views::Label: Implement context menu, keyboard shortcuts for copy/select all.

ui/views/cocoa/bridged_content_view.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/views/cocoa/bridged_content_view.h"
 
 #include "base/logging.h"
 #import "base/mac/mac_util.h"
 #import "base/mac/scoped_nsobject.h"
 #import "base/mac/sdk_forward_declarations.h"
@@ skipping 229 matching lines @@
     if (attribute.strike)
       attrs[NSStrikethroughStyleAttributeName] = line_style;
 
     [str setAttributes:attrs range:range];
   }
 
   [str endEditing];
   return str.autorelease();
 }
 
+ui::TextEditCommand GetTextEditCommandForMenuAction(SEL action) {
+  if (action == @selector(undo:))
+    return ui::TextEditCommand::UNDO;
+  if (action == @selector(redo:))
+    return ui::TextEditCommand::REDO;
+  if (action == @selector(cut:))
+    return ui::TextEditCommand::CUT;
+  if (action == @selector(copy:))
+    return ui::TextEditCommand::COPY;
+  if (action == @selector(paste:))
+    return ui::TextEditCommand::PASTE;
+  if (action == @selector(selectAll:))
+    return ui::TextEditCommand::SELECT_ALL;
+  return ui::TextEditCommand::INVALID_COMMAND;
+}
+
 }  // namespace
 
 @interface BridgedContentView ()
 
 // Returns the active menu controller corresponding to |hostedView_|,
 // nil otherwise.
 - (MenuController*)activeMenuController;
 
 // Passes |event| to the InputMethod for dispatch.
 - (void)handleKeyEvent:(ui::KeyEvent*)event;
@@ skipping 253 matching lines @@
   }
 }
 
 - (views::DragDropClientMac*)dragDropClient {
   views::BridgedNativeWidget* bridge =
       views::NativeWidgetMac::GetBridgeForNativeWindow([self window]);
   return bridge ? bridge->drag_drop_client() : nullptr;
 }
 
 - (void)undo:(id)sender {
-  // This DCHECK is more strict than a similar check in handleAction:. It can be

[msw, 2016/11/09 18:32:52]

Someone more familiar with Mac should review this CL too.

[karandeepb, 2016/11/15 10:54:31]

Yeah I'll get Trent to review this. 

-  // done here because the actors sending these actions should be calling
-  // validateUserInterfaceItem: before enabling UI that allows these messages to
-  // be sent. Checking it here would be too late to provide correct UI feedback
-  // (e.g. there will be no "beep").
-  DCHECK(textInputClient_->IsTextEditCommandEnabled(ui::TextEditCommand::UNDO));
   [self handleAction:ui::TextEditCommand::UNDO
              keyCode:ui::VKEY_Z
              domCode:ui::DomCode::US_Z
           eventFlags:ui::EF_CONTROL_DOWN];
 }
 
 - (void)redo:(id)sender {
-  DCHECK(textInputClient_->IsTextEditCommandEnabled(ui::TextEditCommand::REDO));
   [self handleAction:ui::TextEditCommand::REDO
              keyCode:ui::VKEY_Z
              domCode:ui::DomCode::US_Z
           eventFlags:ui::EF_CONTROL_DOWN | ui::EF_SHIFT_DOWN];
 }
 
 - (void)cut:(id)sender {
-  DCHECK(textInputClient_->IsTextEditCommandEnabled(ui::TextEditCommand::CUT));
   [self handleAction:ui::TextEditCommand::CUT
              keyCode:ui::VKEY_X
              domCode:ui::DomCode::US_X
           eventFlags:ui::EF_CONTROL_DOWN];
 }
 
 - (void)copy:(id)sender {
-  DCHECK(textInputClient_->IsTextEditCommandEnabled(ui::TextEditCommand::COPY));
   [self handleAction:ui::TextEditCommand::COPY
              keyCode:ui::VKEY_C
              domCode:ui::DomCode::US_C
           eventFlags:ui::EF_CONTROL_DOWN];
 }
 
