button_erase:
+				onClick(CalculatorSpecialButton.erase);
+				break;
+			case R.id.cpp_button_paste:
+				onClick(CalculatorSpecialButton.paste);
+				break;
+			case R.id.cpp_button_copy:
+				onClick(CalculatorSpecialButton.copy);
+				break;
+			case R.id.cpp_button_like:
+				onClick(CalculatorSpecialButton.like);
+				break;
+			case R.id.cpp_button_operators:
+				onClick(CalculatorSpecialButton.operators);
+				break;
+			case R.id.cpp_button_vars:
+				onClick(CalculatorSpecialButton.vars);
+				break;
+			case R.id.cpp_button_equals:
+				onClick(CalculatorSpecialButton.equals);
+				break;
+		}
+	}
+
+	private void onClick(@Nonnull CalculatorSpecialButton b) {
+		onClick(b.getActionCode());
+	}
+
+	private void onClick(@Nonnull String s) {
+		Locator.getInstance().getKeyboard().buttonPressed(s);
+	}
+
+	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);
+		}
+	}
+}

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

@@ -32,9 +32,7 @@ import android.os.Bundle;
 import android.preference.PreferenceManager;
 import android.support.v7.app.ActionBar;
 import android.text.method.LinkMovementMethod;
-import android.util.Log;
 import android.view.*;
-import android.widget.Button;
 import android.widget.TextView;
 import org.solovyev.android.Activities;
 import org.solovyev.android.Android;
@@ -55,10 +53,8 @@ import static android.os.Build.VERSION_CODES.GINGERBREAD_MR1;
 import static android.os.Build.VERSION_CODES.ICE_CREAM_SANDWICH;
 import static android.view.WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON;
 import static org.solovyev.android.calculator.Preferences.Gui.preventScreenFromFading;
-import static org.solovyev.android.calculator.about.CalculatorReleaseNotesFragment.hasReleaseNotes;
+import static org.solovyev.android.calculator.release.ReleaseNotes.hasReleaseNotes;
-import static org.solovyev.android.wizard.WizardUi.continueWizard;
+import static org.solovyev.android.wizard.WizardUi.*;
-import static org.solovyev.android.wizard.WizardUi.createLaunchIntent;
-import static org.solovyev.android.wizard.WizardUi.startWizard;
 
 public class CalculatorActivity extends BaseActivity implements SharedPreferences.OnSharedPreferenceChangeListener, CalculatorEventListener {
 
@@ -215,11 +211,6 @@ public class CalculatorActivity extends BaseActivity implements SharedPreference
 		return super.onKeyDown(keyCode, event);
 	}
 
-	@SuppressWarnings({"UnusedDeclaration"})
-	public void equalsButtonClickHandler(@Nonnull View v) {
-		buttonPressed(CalculatorSpecialButton.equals);
-	}
-
 	@Override
 	protected void onResume() {
 		super.onResume();
@@ -265,80 +256,6 @@ public class CalculatorActivity extends BaseActivity implements SharedPreference
 		}
 	}
 
-	/*
-	**********************************************************************
-	*
-	*                           BUTTON HANDLERS
-	*
-	**********************************************************************
-	*/
-
-	@SuppressWarnings({"UnusedDeclaration"})
-	public void elementaryButtonClickHandler(@Nonnull View v) {
-		throw new UnsupportedOperationException("Not implemented yet!");
-	}
-
-	public void historyButtonClickHandler(@Nonnull View v) {
-		buttonPressed(CalculatorSpecialButton.history);
-	}
-
-	public void eraseButtonClickHandler(@Nonnull View v) {
-		buttonPressed(CalculatorSpecialButton.erase);
-	}
-
-	public void simplifyButtonClickHandler(@Nonnull View v) {
-		throw new UnsupportedOperationException("Not implemented yet!");
-	}
-
-	public void pasteButtonClickHandler(@Nonnull View v) {
-		buttonPressed(CalculatorSpecialButton.paste);
-	}
-
-	public void copyButtonClickHandler(@Nonnull View v) {
-		buttonPressed(CalculatorSpecialButton.copy);
-	}
-
-	@Nonnull
-	private static CalculatorKeyboard getKeyboard() {
-		return Locator.getInstance().getKeyboard();
-	}
-
-	public void clearButtonClickHandler(@Nonnull View v) {
-		buttonPressed(CalculatorSpecialButton.clear);
-	}
-
-	public void digitButtonClickHandler(@Nonnull View v) {
-		Log.d(String.valueOf(v.getId()), "digitButtonClickHandler() for: " + v.getId() + ". Pressed: " + v.isPressed());
-
-		if (v instanceof Button) {
-			buttonPressed(((Button) v).getText().toString());
-		}
-	}
-
-	private void buttonPressed(@Nonnull CalculatorSpecialButton button) {
-		buttonPressed(button.getActionCode());
-	}
-
-	private void buttonPressed(@Nonnull String text) {
-		getKeyboard().buttonPressed(text);
-	}
-
-	public void functionsButtonClickHandler(@Nonnull View v) {
-		buttonPressed(CalculatorSpecialButton.functions);
-	}
-
-	public void operatorsButtonClickHandler(@Nonnull View v) {
-		buttonPressed(CalculatorSpecialButton.operators);
-	}
-
-	public void varsButtonClickHandler(@Nonnull View v) {
-		buttonPressed(CalculatorSpecialButton.vars);
-	}
-
-	public void likeButtonClickHandler(@Nonnull View v) {
-		buttonPressed(CalculatorSpecialButton.like);
-	}
-
 	@Override
 	public void onCalculatorEvent(@Nonnull CalculatorEventData calculatorEventData, @Nonnull CalculatorEventType calculatorEventType, @Nullable Object data) {
 		switch (calculatorEventType) {

android-app/src/main/java/org/solovyev/android/calculator/CalculatorButtons.java

@@ -59,7 +59,7 @@ public final class CalculatorButtons {
 	}
 
 
-	public static void processButtons(@Nonnull Preferences.Gui.Theme theme,
+	public static void fixButtonsTextSize(@Nonnull Preferences.Gui.Theme theme,
 										  @Nonnull Preferences.Gui.Layout layout,
 										  @Nonnull View root) {
 		if (!layout.isOptimized()) {

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

@@ -158,7 +158,10 @@ public class FragmentUi extends BaseUi {
 			}
 		}
 
+		if (fragment instanceof CalculatorKeyboardFragment) {
 			processButtons(fragment.getActivity(), root);
+		}
+		fixFonts(root);
 
 		if (titleResId >= 0) {
 			this.setPaneTitle(fragment, titleResId);

android-app/src/main/java/org/solovyev/android/calculator/Preferences.java

@@ -101,31 +101,30 @@ public final class Preferences {
 
 		public static enum Theme {
 
-			default_theme(R.style.cpp_gray_theme),
+			default_theme(R.style.cpp_gray_theme, R.style.Theme_Wizard),
-			violet_theme(R.style.cpp_violet_theme),
+			violet_theme(R.style.cpp_violet_theme, R.style.Theme_Wizard),
-			light_blue_theme(R.style.cpp_light_blue_theme),
+			light_blue_theme(R.style.cpp_light_blue_theme, R.style.Theme_Wizard),
-			metro_blue_theme(R.style.cpp_metro_blue_theme),
+			metro_blue_theme(R.style.cpp_metro_blue_theme, R.style.Theme_Wizard),
-			metro_purple_theme(R.style.cpp_metro_purple_theme),
+			metro_purple_theme(R.style.cpp_metro_purple_theme, R.style.Theme_Wizard),
-			metro_green_theme(R.style.cpp_metro_green_theme),
+			metro_green_theme(R.style.cpp_metro_green_theme, R.style.Theme_Wizard),
-			material_theme(R.style.cpp_material_theme),
+			material_theme(R.style.cpp_material_theme, R.style.Theme_Wizard),
 			;
 
-			@Nonnull
+			private final int themeId;
-			private final Integer themeId;
+			private final int wizardThemeId;
 
-			Theme(@Nonnull Integer themeId) {
+			Theme(int themeId, int wizardThemeId) {
 				this.themeId = themeId;
+				this.wizardThemeId = wizardThemeId;
 			}
 
-			@Nonnull
+			public int getThemeId() {
-			public Integer getThemeId() {
 				return getThemeId(null);
 			}
 
-			@Nonnull
+			public int getThemeId(@Nullable Activity activity) {
-			public Integer getThemeId(@Nullable Activity activity) {
 				if (activity instanceof WizardActivity) {
-					return R.style.Theme_Wizard;
+					return wizardThemeId;
 				}
 				return themeId;
 			}

android-app/src/main/java/org/solovyev/android/calculator/about/CalculatorReleaseNotesFragment.java

@@ -22,23 +22,15 @@
 
 package org.solovyev.android.calculator.about;
 
-import android.content.Context;
 import android.os.Bundle;
 import android.text.Html;
 import android.text.method.LinkMovementMethod;
 import android.view.View;
 import android.widget.TextView;
-import org.solovyev.android.calculator.CalculatorApplication;
 import org.solovyev.android.calculator.CalculatorFragment;
 import org.solovyev.android.calculator.CalculatorFragmentType;
 import org.solovyev.android.calculator.R;
-import org.solovyev.common.text.Strings;
+import org.solovyev.android.calculator.release.ReleaseNotes;
-
-import javax.annotation.Nonnull;
-import java.util.ArrayList;
-import java.util.List;
-
-import static org.solovyev.android.Android.getAppVersionCode;
 
 /**
  * User: serso
@@ -58,88 +50,6 @@ public class CalculatorReleaseNotesFragment extends CalculatorFragment {
 		final TextView releaseNotes = (TextView) root.findViewById(R.id.releaseNotesTextView);
 		releaseNotes.setMovementMethod(LinkMovementMethod.getInstance());
 
