TalkBackPreferencesActivity.java 文件源码

/**
 * Touch exploration preference management code
 *
 * @param category The touch exploration category.
 */
private void checkTouchExplorationSupportInner(PreferenceGroup category) {
    final TwoStatePreference prefTouchExploration =
            (TwoStatePreference) findPreferenceByResId(
                    R.string.pref_explore_by_touch_reflect_key);
    if (prefTouchExploration == null) {
        return;
    }

    // Remove single-tap preference if it's not supported on this device.
    final TwoStatePreference prefSingleTap = (TwoStatePreference) findPreferenceByResId(
            R.string.pref_single_tap_key);
    if ((prefSingleTap != null)
            && (Build.VERSION.SDK_INT <
            ProcessorFocusAndSingleTap.MIN_API_LEVEL_SINGLE_TAP)) {
        category.removePreference(prefSingleTap);
    }

    // Ensure that changes to the reflected preference's checked state never
    // trigger content observers.
    prefTouchExploration.setPersistent(false);

    // Synchronize the reflected state.
    updateTouchExplorationState();

    // Set up listeners that will keep the state synchronized.
    prefTouchExploration.setOnPreferenceChangeListener(mTouchExplorationChangeListener);

    // Hook in the external PreferenceActivity for gesture management
    final Preference shortcutsScreen = findPreferenceByResId(
            R.string.pref_category_manage_gestures_key);

    Activity activity = getActivity();
    if (activity != null) {
        final Intent shortcutsIntent = new Intent(
                activity, TalkBackShortcutPreferencesActivity.class);
        shortcutsScreen.setIntent(shortcutsIntent);
    }
}