src/com/android/settings/accessibility/CaptionAppearanceFragment.java - LeafOS-Project/android_packages_apps_Settings - Gitiles

 /*
  * Copyright (C) 2019 The Android Open Source Project
  *
  * 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.
  */

 package com.android.settings.accessibility;

 import static com.android.settings.accessibility.AccessibilityUtil.State.ON;

 import android.app.settings.SettingsEnums;
 import android.content.ContentResolver;
 import android.content.Context;
 import android.content.res.Resources;
 import android.graphics.Color;
 import android.os.Bundle;
 import android.os.Handler;
 import android.os.Looper;
 import android.provider.Settings;
 import android.view.View;
 import android.view.accessibility.CaptioningManager;

 import androidx.preference.ListPreference;
 import androidx.preference.Preference;
 import androidx.preference.Preference.OnPreferenceChangeListener;
 import androidx.preference.PreferenceCategory;

 import com.android.internal.widget.SubtitleView;
 import com.android.settings.R;
 import com.android.settings.accessibility.ListDialogPreference.OnValueChangedListener;
 import com.android.settings.dashboard.DashboardFragment;
 import com.android.settings.search.BaseSearchIndexProvider;
 import com.android.settingslib.accessibility.AccessibilityUtils;
 import com.android.settingslib.search.SearchIndexable;
 import com.android.settingslib.widget.LayoutPreference;

 import java.util.ArrayList;
 import java.util.List;
 import java.util.Locale;

 /** Settings fragment containing font style of captioning properties. */
 @SearchIndexable(forTarget = SearchIndexable.ALL & ~SearchIndexable.ARC)
 public class CaptionAppearanceFragment extends DashboardFragment
         implements OnPreferenceChangeListener, OnValueChangedListener {

     private static final String TAG = "CaptionAppearanceFragment";
     private static final String PREF_CAPTION_PREVIEW = "caption_preview";
     private static final String PREF_BACKGROUND_COLOR = "captioning_background_color";
     private static final String PREF_BACKGROUND_OPACITY = "captioning_background_opacity";
     private static final String PREF_FOREGROUND_COLOR = "captioning_foreground_color";
     private static final String PREF_FOREGROUND_OPACITY = "captioning_foreground_opacity";
     private static final String PREF_WINDOW_COLOR = "captioning_window_color";
     private static final String PREF_WINDOW_OPACITY = "captioning_window_opacity";
     private static final String PREF_EDGE_COLOR = "captioning_edge_color";
     private static final String PREF_EDGE_TYPE = "captioning_edge_type";
     private static final String PREF_FONT_SIZE = "captioning_font_size";
     private static final String PREF_TYPEFACE = "captioning_typeface";
     private static final String PREF_PRESET = "captioning_preset";
     private static final String PREF_CUSTOM = "custom";

     /* WebVtt specifies line height as 5.3% of the viewport height. */
     private static final float LINE_HEIGHT_RATIO = 0.0533f;

     private CaptioningManager mCaptioningManager;
     private SubtitleView mPreviewText;
     private View mPreviewWindow;
     private View mPreviewViewport;

     // Standard options.
     private ListPreference mFontSize;
     private PresetPreference mPreset;

     // Custom options.
     private ListPreference mTypeface;
     private ColorPreference mForegroundColor;
     private ColorPreference mForegroundOpacity;
     private EdgeTypePreference mEdgeType;
     private ColorPreference mEdgeColor;
     private ColorPreference mBackgroundColor;
     private ColorPreference mBackgroundOpacity;
     private ColorPreference mWindowColor;
     private ColorPreference mWindowOpacity;
     private PreferenceCategory mCustom;

     private boolean mShowingCustom;

     private final List<Preference> mPreferenceList = new ArrayList<>();

     private final Handler mHandler = new Handler(Looper.getMainLooper());
     private final View.OnLayoutChangeListener mLayoutChangeListener =
             new View.OnLayoutChangeListener() {
                 @Override
                 public void onLayoutChange(View v, int left, int top, int right, int bottom,
                         int oldLeft, int oldTop, int oldRight, int oldBottom) {
                     // Remove the listener once the callback is triggered.
                     mPreviewViewport.removeOnLayoutChangeListener(this);
                     mHandler.post(() ->refreshPreviewText());
                 }
             };

     @Override
     public int getMetricsCategory() {
         return SettingsEnums.ACCESSIBILITY_CAPTION_APPEARANCE;
     }

     @Override
     public void onCreatePreferences(Bundle savedInstanceState, String rootKey) {
         super.onCreatePreferences(savedInstanceState, rootKey);

         mCaptioningManager = (CaptioningManager) getSystemService(Context.CAPTIONING_SERVICE);

         initializeAllPreferences();
         updateAllPreferences();
         refreshShowingCustom();
         installUpdateListeners();
         refreshPreviewText();
     }