-		releaseNotes.setText(Html.fromHtml(getReleaseNotes(this.getActivity())));
+		releaseNotes.setText(Html.fromHtml(ReleaseNotes.getReleaseNotes(this.getActivity())));
-	}
-
-	@Nonnull
-	public static String getReleaseNotes(@Nonnull Context context) {
-		return getReleaseNotesString(context, 0);
-	}
-
-	@Nonnull
-	public static String getReleaseNotesString(@Nonnull Context context, int minVersion) {
-		final StringBuilder result = new StringBuilder();
-
-		final String releaseNotesForTitle = context.getString(R.string.c_release_notes_for_title);
-		final int currentVersionCode = getAppVersionCode(context);
-
-		final TextHelper textHelper = new TextHelper(context.getResources(), CalculatorApplication.class.getPackage().getName());
-
-		boolean first = true;
-		for (int versionCode = currentVersionCode; versionCode >= minVersion; versionCode--) {
-			final String versionName = getVersionName(textHelper, versionCode);
-			String releaseNotesForVersion = textHelper.getText(makeReleaseNotesResourceId(versionCode));
-			if (!Strings.isEmpty(releaseNotesForVersion)) {
-				if (!first) {
-					result.append("<br/><br/>");
-				} else {
-					first = false;
-				}
-				releaseNotesForVersion = releaseNotesForVersion.replace("\n", "<br/>");
-				result.append("<b>").append(releaseNotesForTitle).append(versionName).append("</b><br/><br/>");
-				result.append(releaseNotesForVersion);
-			}
-		}
-
-		return result.toString();
-	}
-
-	@Nonnull
-	public static List<Integer> getReleaseNotesVersions(@Nonnull Context context, int minVersion) {
-		final List<Integer> releaseNotes = new ArrayList<>();
-
-		final int currentVersionCode = getAppVersionCode(context);
-		final TextHelper textHelper = new TextHelper(context.getResources(), CalculatorApplication.class.getPackage().getName());
-
-		for (int versionCode = currentVersionCode; versionCode >= minVersion; versionCode--) {
-			final String releaseNotesForVersion = textHelper.getText(makeReleaseNotesResourceId(versionCode));
-			if (!Strings.isEmpty(releaseNotesForVersion)) {
-				releaseNotes.add(versionCode);
-			}
-		}
-
-		return releaseNotes;
-	}
-
-	public static boolean hasReleaseNotes(@Nonnull Context context, int minVersion) {
-		final int currentVersionCode = getAppVersionCode(context);
-		final TextHelper textHelper = new TextHelper(context.getResources(), CalculatorApplication.class.getPackage().getName());
-
-		for (int versionCode = currentVersionCode; versionCode >= minVersion; versionCode--) {
-			String releaseNotesForVersion = textHelper.getText(makeReleaseNotesResourceId(versionCode));
-			if (!Strings.isEmpty(releaseNotesForVersion)) {
-				return true;
-			}
-		}
-
-		return false;
-	}
-
-	@Nonnull
-	public static String getVersionName(@Nonnull TextHelper textHelper, int versionCode) {
-		final String versionName = textHelper.getText(makeVersionResourceId(versionCode));
-		if (versionName != null) {
-			return versionName;
-		} else {
-			return String.valueOf(versionCode);
-		}
-	}
-
-	public static String makeReleaseNotesResourceId(int versionCode) {
-		return "c_release_notes_for_" + versionCode;
-	}
-
-	private static String makeVersionResourceId(int versionCode) {
-		return "c_release_notes_for_" + versionCode + "_version";
 	}
 }

android-app/src/main/java/org/solovyev/android/calculator/release/ReleaseNoteFragment.java

@@ -9,7 +9,6 @@ import android.widget.TextView;
 import com.google.common.base.Strings;
 import org.solovyev.android.calculator.CalculatorApplication;
 import org.solovyev.android.calculator.R;
-import org.solovyev.android.calculator.about.CalculatorReleaseNotesFragment;
 import org.solovyev.android.calculator.about.TextHelper;
 import org.solovyev.android.calculator.wizard.WizardFragment;
 
@@ -45,12 +44,12 @@ public class ReleaseNoteFragment extends WizardFragment {
 
 	@Nonnull
 	private String getReleaseNoteVersion(@Nonnull TextHelper textHelper) {
-		return CalculatorReleaseNotesFragment.getVersionName(textHelper, version);
+		return ReleaseNotes.getVersionName(textHelper, version);
 	}
 
 	@Nonnull
 	private String getReleaseNote(@Nonnull TextHelper textHelper) {
-		final String resourceId = CalculatorReleaseNotesFragment.makeReleaseNotesResourceId(version);
+		final String resourceId = ReleaseNotes.makeReleaseNotesResourceId(version);
 		return Strings.nullToEmpty(textHelper.getText(resourceId)).replace("\n", "<br/>");
 	}
 }

android-app/src/main/java/org/solovyev/android/calculator/release/ReleaseNotes.java

@@ -0,0 +1,103 @@
+package org.solovyev.android.calculator.release;
+
+import android.content.Context;
+import org.solovyev.android.calculator.CalculatorApplication;
+import org.solovyev.android.calculator.R;
+import org.solovyev.android.calculator.about.TextHelper;
+import org.solovyev.common.text.Strings;
+
+import javax.annotation.Nonnull;
+import java.util.ArrayList;
+import java.util.List;
+
+import static org.solovyev.android.Android.getAppVersionCode;
+
+public final class ReleaseNotes {
+	@Nonnull
+	public static String getReleaseNotes(@Nonnull Context context) {
+		return getReleaseNotesString(context, 0);
+	}
+
+	@Nonnull
+	public static String getReleaseNotesString(@Nonnull Context context, int minVersion) {
+		final StringBuilder result = new StringBuilder();
+
+		final String releaseNotesForTitle = context.getString(R.string.c_release_notes_for_title);
+		final int currentVersionCode = getAppVersionCode(context);
+
+		final TextHelper textHelper = new TextHelper(context.getResources(), CalculatorApplication.class.getPackage().getName());
+
+		boolean first = true;
+		for (int versionCode = currentVersionCode; versionCode >= minVersion; versionCode--) {
+			final String versionName = getVersionName(textHelper, versionCode);
+			String releaseNotesForVersion = textHelper.getText(makeReleaseNotesResourceId(versionCode));
+			if (!Strings.isEmpty(releaseNotesForVersion)) {
+				if (!first) {
+					result.append("<br/><br/>");
+				} else {
+					first = false;
+				}
+				releaseNotesForVersion = releaseNotesForVersion.replace("\n", "<br/>");
+				result.append("<b>").append(releaseNotesForTitle).append(versionName).append("</b><br/><br/>");
+				result.append(releaseNotesForVersion);
+			}
+		}
+
+		return result.toString();
+	}
+
+	@Nonnull
+	public static List<Integer> getReleaseNotesVersions(@Nonnull Context context, int minVersion) {
+		final List<Integer> releaseNotes = new ArrayList<>();
+
+		final int currentVersionCode = getAppVersionCode(context);
+		final TextHelper textHelper = new TextHelper(context.getResources(), CalculatorApplication.class.getPackage().getName());
+
+		for (int versionCode = currentVersionCode; versionCode >= minVersion; versionCode--) {
+			if (versionCode == 136) {
+				releaseNotes.add(136);
+			}
+			final String releaseNotesForVersion = textHelper.getText(makeReleaseNotesResourceId(versionCode));
+			if (!Strings.isEmpty(releaseNotesForVersion)) {
+				releaseNotes.add(versionCode);
+			}
+		}
+
+		return releaseNotes;
+	}
+
+	public static boolean hasReleaseNotes(@Nonnull Context context, int minVersion) {
+		final int currentVersionCode = getAppVersionCode(context);
+		final TextHelper textHelper = new TextHelper(context.getResources(), CalculatorApplication.class.getPackage().getName());
+
+		for (int versionCode = currentVersionCode; versionCode >= minVersion; versionCode--) {
+			if (versionCode == 136) {
+				return true;
+			}
+			String releaseNotesForVersion = textHelper.getText(makeReleaseNotesResourceId(versionCode));
+			if (!Strings.isEmpty(releaseNotesForVersion)) {
+				return true;
+			}
+		}
+
+		return false;
+	}
+
+	@Nonnull
+	public static String getVersionName(@Nonnull TextHelper textHelper, int versionCode) {
+		final String versionName = textHelper.getText(makeVersionResourceId(versionCode));
+		if (versionName != null) {
+			return versionName;
+		} else {
+			return String.valueOf(versionCode);
+		}
+	}
+
+	public static String makeReleaseNotesResourceId(int versionCode) {
+		return "c_release_notes_for_" + versionCode;
+	}
+
+	private static String makeVersionResourceId(int versionCode) {
+		return "c_release_notes_for_" + versionCode + "_version";
+	}
+}

android-app/src/main/java/org/solovyev/android/calculator/wizard/CalculatorWizardStep.java

@@ -41,6 +41,7 @@ enum CalculatorWizardStep implements org.solovyev.android.wizard.WizardStep {
 		}
 	},
 	choose_mode(ChooseModeWizardStep.class, R.string.cpp_wizard_mode_title),
+	choose_theme(ChooseThemeWizardStep.class, R.string.cpp_wizard_theme_title),
 	on_screen_calculator(OnScreenCalculatorWizardStep.class, R.string.cpp_wizard_onscreen_calculator_title),
 	drag_button(DragButtonWizardStep.class, R.string.cpp_wizard_dragbutton_title),
 	last(FinalWizardStep.class, R.string.cpp_wizard_final_title);

android-app/src/main/java/org/solovyev/android/calculator/wizard/CalculatorWizards.java

