MacViews: Implement NSAccessibilityPressAction for Views with clickable roles.

ui/accessibility/platform/ax_platform_node_mac.mm

Index: ui/accessibility/platform/ax_platform_node_mac.mm
diff --git a/ui/accessibility/platform/ax_platform_node_mac.mm b/ui/accessibility/platform/ax_platform_node_mac.mm
index 5bfa69c675fa5c1124ea5fcf8954307ef461170f..a7d41b4f98e78822d73637ac9df905fa1b4ac747 100644
--- a/ui/accessibility/platform/ax_platform_node_mac.mm
+++ b/ui/accessibility/platform/ax_platform_node_mac.mm
@@ -11,6 +11,7 @@
 #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"
@@ -304,7 +305,25 @@ void NotifyMacEvent(AXPlatformNodeCocoa* target, ui::AXEvent event_type) {
 }
 
 - (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 {