Java Code Examples for androidx.core.view.accessibility.AccessibilityNodeInfoCompat#ACTION_SCROLL_BACKWARD

@Override
public boolean performAccessibilityAction(View host, int action, Bundle args) {
    if (super.performAccessibilityAction(host, action, args)) {
        return true;
    }
    switch (action) {
        case AccessibilityNodeInfoCompat.ACTION_SCROLL_FORWARD: {
            if (canScrollHorizontally(1)) {
                setCurrentItem(mCurItem + 1);
                return true;
            }
        }
        return false;
        case AccessibilityNodeInfoCompat.ACTION_SCROLL_BACKWARD: {
            if (canScrollHorizontally(-1)) {
                setCurrentItem(mCurItem - 1);
                return true;
            }
        }
        return false;
    }
    return false;
}
 

@Override
public boolean performAccessibilityAction(View host, int action, Bundle args) {
    if (super.performAccessibilityAction(host, action, args)) {
        return true;
    }
    switch (action) {
        case AccessibilityNodeInfoCompat.ACTION_SCROLL_FORWARD: {
            if (internalCanScrollVertically(1)) {
                setCurrentItem(mCurItem + 1);
                return true;
            }
        }
        return false;
        case AccessibilityNodeInfoCompat.ACTION_SCROLL_BACKWARD: {
            if (internalCanScrollVertically(-1)) {
                setCurrentItem(mCurItem - 1);
                return true;
            }
        }
        return false;
    }
    return false;
}
 

@Override
public boolean performAccessibilityAction(View host, int action, Bundle args) {
    if (super.performAccessibilityAction(host, action, args)) {
        return true;
    }
    switch (action) {
        case AccessibilityNodeInfoCompat.ACTION_SCROLL_FORWARD: {
            if (canScrollHorizontally(1)) {
                setCurrentItem(mCurItem + 1);
                return true;
            }
        } return false;
        case AccessibilityNodeInfoCompat.ACTION_SCROLL_BACKWARD: {
            if (canScrollHorizontally(-1)) {
                setCurrentItem(mCurItem - 1);
                return true;
            }
        } return false;
    }
    return false;
}
 

/**
 * Returns the scroll action for the given {@link TraversalStrategy.SearchDirection} if the scroll
 * action is available on the current SDK version. Otherwise, returns 0.
 */
public static int convertSearchDirectionToScrollAction(
    @TraversalStrategy.SearchDirection int direction) {
  if (direction == TraversalStrategy.SEARCH_FOCUS_FORWARD) {
    return AccessibilityNodeInfoCompat.ACTION_SCROLL_FORWARD;
  } else if (direction == TraversalStrategy.SEARCH_FOCUS_BACKWARD) {
    return AccessibilityNodeInfoCompat.ACTION_SCROLL_BACKWARD;
  } else {
    if (direction == TraversalStrategy.SEARCH_FOCUS_LEFT) {
      return AccessibilityAction.ACTION_SCROLL_LEFT.getId();
    } else if (direction == TraversalStrategy.SEARCH_FOCUS_RIGHT) {
      return AccessibilityAction.ACTION_SCROLL_RIGHT.getId();
    } else if (direction == TraversalStrategy.SEARCH_FOCUS_UP) {
      return AccessibilityAction.ACTION_SCROLL_UP.getId();
    } else if (direction == TraversalStrategy.SEARCH_FOCUS_DOWN) {
      return AccessibilityAction.ACTION_SCROLL_DOWN.getId();
    }
  }