     @Override
     protected int getPreferenceScreenResId() {
         return R.xml.captioning_appearance;
     }

     @Override
     protected String getLogTag() {
         return TAG;
     }

     private void refreshPreviewText() {
         final Context context = getActivity();
         if (context == null) {
             // We've been destroyed, abort!
             return;
         }

         final SubtitleView preview = mPreviewText;
         if (preview != null) {
             final int styleId = mCaptioningManager.getRawUserStyle();
             applyCaptionProperties(mCaptioningManager, preview, mPreviewViewport, styleId);

             final Locale locale = mCaptioningManager.getLocale();
             if (locale != null) {
                 final CharSequence localizedText = AccessibilityUtils.getTextForLocale(
                         context, locale, R.string.captioning_preview_text);
                 preview.setText(localizedText);
             } else {
                 preview.setText(R.string.captioning_preview_text);
             }

             final CaptioningManager.CaptionStyle style = mCaptioningManager.getUserStyle();
             if (style.hasWindowColor()) {
                 mPreviewWindow.setBackgroundColor(style.windowColor);
             } else {
                 final CaptioningManager.CaptionStyle defStyle =
                         CaptioningManager.CaptionStyle.DEFAULT;
                 mPreviewWindow.setBackgroundColor(defStyle.windowColor);
             }
         }
     }

     /**
      * Updates font style of captioning properties for preview screen.
      *
      * @param manager caption manager
      * @param previewText preview text
      * @param previewWindow preview window
      * @param styleId font style id
      */
     public static void applyCaptionProperties(CaptioningManager manager, SubtitleView previewText,
             View previewWindow, int styleId) {
         previewText.setStyle(styleId);

         final Context context = previewText.getContext();
         final ContentResolver cr = context.getContentResolver();
         final float fontScale = manager.getFontScale();
         if (previewWindow != null) {
             // Assume the viewport is clipped with a 16:9 aspect ratio.
             final float virtualHeight = Math.max(9 * previewWindow.getWidth(),
                     16 * previewWindow.getHeight()) / 16.0f;
             previewText.setTextSize(virtualHeight * LINE_HEIGHT_RATIO * fontScale);
         } else {
             final float textSize = context.getResources().getDimension(
                     R.dimen.caption_preview_text_size);
             previewText.setTextSize(textSize * fontScale);
         }

         final Locale locale = manager.getLocale();
         if (locale != null) {
             final CharSequence localizedText = AccessibilityUtils.getTextForLocale(
                     context, locale, R.string.captioning_preview_characters);
             previewText.setText(localizedText);
         } else {
             previewText.setText(R.string.captioning_preview_characters);
         }
     }

     private void initializeAllPreferences() {
         final LayoutPreference captionPreview = findPreference(PREF_CAPTION_PREVIEW);

         mPreviewText = captionPreview.findViewById(R.id.preview_text);

         mPreviewWindow = captionPreview.findViewById(R.id.preview_window);

         mPreviewViewport = captionPreview.findViewById(R.id.preview_viewport);
         mPreviewViewport.addOnLayoutChangeListener(mLayoutChangeListener);

         final Resources res = getResources();
         final int[] presetValues = res.getIntArray(R.array.captioning_preset_selector_values);
         final String[] presetTitles = res.getStringArray(R.array.captioning_preset_selector_titles);
         mPreset = (PresetPreference) findPreference(PREF_PRESET);
         mPreset.setValues(presetValues);
         mPreset.setTitles(presetTitles);

         mFontSize = (ListPreference) findPreference(PREF_FONT_SIZE);

         // Initialize the preference list
         mPreferenceList.add(mFontSize);
         mPreferenceList.add(mPreset);

         mCustom = (PreferenceCategory) findPreference(PREF_CUSTOM);
         mShowingCustom = true;

         final int[] colorValues = res.getIntArray(R.array.captioning_color_selector_values);
         final String[] colorTitles = res.getStringArray(R.array.captioning_color_selector_titles);
         mForegroundColor = (ColorPreference) mCustom.findPreference(PREF_FOREGROUND_COLOR);
         mForegroundColor.setTitles(colorTitles);
         mForegroundColor.setValues(colorValues);

         final int[] opacityValues = res.getIntArray(R.array.captioning_opacity_selector_values);
         final String[] opacityTitles = res.getStringArray(
                 R.array.captioning_opacity_selector_titles);
         mForegroundOpacity = (ColorPreference) mCustom.findPreference(PREF_FOREGROUND_OPACITY);
         mForegroundOpacity.setTitles(opacityTitles);
         mForegroundOpacity.setValues(opacityValues);

         mEdgeColor = (ColorPreference) mCustom.findPreference(PREF_EDGE_COLOR);
         mEdgeColor.setTitles(colorTitles);
         mEdgeColor.setValues(colorValues);