@@ -3,8 +3,8 @@ package org.solovyev.android.calculator.wizard;
 import android.app.Activity;
 import android.content.Context;
 import android.os.Bundle;
-import org.solovyev.android.calculator.about.CalculatorReleaseNotesFragment;
 import org.solovyev.android.calculator.release.ReleaseNoteStep;
+import org.solovyev.android.calculator.release.ReleaseNotes;
 import org.solovyev.android.wizard.*;
 
 import javax.annotation.Nonnull;
@@ -79,13 +79,21 @@ public class CalculatorWizards implements Wizards {
 	static WizardFlow newReleaseNotesWizardFlow(@Nonnull Context context, @Nullable Bundle arguments) {
 		final List<WizardStep> wizardSteps = new ArrayList<WizardStep>();
 		final int startVersion = arguments != null ? arguments.getInt(RELEASE_NOTES_VERSION, 0) : 0;
-		List<Integer> versions = CalculatorReleaseNotesFragment.getReleaseNotesVersions(context, startVersion);
+		List<Integer> versions = ReleaseNotes.getReleaseNotesVersions(context, startVersion);
 		final int size = versions.size();
 		if (size > 7) {
 			versions = versions.subList(0, 7);
 		}
+
 		for (Integer version : versions) {
+			switch (version) {
+				case 136:
+					wizardSteps.add(CalculatorWizardStep.choose_theme);
+					break;
+				default:
 					wizardSteps.add(new ReleaseNoteStep(version));
+					break;
+			}
 		}
 		return new ListWizardFlow(wizardSteps);
 	}

android-app/src/main/java/org/solovyev/android/calculator/wizard/ChooseLayoutWizardStep.java

@@ -58,7 +58,7 @@ public class ChooseLayoutWizardStep extends WizardFragment implements AdapterVie
 
 		image = (ImageView) root.findViewById(R.id.wizard_layout_image);
 		final Spinner spinner = (Spinner) root.findViewById(R.id.wizard_layout_spinner);
-		spinner.setAdapter(new WizardArrayAdapter(getActivity(), R.array.cpp_layouts));
+		spinner.setAdapter(WizardArrayAdapter.create(getActivity(), R.array.cpp_layouts));
 		spinner.setSelection(layout == big_buttons ? 0 : 1);
 		spinner.setOnItemSelectedListener(this);
 

android-app/src/main/java/org/solovyev/android/calculator/wizard/ChooseModeWizardStep.java

@@ -55,7 +55,7 @@ public class ChooseModeWizardStep extends WizardFragment implements AdapterView.
 
 		final CalculatorMode mode = CalculatorMode.fromGuiLayout(Preferences.Gui.layout.getPreference(getPreferences()));
 		final Spinner spinner = (Spinner) root.findViewById(R.id.wizard_mode_spinner);
-		spinner.setAdapter(new WizardArrayAdapter(getActivity(), R.array.cpp_modes));
+		spinner.setAdapter(WizardArrayAdapter.create(getActivity(), R.array.cpp_modes));
 		spinner.setSelection(mode == simple ? 0 : 1);
 		spinner.setOnItemSelectedListener(this);
 

android-app/src/main/java/org/solovyev/android/calculator/wizard/ChooseThemeWizardStep.java

@@ -0,0 +1,117 @@
+/*
+ * 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.wizard;
+
+import android.os.Bundle;
+import android.support.annotation.StringRes;
+import android.view.ContextThemeWrapper;
+import android.view.LayoutInflater;
+import android.view.View;
+import android.widget.AdapterView;
+import android.widget.FrameLayout;
+import android.widget.Spinner;
+import org.solovyev.android.calculator.Preferences;
+import org.solovyev.android.calculator.R;
+
+import javax.annotation.Nonnull;
+import java.util.ArrayList;
+import java.util.List;
+
+import static org.solovyev.android.calculator.CalculatorApplication.getPreferences;
+
+public class ChooseThemeWizardStep extends WizardFragment implements AdapterView.OnItemSelectedListener {
+
+	private FrameLayout preview;
+	@Nonnull
+	private final List<ThemeUi> themes = new ArrayList<>();
+	private WizardArrayAdapter<ThemeUi> adapter;
+
+	@Override
+	protected int getViewResId() {
+		return R.layout.cpp_wizard_step_choose_theme;
+	}
+
+	@Override
+	public void onViewCreated(View root, Bundle savedInstanceState) {
+		super.onViewCreated(root, savedInstanceState);
+
+		final Preferences.Gui.Theme theme = Preferences.Gui.getTheme(getPreferences());
+		final Spinner spinner = (Spinner) root.findViewById(R.id.wizard_theme_spinner);
+		themes.clear();
+		themes.add(new ThemeUi(Preferences.Gui.Theme.material_theme, R.string.p_material_theme));
+		themes.add(new ThemeUi(Preferences.Gui.Theme.metro_blue_theme, R.string.p_metro_blue_theme));
+		themes.add(new ThemeUi(Preferences.Gui.Theme.metro_green_theme, R.string.p_metro_green_theme));
+		themes.add(new ThemeUi(Preferences.Gui.Theme.metro_purple_theme, R.string.p_metro_purple_theme));
+		adapter = new WizardArrayAdapter<>(getActivity(), themes);
+		spinner.setAdapter(adapter);
+		spinner.setSelection(findPosition(theme));
+		spinner.setOnItemSelectedListener(this);
+
+		preview = (FrameLayout) root.findViewById(R.id.wizard_theme_preview);
+		updateImage(theme);
+	}
+
+	private int findPosition(@Nonnull Preferences.Gui.Theme theme) {
+		for (int i = 0; i < themes.size(); i++) {
+			if (theme.equals(themes.get(i).theme)) {
+				return i;
+			}
+
+		}
+		return 0;
+	}
+
+	private void updateImage(@Nonnull Preferences.Gui.Theme theme) {
+		preview.removeAllViews();
+		final ContextThemeWrapper context = new ContextThemeWrapper(getActivity(), theme.getThemeId());
+		LayoutInflater.from(context).inflate(R.layout.cpp_wizard_step_choose_theme_preview, preview);
+	}
+
+	@Override
+	public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
+		final ThemeUi theme = adapter.getItem(position);
+		Preferences.Gui.theme.putPreference(getPreferences(), theme.theme);
+		updateImage(theme.theme);
+	}
+
+	@Override
+	public void onNothingSelected(AdapterView<?> parent) {
+	}
+
+	private final class ThemeUi {
+		@Nonnull
+		final Preferences.Gui.Theme theme;
+		@Nonnull
+		final String name;
+
+		public ThemeUi(@Nonnull Preferences.Gui.Theme theme, @StringRes int name) {
+			this.theme = theme;
+			this.name = getString(name);
+		}
+
+		@Override
+		public String toString() {
+			return name;
+		}
+	}
+}

android-app/src/main/java/org/solovyev/android/calculator/wizard/WizardArrayAdapter.java

@@ -7,10 +7,23 @@ import android.widget.ArrayAdapter;
 import android.widget.TextView;
 import org.solovyev.android.calculator.R;
 
-final class WizardArrayAdapter extends ArrayAdapter<String> {
+import javax.annotation.Nonnull;
+import java.util.List;
 
-	public WizardArrayAdapter(Context context, int array) {
+final class WizardArrayAdapter<T> extends ArrayAdapter<T> {
-		super(context, R.layout.support_simple_spinner_dropdown_item, context.getResources().getStringArray(array));
+
+	public WizardArrayAdapter(@Nonnull Context context, @Nonnull T[] items) {
+		super(context, R.layout.support_simple_spinner_dropdown_item, items);
+		setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
+	}
+
+	@Nonnull
+	public static WizardArrayAdapter<String> create(@Nonnull Context context, int array) {
+		return new WizardArrayAdapter<>(context, context.getResources().getStringArray(array));
+	}
+
+	public WizardArrayAdapter(@Nonnull Context context, @Nonnull List<T> items) {
+		super(context, R.layout.support_simple_spinner_dropdown_item, items);
 		setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
 	}
 

android-app/src/main/res/layout-land/cpp_app_keyboard.xml

@@ -34,21 +34,21 @@
 		a:baselineAligned="false"
 		a:orientation="horizontal">
 
-		<include layout="@layout/cpp_drag_button_vars" />
+		<include layout="@layout/cpp_app_button_vars" />
 
 		<include layout="@layout/cpp_app_button_copy" />
 
-		<include layout="@layout/cpp_drag_button_7" />
+		<include layout="@layout/cpp_app_button_7" />
 
-		<include layout="@layout/cpp_drag_button_8" />
+		<include layout="@layout/cpp_app_button_8" />
 
-		<include layout="@layout/cpp_drag_button_9" />
+		<include layout="@layout/cpp_app_button_9" />
 
-		<include layout="@layout/cpp_drag_button_multiplication" />
+		<include layout="@layout/cpp_app_button_multiplication" />
 
-		<include layout="@layout/cpp_drag_button_division" />
+		<include layout="@layout/cpp_app_button_division" />
 
-		<include layout="@layout/cpp_drag_button_equals" />
+		<include layout="@layout/cpp_app_button_equals" />
 
 	</LinearLayout>
 
@@ -59,21 +59,21 @@
 		a:baselineAligned="false"
 		a:orientation="horizontal">
 
-		<include layout="@layout/cpp_drag_button_functions" />
+		<include layout="@layout/cpp_app_button_functions" />
 
 		<include layout="@layout/cpp_app_button_paste" />
 
-		<include layout="@layout/cpp_drag_button_4" />
+		<include layout="@layout/cpp_app_button_4" />
 
-		<include layout="@layout/cpp_drag_button_5" />
+		<include layout="@layout/cpp_app_button_5" />
 
-		<include layout="@layout/cpp_drag_button_6" />
+		<include layout="@layout/cpp_app_button_6" />
 
-		<include layout="@layout/cpp_drag_button_plus" />
+		<include layout="@layout/cpp_app_button_plus" />
 
