android.view.accessibility.AccessibilityNodeInfo#setRangeInfo ( )源码实例Demo

/** @hide */
@Override
public void onInitializeAccessibilityNodeInfoInternal(AccessibilityNodeInfo info) {
    super.onInitializeAccessibilityNodeInfoInternal(info);

    if (!isIndeterminate()) {
        AccessibilityNodeInfo.RangeInfo rangeInfo = AccessibilityNodeInfo.RangeInfo.obtain(
                AccessibilityNodeInfo.RangeInfo.RANGE_TYPE_INT, getMin(), getMax(),
                getProgress());
        info.setRangeInfo(rangeInfo);
    }
}
 

@Override
public void onInitializeAccessibilityNodeInfo(View host, AccessibilityNodeInfo info) {
  super.onInitializeAccessibilityNodeInfo(host, info);
  info.setClassName(ProgressBar.class.getName());
  AudioManager audioManager =
      (AudioManager) getContext().getSystemService(Context.AUDIO_SERVICE);
  if ((audioManager == null) || (VERSION.SDK_INT < VERSION_CODES.N)) {
    return;
  }

  // Setting the range info on a device pre-N causes the volume percent to be always announced
  // as "0 percent." Not setting the range info on M-devices results in the percentage
  // corresponding to the volume slider to be announced. This is slightly different from the
  // actual volume percentage due to how progress bars are set. Therefore, we should prefer the
  // range info spoken feedback when possible, but when not available (i.e. on M-devices) use
  // the spoken feedback corresponding to the progress bar progress instead.
  float minVolume = audioManager.getStreamMinVolume(volumeStreamType);
  float maxVolume = audioManager.getStreamMaxVolume(volumeStreamType);
  float currentVolume = audioManager.getStreamVolume(volumeStreamType);

  // Note that this corresponds to the actual volume percentage given by the Volume Settings
  // page, which may be different than what TalkBack uses. Volume Settings calculates percentage
  // of total volume and not percentage of the valid volume range, otherwise we would subtract
  // minimum volume from the current volume.
  float percent = ((currentVolume) / (maxVolume - minVolume)) * 100;

  AccessibilityNodeInfo.RangeInfo rangeInfo =
      AccessibilityNodeInfo.RangeInfo.obtain(RangeInfo.RANGE_TYPE_PERCENT, 0, 100, percent);
  info.setRangeInfo(rangeInfo);
}
 

@Override
protected void setAccessibilityNodeInfoRangeInfo(AccessibilityNodeInfo node,
        int rangeType, float min, float max, float current) {
    node.setRangeInfo(AccessibilityNodeInfo.RangeInfo.obtain(
            rangeType, min, max, current));
}