         // Add "none" as an additional option for backgrounds.
         final int[] bgColorValues = new int[colorValues.length + 1];
         final String[] bgColorTitles = new String[colorTitles.length + 1];
         System.arraycopy(colorValues, 0, bgColorValues, 1, colorValues.length);
         System.arraycopy(colorTitles, 0, bgColorTitles, 1, colorTitles.length);
         bgColorValues[0] = Color.TRANSPARENT;
         bgColorTitles[0] = getString(R.string.color_none);
         mBackgroundColor = (ColorPreference) mCustom.findPreference(PREF_BACKGROUND_COLOR);
         mBackgroundColor.setTitles(bgColorTitles);
         mBackgroundColor.setValues(bgColorValues);

         mBackgroundOpacity = (ColorPreference) mCustom.findPreference(PREF_BACKGROUND_OPACITY);
         mBackgroundOpacity.setTitles(opacityTitles);
         mBackgroundOpacity.setValues(opacityValues);

         mWindowColor = (ColorPreference) mCustom.findPreference(PREF_WINDOW_COLOR);
         mWindowColor.setTitles(bgColorTitles);
         mWindowColor.setValues(bgColorValues);

         mWindowOpacity = (ColorPreference) mCustom.findPreference(PREF_WINDOW_OPACITY);
         mWindowOpacity.setTitles(opacityTitles);
         mWindowOpacity.setValues(opacityValues);

         mEdgeType = (EdgeTypePreference) mCustom.findPreference(PREF_EDGE_TYPE);
         mTypeface = (ListPreference) mCustom.findPreference(PREF_TYPEFACE);
     }

     private void installUpdateListeners() {
         mPreset.setOnValueChangedListener(this);
         mForegroundColor.setOnValueChangedListener(this);
         mForegroundOpacity.setOnValueChangedListener(this);
         mEdgeColor.setOnValueChangedListener(this);
         mBackgroundColor.setOnValueChangedListener(this);
         mBackgroundOpacity.setOnValueChangedListener(this);
         mWindowColor.setOnValueChangedListener(this);
         mWindowOpacity.setOnValueChangedListener(this);
         mEdgeType.setOnValueChangedListener(this);

         mTypeface.setOnPreferenceChangeListener(this);
         mFontSize.setOnPreferenceChangeListener(this);
     }

     private void updateAllPreferences() {
         final int preset = mCaptioningManager.getRawUserStyle();
         mPreset.setValue(preset);

         final float fontSize = mCaptioningManager.getFontScale();
         mFontSize.setValue(Float.toString(fontSize));

         final ContentResolver cr = getContentResolver();
         final CaptioningManager.CaptionStyle attrs = CaptioningManager.CaptionStyle.getCustomStyle(
                 cr);
         mEdgeType.setValue(attrs.edgeType);
         mEdgeColor.setValue(attrs.edgeColor);

         final int foregroundColor = attrs.hasForegroundColor() ? attrs.foregroundColor
                 : CaptioningManager.CaptionStyle.COLOR_UNSPECIFIED;
         parseColorOpacity(mForegroundColor, mForegroundOpacity, foregroundColor);

         final int backgroundColor = attrs.hasBackgroundColor() ? attrs.backgroundColor
                 : CaptioningManager.CaptionStyle.COLOR_UNSPECIFIED;
         parseColorOpacity(mBackgroundColor, mBackgroundOpacity, backgroundColor);

         final int windowColor = attrs.hasWindowColor() ? attrs.windowColor
                 : CaptioningManager.CaptionStyle.COLOR_UNSPECIFIED;
         parseColorOpacity(mWindowColor, mWindowOpacity, windowColor);

         final String rawTypeface = attrs.mRawTypeface;
         mTypeface.setValue(rawTypeface == null ? "" : rawTypeface);
     }

     /**
      * Unpacks the specified color value and update the preferences.
      *
      * @param color   color preference
      * @param opacity opacity preference
      * @param value   packed value
      */
     private void parseColorOpacity(ColorPreference color, ColorPreference opacity, int value) {
         final int colorValue;
         final int opacityValue;
         if (!CaptioningManager.CaptionStyle.hasColor(value)) {
             // "Default" color with variable alpha.
             colorValue = CaptioningManager.CaptionStyle.COLOR_UNSPECIFIED;
             opacityValue = (value & 0xFF) << 24;
         } else if ((value >>> 24) == 0) {
             // "None" color with variable alpha.
             colorValue = Color.TRANSPARENT;
             opacityValue = (value & 0xFF) << 24;
         } else {
             // Normal color.
             colorValue = value | 0xFF000000;
             opacityValue = value & 0xFF000000;
         }