  return 0;
}
 

private static SwitchAccessMenuItemEnum.MenuItem getMenuItemForAction(SwitchAccessAction action) {
  switch (action.getId()) {
    case AccessibilityNodeInfoCompat.ACTION_CLICK:
      return SwitchAccessMenuItemEnum.MenuItem.ACTION_MENU_CLICK;
    case AccessibilityNodeInfoCompat.ACTION_LONG_CLICK:
      return SwitchAccessMenuItemEnum.MenuItem.ACTION_MENU_LONG_CLICK;
    case AccessibilityNodeInfoCompat.ACTION_SCROLL_FORWARD:
      return SwitchAccessMenuItemEnum.MenuItem.ACTION_MENU_SCROLL_FORWARD;
    case AccessibilityNodeInfoCompat.ACTION_SCROLL_BACKWARD:
      return SwitchAccessMenuItemEnum.MenuItem.ACTION_MENU_SCROLL_BACKWARD;
    case AccessibilityNodeInfoCompat.ACTION_DISMISS:
      return SwitchAccessMenuItemEnum.MenuItem.ACTION_MENU_DISMISS;
    case AccessibilityNodeInfoCompat.ACTION_COLLAPSE:
      return SwitchAccessMenuItemEnum.MenuItem.ACTION_MENU_COLLAPSE;
    case AccessibilityNodeInfoCompat.ACTION_EXPAND:
      return SwitchAccessMenuItemEnum.MenuItem.ACTION_MENU_EXPAND;
    case AccessibilityNodeInfoCompat.ACTION_SET_SELECTION:
      return getMenuItemForSetSelectionAction(action);
    case AccessibilityNodeInfoCompat.ACTION_CUT:
      return getMenuItemForCutAction(action);
    case AccessibilityNodeInfoCompat.ACTION_COPY:
      return getMenuItemForCopyAction(action);
    case AccessibilityNodeInfoCompat.ACTION_PASTE:
      return SwitchAccessMenuItemEnum.MenuItem.ACTION_MENU_PASTE;
    case TextEditingUtils.ACTION_DELETE_TEXT:
      return getMenuItemForDeleteTextAction(action);
    case AccessibilityNodeInfoCompat.ACTION_NEXT_AT_MOVEMENT_GRANULARITY:
      return getMenuItemForNextAtMovementGranularityAction(action);
    case AccessibilityNodeInfoCompat.ACTION_PREVIOUS_AT_MOVEMENT_GRANULARITY:
      return getMenuItemForPreviousAtMovementGranularityAction(action);
    case TextEditingUtils.ACTION_UNDO:
      return SwitchAccessMenuItemEnum.MenuItem.ACTION_MENU_UNDO;
    case TextEditingUtils.ACTION_REDO:
      return SwitchAccessMenuItemEnum.MenuItem.ACTION_MENU_REDO;
    default:
      // Other actions such as "App info", "Add to home screen" etc.
      return SwitchAccessMenuItemEnum.MenuItem.ACTION_MENU_CUSTOM_ACTION;
  }
}
 

/**
 * Returns scrollable node filter for given {@link NavigationAction}.
 *
 * <p>This is consistent with what we used in {@link
 * TraversalStrategyUtils#isAutoScrollEdgeListItem(AccessibilityNodeInfoCompat, boolean, int,
 * TraversalStrategy)}. It consists of {@link NodeActionFilter} to check supported scroll action,
 * and {@link AccessibilityNodeInfoUtils#FILTER_AUTO_SCROLL} to match white-listed {@link Role}.
 */
@Nullable
private static Filter<AccessibilityNodeInfoCompat> getScrollFilter(
    NavigationAction navigationAction) {
  final int scrollAction;
  switch (navigationAction.actionType) {
    case NavigationAction.SCROLL_FORWARD:
      scrollAction = AccessibilityNodeInfoCompat.ACTION_SCROLL_FORWARD;
      break;
    case NavigationAction.SCROLL_BACKWARD:
      scrollAction = AccessibilityNodeInfoCompat.ACTION_SCROLL_BACKWARD;
      break;
    case NavigationAction.DIRECTIONAL_NAVIGATION:
      scrollAction =
          TraversalStrategyUtils.convertSearchDirectionToScrollAction(
              navigationAction.searchDirection);
      break;
    default:
      scrollAction = 0;
      break;
  }

  if (scrollAction == 0) {
    return null;
  }

  if ((navigationAction.actionType == NavigationAction.SCROLL_FORWARD)
      || (navigationAction.actionType == NavigationAction.SCROLL_BACKWARD)) {
    return new NodeActionFilter(scrollAction).and(SCROLLABLE_ROLE_FILTER_FOR_SCROLL_GESTURE);
  } else {
    return new NodeActionFilter(scrollAction)
        .and(SCROLLABLE_ROLE_FILTER_FOR_DIRECTION_NAVIGATION);
  }
}
 

private void navigateSlider(
    int button, @NonNull AccessibilityNodeInfoCompat node, EventId eventId) {
  int action;
  if (button == VolumeButtonPatternDetector.VOLUME_UP) {
    action = AccessibilityNodeInfoCompat.ACTION_SCROLL_FORWARD;
  } else if (button == VolumeButtonPatternDetector.VOLUME_DOWN) {
    action = AccessibilityNodeInfoCompat.ACTION_SCROLL_BACKWARD;
  } else {
    return;
  }