-		<include layout="@layout/cpp_drag_button_subtraction" />
+		<include layout="@layout/cpp_app_button_minus" />
 
-		<include layout="@layout/cpp_drag_button_round_brackets" />
+		<include layout="@layout/cpp_app_button_round_brackets" />
 
 	</LinearLayout>
 
@@ -84,21 +84,21 @@
 		a:baselineAligned="false"
 		a:orientation="horizontal">
 
-		<include layout="@layout/cpp_drag_button_operators" />
+		<include layout="@layout/cpp_app_button_operators" />
 
 		<include layout="@layout/cpp_app_button_donate" />
 
-		<include layout="@layout/cpp_drag_button_1" />
+		<include layout="@layout/cpp_app_button_1" />
 
-		<include layout="@layout/cpp_drag_button_2" />
+		<include layout="@layout/cpp_app_button_2" />
 
-		<include layout="@layout/cpp_drag_button_3" />
+		<include layout="@layout/cpp_app_button_3" />
 
-		<include layout="@layout/cpp_drag_button_0" />
+		<include layout="@layout/cpp_app_button_0" />
 
-		<include layout="@layout/cpp_drag_button_dot" />
+		<include layout="@layout/cpp_app_button_dot" />
 
-		<include layout="@layout/cpp_drag_button_history" />
+		<include layout="@layout/cpp_app_button_history" />
 
 	</LinearLayout>
 

android-app/src/main/res/layout-land/cpp_app_keyboard_mobile.xml

@@ -32,21 +32,21 @@
 			a:layout_width="match_parent"
 			a:layout_height="0dp">
 
-		<include layout="@layout/cpp_drag_button_vars"/>
+		<include layout="@layout/cpp_app_button_vars"/>
 
 		<include layout="@layout/cpp_app_button_copy"/>
 
-		<include layout="@layout/cpp_drag_button_7"/>
+		<include layout="@layout/cpp_app_button_7"/>
 
-		<include layout="@layout/cpp_drag_button_8"/>
+		<include layout="@layout/cpp_app_button_8"/>
 
-		<include layout="@layout/cpp_drag_button_9"/>
+		<include layout="@layout/cpp_app_button_9"/>
 
-		<include layout="@layout/cpp_drag_button_multiplication"/>
+		<include layout="@layout/cpp_app_button_multiplication"/>
 
-		<include layout="@layout/cpp_drag_button_division"/>
+		<include layout="@layout/cpp_app_button_division"/>
 
-		<include layout="@layout/cpp_drag_button_equals"/>
+		<include layout="@layout/cpp_app_button_equals"/>
 
 	</LinearLayout>
 
@@ -55,21 +55,21 @@
 			a:layout_width="match_parent"
 			a:layout_height="0dp">
 
-		<include layout="@layout/cpp_drag_button_functions"/>
+		<include layout="@layout/cpp_app_button_functions"/>
 
 		<include layout="@layout/cpp_app_button_paste"/>
 
-		<include layout="@layout/cpp_drag_button_4"/>
+		<include layout="@layout/cpp_app_button_4"/>
 
-		<include layout="@layout/cpp_drag_button_5"/>
+		<include layout="@layout/cpp_app_button_5"/>
 
-		<include layout="@layout/cpp_drag_button_6"/>
+		<include layout="@layout/cpp_app_button_6"/>
 
-		<include layout="@layout/cpp_drag_button_plus"/>
+		<include layout="@layout/cpp_app_button_plus"/>
 
-		<include layout="@layout/cpp_drag_button_subtraction"/>
+		<include layout="@layout/cpp_app_button_minus"/>
 
-		<include layout="@layout/cpp_drag_button_round_brackets"/>
+		<include layout="@layout/cpp_app_button_round_brackets"/>
 
 	</LinearLayout>
 
@@ -78,21 +78,21 @@
 			a:layout_width="match_parent"
 			a:layout_height="0dp">
 
-		<include layout="@layout/cpp_drag_button_operators"/>
+		<include layout="@layout/cpp_app_button_operators"/>
 
 		<include layout="@layout/cpp_app_button_donate"/>
 
-		<include layout="@layout/cpp_drag_button_1"/>
+		<include layout="@layout/cpp_app_button_1"/>
 
-		<include layout="@layout/cpp_drag_button_2"/>
+		<include layout="@layout/cpp_app_button_2"/>
 
-		<include layout="@layout/cpp_drag_button_3"/>
+		<include layout="@layout/cpp_app_button_3"/>
 
-		<include layout="@layout/cpp_drag_button_0"/>
+		<include layout="@layout/cpp_app_button_0"/>
 
-		<include layout="@layout/cpp_drag_button_dot"/>
+		<include layout="@layout/cpp_app_button_dot"/>
 
-		<include layout="@layout/cpp_drag_button_history"/>
+		<include layout="@layout/cpp_app_button_history"/>
 
 	</LinearLayout>
 

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

@@ -42,7 +42,7 @@
 			a:orientation="horizontal">
 
 		<include
-				layout="@layout/cpp_drag_button_left"
+				layout="@layout/cpp_app_button_left"
 				a:layout_width="0dp"
 				a:layout_height="match_parent"
 				a:layout_weight="1"/>
@@ -61,13 +61,13 @@
 			a:orientation="horizontal" />
 
 		<include
-				layout="@layout/cpp_drag_button_clear"
+				layout="@layout/cpp_app_button_clear"
 				a:layout_width="0dp"
 				a:layout_height="match_parent"
 				a:layout_weight="1"/>
 
 		<include
-				layout="@layout/cpp_drag_button_right"
+				layout="@layout/cpp_app_button_right"
 				a:layout_width="0dp"
 				a:layout_height="match_parent"
 				a:layout_weight="1"/>

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

@@ -39,7 +39,7 @@
 			a:layout_height="0dp">
 
 		<include
-				layout="@layout/cpp_drag_button_left"
+				layout="@layout/cpp_app_button_left"
 				a:layout_width="0dp"
 				a:layout_height="match_parent"
 				a:layout_weight="1"/>
@@ -57,13 +57,13 @@
 				a:layout_weight="4"/>
 
 		<include
-				layout="@layout/cpp_drag_button_clear"
+				layout="@layout/cpp_app_button_clear"
 				a:layout_width="0dp"
 				a:layout_height="match_parent"
 				a:layout_weight="1"/>
 
 		<include
-				layout="@layout/cpp_drag_button_right"
+				layout="@layout/cpp_app_button_right"
 				a:layout_width="0dp"
 				a:layout_height="match_parent"
 				a:layout_weight="1"/>

android-app/src/main/res/layout-large-land/cpp_app_keyboard.xml

@@ -32,25 +32,25 @@
 			a:layout_width="match_parent"
 			a:layout_height="0dp">
 
-		<include layout="@layout/cpp_drag_button_left"/>
+		<include layout="@layout/cpp_app_button_left"/>
 
 		<include layout="@layout/cpp_app_button_erase"/>
 
 		<include layout="@layout/cpp_app_button_donate"/>
 
-		<include layout="@layout/cpp_drag_button_7"/>
+		<include layout="@layout/cpp_app_button_7"/>
 
-		<include layout="@layout/cpp_drag_button_8"/>
+		<include layout="@layout/cpp_app_button_8"/>
 
-		<include layout="@layout/cpp_drag_button_9"/>
+		<include layout="@layout/cpp_app_button_9"/>
 
-		<include layout="@layout/cpp_drag_button_multiplication"/>
+		<include layout="@layout/cpp_app_button_multiplication"/>
 
-		<include layout="@layout/cpp_drag_button_division"/>
+		<include layout="@layout/cpp_app_button_division"/>
 
-		<include layout="@layout/cpp_drag_button_clear"/>
+		<include layout="@layout/cpp_app_button_clear"/>
 
-		<include layout="@layout/cpp_drag_button_right"/>
+		<include layout="@layout/cpp_app_button_right"/>
 
 	</LinearLayout>
 
@@ -59,25 +59,25 @@
 			a:layout_width="match_parent"
 			a:layout_height="0dp">
 
-		<include layout="@layout/cpp_drag_button_vars"/>
+		<include layout="@layout/cpp_app_button_vars"/>
 
-		<include layout="@layout/cpp_drag_button_functions"/>
+		<include layout="@layout/cpp_app_button_functions"/>
 
-		<include layout="@layout/cpp_drag_button_empty"/>
+		<include layout="@layout/cpp_app_button_empty"/>
 
-		<include layout="@layout/cpp_drag_button_4"/>
+		<include layout="@layout/cpp_app_button_4"/>
 
-		<include layout="@layout/cpp_drag_button_5"/>
+		<include layout="@layout/cpp_app_button_5"/>
 
-		<include layout="@layout/cpp_drag_button_6"/>
+		<include layout="@layout/cpp_app_button_6"/>
 
-		<include layout="@layout/cpp_drag_button_plus"/>
+		<include layout="@layout/cpp_app_button_plus"/>
 
-		<include layout="@layout/cpp_drag_button_subtraction"/>
+		<include layout="@layout/cpp_app_button_minus"/>
 
 		<include layout="@layout/cpp_app_button_copy"/>
 
-		<include layout="@layout/cpp_drag_button_equals"/>
+		<include layout="@layout/cpp_app_button_equals"/>
 
 	</LinearLayout>
 
@@ -86,25 +86,25 @@
 			a:layout_width="match_parent"
 			a:layout_height="0dp">
 
-		<include layout="@layout/cpp_drag_button_empty"/>
+		<include layout="@layout/cpp_app_button_empty"/>
 
-		<include layout="@layout/cpp_drag_button_operators"/>
+		<include layout="@layout/cpp_app_button_operators"/>
 
-		<include layout="@layout/cpp_drag_button_dot"/>
+		<include layout="@layout/cpp_app_button_dot"/>
 
-		<include layout="@layout/cpp_drag_button_1"/>
+		<include layout="@layout/cpp_app_button_1"/>
 