         // Opacity value is always white.
         opacity.setValue(opacityValue | 0xFFFFFF);
         color.setValue(colorValue);
     }

     private int mergeColorOpacity(ColorPreference color, ColorPreference opacity) {
         final int colorValue = color.getValue();
         final int opacityValue = opacity.getValue();
         final int value;
         // "Default" is 0x00FFFFFF or, for legacy support, 0x00000100.
         if (!CaptioningManager.CaptionStyle.hasColor(colorValue)) {
             // Encode "default" as 0x00FFFFaa.
             value = 0x00FFFF00 | Color.alpha(opacityValue);
         } else if (colorValue == Color.TRANSPARENT) {
             // Encode "none" as 0x000000aa.
             value = Color.alpha(opacityValue);
         } else {
             // Encode custom color normally.
             value = colorValue & 0x00FFFFFF | opacityValue & 0xFF000000;
         }
         return value;
     }

     private void refreshShowingCustom() {
         final boolean customPreset =
                 mPreset.getValue() == CaptioningManager.CaptionStyle.PRESET_CUSTOM;
         if (!customPreset && mShowingCustom) {
             getPreferenceScreen().removePreference(mCustom);
             mShowingCustom = false;
         } else if (customPreset && !mShowingCustom) {
             getPreferenceScreen().addPreference(mCustom);
             mShowingCustom = true;
         }
     }

     @Override
     public void onValueChanged(ListDialogPreference preference, int value) {
         final ContentResolver cr = getActivity().getContentResolver();
         if (mForegroundColor == preference || mForegroundOpacity == preference) {
             final int merged = mergeColorOpacity(mForegroundColor, mForegroundOpacity);
             Settings.Secure.putInt(
                     cr, Settings.Secure.ACCESSIBILITY_CAPTIONING_FOREGROUND_COLOR, merged);
         } else if (mBackgroundColor == preference || mBackgroundOpacity == preference) {
             final int merged = mergeColorOpacity(mBackgroundColor, mBackgroundOpacity);
             Settings.Secure.putInt(
                     cr, Settings.Secure.ACCESSIBILITY_CAPTIONING_BACKGROUND_COLOR, merged);
         } else if (mWindowColor == preference || mWindowOpacity == preference) {
             final int merged = mergeColorOpacity(mWindowColor, mWindowOpacity);
             Settings.Secure.putInt(
                     cr, Settings.Secure.ACCESSIBILITY_CAPTIONING_WINDOW_COLOR, merged);
         } else if (mEdgeColor == preference) {
             Settings.Secure.putInt(cr, Settings.Secure.ACCESSIBILITY_CAPTIONING_EDGE_COLOR, value);
         } else if (mPreset == preference) {
             Settings.Secure.putInt(cr, Settings.Secure.ACCESSIBILITY_CAPTIONING_PRESET, value);
             refreshShowingCustom();
         } else if (mEdgeType == preference) {
             Settings.Secure.putInt(cr, Settings.Secure.ACCESSIBILITY_CAPTIONING_EDGE_TYPE, value);
         }

         refreshPreviewText();
         enableCaptioningManager();
     }

     @Override
     public boolean onPreferenceChange(Preference preference, Object value) {
         final ContentResolver cr = getActivity().getContentResolver();
         if (mTypeface == preference) {
             Settings.Secure.putString(
                     cr, Settings.Secure.ACCESSIBILITY_CAPTIONING_TYPEFACE, (String) value);
             refreshPreviewText();
             enableCaptioningManager();
         } else if (mFontSize == preference) {
             Settings.Secure.putFloat(
                     cr, Settings.Secure.ACCESSIBILITY_CAPTIONING_FONT_SCALE,
                     Float.parseFloat((String) value));
             refreshPreviewText();
             enableCaptioningManager();
         }

         return true;
     }

     private void enableCaptioningManager() {
         if (mCaptioningManager.isEnabled()) {
             return;
         }
         Settings.Secure.putInt(getContentResolver(),
                 Settings.Secure.ACCESSIBILITY_CAPTIONING_ENABLED, ON);
     }