  PerformActionUtils.performAction(node, action, eventId);
}
 

/**
 * Gets the filter to find the scrollable node according to the specified {@code action} except
 * SeekBar because there is no text that can be searched.
 *
 * @param action filter action to find the nodes, could be {@code
 *     AccessibilityNodeInfoUtils.FILTER_COULD_SCROLL_FORWARD} or {@code
 *     AccessibilityNodeInfoUtils.FILTER_COULD_SCROLL_BACKWARD}
 * @return the node filter or null if the specified action is not valid
 */
static Filter<AccessibilityNodeInfoCompat> getScrollFilter(int action) {
  if (action == AccessibilityNodeInfoCompat.ACTION_SCROLL_FORWARD) {
    return AccessibilityNodeInfoUtils.FILTER_COULD_SCROLL_FORWARD.and(FILTER_NO_SEEK_BAR);
  } else if (action == AccessibilityNodeInfoCompat.ACTION_SCROLL_BACKWARD) {
    return AccessibilityNodeInfoUtils.FILTER_COULD_SCROLL_BACKWARD.and(FILTER_NO_SEEK_BAR);
  } else {
    return null;
  }
}
 

@Override
protected boolean onPerformActionForVirtualView(
    int virtualViewId, int action, Bundle arguments) {
  if (!slider.isEnabled()) {
    return false;
  }

  switch (action) {
    case android.R.id.accessibilityActionSetProgress:
      {
        if (arguments == null
            || !arguments.containsKey(
                AccessibilityNodeInfoCompat.ACTION_ARGUMENT_PROGRESS_VALUE)) {
          return false;
        }
        float value =
            arguments.getFloat(AccessibilityNodeInfoCompat.ACTION_ARGUMENT_PROGRESS_VALUE);
        if (slider.snapThumbToValue(virtualViewId, value)) {
          slider.updateHaloHotspot();
          slider.postInvalidate();
          invalidateVirtualView(virtualViewId);
          return true;
        }
        return false;
      }
    case AccessibilityNodeInfoCompat.ACTION_SCROLL_FORWARD:
    case AccessibilityNodeInfoCompat.ACTION_SCROLL_BACKWARD:
      {
        float increment = slider.calculateStepIncrement(20);
        if (action == AccessibilityNodeInfoCompat.ACTION_SCROLL_BACKWARD) {
          increment = -increment;
        }

        // Swap the increment if we're in RTL.
        if (slider.isRtl()) {
          increment = -increment;
        }

        List<Float> values = slider.getValues();
        float clamped =
            clamp(
                values.get(virtualViewId) + increment,
                slider.getValueFrom(),
                slider.getValueTo());
        if (slider.snapThumbToValue(virtualViewId, clamped)) {
          slider.updateHaloHotspot();
          slider.postInvalidate();
          invalidateVirtualView(virtualViewId);
          return true;
        }
        return false;
      }
    default:
      return false;
  }
}
 

