Adopt system caption settings (original) (raw)

On Android TV, settings are provided for users to define their own caption style. This guide demonstrates how an app can obtain and apply the system-provided caption style.

The caption options can be found under Settings > System > Accessibility > Caption:

Obtain the CaptioningManager

From an activity, you can get the caption service from its Context usingCaptioningManager:

CaptioningManager captioningManager = (CaptioningManager)context.getSystemService(Context.CAPTIONING_SERVICE);

Handle caption style changes

You can then handle caption style changes by implementing CaptioningChangeListener:

if (captioningManager != null) {
  // Define a class to store the CaptionStyle details.
  CurrentCaptionStyle currentCaptionStyle = new CurrentCaptionStyle;
  // Define the listeners.
  captioningManager.addCaptioningChangeListener(new CaptioningChangeListener() {

    @Override
    public void onEnabledChanged(boolean enabled) {
      super.onEnabledChanged(enabled);
      Log.d(TAG, "onEnabledChanged");
      currentCaptionStyle.isEnabled = enabled;
    }

    @Override
    public void onLocaleChanged(@Nullable Locale locale) {
      super.onLocaleChanged(locale);
      Log.d(TAG, "onLocaleChanged");
      currentCaptionStyle.locale = locale;
    }

    @Override
    public void onFontScaleChanged(float fontScale) {
      super.onFontScaleChanged(fontScale);
      Log.d(TAG, "onFontScaleChanged");
      currentCaptionStyle.fontScale = fontScale;
    }

    @Override
    public void onUserStyleChanged(@NonNull CaptionStyle userStyle) {
      super.onUserStyleChanged(userStyle);
      Log.d(TAG, "onUserStyleChanged");
      currentCaptionStyle.hasBackgroundColor = userStyle.hasBackgroundColor();
      currentCaptionStyle.backgroundColor = userStyle.backgroundColor;
      currentCaptionStyle.backgroundOpcity = userStyle.backgroundColor >>> 24;
      currentCaptionStyle.hasForegroundColor = userStyle.hasForegroundColor();
      currentCaptionStyle.foregroundColor = userStyle.foregroundColor;
      currentCaptionStyle.foregroundOpacity = userStyle.foregroundColor >>> 24;
      currentCaptionStyle.hasWindowColor = userStyle.hasWindowColor();
      currentCaptionStyle.windowColor = userStyle.windowColor;
      currentCaptionStyle.windowOpcity = userStyle.windowColor >>> 24;
      currentCaptionStyle.hasEdgeColor = userStyle.hasEdgeColor();
      currentCaptionStyle.edgeColor = userStyle.edgeColor;
      currentCaptionStyle.hasEdgeType = userStyle.hasEdgeType();
      currentCaptionStyle.edgeType = userStyle.edgeType;
      currentCaptionStyle.typeFace = userStyle.getTypeface();
    }

  });

To obtain the system CaptionStyle, you can call getUserStyle()directly:

CaptionStyle systemCaptionStyle = captioningManager.getUserStyle();