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

ui/views/controls/label.h

 // Copyright (c) 2012 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.
 
 #ifndef UI_VIEWS_CONTROLS_LABEL_H_
 #define UI_VIEWS_CONTROLS_LABEL_H_
 
 #include "base/compiler_specific.h"
 #include "base/gtest_prod_util.h"
 #include "base/macros.h"
+#include "ui/base/models/simple_menu_model.h"
 #include "ui/gfx/render_text.h"
+#include "ui/views/context_menu_controller.h"
 #include "ui/views/selection_controller_delegate.h"
 #include "ui/views/view.h"
 
 namespace views {
 class LabelTest;
+class MenuRunner;
 class SelectionController;
 
 // A view subclass that can display a string.
-class VIEWS_EXPORT Label : public View, public SelectionControllerDelegate {
+class VIEWS_EXPORT Label : public View,
+                           public ContextMenuController,
+                           public SelectionControllerDelegate,
+                           public ui::SimpleMenuModel::Delegate {

[msw, 2016/11/09 18:32:53]

It would be nice to use composition instead of inheritance, and have a shared
context menu model/controller class for Textfield and Label, but I don't know if
that's really feasible.

[karandeepb, 2016/11/15 10:54:32]

It may be feasible, but since we are just implementing Copy/Select All, unlike
the text selection case, there isn't much logic to be shared between the two
classes. Also, again, the controller class would need to have a delegate
interface to interact with, which may lead to unnecessary boilerplate.

[msw, 2016/11/15 20:06:45]

Agreed, it's fine as-is for now.

  public:
   // Internal class name.
   static const char kViewClassName[];
 
   // The padding for the focus border when rendering focused text.
   static const int kFocusBorderPadding;
 
   Label();
   explicit Label(const base::string16& text);
   Label(const base::string16& text, const gfx::FontList& font_list);
@@ skipping 170 matching lines @@
   void OnPaint(gfx::Canvas* canvas) override;
   void OnDeviceScaleFactorChanged(float device_scale_factor) override;
   void OnNativeThemeChanged(const ui::NativeTheme* theme) override;
   gfx::NativeCursor GetCursor(const ui::MouseEvent& event) override;
   void OnFocus() override;
   void OnBlur() override;
   bool OnMousePressed(const ui::MouseEvent& event) override;
   bool OnMouseDragged(const ui::MouseEvent& event) override;
   void OnMouseReleased(const ui::MouseEvent& event) override;
   void OnMouseCaptureLost() override;
+  bool AcceleratorPressed(const ui::Accelerator& accelerator) override;
+  bool CanHandleAccelerators() const override;
+  bool OnKeyPressed(const ui::KeyEvent& event) override;

[msw, 2016/11/09 18:32:53]

nit: match the order in view.h

[karandeepb, 2016/11/15 10:54:32]

Done. Order for the existing functions wasn't correct, but I guess it's ok for
the new functions.

 
  private:
   FRIEND_TEST_ALL_PREFIXES(LabelTest, ResetRenderTextData);
   FRIEND_TEST_ALL_PREFIXES(LabelTest, MultilineSupportedRenderText);
   FRIEND_TEST_ALL_PREFIXES(LabelTest, TextChangeWithoutLayout);
   FRIEND_TEST_ALL_PREFIXES(LabelTest, EmptyLabel);
   FRIEND_TEST_ALL_PREFIXES(LabelTest, FocusBounds);
   FRIEND_TEST_ALL_PREFIXES(LabelTest, MultiLineSizingWithElide);
   friend class LabelTest;
 
+  // ui::SimpleMenuModel::Delegate overrides:

[msw, 2016/11/09 18:32:53]

nit: try to keep the same order as the subclass list.

[karandeepb, 2016/11/15 10:54:32]

Done.

+  bool IsCommandIdChecked(int command_id) const override;
+  bool IsCommandIdEnabled(int command_id) const override;
+  void ExecuteCommand(int command_id, int event_flags) override;
+  bool GetAcceleratorForCommandId(int command_id,
+                                  ui::Accelerator* accelerator) const override;
+
+  // ContextMenuController overrides:
+  void ShowContextMenuForView(View* source,
+                              const gfx::Point& point,
+                              ui::MenuSourceType source_type) override;
+
   // SelectionControllerDelegate overrides:
   gfx::RenderText* GetRenderTextForSelectionController() override;
   bool IsReadOnly() const override;
   bool SupportsDrag() const override;
   bool HasTextBeingDragged() const override;
   void SetTextBeingDragged(bool value) override;
   int GetViewHeight() const override;
   int GetViewWidth() const override;
   int GetDragSelectionDelay() const override;
   void OnBeforePointerAction() override;
@@ skipping 25 matching lines @@
   void ApplyTextColors() const;
 
   // Updates any colors that have not been explicitly set from the theme.
   void UpdateColorsFromTheme(const ui::NativeTheme* theme);
 
   bool ShouldShowDefaultTooltip() const;
 
   // Empties |lines_| and updates |stored_selection_range_|.
   void ClearRenderTextLines() const;
 
+  // Returns the currently selected text.
+  base::string16 GetSelectedText() const;
+
+  // Updates the clipboard with the currently selected text.
+  void CopyToClipboard();
+
+  // Builds |context_menu_contents_|.
+  void BuildContextMenuContents();
+
   // An un-elided and single-line RenderText object used for preferred sizing.
   std::unique_ptr<gfx::RenderText> render_text_;
 
   // The RenderText instances used to display elided and multi-line text.
   mutable std::vector<std::unique_ptr<gfx::RenderText>> lines_;
 
   // Persists the current selection range between the calls to
   // ClearRenderTextLines() and MaybeBuildRenderTextLines(). Holds an
   // InvalidRange when not in use.
   mutable gfx::Range stored_selection_range_;
@@ skipping 26 matching lines @@
   bool collapse_when_hidden_;
   int fixed_width_;
   int max_width_;
 
   // TODO(ckocagil): Remove is_first_paint_text_ before crbug.com/441028 is
   // closed.
   bool is_first_paint_text_;
 
   std::unique_ptr<SelectionController> selection_controller_;
 
+  // Context menu related members.
+  std::unique_ptr<ui::SimpleMenuModel> context_menu_contents_;

[msw, 2016/11/09 18:32:53]

nit: avoid unique_ptr, use plain member, if possible.
(but I guess this follows Textfield, so it's okay as-is too)

[karandeepb, 2016/11/15 10:54:32]

Done.

+  std::unique_ptr<views::MenuRunner> context_menu_runner_;
+
   DISALLOW_COPY_AND_ASSIGN(Label);
 };
 
 }  // namespace views
 
 #endif  // UI_VIEWS_CONTROLS_LABEL_H_