public static String actionToString(int action) {
  switch (action) {
    case AccessibilityNodeInfoCompat.ACTION_ACCESSIBILITY_FOCUS:
      return "ACTION_ACCESSIBILITY_FOCUS";
    case AccessibilityNodeInfoCompat.ACTION_CLEAR_ACCESSIBILITY_FOCUS:
      return "ACTION_CLEAR_ACCESSIBILITY_FOCUS";
    case AccessibilityNodeInfoCompat.ACTION_CLEAR_FOCUS:
      return "ACTION_CLEAR_FOCUS";
    case AccessibilityNodeInfoCompat.ACTION_CLEAR_SELECTION:
      return "ACTION_CLEAR_SELECTION";
    case AccessibilityNodeInfoCompat.ACTION_CLICK:
      return "ACTION_CLICK";
    case AccessibilityNodeInfoCompat.ACTION_COLLAPSE:
      return "ACTION_COLLAPSE";
    case AccessibilityNodeInfoCompat.ACTION_COPY:
      return "ACTION_COPY";
    case AccessibilityNodeInfoCompat.ACTION_CUT:
      return "ACTION_CUT";
    case AccessibilityNodeInfoCompat.ACTION_DISMISS:
      return "ACTION_DISMISS";
    case AccessibilityNodeInfoCompat.ACTION_EXPAND:
      return "ACTION_EXPAND";
    case AccessibilityNodeInfoCompat.ACTION_FOCUS:
      return "ACTION_FOCUS";
    case AccessibilityNodeInfoCompat.ACTION_LONG_CLICK:
      return "ACTION_LONG_CLICK";
    case AccessibilityNodeInfoCompat.ACTION_NEXT_AT_MOVEMENT_GRANULARITY:
      return "ACTION_NEXT_AT_MOVEMENT_GRANULARITY";
    case AccessibilityNodeInfoCompat.ACTION_NEXT_HTML_ELEMENT:
      return "ACTION_NEXT_HTML_ELEMENT";
    case AccessibilityNodeInfoCompat.ACTION_PASTE:
      return "ACTION_PASTE";
    case AccessibilityNodeInfoCompat.ACTION_PREVIOUS_AT_MOVEMENT_GRANULARITY:
      return "ACTION_PREVIOUS_AT_MOVEMENT_GRANULARITY";
    case AccessibilityNodeInfoCompat.ACTION_PREVIOUS_HTML_ELEMENT:
      return "ACTION_PREVIOUS_HTML_ELEMENT";
    case AccessibilityNodeInfoCompat.ACTION_SCROLL_BACKWARD:
      return "ACTION_SCROLL_BACKWARD";
    case AccessibilityNodeInfoCompat.ACTION_SCROLL_FORWARD:
      return "ACTION_SCROLL_FORWARD";
    case AccessibilityNodeInfoCompat.ACTION_SELECT:
      return "ACTION_SELECT";
    case AccessibilityNodeInfoCompat.ACTION_SET_SELECTION:
      return "ACTION_SET_SELECTION";
    case AccessibilityNodeInfoCompat.ACTION_SET_TEXT:
      return "ACTION_SET_TEXT";
    default:
      return "(unhandled)";
  }
}
 

/** Returns an icon resource id associated with the current action. */
@Override
public int getIconResource() {
  int actionId = action.getId();
  switch (actionId) {
    case AccessibilityNodeInfoCompat.ACTION_CLICK:
      return R.drawable.ic_select;
    case AccessibilityNodeInfoCompat.ACTION_LONG_CLICK:
      return R.drawable.ic_long_press;
    case AccessibilityNodeInfoCompat.ACTION_SCROLL_FORWARD:
      return R.drawable.ic_scroll_down;
    case AccessibilityNodeInfoCompat.ACTION_SCROLL_BACKWARD:
      return R.drawable.ic_scroll_up;
    case AccessibilityNodeInfoCompat.ACTION_DISMISS:
      return R.drawable.ic_dismiss;
    case AccessibilityNodeInfoCompat.ACTION_NEXT_AT_MOVEMENT_GRANULARITY:
    case AccessibilityNodeInfoCompat.ACTION_PREVIOUS_AT_MOVEMENT_GRANULARITY:
      return R.drawable.ic_text;
    case AccessibilityNodeInfoCompat.ACTION_COLLAPSE:
      return R.drawable.ic_collapse;
    case AccessibilityNodeInfoCompat.ACTION_EXPAND:
      return R.drawable.ic_expand;
    case AccessibilityNodeInfoCompat.ACTION_SET_SELECTION:
      return R.drawable.ic_highlight_text;
    case AccessibilityNodeInfoCompat.ACTION_CUT:
      return R.drawable.ic_cut;
    case AccessibilityNodeInfoCompat.ACTION_COPY:
      return R.drawable.ic_copy;
    case AccessibilityNodeInfoCompat.ACTION_PASTE:
      return R.drawable.ic_paste;
    case TextEditingUtils.ACTION_DELETE_TEXT:
      return R.drawable.ic_delete_text;
    case TextEditingUtils.ACTION_UNDO:
      return R.drawable.ic_undo;
    case TextEditingUtils.ACTION_REDO:
      return R.drawable.ic_redo;
    default:
      // We don't know what the action is. Don't show an icon.
      return 0;
  }
}
 