     @Override
     public int getHelpResource() {
         return R.string.help_url_caption;
     }

     public static final BaseSearchIndexProvider SEARCH_INDEX_DATA_PROVIDER =
             new BaseSearchIndexProvider(R.xml.captioning_appearance);
 }
	/*
	* Copyright (C) 2019 The Android Open Source Project
	*
	* 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.
	*/

	package com.android.settings.accessibility;

	import static com.android.settings.accessibility.AccessibilityUtil.State.ON;

	import android.app.settings.SettingsEnums;
	import android.content.ContentResolver;
	import android.content.Context;
	import android.content.res.Resources;
	import android.graphics.Color;
	import android.os.Bundle;
	import android.os.Handler;
	import android.os.Looper;
	import android.provider.Settings;
	import android.view.View;
	import android.view.accessibility.CaptioningManager;

	import androidx.preference.ListPreference;
	import androidx.preference.Preference;
	import androidx.preference.Preference.OnPreferenceChangeListener;
	import androidx.preference.PreferenceCategory;

	import com.android.internal.widget.SubtitleView;
	import com.android.settings.R;
	import com.android.settings.accessibility.ListDialogPreference.OnValueChangedListener;
	import com.android.settings.dashboard.DashboardFragment;
	import com.android.settings.search.BaseSearchIndexProvider;
	import com.android.settingslib.accessibility.AccessibilityUtils;
	import com.android.settingslib.search.SearchIndexable;
	import com.android.settingslib.widget.LayoutPreference;

	import java.util.ArrayList;
	import java.util.List;
	import java.util.Locale;

	/** Settings fragment containing font style of captioning properties. */
	@SearchIndexable(forTarget = SearchIndexable.ALL & ~SearchIndexable.ARC)
	public class CaptionAppearanceFragment extends DashboardFragment
	implements OnPreferenceChangeListener, OnValueChangedListener {

	private static final String TAG = "CaptionAppearanceFragment";
	private static final String PREF_CAPTION_PREVIEW = "caption_preview";
	private static final String PREF_BACKGROUND_COLOR = "captioning_background_color";
	private static final String PREF_BACKGROUND_OPACITY = "captioning_background_opacity";
	private static final String PREF_FOREGROUND_COLOR = "captioning_foreground_color";
	private static final String PREF_FOREGROUND_OPACITY = "captioning_foreground_opacity";
	private static final String PREF_WINDOW_COLOR = "captioning_window_color";
	private static final String PREF_WINDOW_OPACITY = "captioning_window_opacity";
	private static final String PREF_EDGE_COLOR = "captioning_edge_color";
	private static final String PREF_EDGE_TYPE = "captioning_edge_type";
	private static final String PREF_FONT_SIZE = "captioning_font_size";
	private static final String PREF_TYPEFACE = "captioning_typeface";
	private static final String PREF_PRESET = "captioning_preset";
	private static final String PREF_CUSTOM = "custom";

	/* WebVtt specifies line height as 5.3% of the viewport height. */
	private static final float LINE_HEIGHT_RATIO = 0.0533f;

	private CaptioningManager mCaptioningManager;
	private SubtitleView mPreviewText;
	private View mPreviewWindow;
	private View mPreviewViewport;

	// Standard options.
	private ListPreference mFontSize;
	private PresetPreference mPreset;

	// Custom options.
	private ListPreference mTypeface;
	private ColorPreference mForegroundColor;
	private ColorPreference mForegroundOpacity;
	private EdgeTypePreference mEdgeType;
	private ColorPreference mEdgeColor;
	private ColorPreference mBackgroundColor;
	private ColorPreference mBackgroundOpacity;
	private ColorPreference mWindowColor;
	private ColorPreference mWindowOpacity;
	private PreferenceCategory mCustom;

	private boolean mShowingCustom;

	private final List<Preference> mPreferenceList = new ArrayList<>();

	private final Handler mHandler = new Handler(Looper.getMainLooper());
	private final View.OnLayoutChangeListener mLayoutChangeListener =
	new View.OnLayoutChangeListener() {
	@Override
	public void onLayoutChange(View v, int left, int top, int right, int bottom,
	int oldLeft, int oldTop, int oldRight, int oldBottom) {
	// Remove the listener once the callback is triggered.
	mPreviewViewport.removeOnLayoutChangeListener(this);
	mHandler.post(() ->refreshPreviewText());
	}
	};

	@Override
	public int getMetricsCategory() {
	return SettingsEnums.ACCESSIBILITY_CAPTION_APPEARANCE;
	}

	@Override
	public void onCreatePreferences(Bundle savedInstanceState, String rootKey) {
	super.onCreatePreferences(savedInstanceState, rootKey);

	mCaptioningManager = (CaptioningManager) getSystemService(Context.CAPTIONING_SERVICE);

	initializeAllPreferences();
	updateAllPreferences();
	refreshShowingCustom();
	installUpdateListeners();
	refreshPreviewText();
	}

