Added scroll and text selection change accessibility events.
1. Added scrolling accessibility event to provicde feedback
when a view is scrolled.
Note: We need scroll events for ICS since even though we have
touch exploration the user does not know when something
is scrollable and not feedback is provided while scrolling.
bug:4902097
2. Added a text selection change event to provide feedback
for selection changes including cursor movement.
Note: We need the text selection change events for ICS since
even though the IME supports navigation in text fields
the user receives no feedback for the current selection/
cursor position.
bug:4586186
3. Added a scrollable property to both AccessibilityEvent and
AccessibilityNodeInfo. The info has to describe the source
in terms of all properties that make sense for accessibility
purposes and the event has this property (kinda duplicated)
since clients will aways want to know if the source is
scrollable to provided clue to the user and we want to avoid
pulling the info of the source for every accessibility event.
Change-Id: I232d6825da78e6a12d52125f51320217e6fadb11
diff --git a/core/java/android/view/View.java b/core/java/android/view/View.java
index 7e75c4e..5743134 100644
--- a/core/java/android/view/View.java
+++ b/core/java/android/view/View.java
@@ -2326,6 +2326,7 @@
private CheckForLongPress mPendingCheckForLongPress;
private CheckForTap mPendingCheckForTap = null;
private PerformClick mPerformClick;
+ private SendViewScrolledAccessibilityEvent mSendViewScrolledAccessibilityEvent;
private UnsetPressedState mUnsetPressedState;
@@ -3699,7 +3700,6 @@
* @see #dispatchPopulateAccessibilityEvent(AccessibilityEvent)
*/
public void onPopulateAccessibilityEvent(AccessibilityEvent event) {
-
}
/**
@@ -3728,12 +3728,23 @@
event.setEnabled(isEnabled());
event.setContentDescription(mContentDescription);
- if (event.getEventType() == AccessibilityEvent.TYPE_VIEW_FOCUSED && mAttachInfo != null) {
- ArrayList<View> focusablesTempList = mAttachInfo.mFocusablesTempList;
- getRootView().addFocusables(focusablesTempList, View.FOCUS_FORWARD, FOCUSABLES_ALL);
- event.setItemCount(focusablesTempList.size());
- event.setCurrentItemIndex(focusablesTempList.indexOf(this));
- focusablesTempList.clear();
+ final int eventType = event.getEventType();
+ switch (eventType) {
+ case AccessibilityEvent.TYPE_VIEW_FOCUSED: {
+ if (mAttachInfo != null) {
+ ArrayList<View> focusablesTempList = mAttachInfo.mFocusablesTempList;
+ getRootView().addFocusables(focusablesTempList, View.FOCUS_FORWARD,
+ FOCUSABLES_ALL);
+ event.setItemCount(focusablesTempList.size());
+ event.setCurrentItemIndex(focusablesTempList.indexOf(this));
+ focusablesTempList.clear();
+ }
+ } break;
+ case AccessibilityEvent.TYPE_VIEW_SCROLLED: {
+ event.setScrollX(mScrollX);
+ event.setScrollY(mScrollY);
+ event.setItemCount(getHeight());
+ } break;
}
}
@@ -6165,6 +6176,16 @@
}
/**
+ * Remove the pending callback for sending a
+ * {@link AccessibilityEvent#TYPE_VIEW_SCROLLED} accessibility event.
+ */
+ private void removeSendViewScrolledAccessibilityEventCallback() {
+ if (mSendViewScrolledAccessibilityEvent != null) {
+ removeCallbacks(mSendViewScrolledAccessibilityEvent);
+ }
+ }
+
+ /**
* Sets the TouchDelegate for this View.
*/
public void setTouchDelegate(TouchDelegate delegate) {
@@ -6337,6 +6358,10 @@
* @param oldt Previous vertical scroll origin.
*/
protected void onScrollChanged(int l, int t, int oldl, int oldt) {
+ if (AccessibilityManager.getInstance(mContext).isEnabled()) {
+ postSendViewScrolledAccessibilityEventCallback();
+ }
+
mBackgroundSizeChanged = true;
final AttachInfo ai = mAttachInfo;
@@ -8263,6 +8288,22 @@
}
/**
+ * Post a callback to send a {@link AccessibilityEvent#TYPE_VIEW_SCROLLED} event.
+ * This event is sent at most once every
+ * {@link ViewConfiguration#getSendRecurringAccessibilityEventsInterval()}.
+ */
+ private void postSendViewScrolledAccessibilityEventCallback() {
+ if (mSendViewScrolledAccessibilityEvent == null) {
+ mSendViewScrolledAccessibilityEvent = new SendViewScrolledAccessibilityEvent();
+ }
+ if (!mSendViewScrolledAccessibilityEvent.mIsPending) {
+ mSendViewScrolledAccessibilityEvent.mIsPending = true;
+ postDelayed(mSendViewScrolledAccessibilityEvent,
+ ViewConfiguration.getSendRecurringAccessibilityEventsInterval());
+ }
+ }
+
+ /**
* Called by a parent to request that a child update its values for mScrollX
* and mScrollY if necessary. This will typically be done if the child is
* animating a scroll using a {@link android.widget.Scroller Scroller}
@@ -9019,6 +9060,7 @@
removeUnsetPressCallback();
removeLongPressCallback();
removePerformClickCallback();
+ removeSendViewScrolledAccessibilityEventCallback();
destroyDrawingCache();
@@ -13820,6 +13862,18 @@
host.invalidate(true);
}
}
+ }
+ /**
+ * Resuable callback for sending
+ * {@link AccessibilityEvent#TYPE_VIEW_SCROLLED} accessibility event.
+ */
+ private class SendViewScrolledAccessibilityEvent implements Runnable {
+ public volatile boolean mIsPending;
+
+ public void run() {
+ sendAccessibilityEvent(AccessibilityEvent.TYPE_VIEW_SCROLLED);
+ mIsPending = false;
+ }
}
}