@Override
public void run() {
  int[] layoutCoordinates = new int[2];
  for (TreeScanLeafNode node : nodes) {
    Rect rect = node.getRectForNodeHighlight();
    if (rect == null) {
      continue;
    }
    int halfStrokeWidth = (int) highlightPaint.getStrokeWidth() / 2;
    GradientDrawable mainHighlightDrawable = getHighlightDrawable(halfStrokeWidth, rect);
    @KeyFor("MAIN_TO_OUTER_HIGHLIGHT_COLOR_MAP")
    int mainPaintColor = highlightPaint.getColor();
    mainHighlightDrawable.setStroke(halfStrokeWidth, mainPaintColor);

    GradientDrawable outerHighlightDrawable = null;
    if (MAIN_TO_OUTER_HIGHLIGHT_COLOR_MAP.containsKey(mainPaintColor)) {
      outerHighlightDrawable = getHighlightDrawable(halfStrokeWidth, rect);
      outerHighlightDrawable.setStroke(
          halfStrokeWidth / 2, MAIN_TO_OUTER_HIGHLIGHT_COLOR_MAP.get(mainPaintColor));
    }

    // Determine which scroll arrows we should show.
    boolean shouldShowUpArrow = false;
    boolean shouldShowDownArrow = false;
    boolean shouldShowRightArrow = false;
    boolean shouldShowLeftArrow = false;
    boolean supportsScrollForward = false;
    boolean supportsScrollBackward = false;
    if (FeatureFlags.scrollArrows()
        && (VERSION.SDK_INT >= VERSION_CODES.N)
        && node.isScrollable()) {
      for (AccessibilityActionCompat action : node.getActionList()) {
        if (action.getId() == AccessibilityNodeInfoCompat.ACTION_SCROLL_BACKWARD) {
          supportsScrollBackward = true;
        } else if (action.getId() == AccessibilityNodeInfoCompat.ACTION_SCROLL_FORWARD) {
          supportsScrollForward = true;
        } else if (VERSION.SDK_INT >= VERSION_CODES.N_MR1) {
          if (action.getId() == AccessibilityActionCompat.ACTION_SCROLL_UP.getId()) {
            shouldShowUpArrow = true;
          } else if (action.getId() == AccessibilityActionCompat.ACTION_SCROLL_DOWN.getId()) {
            shouldShowDownArrow = true;
          } else if (action.getId() == AccessibilityActionCompat.ACTION_SCROLL_RIGHT.getId()) {
            shouldShowRightArrow = true;
          } else if (action.getId() == AccessibilityActionCompat.ACTION_SCROLL_LEFT.getId()) {
            shouldShowLeftArrow = true;
          }
        }
      }

      // If only the less granular version of a scroll action is supported, show the possible
      // scroll directions for that scroll action.
      if (supportsScrollForward && !shouldShowDownArrow && !shouldShowRightArrow) {
        shouldShowDownArrow = true;
        shouldShowRightArrow = true;
      }
      if (supportsScrollBackward && !shouldShowUpArrow && !shouldShowLeftArrow) {
        shouldShowUpArrow = true;
        shouldShowLeftArrow = true;
      }
    }

    ImageView imageView = new ImageView(overlayController.getContext());
    imageView.setBackground(
        getFinalHighlightDrawable(
            shouldShowUpArrow,
            shouldShowDownArrow,
            shouldShowRightArrow,
            shouldShowLeftArrow,
            mainHighlightDrawable,
            outerHighlightDrawable));