-		<include layout="@layout/cpp_drag_button_2"/>
+		<include layout="@layout/cpp_app_button_2"/>
 
-		<include layout="@layout/cpp_drag_button_3"/>
+		<include layout="@layout/cpp_app_button_3"/>
 
-		<include layout="@layout/cpp_drag_button_0"/>
+		<include layout="@layout/cpp_app_button_0"/>
 
-		<include layout="@layout/cpp_drag_button_round_brackets"/>
+		<include layout="@layout/cpp_app_button_round_brackets"/>
 
 		<include layout="@layout/cpp_app_button_paste"/>
 
-		<include layout="@layout/cpp_drag_button_history"/>
+		<include layout="@layout/cpp_app_button_history"/>
 
 	</LinearLayout>
 

android-app/src/main/res/layout-large/cpp_app_keyboard.xml

@@ -32,19 +32,19 @@
 			a:layout_width="match_parent"
 			a:layout_height="0dp">
 
-		<include layout="@layout/cpp_drag_button_left"/>
+		<include layout="@layout/cpp_app_button_left"/>
 
 		<include layout="@layout/cpp_app_button_erase"/>
 
-		<include layout="@layout/cpp_drag_button_7"/>
+		<include layout="@layout/cpp_app_button_7"/>
 
-		<include layout="@layout/cpp_drag_button_8"/>
+		<include layout="@layout/cpp_app_button_8"/>
 
-		<include layout="@layout/cpp_drag_button_9"/>
+		<include layout="@layout/cpp_app_button_9"/>
 
-		<include layout="@layout/cpp_drag_button_multiplication"/>
+		<include layout="@layout/cpp_app_button_multiplication"/>
 
-		<include layout="@layout/cpp_drag_button_right"/>
+		<include layout="@layout/cpp_app_button_right"/>
 
 	</LinearLayout>
 
@@ -53,17 +53,17 @@
 			a:layout_width="match_parent"
 			a:layout_height="0dp">
 
-		<include layout="@layout/cpp_drag_button_vars"/>
+		<include layout="@layout/cpp_app_button_vars"/>
 
-		<include layout="@layout/cpp_drag_button_clear"/>
+		<include layout="@layout/cpp_app_button_clear"/>
 
-		<include layout="@layout/cpp_drag_button_4"/>
+		<include layout="@layout/cpp_app_button_4"/>
 
-		<include layout="@layout/cpp_drag_button_5"/>
+		<include layout="@layout/cpp_app_button_5"/>
 
-		<include layout="@layout/cpp_drag_button_6"/>
+		<include layout="@layout/cpp_app_button_6"/>
 
-		<include layout="@layout/cpp_drag_button_division"/>
+		<include layout="@layout/cpp_app_button_division"/>
 
 		<include layout="@layout/cpp_app_button_copy"/>
 
@@ -74,17 +74,17 @@
 			a:layout_width="match_parent"
 			a:layout_height="0dp">
 
-		<include layout="@layout/cpp_drag_button_functions"/>
+		<include layout="@layout/cpp_app_button_functions"/>
 
-		<include layout="@layout/cpp_drag_button_equals"/>
+		<include layout="@layout/cpp_app_button_equals"/>
 
-		<include layout="@layout/cpp_drag_button_1"/>
+		<include layout="@layout/cpp_app_button_1"/>
 
-		<include layout="@layout/cpp_drag_button_2"/>
+		<include layout="@layout/cpp_app_button_2"/>
 
-		<include layout="@layout/cpp_drag_button_3"/>
+		<include layout="@layout/cpp_app_button_3"/>
 
-		<include layout="@layout/cpp_drag_button_plus"/>
+		<include layout="@layout/cpp_app_button_plus"/>
 
 		<include layout="@layout/cpp_app_button_paste"/>
 
@@ -95,19 +95,19 @@
 			a:layout_width="match_parent"
 			a:layout_height="0dp">
 
-		<include layout="@layout/cpp_drag_button_operators"/>
+		<include layout="@layout/cpp_app_button_operators"/>
 
 		<include layout="@layout/cpp_app_button_donate"/>
 
-		<include layout="@layout/cpp_drag_button_round_brackets"/>
+		<include layout="@layout/cpp_app_button_round_brackets"/>
 
-		<include layout="@layout/cpp_drag_button_0"/>
+		<include layout="@layout/cpp_app_button_0"/>
 
-		<include layout="@layout/cpp_drag_button_dot"/>
+		<include layout="@layout/cpp_app_button_dot"/>
 
-		<include layout="@layout/cpp_drag_button_subtraction"/>
+		<include layout="@layout/cpp_app_button_minus"/>
 
-		<include layout="@layout/cpp_drag_button_history"/>
+		<include layout="@layout/cpp_app_button_history"/>
 
 	</LinearLayout>
 

android-app/src/main/res/layout-xlarge-land/cpp_app_keyboard.xml

@@ -32,33 +32,33 @@
 			a:layout_width="match_parent"
 			a:layout_height="0dp">
 
-		<include layout="@layout/cpp_drag_button_left"/>
+		<include layout="@layout/cpp_app_button_left"/>
 
-		<include layout="@layout/cpp_drag_button_vars"/>
+		<include layout="@layout/cpp_app_button_vars"/>
 
 		<include layout="@layout/cpp_app_button_copy"/>
 
-		<include layout="@layout/cpp_drag_button_6"/>
+		<include layout="@layout/cpp_app_button_6"/>
 
-		<include layout="@layout/cpp_drag_button_7"/>
+		<include layout="@layout/cpp_app_button_7"/>
 
-		<include layout="@layout/cpp_drag_button_8"/>
+		<include layout="@layout/cpp_app_button_8"/>
 
-		<include layout="@layout/cpp_drag_button_9"/>
+		<include layout="@layout/cpp_app_button_9"/>
 
-		<include layout="@layout/cpp_drag_button_0"/>
+		<include layout="@layout/cpp_app_button_0"/>
 
-		<include layout="@layout/cpp_drag_button_multiplication"/>
+		<include layout="@layout/cpp_app_button_multiplication"/>
 
-		<include layout="@layout/cpp_drag_button_division"/>
+		<include layout="@layout/cpp_app_button_division"/>
 
-		<include layout="@layout/cpp_drag_button_equals"/>
+		<include layout="@layout/cpp_app_button_equals"/>
 
-		<include layout="@layout/cpp_drag_button_operators"/>
+		<include layout="@layout/cpp_app_button_operators"/>
 
 		<include layout="@layout/cpp_app_button_donate"/>
 
-		<include layout="@layout/cpp_drag_button_right"/>
+		<include layout="@layout/cpp_app_button_right"/>
 
 	</LinearLayout>
 
@@ -69,31 +69,31 @@
 
 		<include layout="@layout/cpp_app_button_erase"/>
 
-		<include layout="@layout/cpp_drag_button_functions"/>
+		<include layout="@layout/cpp_app_button_functions"/>
 
 		<include layout="@layout/cpp_app_button_paste"/>
 
-		<include layout="@layout/cpp_drag_button_1"/>
+		<include layout="@layout/cpp_app_button_1"/>
 
-		<include layout="@layout/cpp_drag_button_2"/>
+		<include layout="@layout/cpp_app_button_2"/>
 
-		<include layout="@layout/cpp_drag_button_3"/>
+		<include layout="@layout/cpp_app_button_3"/>
 
-		<include layout="@layout/cpp_drag_button_4"/>
+		<include layout="@layout/cpp_app_button_4"/>
 
-		<include layout="@layout/cpp_drag_button_5"/>
+		<include layout="@layout/cpp_app_button_5"/>
 
-		<include layout="@layout/cpp_drag_button_plus"/>
+		<include layout="@layout/cpp_app_button_plus"/>
 
-		<include layout="@layout/cpp_drag_button_subtraction"/>
+		<include layout="@layout/cpp_app_button_minus"/>
 
-		<include layout="@layout/cpp_drag_button_round_brackets"/>
+		<include layout="@layout/cpp_app_button_round_brackets"/>
 
-		<include layout="@layout/cpp_drag_button_dot"/>
+		<include layout="@layout/cpp_app_button_dot"/>
 
-		<include layout="@layout/cpp_drag_button_history"/>
+		<include layout="@layout/cpp_app_button_history"/>
 
-		<include layout="@layout/cpp_drag_button_clear"/>
+		<include layout="@layout/cpp_app_button_clear"/>
 
 	</LinearLayout>
 

android-app/src/main/res/layout-xlarge/cpp_app_keyboard.xml

@@ -32,21 +32,21 @@
 			a:layout_width="match_parent"
 			a:layout_height="0dp">
 
-		<include layout="@layout/cpp_drag_button_left"/>
+		<include layout="@layout/cpp_app_button_left"/>
 
 		<include layout="@layout/cpp_app_button_erase"/>
 
-		<include layout="@layout/cpp_drag_button_empty"/>
+		<include layout="@layout/cpp_app_button_empty"/>
 
-		<include layout="@layout/cpp_drag_button_empty"/>
+		<include layout="@layout/cpp_app_button_empty"/>
 
-		<include layout="@layout/cpp_drag_button_empty"/>
+		<include layout="@layout/cpp_app_button_empty"/>
 
-		<include layout="@layout/cpp_drag_button_empty"/>
+		<include layout="@layout/cpp_app_button_empty"/>
 
-		<include layout="@layout/cpp_drag_button_clear"/>
+		<include layout="@layout/cpp_app_button_clear"/>
 
-		<include layout="@layout/cpp_drag_button_right"/>
+		<include layout="@layout/cpp_app_button_right"/>
 
 	</LinearLayout>
 
@@ -55,21 +55,21 @@
 			a:layout_width="match_parent"
 			a:layout_height="0dp">
 
-		<include layout="@layout/cpp_drag_button_vars"/>
+		<include layout="@layout/cpp_app_button_vars"/>
 