 - (void)paste:(id)sender {
-  DCHECK(
-      textInputClient_->IsTextEditCommandEnabled(ui::TextEditCommand::PASTE));
   [self handleAction:ui::TextEditCommand::PASTE
              keyCode:ui::VKEY_V
              domCode:ui::DomCode::US_V
           eventFlags:ui::EF_CONTROL_DOWN];
 }
 
 - (void)selectAll:(id)sender {
-  DCHECK(textInputClient_->IsTextEditCommandEnabled(
-      ui::TextEditCommand::SELECT_ALL));
   [self handleAction:ui::TextEditCommand::SELECT_ALL
              keyCode:ui::VKEY_A
              domCode:ui::DomCode::US_A
           eventFlags:ui::EF_CONTROL_DOWN];
 }
 
 // BaseView implementation.
 
 // Don't use tracking areas from BaseView. BridgedContentView's tracks
 // NSTrackingCursorUpdate and Apple's documentation suggests it's incompatible.
@@ skipping 790 matching lines @@
     textInputClient_->ConfirmCompositionText();
 }
 
 - (NSArray*)validAttributesForMarkedText {
   return @[];
 }
 
 // NSUserInterfaceValidations protocol implementation.
 
 - (BOOL)validateUserInterfaceItem:(id<NSValidatedUserInterfaceItem>)item {
-  if (!textInputClient_)
+  ui::TextEditCommand command = GetTextEditCommandForMenuAction([item action]);
+
+  if (command == ui::TextEditCommand::INVALID_COMMAND)
     return NO;
 
-  SEL action = [item action];
+  if (textInputClient_)
+    return textInputClient_->IsTextEditCommandEnabled(command);
 
-  if (action == @selector(undo:))
-    return textInputClient_->IsTextEditCommandEnabled(
-        ui::TextEditCommand::UNDO);
-  if (action == @selector(redo:))
-    return textInputClient_->IsTextEditCommandEnabled(
-        ui::TextEditCommand::REDO);
-  if (action == @selector(cut:))
-    return textInputClient_->IsTextEditCommandEnabled(ui::TextEditCommand::CUT);
-  if (action == @selector(copy:))
-    return textInputClient_->IsTextEditCommandEnabled(
-        ui::TextEditCommand::COPY);
-  if (action == @selector(paste:))
-    return textInputClient_->IsTextEditCommandEnabled(
-        ui::TextEditCommand::PASTE);
-  if (action == @selector(selectAll:))
-    return textInputClient_->IsTextEditCommandEnabled(
-        ui::TextEditCommand::SELECT_ALL);
-
-  return NO;
+  // We can't simply return NO since views like Labels which do not implement
+  // the TextInputClient interface, may also need to intercept these menu
+  // actions. As a rough approximation, check whether the focused view can
+  // process accelerators. This works since BrowserView also dispatches
+  // Cut/Copy/Paste edit commands in the Chrome menu using accelerators.
+  views::FocusManager* focus_manager =
+      hostedView_->GetWidget()->GetFocusManager();
+  return focus_manager && focus_manager->GetFocusedView() &&
+         focus_manager->GetFocusedView()->CanHandleAccelerators();
 }
 
 // NSDraggingSource protocol implementation.
 
 - (NSDragOperation)draggingSession:(NSDraggingSession*)session
     sourceOperationMaskForDraggingContext:(NSDraggingContext)context {
   return NSDragOperationEvery;
 }
 
 - (void)draggingSession:(NSDraggingSession*)session
@@ skipping 18 matching lines @@
   return [hostedView_->GetNativeViewAccessible() accessibilityHitTest:point];
 }
 
 - (id)accessibilityFocusedUIElement {
   if (!hostedView_)
     return nil;
   return [hostedView_->GetNativeViewAccessible() accessibilityFocusedUIElement];
 }
 
 @end