    // Align image with node we're highlighting
    final RelativeLayout.LayoutParams layoutParams =
        new RelativeLayout.LayoutParams(rect.width(), rect.height());
    layoutParams.leftMargin = rect.left - layoutCoordinates[0];
    layoutParams.topMargin = rect.top - layoutCoordinates[1];
    imageView.setLayoutParams(layoutParams);
    overlayController.addViewAndShow(imageView);
  }
}
 

/**
 * Handles {@link NavigationAction#SCROLL_FORWARD} and {@link NavigationAction#SCROLL_BACKWARD}
 * actions.
 *
 * @return {@code true} if any accessibility action is successfully performed.
 */
private boolean onScrollAction(
    AccessibilityNodeInfoCompat pivot, NavigationAction navigationAction, EventId eventId) {
  // Node to be recycled.
  AccessibilityNodeInfoCompat scrollableNode = null;
  AccessibilityNodeInfoCompat rootNode = null;
  try {
    final int scrollAction;
    if (navigationAction.actionType == NavigationAction.SCROLL_FORWARD) {
      scrollAction = AccessibilityNodeInfoCompat.ACTION_SCROLL_FORWARD;
    } else if (navigationAction.actionType == NavigationAction.SCROLL_BACKWARD) {
      scrollAction = AccessibilityNodeInfoCompat.ACTION_SCROLL_BACKWARD;
    } else {
      throw new IllegalArgumentException("Unknown scroll action.");
    }

    final Filter<AccessibilityNodeInfoCompat> nodeFilter = getScrollFilter(navigationAction);
    if (nodeFilter == null) {
      return false;
    }

    if (AccessibilityNodeInfoUtils.supportsAction(pivot, scrollAction)) {
      // Try to scroll the node itself first. It's useful when focusing on a SeekBar.
      scrollableNode = AccessibilityNodeInfoUtils.obtain(pivot);
    } else if ((pivot != null) && pivot.isAccessibilityFocused()) {
      scrollableNode = AccessibilityNodeInfoUtils.getSelfOrMatchingAncestor(pivot, nodeFilter);
    }

    if (scrollableNode == null) {
      rootNode = AccessibilityNodeInfoUtils.getRoot(pivot);
      if (rootNode != null) {
        scrollableNode = AccessibilityNodeInfoUtils.searchFromBfs(rootNode, nodeFilter);
      }
    }
    return (scrollableNode != null)
        && performScrollActionInternal(
            ScrollEventInterpreter.ACTION_SCROLL_SHORTCUT,
            scrollableNode,
            pivot,
            scrollAction,
            navigationAction,
            eventId);
  } finally {
    AccessibilityNodeInfoUtils.recycleNodes(scrollableNode, rootNode);
  }
}
 

/**
 * Performs scroll action on the scrollable node of {@link #initialFocusedWindow} except SeekBar
 * because there is no text that can be searched.
 *
 * @param action The accessibility scroll action. Should be {@link
 *     AccessibilityNodeInfoCompat#ACTION_SCROLL_BACKWARD} or {@link
 *     AccessibilityNodeInfoCompat#ACTION_SCROLL_FORWARD}.
 */
private boolean scrollScreen(int action) {
  if (action != AccessibilityNodeInfoCompat.ACTION_SCROLL_BACKWARD
      && action != AccessibilityNodeInfoCompat.ACTION_SCROLL_FORWARD) {
    return false;
  }

  AccessibilityNode scrollableNode = getScrollableNode(action);
  if (scrollableNode == null) {
    refreshUiState();
    return false;
  }

  // Check if we need to update focused node after scrolling, the condition is copied from
  // FocusProcessorForLogicalNavigation.performScrollActionInternal()
  boolean needToUpdateFocus =
      (initialFocusedNode != null) && initialFocusedNode.hasAncestor(scrollableNode);

  scrollCallback =
      new AutoScrollCallback() {
        @Override
        public void onAutoScrolled(AccessibilityNode scrolledNode, EventId eventId) {
          if (needToUpdateFocus) {
            // Need to update focus node to get next correct scrollable node.
            // Refer to .
            onScrolledWithFocusUpdate(scrolledNode, action);
          } else {
            onScrolled();
          }
        }