 		<include layout="@layout/cpp_app_button_copy"/>
 
-		<include layout="@layout/cpp_drag_button_7"/>
+		<include layout="@layout/cpp_app_button_7"/>
 
-		<include layout="@layout/cpp_drag_button_8"/>
+		<include layout="@layout/cpp_app_button_8"/>
 
-		<include layout="@layout/cpp_drag_button_9"/>
+		<include layout="@layout/cpp_app_button_9"/>
 
-		<include layout="@layout/cpp_drag_button_multiplication"/>
+		<include layout="@layout/cpp_app_button_multiplication"/>
 
-		<include layout="@layout/cpp_drag_button_division"/>
+		<include layout="@layout/cpp_app_button_division"/>
 
-		<include layout="@layout/cpp_drag_button_equals"/>
+		<include layout="@layout/cpp_app_button_equals"/>
 
 	</LinearLayout>
 
@@ -78,21 +78,21 @@
 			a:layout_width="match_parent"
 			a:layout_height="0dp">
 
-		<include layout="@layout/cpp_drag_button_functions"/>
+		<include layout="@layout/cpp_app_button_functions"/>
 
 		<include layout="@layout/cpp_app_button_paste"/>
 
-		<include layout="@layout/cpp_drag_button_4"/>
+		<include layout="@layout/cpp_app_button_4"/>
 
-		<include layout="@layout/cpp_drag_button_5"/>
+		<include layout="@layout/cpp_app_button_5"/>
 
-		<include layout="@layout/cpp_drag_button_6"/>
+		<include layout="@layout/cpp_app_button_6"/>
 
-		<include layout="@layout/cpp_drag_button_plus"/>
+		<include layout="@layout/cpp_app_button_plus"/>
 
-		<include layout="@layout/cpp_drag_button_subtraction"/>
+		<include layout="@layout/cpp_app_button_minus"/>
 
-		<include layout="@layout/cpp_drag_button_round_brackets"/>
+		<include layout="@layout/cpp_app_button_round_brackets"/>
 
 	</LinearLayout>
 
@@ -101,21 +101,21 @@
 			a:layout_width="match_parent"
 			a:layout_height="0dp">
 
-		<include layout="@layout/cpp_drag_button_operators"/>
+		<include layout="@layout/cpp_app_button_operators"/>
 
 		<include layout="@layout/cpp_app_button_donate"/>
 
-		<include layout="@layout/cpp_drag_button_1"/>
+		<include layout="@layout/cpp_app_button_1"/>
 
-		<include layout="@layout/cpp_drag_button_2"/>
+		<include layout="@layout/cpp_app_button_2"/>
 
-		<include layout="@layout/cpp_drag_button_3"/>
+		<include layout="@layout/cpp_app_button_3"/>
 
-		<include layout="@layout/cpp_drag_button_0"/>
+		<include layout="@layout/cpp_app_button_0"/>
 
-		<include layout="@layout/cpp_drag_button_dot"/>
+		<include layout="@layout/cpp_app_button_dot"/>
 
-		<include layout="@layout/cpp_drag_button_history"/>
+		<include layout="@layout/cpp_app_button_history"/>
 
 	</LinearLayout>
 

android-app/src/main/res/layout/cpp_app_button_0.xml

@@ -29,5 +29,4 @@
 													a:text="0"
 													c:textDown="000"
 													c:directionTextScale="0.5"
-													style="?cpp_digit_button_style"
+													style="?cpp_digit_button_style"/>
-													a:onClick="digitButtonClickHandler"/>

android-app/src/main/res/layout/cpp_app_button_1.xml

@@ -29,5 +29,4 @@
 													c:textUp="sin"
 													c:textLeft="A"
 													c:textDown="asin"
-													style="?cpp_digit_button_style"
+													style="?cpp_digit_button_style"/>
-													a:onClick="digitButtonClickHandler"/>

android-app/src/main/res/layout/cpp_app_button_2.xml

@@ -29,5 +29,4 @@
 													c:textUp="cos"
 													c:textLeft="B"
 													c:textDown="acos"
-													style="?cpp_digit_button_style"
+													style="?cpp_digit_button_style"/>
-													a:onClick="digitButtonClickHandler"/>

android-app/src/main/res/layout/cpp_app_button_3.xml

@@ -29,5 +29,4 @@
 													c:textUp="tan"
 													c:textLeft="C"
 													c:textDown="atan"
-													style="?cpp_digit_button_style"
+													style="?cpp_digit_button_style"/>
-													a:onClick="digitButtonClickHandler"/>

android-app/src/main/res/layout/cpp_app_button_4.xml

@@ -28,5 +28,4 @@
 													c:textUp="x"
 													c:textLeft="D"
 													c:textDown="y"
-													style="?cpp_digit_button_style"
+													style="?cpp_digit_button_style"/>
-													a:onClick="digitButtonClickHandler"/>

android-app/src/main/res/layout/cpp_app_button_5.xml

@@ -28,5 +28,4 @@
 													c:textUp="t"
 													c:textLeft="E"
 													c:textDown="j"
-													style="?cpp_digit_button_style"
+													style="?cpp_digit_button_style"/>
-													a:onClick="digitButtonClickHandler"/>

android-app/src/main/res/layout/cpp_app_button_6.xml

@@ -30,5 +30,4 @@
 													   c:textLeft="F"
 													   c:textDown="rad"
 													   c:directionTextScale="0.33;0.30;0.33;0.33"
-													   style="?cpp_digit_button_style"
+													   style="?cpp_digit_button_style"/>
-													   a:onClick="digitButtonClickHandler"/>

android-app/src/main/res/layout/cpp_app_button_7.xml

@@ -30,5 +30,4 @@
 													c:textLeft="0b:"
 													c:textDown="!"
 													c:directionTextScale="0.5;0.5;0.5;0.33"
-													style="?cpp_digit_button_style"
+													style="?cpp_digit_button_style"/>
-													a:onClick="digitButtonClickHandler"/>

android-app/src/main/res/layout/cpp_app_button_8.xml

@@ -30,5 +30,4 @@
 													c:textLeft="0d:"
 													c:textDown="lg"
 													c:directionTextScale="0.5;0.5;0.5;0.33"
-													style="?cpp_digit_button_style"
+													style="?cpp_digit_button_style"/>
-													a:onClick="digitButtonClickHandler"/>

android-app/src/main/res/layout/cpp_app_button_9.xml

@@ -30,5 +30,4 @@
 													c:textLeft="0x:"
 													c:textUp="π"
 													c:directionTextScale="0.5;0.5;0.5;0.33"
-													style="?cpp_digit_button_style"
+													style="?cpp_digit_button_style"/>
-													a:onClick="digitButtonClickHandler"/>

android-app/src/main/res/layout/cpp_app_button_clear.xml

@@ -30,5 +30,4 @@
 														 c:textDown="bin"
 														 c:textLeft="hex"
 														 a:textStyle="bold"
-														 style="?cpp_control_image_button_style"
+														 style="?cpp_control_image_button_style"/>
-														 a:onClick="clearButtonClickHandler"/>

android-app/src/main/res/layout/cpp_app_button_copy.xml

@@ -25,5 +25,4 @@
 <ImageButton xmlns:a="http://schemas.android.com/apk/res/android"
 			 a:id="@id/cpp_button_copy"
 			 a:src="@drawable/kb_copy"
-			 style="?cpp_control_image_button_style"
+			 style="?cpp_control_image_button_style"/>
-			 a:onClick="copyButtonClickHandler"/>

android-app/src/main/res/layout/cpp_app_button_division.xml

@@ -29,5 +29,4 @@
 													a:text="/"
 													c:textDown="√"
 													c:directionTextScale="0.5"
-													style="?cpp_operation_button_style"
+													style="?cpp_operation_button_style"/>
-													a:onClick="digitButtonClickHandler"/>

android-app/src/main/res/layout/cpp_app_button_donate.xml

@@ -25,5 +25,4 @@
 <ImageButton xmlns:a="http://schemas.android.com/apk/res/android"
 			 a:id="@id/cpp_button_like"
 			 a:src="@drawable/kb_share"
-			 style="?cpp_control_image_button_style"
+			 style="?cpp_control_image_button_style"/>
-			 a:onClick="likeButtonClickHandler"/>

android-app/src/main/res/layout/cpp_app_button_dot.xml

@@ -28,5 +28,4 @@
 													a:text="."
 													c:textUp=","
 													c:directionTextScale="0.5"
-													style="?cpp_digit_button_style"
+													style="?cpp_digit_button_style"/>
-													a:onClick="digitButtonClickHandler"/>

android-app/src/main/res/layout/cpp_app_button_equals.xml

@@ -28,5 +28,4 @@
 													a:text="="
 													c:textDown="@string/cpp_plot_button_text"
 													c:directionTextScale="0.5;0.5;0.33;0.5"
-													style="?cpp_control_button_style"
+													style="?cpp_control_button_style"/>
-													a:onClick="equalsButtonClickHandler"/>

android-app/src/main/res/layout/cpp_app_button_erase.xml

@@ -25,5 +25,4 @@
 <ImageButton xmlns:a="http://schemas.android.com/apk/res/android"
 			 a:id="@id/cpp_button_erase"
 			 a:src="@drawable/kb_erase"
-			 style="?cpp_control_image_button_style"
+			 style="?cpp_control_image_button_style"/>
-			 a:onClick="eraseButtonClickHandler"/>

android-app/src/main/res/layout/cpp_app_button_functions.xml

@@ -25,9 +25,8 @@
 <org.solovyev.android.calculator.drag.DirectionDragButton xmlns:a="http://schemas.android.com/apk/res/android"
 													xmlns:c="http://schemas.android.com/apk/res-auto"
 													a:id="@id/cpp_button_functions"
-													c:directionTextScale="0.5"
+													c:directionTextScale="0.4"
 													c:textUp="+ƒ"
 													a:text="ƒ(x)"
 													a:textStyle="italic"
-													a:onClick="functionsButtonClickHandler"
 													style="?cpp_control_button_style"/>

