MacViews: Implement NSAccessibilityPressAction for Views with clickable roles.

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>
 
 #include "base/macros.h"
 #include "base/strings/sys_string_conversions.h"
 #include "ui/accessibility/ax_action_data.h"
 #include "ui/accessibility/ax_node_data.h"
+#include "ui/accessibility/ax_utils.h"
 #include "ui/accessibility/platform/ax_platform_node_delegate.h"
 #include "ui/base/l10n/l10n_util.h"
 #import "ui/gfx/mac/coordinate_conversion.h"
 #include "ui/strings/grit/ui_strings.h"
 
 namespace {
 
 struct RoleMapEntry {
   ui::AXRole value;
   NSString* nativeValue;
@@ skipping 273 matching lines @@
 
 - (BOOL)accessibilityNotifiesWhenDestroyed {
   return YES;
 }
 
 - (id)accessibilityFocusedUIElement {
   return node_->GetDelegate()->GetFocus();
 }
 
 - (NSArray*)accessibilityActionNames {
-  return nil;
+  base::scoped_nsobject<NSMutableArray> axActions(
+      [[NSMutableArray alloc] init]);
+
+  // VoiceOver expects the "press" action to be first.
+  if (ui::IsRoleClickable(node_->GetData().role))
+    [axActions addObject:NSAccessibilityPressAction];

[tapted, 2017/02/09 02:45:18]

Do we expect much more to appear in future? E.g. we could just have

  return ui::IsRoleClickable(node_->GetData().role) ?
      @[NSAccessibilityPressAction] : @[];

(do we need to worry about NSAccessibilityShowMenuAction
NSAccessibilityPickAction NSAccessibilityConfirmAction -- should these all map
to DO_DEFAULT?)

Is it worth mentioning that ui::AX_ACTION_SET_VALUE doesn't need to be reported
here for Mac?

[Patti Lor, 2017/02/09 23:11:23]

I think so, yes - "ConfirmAction" simulates pressing the return key, so clicking
on the view where we've invoked it != doing the default thing for the dialog the
view belongs to. "ShowMenu" does a right click? Not sure about "PickAction" but
"DeleteAction" "CancelAction" etc are probably within scope to implement too.

I'm not sure what you mean about AX_ACTION_SET_VALUE? I'm going to guess you
wanted a comment explaining why some things are Views ui::AX_ACTIONs but not on
Mac, added it now :)

[tapted, 2017/02/09 23:25:05]

Ack.
ah - yep that's exactly what I meant

+
+  return axActions.autorelease();
+}
+
+- (void)accessibilityPerformAction:(NSString*)action {
+  DCHECK([[self accessibilityActionNames] containsObject:action]);
+  ui::AXActionData data;
+  if ([action isEqualToString:NSAccessibilityPressAction]) {

[tapted, 2017/02/09 02:45:18]

nit: curlies not required

[Patti Lor, 2017/02/09 23:11:23]

Done.

+    data.action = ui::AX_ACTION_DO_DEFAULT;
+  }
+
+  if (data.action != ui::AX_ACTION_NONE)
+    node_->GetDelegate()->AccessibilityPerformAction(data);
 }
 
 - (NSArray*)accessibilityAttributeNames {
   // These attributes are required on all accessibility objects.
   NSArray* const kAllRoleAttributes = @[
     NSAccessibilityChildrenAttribute,
     NSAccessibilityParentAttribute,
     NSAccessibilityPositionAttribute,
     NSAccessibilityRoleAttribute,
     NSAccessibilitySizeAttribute,
@@ skipping 313 matching lines @@
   }
   NotifyMacEvent(native_node_, event_type);
 }
 
 int AXPlatformNodeMac::GetIndexInParent() {
   // TODO(dmazzoni): implement this.  http://crbug.com/396137
   return -1;
 }
 
 }  // namespace ui