Bug 1182214 - Update highlight rect as you scroll. r=yzen

accessible/jsat/Presentation.jsm

@@ -108,8 +108,9 @@ Presenter.prototype = {
    * The viewport has changed, either a scroll, pan, zoom, or
    *    landscape/portrait toggle.
    * @param {Window} aWindow window of viewport that changed.
+   * @param {PivotContext} aCurrentContext context of last pivot change.
    */
-  viewportChanged: function viewportChanged(aWindow) {}, // jshint ignore:line
+  viewportChanged: function viewportChanged(aWindow, aCurrentContext) {}, // jshint ignore:line
 
   /**
    * We have entered or left text editing mode.
@@ -142,9 +143,7 @@ Presenter.prototype = {
 /**
  * Visual presenter. Draws a box around the virtual cursor's position.
  */
-function VisualPresenter() {
-  this._displayedAccessibles = new WeakMap();
-}
+function VisualPresenter() {}
 
 VisualPresenter.prototype = Object.create(Presenter.prototype);
 
@@ -156,15 +155,14 @@ VisualPresenter.prototype.type = 'Visual';
 VisualPresenter.prototype.BORDER_PADDING = 2;
 
 VisualPresenter.prototype.viewportChanged =
-  function VisualPresenter_viewportChanged(aWindow) {
-    let currentDisplay = this._displayedAccessibles.get(aWindow);
-    if (!currentDisplay) {
+  function VisualPresenter_viewportChanged(aWindow, aCurrentContext) {
+    if (!aCurrentContext) {
       return null;
     }
 
-    let currentAcc = currentDisplay.accessible;
-    let start = currentDisplay.startOffset;
-    let end = currentDisplay.endOffset;
+    let currentAcc = aCurrentContext.accessibleForBounds;
+    let start = aCurrentContext.startOffset;
+    let end = aCurrentContext.endOffset;
     if (Utils.isAliveAndVisible(currentAcc)) {
       let bounds = (start === -1 && end === -1) ? Utils.getBounds(currentAcc) :
                    Utils.getTextBounds(currentAcc, start, end);
@@ -189,11 +187,6 @@ VisualPresenter.prototype.pivotChanged =
       return null;
     }
 
-    this._displayedAccessibles.set(aContext.accessible.document.window,
-                                   { accessible: aContext.accessibleForBounds,
-                                     startOffset: aContext.startOffset,
-                                     endOffset: aContext.endOffset });
-
     try {
       aContext.accessibleForBounds.scrollTo(
         Ci.nsIAccessibleScrollType.SCROLL_TYPE_ANYWHERE);
@@ -413,21 +406,33 @@ AndroidPresenter.prototype.textSelectionChanged =
   };
 
 AndroidPresenter.prototype.viewportChanged =
-  function AndroidPresenter_viewportChanged(aWindow) {
+  function AndroidPresenter_viewportChanged(aWindow, aCurrentContext) {
     if (Utils.AndroidSdkVersion < 14) {
       return null;
     }
 
+    let events = [{
+      eventType: this.ANDROID_VIEW_SCROLLED,
+      text: [],
+      scrollX: aWindow.scrollX,
+      scrollY: aWindow.scrollY,
+      maxScrollX: aWindow.scrollMaxX,
+      maxScrollY: aWindow.scrollMaxY
+    }];
+
+    if (Utils.AndroidSdkVersion >= 16 && aCurrentContext) {
+      let currentAcc = aCurrentContext.accessibleForBounds;
+      if (Utils.isAliveAndVisible(currentAcc)) {
+        events.push({
+          eventType: this.ANDROID_VIEW_ACCESSIBILITY_FOCUSED,
+          bounds: Utils.getBounds(currentAcc)
+        });
+      }
+    }
+
     return {
       type: this.type,
-      details: [{
-        eventType: this.ANDROID_VIEW_SCROLLED,
-        text: [],
-        scrollX: aWindow.scrollX,
-        scrollY: aWindow.scrollY,
-        maxScrollX: aWindow.scrollMaxX,
-        maxScrollY: aWindow.scrollMaxY
-      }]
+      details: events
     };
   };
 
@@ -683,10 +688,17 @@ this.Presentation = { // jshint ignore:line
     return this.presenters;
   },
 
+  get displayedAccessibles() {
+    delete this.displayedAccessibles;
+    this.displayedAccessibles = new WeakMap();
+  },
+
   pivotChanged: function Presentation_pivotChanged(
     aPosition, aOldPosition, aReason, aStartOffset, aEndOffset, aIsUserInput) {
     let context = new PivotContext(
       aPosition, aOldPosition, aStartOffset, aEndOffset);
+    this.displayedAccessibles.set(context.accessible.document.window, context);
+
     return [p.pivotChanged(context, aReason, aIsUserInput)
       for each (p in this.presenters)]; // jshint ignore:line
   },
@@ -724,7 +736,9 @@ this.Presentation = { // jshint ignore:line
   },
 
   viewportChanged: function Presentation_viewportChanged(aWindow) {
-    return [p.viewportChanged(aWindow) for each (p in this.presenters)]; // jshint ignore:line
+    let context = this.displayedAccessibles.get(aWindow);
+    return [p.viewportChanged(aWindow, context) // jshint ignore:line
+      for each (p in this.presenters)]; // jshint ignore:line
   },
 
   editingModeChanged: function Presentation_editingModeChanged(aIsEditing) {