android-app/src/main/res/layout/cpp_app_button_history.xml

@@ -29,5 +29,4 @@
 													c:textDown="@string/c_redo"
 													c:directionTextScale="0.27"
 													style="?cpp_control_button_style"
-													a:textStyle="bold"
+													a:textStyle="bold"/>
-													a:onClick="historyButtonClickHandler"/>

android-app/src/main/res/layout/cpp_app_button_left.xml

@@ -28,5 +28,4 @@
 													c:textUp="◁◁"
 													a:text="◁"
 													c:directionTextScale="0.5"
-													style="?cpp_control_button_style"
+													style="?cpp_control_button_style"/>
-													a:onClick="digitButtonClickHandler"/>

android-app/src/main/res/layout/cpp_app_button_minus.xml

@@ -26,6 +26,5 @@
 													a:id="@id/cpp_button_subtraction"
 													c:textDown="∂,…"
 													a:text="-"
-													c:directionTextScale="0.5"
+													c:directionTextScale="0.4"
-													style="?cpp_operation_button_style"
+													style="?cpp_operation_button_style"/>
-													a:onClick="digitButtonClickHandler"/>

android-app/src/main/res/layout/cpp_app_button_multiplication.xml

@@ -30,5 +30,4 @@
 													c:textDown="^2"
 													c:textLeft="Π"
 													style="?cpp_operation_button_style"
-													c:directionTextScale="0.5"
+													c:directionTextScale="0.5"/>
-													a:onClick="digitButtonClickHandler"/>

android-app/src/main/res/layout/cpp_app_button_operators.xml

@@ -25,5 +25,4 @@
 <org.solovyev.android.calculator.drag.DirectionDragButton xmlns:a="http://schemas.android.com/apk/res/android"
 													a:id="@id/cpp_button_operators"
 													a:text="∂,…"
-													a:onClick="operatorsButtonClickHandler"
 													style="?cpp_control_button_style"/>

android-app/src/main/res/layout/cpp_app_button_paste.xml

@@ -25,5 +25,4 @@
 <ImageButton xmlns:a="http://schemas.android.com/apk/res/android"
 			 a:id="@id/cpp_button_paste"
 			 a:src="@drawable/kb_paste"
-			 style="?cpp_control_image_button_style"
+			 style="?cpp_control_image_button_style"/>
-			 a:onClick="pasteButtonClickHandler"/>

android-app/src/main/res/layout/cpp_app_button_plus.xml

@@ -28,5 +28,4 @@
 													c:textUp="°"
 													c:textDown="E"
 													a:text="+"
-													style="?cpp_operation_button_style"
+													style="?cpp_operation_button_style"/>
-													a:onClick="digitButtonClickHandler"/>

android-app/src/main/res/layout/cpp_app_button_right.xml

@@ -28,5 +28,4 @@
 													c:textUp="▷▷"
 													a:text="▷"
 													c:directionTextScale="0.5"
-													style="?cpp_control_button_style"
+													style="?cpp_control_button_style"/>
-													a:onClick="digitButtonClickHandler"/>

android-app/src/main/res/layout/cpp_app_button_round_brackets.xml

@@ -30,5 +30,4 @@
 													c:textDown=")"
 													c:textLeft="(…)"
 													c:directionTextScale="0.5;0.5;0.5;0.33"
-													style="?cpp_digit_button_style"
+													style="?cpp_digit_button_style"/>
-													a:onClick="digitButtonClickHandler"/>

android-app/src/main/res/layout/cpp_app_button_vars.xml

@@ -25,9 +25,8 @@
 <org.solovyev.android.calculator.drag.DirectionDragButton xmlns:a="http://schemas.android.com/apk/res/android"
 													xmlns:c="http://schemas.android.com/apk/res-auto"
 													a:id="@id/cpp_button_vars"
-													c:directionTextScale="0.5"
+													c:directionTextScale="0.4"
 													c:textUp="+π"
 													a:text="π,…"
 													a:textStyle="italic"
-													a:onClick="varsButtonClickHandler"
 													style="?cpp_control_button_style"/>

android-app/src/main/res/layout/cpp_app_keyboard.xml

@@ -32,15 +32,15 @@
 			a:layout_width="match_parent"
 			a:layout_height="0dp">
 
-		<include layout="@layout/cpp_drag_button_7"/>
+		<include layout="@layout/cpp_app_button_7"/>
 
-		<include layout="@layout/cpp_drag_button_8"/>
+		<include layout="@layout/cpp_app_button_8"/>
 
-		<include layout="@layout/cpp_drag_button_9"/>
+		<include layout="@layout/cpp_app_button_9"/>
 
-		<include layout="@layout/cpp_drag_button_multiplication"/>
+		<include layout="@layout/cpp_app_button_multiplication"/>
 
-		<include layout="@layout/cpp_drag_button_clear"/>
+		<include layout="@layout/cpp_app_button_clear"/>
 
 	</LinearLayout>
 
@@ -49,13 +49,13 @@
 			a:layout_width="match_parent"
 			a:layout_height="0dp">
 
-		<include layout="@layout/cpp_drag_button_4"/>
+		<include layout="@layout/cpp_app_button_4"/>
 
-		<include layout="@layout/cpp_drag_button_5"/>
+		<include layout="@layout/cpp_app_button_5"/>
 
-		<include layout="@layout/cpp_drag_button_6"/>
+		<include layout="@layout/cpp_app_button_6"/>
 
-		<include layout="@layout/cpp_drag_button_division"/>
+		<include layout="@layout/cpp_app_button_division"/>
 
 		<include layout="@layout/cpp_app_button_erase"/>
 
@@ -66,13 +66,13 @@
 			a:layout_width="match_parent"
 			a:layout_height="0dp">
 
-		<include layout="@layout/cpp_drag_button_1"/>
+		<include layout="@layout/cpp_app_button_1"/>
 
-		<include layout="@layout/cpp_drag_button_2"/>
+		<include layout="@layout/cpp_app_button_2"/>
 
-		<include layout="@layout/cpp_drag_button_3"/>
+		<include layout="@layout/cpp_app_button_3"/>
 
-		<include layout="@layout/cpp_drag_button_plus"/>
+		<include layout="@layout/cpp_app_button_plus"/>
 
 		<include layout="@layout/cpp_app_button_copy"/>
 
@@ -83,13 +83,13 @@
 			a:layout_width="match_parent"
 			a:layout_height="0dp">
 
-		<include layout="@layout/cpp_drag_button_round_brackets"/>
+		<include layout="@layout/cpp_app_button_round_brackets"/>
 
-		<include layout="@layout/cpp_drag_button_0"/>
+		<include layout="@layout/cpp_app_button_0"/>
 
-		<include layout="@layout/cpp_drag_button_dot"/>
+		<include layout="@layout/cpp_app_button_dot"/>
 
-		<include layout="@layout/cpp_drag_button_subtraction"/>
+		<include layout="@layout/cpp_app_button_minus"/>
 
 		<include layout="@layout/cpp_app_button_paste"/>
 
@@ -101,15 +101,15 @@
 			a:layout_width="match_parent"
 			a:layout_height="0dp">
 
-		<include layout="@layout/cpp_drag_button_left"/>
+		<include layout="@layout/cpp_app_button_left"/>
 
-		<include layout="@layout/cpp_drag_button_right"/>
+		<include layout="@layout/cpp_app_button_right"/>
 
-		<include layout="@layout/cpp_drag_button_vars"/>
+		<include layout="@layout/cpp_app_button_vars"/>
 
-		<include layout="@layout/cpp_drag_button_functions"/>
+		<include layout="@layout/cpp_app_button_functions"/>
 
-		<include layout="@layout/cpp_drag_button_history"/>
+		<include layout="@layout/cpp_app_button_history"/>
 
 	</LinearLayout>
 

android-app/src/main/res/layout/cpp_app_keyboard_mobile.xml

@@ -32,15 +32,15 @@
 			a:layout_width="match_parent"
 			a:layout_height="0dp">
 
-		<include layout="@layout/cpp_drag_button_7"/>
+		<include layout="@layout/cpp_app_button_7"/>
 
-		<include layout="@layout/cpp_drag_button_8"/>
+		<include layout="@layout/cpp_app_button_8"/>
 
-		<include layout="@layout/cpp_drag_button_9"/>
+		<include layout="@layout/cpp_app_button_9"/>
 
-		<include layout="@layout/cpp_drag_button_multiplication"/>
+		<include layout="@layout/cpp_app_button_multiplication"/>
 
-		<include layout="@layout/cpp_drag_button_clear"/>
+		<include layout="@layout/cpp_app_button_clear"/>
 
 	</LinearLayout>
 
@@ -49,13 +49,13 @@
 			a:layout_width="match_parent"
 			a:layout_height="0dp">
 
-		<include layout="@layout/cpp_drag_button_4"/>
+		<include layout="@layout/cpp_app_button_4"/>
 
-		<include layout="@layout/cpp_drag_button_5"/>
+		<include layout="@layout/cpp_app_button_5"/>
 
-		<include layout="@layout/cpp_drag_button_6"/>
+		<include layout="@layout/cpp_app_button_6"/>
 
-		<include layout="@layout/cpp_drag_button_division"/>
+		<include layout="@layout/cpp_app_button_division"/>
 
 		<include layout="@layout/cpp_app_button_erase"/>
 
@@ -66,13 +66,13 @@
 			a:layout_width="match_parent"
 			a:layout_height="0dp">
 
-		<include layout="@layout/cpp_drag_button_1"/>
+		<include layout="@layout/cpp_app_button_1"/>
 