        @Override
        public void onAutoScrollFailed(AccessibilityNode nodeToScroll) {
          searchStrategy.cacheNodeTree(initialFocusedWindow);
          // Search again since the result was already cleared before scrolling start.
          searchStrategy.searchKeyword(keywordEditText.getText().toString());

          // Disable the button since the scroll is failed, keep user from requesting again.
          if (action == AccessibilityNodeInfoCompat.ACTION_SCROLL_BACKWARD) {
            disableImageButton(prevScreenButton);
          } else {
            disableImageButton(nextScreenButton);
          }
        }
      };

  boolean result = false;

  try {
    pipeline.returnFeedback(
        EVENT_ID_UNTRACKED,
        Feedback.scroll(scrollableNode, ACTION_AUTO_SCROLL, action, Source.SEARCH));
  } finally {
    AccessibilityNode.recycle("SearchScreenOverlay.scrollScreen()", scrollableNode);
  }

  if (result) {
    // Screen is scrolled, clears previous search results.
    clearSearchResult();
  } else {
    // User clicks on the scroll button but the scrolling doesn't happen. Refresh button's state
    // to see if they should be disabled.
    refreshUiState();
  }

  return result;
}
 

/**
 * When scroll forward/backward events are received, jump the time to the higher/lower
 * discrete, visible value on the circle.
 */
@Override
public boolean performAccessibilityAction(int action, Bundle arguments) {
    if (super.performAccessibilityAction(action, arguments)) {
        return true;
    }

    int changeMultiplier = 0;
    int forward;
    int backward;
    if (Build.VERSION.SDK_INT >= 16) {
        forward = AccessibilityNodeInfo.ACTION_SCROLL_FORWARD;
        backward = AccessibilityNodeInfo.ACTION_SCROLL_BACKWARD;
    } else {
        forward = AccessibilityNodeInfoCompat.ACTION_SCROLL_FORWARD;
        backward = AccessibilityNodeInfoCompat.ACTION_SCROLL_BACKWARD;
    }
    if (action == forward) {
        changeMultiplier = 1;
    } else if (action == backward) {
        changeMultiplier = -1;
    }
    if (changeMultiplier != 0) {
        int value = getCurrentlyShowingValue();
        int stepSize = 0;
        int currentItemShowing = getCurrentItemShowing();
        if (currentItemShowing == HOUR_INDEX) {
            stepSize = HOUR_VALUE_TO_DEGREES_STEP_SIZE;
            value %= 12;
        } else if (currentItemShowing == MINUTE_INDEX) {
            stepSize = MINUTE_VALUE_TO_DEGREES_STEP_SIZE;
        } else if (currentItemShowing == SECOND_INDEX) {
            stepSize = SECOND_VALUE_TO_DEGREES_STEP_SIZE;
        }

        int degrees = value * stepSize;
        degrees = snapOnly30s(degrees, changeMultiplier);
        value = degrees / stepSize;
        int maxValue = 0;
        int minValue = 0;
        if (currentItemShowing == HOUR_INDEX) {
            if (mIs24HourMode) {
                maxValue = 23;
            } else {
                maxValue = 12;
                minValue = 1;
            }
        } else {
            maxValue = 55;
        }
        if (value > maxValue) {
            // If we scrolled forward past the highest number, wrap around to the lowest.
            value = minValue;
        } else if (value < minValue) {
            // If we scrolled backward past the lowest number, wrap around to the highest.
            value = maxValue;
        }

        Timepoint newSelection;
        switch(currentItemShowing) {
            case HOUR_INDEX:
                newSelection = new Timepoint(
                        value,
                        mCurrentTime.getMinute(),
                        mCurrentTime.getSecond()
                );
                break;
            case MINUTE_INDEX:
                newSelection = new Timepoint(
                        mCurrentTime.getHour(),
                        value,
                        mCurrentTime.getSecond()
                );
                break;
            case SECOND_INDEX:
                newSelection = new Timepoint(
                        mCurrentTime.getHour(),
                        mCurrentTime.getMinute(),
                        value
                );
                break;
            default:
                newSelection = mCurrentTime;
        }

        setItem(currentItemShowing, newSelection);
        mListener.onValueSelected(newSelection);
        return true;
    }

    return false;
}