	@Override
	protected int getPreferenceScreenResId() {
	return R.xml.captioning_appearance;
	}

	@Override
	protected String getLogTag() {
	return TAG;
	}

	private void refreshPreviewText() {
	final Context context = getActivity();
	if (context == null) {
	// We've been destroyed, abort!
	return;
	}

	final SubtitleView preview = mPreviewText;
	if (preview != null) {
	final int styleId = mCaptioningManager.getRawUserStyle();
	applyCaptionProperties(mCaptioningManager, preview, mPreviewViewport, styleId);

	final Locale locale = mCaptioningManager.getLocale();
	if (locale != null) {
	final CharSequence localizedText = AccessibilityUtils.getTextForLocale(
	context, locale, R.string.captioning_preview_text);
	preview.setText(localizedText);
	} else {
	preview.setText(R.string.captioning_preview_text);
	}

	final CaptioningManager.CaptionStyle style = mCaptioningManager.getUserStyle();
	if (style.hasWindowColor()) {
	mPreviewWindow.setBackgroundColor(style.windowColor);
	} else {
	final CaptioningManager.CaptionStyle defStyle =
	CaptioningManager.CaptionStyle.DEFAULT;
	mPreviewWindow.setBackgroundColor(defStyle.windowColor);
	}
	}
	}

	/**
	* Updates font style of captioning properties for preview screen.
	*
	* @param manager caption manager
	* @param previewText preview text
	* @param previewWindow preview window
	* @param styleId font style id
	*/
	public static void applyCaptionProperties(CaptioningManager manager, SubtitleView previewText,
	View previewWindow, int styleId) {
	previewText.setStyle(styleId);

	final Context context = previewText.getContext();
	final ContentResolver cr = context.getContentResolver();
	final float fontScale = manager.getFontScale();
	if (previewWindow != null) {
	// Assume the viewport is clipped with a 16:9 aspect ratio.
	final float virtualHeight = Math.max(9 * previewWindow.getWidth(),
	16 * previewWindow.getHeight()) / 16.0f;
	previewText.setTextSize(virtualHeight * LINE_HEIGHT_RATIO * fontScale);
	} else {
	final float textSize = context.getResources().getDimension(
	R.dimen.caption_preview_text_size);
	previewText.setTextSize(textSize * fontScale);
	}

	final Locale locale = manager.getLocale();
	if (locale != null) {
	final CharSequence localizedText = AccessibilityUtils.getTextForLocale(
	context, locale, R.string.captioning_preview_characters);
	previewText.setText(localizedText);
	} else {
	previewText.setText(R.string.captioning_preview_characters);
	}
	}

	private void initializeAllPreferences() {
	final LayoutPreference captionPreview = findPreference(PREF_CAPTION_PREVIEW);

	mPreviewText = captionPreview.findViewById(R.id.preview_text);

	mPreviewWindow = captionPreview.findViewById(R.id.preview_window);

	mPreviewViewport = captionPreview.findViewById(R.id.preview_viewport);
	mPreviewViewport.addOnLayoutChangeListener(mLayoutChangeListener);

	final Resources res = getResources();
	final int[] presetValues = res.getIntArray(R.array.captioning_preset_selector_values);
	final String[] presetTitles = res.getStringArray(R.array.captioning_preset_selector_titles);
	mPreset = (PresetPreference) findPreference(PREF_PRESET);
	mPreset.setValues(presetValues);
	mPreset.setTitles(presetTitles);

	mFontSize = (ListPreference) findPreference(PREF_FONT_SIZE);

	// Initialize the preference list
	mPreferenceList.add(mFontSize);
	mPreferenceList.add(mPreset);

	mCustom = (PreferenceCategory) findPreference(PREF_CUSTOM);
	mShowingCustom = true;

	final int[] colorValues = res.getIntArray(R.array.captioning_color_selector_values);
	final String[] colorTitles = res.getStringArray(R.array.captioning_color_selector_titles);
	mForegroundColor = (ColorPreference) mCustom.findPreference(PREF_FOREGROUND_COLOR);
	mForegroundColor.setTitles(colorTitles);
	mForegroundColor.setValues(colorValues);

	final int[] opacityValues = res.getIntArray(R.array.captioning_opacity_selector_values);
	final String[] opacityTitles = res.getStringArray(
	R.array.captioning_opacity_selector_titles);
	mForegroundOpacity = (ColorPreference) mCustom.findPreference(PREF_FOREGROUND_OPACITY);
	mForegroundOpacity.setTitles(opacityTitles);
	mForegroundOpacity.setValues(opacityValues);

	mEdgeColor = (ColorPreference) mCustom.findPreference(PREF_EDGE_COLOR);
	mEdgeColor.setTitles(colorTitles);
	mEdgeColor.setValues(colorValues);