-		<include layout="@layout/cpp_drag_button_2"/>
+		<include layout="@layout/cpp_app_button_2"/>
 
-		<include layout="@layout/cpp_drag_button_3"/>
+		<include layout="@layout/cpp_app_button_3"/>
 
-		<include layout="@layout/cpp_drag_button_plus"/>
+		<include layout="@layout/cpp_app_button_plus"/>
 
 		<include layout="@layout/cpp_app_button_copy"/>
 
@@ -83,13 +83,13 @@
 			a:layout_width="match_parent"
 			a:layout_height="0dp">
 
-		<include layout="@layout/cpp_drag_button_round_brackets"/>
+		<include layout="@layout/cpp_app_button_round_brackets"/>
 
-		<include layout="@layout/cpp_drag_button_0"/>
+		<include layout="@layout/cpp_app_button_0"/>
 
-		<include layout="@layout/cpp_drag_button_dot"/>
+		<include layout="@layout/cpp_app_button_dot"/>
 
-		<include layout="@layout/cpp_drag_button_subtraction"/>
+		<include layout="@layout/cpp_app_button_minus"/>
 
 		<include layout="@layout/cpp_app_button_paste"/>
 
@@ -101,15 +101,15 @@
 			a:layout_width="match_parent"
 			a:layout_height="0dp">
 
-		<include layout="@layout/cpp_drag_button_left"/>
+		<include layout="@layout/cpp_app_button_left"/>
 
-		<include layout="@layout/cpp_drag_button_right"/>
+		<include layout="@layout/cpp_app_button_right"/>
 
-		<include layout="@layout/cpp_drag_button_vars"/>
+		<include layout="@layout/cpp_app_button_vars"/>
 
-		<include layout="@layout/cpp_drag_button_functions"/>
+		<include layout="@layout/cpp_app_button_functions"/>
 
-		<include layout="@layout/cpp_drag_button_history"/>
+		<include layout="@layout/cpp_app_button_history"/>
 
 	</LinearLayout>
 

android-app/src/main/res/layout/cpp_wizard_step_choose_theme.xml

@@ -0,0 +1,52 @@
+<?xml version="1.0" encoding="utf-8"?>
+
+<!--
+  ~ 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
+  -->
+
+<LinearLayout xmlns:a="http://schemas.android.com/apk/res/android"
+	a:layout_width="match_parent"
+	a:layout_height="match_parent"
+	a:orientation="vertical"
+	a:gravity="center">
+
+	<TextView
+		a:layout_width="wrap_content"
+		a:layout_height="wrap_content"
+		a:textAppearance="@android:style/TextAppearance.Large"
+		style="@style/WizardLabel"
+		a:text="@string/cpp_wizard_theme_title" />
+
+	<Spinner
+		a:id="@+id/wizard_theme_spinner"
+		a:layout_width="wrap_content"
+		a:layout_height="wrap_content"
+		style="@style/WizardLabel" />
+
+	<FrameLayout
+		a:id="@+id/wizard_theme_preview"
+		a:layout_width="wrap_content"
+		a:layout_height="wrap_content"
+		style="@style/WizardLabel.Last"
+		a:orientation="vertical"
+		/>
+
+</LinearLayout>

android-app/src/main/res/layout/cpp_wizard_step_choose_theme_preview.xml

@@ -0,0 +1,57 @@
+<?xml version="1.0" encoding="utf-8"?>
+
+<!--
+  ~ 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
+  -->
+
+<LinearLayout xmlns:a="http://schemas.android.com/apk/res/android"
+	a:layout_width="wrap_content"
+	a:layout_height="wrap_content"
+	a:orientation="vertical"
+	a:padding="3dp"
+	a:background="?attr/cpp_main_bg">
+
+	<LinearLayout
+		a:layout_width="match_parent"
+		a:layout_height="wrap_content"
+		a:orientation="horizontal">
+
+		<include layout="@layout/cpp_app_button_0" />
+
+		<include layout="@layout/cpp_app_button_copy" />
+
+		<include layout="@layout/cpp_app_button_plus" />
+
+	</LinearLayout>
+
+	<LinearLayout
+		a:layout_width="match_parent"
+		a:layout_height="wrap_content"
+		a:orientation="horizontal">
+
+		<include layout="@layout/cpp_app_button_1" />
+
+		<include layout="@layout/cpp_app_button_paste" />
+
+		<include layout="@layout/cpp_app_button_minus" />
+
+	</LinearLayout>
+</LinearLayout>

android-app/src/main/res/layout/drag_button_calibration.xml

@@ -1,82 +0,0 @@
-<?xml version="1.0" encoding="utf-8"?>
-
-<!--
-  ~ 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
-  -->
-
-<LinearLayout xmlns:a="http://schemas.android.com/apk/res/android"
-			  xmlns:c="http://schemas.android.com/apk/res-auto"
-			  a:orientation="vertical"
-			  a:layout_width="fill_parent"
-			  a:layout_height="fill_parent"
-			  a:background="#ff000000">
-
-	<LinearLayout
-			a:id="@+id/simplePad"
-			a:layout_width="fill_parent"
-			a:layout_height="fill_parent"
-			a:orientation="vertical"
-			a:layout_gravity="center">
-
-		<LinearLayout
-				a:layout_weight="1"
-				a:layout_width="fill_parent"
-				a:layout_height="0dp">
-
-			<ImageView
-					a:id="@+id/calibrationArrowLeft"
-					a:layout_gravity="left"
-					a:layout_width="80dp"
-					a:layout_height="80dp"/>
-
-			<org.solovyev.android.calculator.drag.DirectionDragButton
-					a:id="@+id/calibrationButtonLeft"
-					a:text=""
-					c:textUp="@string/c_up"
-					c:textDown="@string/c_down"
-					a:layout_width="80dp"
-					a:layout_height="80dp"
-					style="?cpp_digit_button_style"/>
-
-			<org.solovyev.android.calculator.drag.DirectionDragButton
-					a:id="@+id/calibrationButtonRight"
-					a:text=""
-					c:textUp="@string/c_up"
-					c:textDown="@string/c_down"
-					a:layout_width="80dp"
-					a:layout_height="80dp"
-					style="?cpp_digit_button_style"/>
-
-			<ImageView
-					a:id="@+id/calibrationArrowRight"
-					a:layout_gravity="right"
-					a:layout_width="80dp"
-					a:layout_height="80dp"/>
-		</LinearLayout>
-	</LinearLayout>
-
-	<Button
-			a:id="@+id/calibrationStart"
-			a:text="@string/c_restart"
-			a:layout_width="wrap_content"
-			a:layout_height="wrap_content"
-			a:layout_gravity="bottom"/>
-</LinearLayout>

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

@@ -43,7 +43,7 @@
 		a:baselineAligned="false">
 
 		<include
-			layout="@layout/cpp_drag_button_equals"
+			layout="@layout/cpp_app_button_equals"
 			a:layout_width="0dp"
 			a:layout_height="match_parent"
 			a:layout_weight="1" />

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

@@ -42,7 +42,7 @@
 			a:layout_height="0dp">
 
 		<include
-				layout="@layout/cpp_drag_button_equals"
+				layout="@layout/cpp_app_button_equals"
 				a:layout_weight="1"
 				a:layout_width="0dp"
 				a:layout_height="match_parent"/>

android-app/src/main/res/values/attributes.xml

@@ -34,5 +34,6 @@
 	<attr name="cpp_pane_style_transparent" format="reference"/>
 	<attr name="cpp_main_layout_style" format="reference"/>
 	<attr name="cpp_main_multi_pane_layout_style" format="reference"/>
+	<attr name="cpp_main_bg" format="reference"/>
 
 </resources>

android-app/src/main/res/values/text_wizard.xml

@@ -27,6 +27,7 @@
   <string name="cpp_wizard_welcome_title">Welcome</string>
   <string name="cpp_wizard_layout_title">Choose layout</string>
   <string name="cpp_wizard_mode_title">Choose mode</string>
+  <string name="cpp_wizard_theme_title">Choose theme</string>
   <string name="cpp_wizard_onscreen_calculator_title">Calculator in a separate window</string>
   <string name="cpp_wizard_dragbutton_title">Drag button basics</string>
   <string name="cpp_wizard_final_done">The app is set up and ready to use.</string>

android-app/src/main/res/values/theme_gray.xml

@@ -145,6 +145,7 @@
 
 		<item name="cpp_pane_style">@style/cpp_default_pane_style</item>
 		<item name="cpp_pane_style_transparent">@style/cpp_default_pane_style_transparent</item>
+		<item name="cpp_main_bg">@color/cpp_main_bg</item>
 	</style>
 
 	<style name="cpp_gray_dialog_theme" parent="Theme.Dialog">
@@ -166,6 +167,7 @@
 
 		<item name="cpp_pane_style">@style/cpp_default_pane_style</item>
 		<item name="cpp_pane_style_transparent">@style/cpp_default_pane_style_transparent</item>
+		<item name="cpp_main_bg">@color/cpp_main_bg</item>
 	</style>
 
 </resources>

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

@@ -22,6 +22,8 @@
 
 package org.solovyev.android.calculator;
 
+import org.solovyev.common.text.Strings;
+
 import javax.annotation.Nonnull;
 import javax.annotation.Nullable;
 
@@ -100,7 +102,13 @@ public enum CalculatorSpecialButton {
 	equals("=") {
 		@Override
 		public void onClick(@Nonnull CalculatorKeyboard keyboard) {
-			Locator.getInstance().getCalculator().evaluate();
+			final CalculatorDisplayViewState displayViewState = Locator.getInstance().getDisplay().getViewState();
+			if (displayViewState.isValid()) {
+				final CharSequence text = displayViewState.getText();
+				if (!Strings.isEmpty(text)) {
+					Locator.getInstance().getEditor().setText(text.toString());
+				}
+			}
 		}
 	},
 	clear("clear") {