MacViews a11y: Sync VoiceOver cursor with keyboard focus.

ui/accessibility/platform/ax_platform_node_mac.mm

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #import "ui/accessibility/platform/ax_platform_node_mac.h"
 
 #import <Cocoa/Cocoa.h>
 #include <stddef.h>
 
+#import "base/mac/sdk_forward_declarations.h"
 #include "base/macros.h"
 #include "base/strings/sys_string_conversions.h"
 #include "ui/accessibility/ax_node_data.h"
 #include "ui/accessibility/ax_view_state.h"
 #include "ui/accessibility/platform/ax_platform_node_delegate.h"
 #import "ui/gfx/mac/coordinate_conversion.h"
 
 namespace {
 
 struct RoleMapEntry {
@@ skipping 170 matching lines @@
   };
 
   RoleMap subrole_map;
   for (size_t i = 0; i < arraysize(subroles); ++i)
     subrole_map[subroles[i].value] = subroles[i].nativeValue;
   return subrole_map;
 }
 
 EventMap BuildEventMap() {
   const EventMapEntry events[] = {
+      {ui::AX_EVENT_FOCUS, NSAccessibilityFocusedUIElementChangedNotification},
       {ui::AX_EVENT_TEXT_CHANGED, NSAccessibilityTitleChangedNotification},
       {ui::AX_EVENT_VALUE_CHANGED, NSAccessibilityValueChangedNotification},
       {ui::AX_EVENT_TEXT_SELECTION_CHANGED,
        NSAccessibilitySelectedTextChangedNotification},
       // TODO(patricialor): Add more events.
   };
 
   EventMap event_map;
   for (size_t i = 0; i < arraysize(events); ++i)
     event_map[events[i].value] = events[i].nativeValue;
   return event_map;
 }
 
-void NotifyMacEvent(NSView* target, ui::AXEvent event_type) {
+void NotifyMacEvent(id target, ui::AXEvent event_type) {

[tapted, 2016/09/26 05:19:17]

can this instead change from NSView* -> AXPlatformNodeCocoa*, rather than id?

[Patti Lor, 2016/09/28 00:29:14]

Done.

   NSAccessibilityPostNotification(
       target, [AXPlatformNodeCocoa nativeNotificationFromAXEvent:event_type]);
 }
 
 }  // namespace
 
 @interface AXPlatformNodeCocoa ()
 // Helper function for string attributes that don't require extra processing.
 - (NSString*)getStringAttribute:(ui::AXStringAttribute)attribute;
 @end
@@ skipping 22 matching lines @@
 }
 
 - (instancetype)initWithNode:(ui::AXPlatformNodeBase*)node {
   if ((self = [super init])) {
     node_ = node;
   }
   return self;
 }
 
 - (void)detach {
+  if (!node_)
+    return;
+  NSAccessibilityPostNotification(
+      self, NSAccessibilityUIElementDestroyedNotification);
+  NSAccessibilityUnregisterUniqueIdForUIElement(self);
   node_ = nil;
 }
 
 - (NSRect)boundsInScreen {
   if (!node_)
     return NSZeroRect;
   return gfx::ScreenRectToNSRect(node_->GetBoundsInScreen());
 }
 
 - (NSString*)getStringAttribute:(ui::AXStringAttribute)attribute {
@@ skipping 10 matching lines @@
 }
 
 - (id)accessibilityHitTest:(NSPoint)point {
   for (AXPlatformNodeCocoa* child in [self AXChildren]) {
     if (NSPointInRect(point, child.boundsInScreen))
       return [child accessibilityHitTest:point];
   }
   return NSAccessibilityUnignoredAncestor(self);
 }
 
+- (BOOL)accessibilityNotifiesWhenDestroyed {
+  return YES;
+}
+
+- (BOOL)accessibilityShouldUseUniqueId {

[tapted, 2016/09/26 05:19:17]

This needs a note that it was never part of the informal protocol definition,
but is required for <reason>. It's OK to repeat stuff from
browser_accessibility_cocoa.mm

[Patti Lor, 2016/09/28 00:29:14]

See above comment - deleted this method entirely.

+  return YES;
+}
+
 - (NSArray*)accessibilityActionNames {
   return nil;
 }
 
 - (NSArray*)accessibilityAttributeNames {
   // These attributes are required on all accessibility objects.
   NSArray* const kAllRoleAttributes = @[
     NSAccessibilityChildrenAttribute,
     NSAccessibilityParentAttribute,
     NSAccessibilityPositionAttribute,
@@ skipping 212 matching lines @@
   AXPlatformNodeBase::Destroy();
 }
 
 gfx::NativeViewAccessible AXPlatformNodeMac::GetNativeViewAccessible() {
   if (!native_node_)
     native_node_.reset([[AXPlatformNodeCocoa alloc] initWithNode:this]);
   return native_node_.get();
 }
 
 void AXPlatformNodeMac::NotifyAccessibilityEvent(ui::AXEvent event_type) {
-  NSView* target = GetDelegate()->GetTargetForNativeAccessibilityEvent();
-
+  if (!native_node_)

[tapted, 2016/09/26 05:19:17]

nit: This extra check isn't needed - I'd go for just

GetNativeViewAccessible();

or

AXPlatformNodeCocoa* node = GetNativeViewAccessible();

[Patti Lor, 2016/09/28 00:29:14]

Done.

+    GetNativeViewAccessible();
   // Add mappings between ui::AXEvent and NSAccessibility notifications using
   // the EventMap above. This switch contains exceptions to those mappings.
   switch (event_type) {
     case ui::AX_EVENT_TEXT_CHANGED:
       // If the view is a user-editable textfield, this should change the value.
       if (GetData().role == ui::AX_ROLE_TEXT_FIELD) {
-        NotifyMacEvent(target, ui::AX_EVENT_VALUE_CHANGED);
+        NotifyMacEvent(native_node_, ui::AX_EVENT_VALUE_CHANGED);
         return;
       }
       break;
     default:
       break;
   }
-  NotifyMacEvent(target, event_type);
+  NotifyMacEvent(native_node_, event_type);
 }
 
 int AXPlatformNodeMac::GetIndexInParent() {
   // TODO(dmazzoni): implement this.  http://crbug.com/396137
   return -1;
 }
 
 }  // namespace ui