	// Add "none" as an additional option for backgrounds.
	final int[] bgColorValues = new int[colorValues.length + 1];
	final String[] bgColorTitles = new String[colorTitles.length + 1];
	System.arraycopy(colorValues, 0, bgColorValues, 1, colorValues.length);
	System.arraycopy(colorTitles, 0, bgColorTitles, 1, colorTitles.length);
	bgColorValues[0] = Color.TRANSPARENT;
	bgColorTitles[0] = getString(R.string.color_none);
	mBackgroundColor = (ColorPreference) mCustom.findPreference(PREF_BACKGROUND_COLOR);
	mBackgroundColor.setTitles(bgColorTitles);
	mBackgroundColor.setValues(bgColorValues);

	mBackgroundOpacity = (ColorPreference) mCustom.findPreference(PREF_BACKGROUND_OPACITY);
	mBackgroundOpacity.setTitles(opacityTitles);
	mBackgroundOpacity.setValues(opacityValues);

	mWindowColor = (ColorPreference) mCustom.findPreference(PREF_WINDOW_COLOR);
	mWindowColor.setTitles(bgColorTitles);
	mWindowColor.setValues(bgColorValues);

	mWindowOpacity = (ColorPreference) mCustom.findPreference(PREF_WINDOW_OPACITY);
	mWindowOpacity.setTitles(opacityTitles);
	mWindowOpacity.setValues(opacityValues);

	mEdgeType = (EdgeTypePreference) mCustom.findPreference(PREF_EDGE_TYPE);
	mTypeface = (ListPreference) mCustom.findPreference(PREF_TYPEFACE);
	}

	private void installUpdateListeners() {
	mPreset.setOnValueChangedListener(this);
	mForegroundColor.setOnValueChangedListener(this);
	mForegroundOpacity.setOnValueChangedListener(this);
	mEdgeColor.setOnValueChangedListener(this);
	mBackgroundColor.setOnValueChangedListener(this);
	mBackgroundOpacity.setOnValueChangedListener(this);
	mWindowColor.setOnValueChangedListener(this);
	mWindowOpacity.setOnValueChangedListener(this);
	mEdgeType.setOnValueChangedListener(this);

	mTypeface.setOnPreferenceChangeListener(this);
	mFontSize.setOnPreferenceChangeListener(this);
	}

	private void updateAllPreferences() {
	final int preset = mCaptioningManager.getRawUserStyle();
	mPreset.setValue(preset);

	final float fontSize = mCaptioningManager.getFontScale();
	mFontSize.setValue(Float.toString(fontSize));

	final ContentResolver cr = getContentResolver();
	final CaptioningManager.CaptionStyle attrs = CaptioningManager.CaptionStyle.getCustomStyle(
	cr);
	mEdgeType.setValue(attrs.edgeType);
	mEdgeColor.setValue(attrs.edgeColor);

	final int foregroundColor = attrs.hasForegroundColor() ? attrs.foregroundColor
	: CaptioningManager.CaptionStyle.COLOR_UNSPECIFIED;
	parseColorOpacity(mForegroundColor, mForegroundOpacity, foregroundColor);

	final int backgroundColor = attrs.hasBackgroundColor() ? attrs.backgroundColor
	: CaptioningManager.CaptionStyle.COLOR_UNSPECIFIED;
	parseColorOpacity(mBackgroundColor, mBackgroundOpacity, backgroundColor);

	final int windowColor = attrs.hasWindowColor() ? attrs.windowColor
	: CaptioningManager.CaptionStyle.COLOR_UNSPECIFIED;
	parseColorOpacity(mWindowColor, mWindowOpacity, windowColor);

	final String rawTypeface = attrs.mRawTypeface;
	mTypeface.setValue(rawTypeface == null ? "" : rawTypeface);
	}

	/**
	* Unpacks the specified color value and update the preferences.
	*
	* @param color color preference
	* @param opacity opacity preference
	* @param value packed value
	*/
	private void parseColorOpacity(ColorPreference color, ColorPreference opacity, int value) {
	final int colorValue;
	final int opacityValue;
	if (!CaptioningManager.CaptionStyle.hasColor(value)) {
	// "Default" color with variable alpha.
	colorValue = CaptioningManager.CaptionStyle.COLOR_UNSPECIFIED;
	opacityValue = (value & 0xFF) << 24;
	} else if ((value >>> 24) == 0) {
	// "None" color with variable alpha.
	colorValue = Color.TRANSPARENT;
	opacityValue = (value & 0xFF) << 24;
	} else {
	// Normal color.
	colorValue = value \| 0xFF000000;
	opacityValue = value & 0xFF000000;
	}

	// Opacity value is always white.
	opacity.setValue(opacityValue \| 0xFFFFFF);
	color.setValue(colorValue);
	}

	private int mergeColorOpacity(ColorPreference color, ColorPreference opacity) {
	final int colorValue = color.getValue();
	final int opacityValue = opacity.getValue();
	final int value;
	// "Default" is 0x00FFFFFF or, for legacy support, 0x00000100.
	if (!CaptioningManager.CaptionStyle.hasColor(colorValue)) {
	// Encode "default" as 0x00FFFFaa.
	value = 0x00FFFF00 \| Color.alpha(opacityValue);
	} else if (colorValue == Color.TRANSPARENT) {
	// Encode "none" as 0x000000aa.
	value = Color.alpha(opacityValue);
	} else {
	// Encode custom color normally.
	value = colorValue & 0x00FFFFFF \| opacityValue & 0xFF000000;
	}
	return value;
	}

	private void refreshShowingCustom() {
	final boolean customPreset =
	mPreset.getValue() == CaptioningManager.CaptionStyle.PRESET_CUSTOM;
	if (!customPreset && mShowingCustom) {
	getPreferenceScreen().removePreference(mCustom);
	mShowingCustom = false;
	} else if (customPreset && !mShowingCustom) {
	getPreferenceScreen().addPreference(mCustom);
	mShowingCustom = true;
	}
	}

	@Override
	public void onValueChanged(ListDialogPreference preference, int value) {
	final ContentResolver cr = getActivity().getContentResolver();
	if (mForegroundColor == preference \|\| mForegroundOpacity == preference) {
	final int merged = mergeColorOpacity(mForegroundColor, mForegroundOpacity);
	Settings.Secure.putInt(
	cr, Settings.Secure.ACCESSIBILITY_CAPTIONING_FOREGROUND_COLOR, merged);
	} else if (mBackgroundColor == preference \|\| mBackgroundOpacity == preference) {
	final int merged = mergeColorOpacity(mBackgroundColor, mBackgroundOpacity);
	Settings.Secure.putInt(
	cr, Settings.Secure.ACCESSIBILITY_CAPTIONING_BACKGROUND_COLOR, merged);
	} else if (mWindowColor == preference \|\| mWindowOpacity == preference) {
	final int merged = mergeColorOpacity(mWindowColor, mWindowOpacity);
	Settings.Secure.putInt(
	cr, Settings.Secure.ACCESSIBILITY_CAPTIONING_WINDOW_COLOR, merged);
	} else if (mEdgeColor == preference) {
	Settings.Secure.putInt(cr, Settings.Secure.ACCESSIBILITY_CAPTIONING_EDGE_COLOR, value);
	} else if (mPreset == preference) {
	Settings.Secure.putInt(cr, Settings.Secure.ACCESSIBILITY_CAPTIONING_PRESET, value);
	refreshShowingCustom();
	} else if (mEdgeType == preference) {
	Settings.Secure.putInt(cr, Settings.Secure.ACCESSIBILITY_CAPTIONING_EDGE_TYPE, value);
	}

	refreshPreviewText();
	enableCaptioningManager();
	}

	@Override
	public boolean onPreferenceChange(Preference preference, Object value) {
	final ContentResolver cr = getActivity().getContentResolver();
	if (mTypeface == preference) {
	Settings.Secure.putString(
	cr, Settings.Secure.ACCESSIBILITY_CAPTIONING_TYPEFACE, (String) value);
	refreshPreviewText();
	enableCaptioningManager();
	} else if (mFontSize == preference) {
	Settings.Secure.putFloat(
	cr, Settings.Secure.ACCESSIBILITY_CAPTIONING_FONT_SCALE,
	Float.parseFloat((String) value));
	refreshPreviewText();
	enableCaptioningManager();
	}

	return true;
	}

	private void enableCaptioningManager() {
	if (mCaptioningManager.isEnabled()) {
	return;
	}
	Settings.Secure.putInt(getContentResolver(),
	Settings.Secure.ACCESSIBILITY_CAPTIONING_ENABLED, ON);
	}

	@Override
	public int getHelpResource() {
	return R.string.help_url_caption;
	}

	public static final BaseSearchIndexProvider SEARCH_INDEX_DATA_PROVIDER =
	new BaseSearchIndexProvider(R.xml.captioning_appearance);
	}