views: add focus to TabbedPane

ui/views/controls/tabbed_pane/tabbed_pane.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_TABBED_PANE_TABBED_PANE_H_
 #define UI_VIEWS_CONTROLS_TABBED_PANE_TABBED_PANE_H_
 
 #include "base/compiler_specific.h"
 #include "base/macros.h"
 #include "base/strings/string16.h"
 #include "ui/views/view.h"
 
 namespace views {
 
+class Label;
 class Tab;
 class TabbedPaneListener;
 class TabStrip;
 
 // TabbedPane is a view that shows tabs. When the user clicks on a tab, the
 // associated view is displayed.
 class VIEWS_EXPORT TabbedPane : public View {
  public:
   // Internal class name.
   static const char kViewClassName[];
 
   TabbedPane();
   ~TabbedPane() override;
 
   TabbedPaneListener* listener() const { return listener_; }
   void set_listener(TabbedPaneListener* listener) { listener_ = listener; }
 
   int selected_tab_index() const { return selected_tab_index_; }
 
   // Returns the number of tabs.
   int GetTabCount();
 
-  // Returns the contents of the selected tab or NULL if there is none.
-  View* GetSelectedTab();
-
   // Adds a new tab at the end of this TabbedPane with the specified |title|.
   // |contents| is the view displayed when the tab is selected and is owned by
   // the TabbedPane.
   void AddTab(const base::string16& title, View* contents);
 
   // Adds a new tab at |index| with |title|. |contents| is the view displayed
   // when the tab is selected and is owned by the TabbedPane. If the tabbed pane
   // is currently empty, the new tab is selected.
   void AddTabAtIndex(int index, const base::string16& title, View* contents);
 
   // Selects the tab at |index|, which must be valid.
   void SelectTabAt(int index);
 
   // Selects |tab| (the tabstrip view, not its content) if it is valid.
   void SelectTab(Tab* tab);
 
   // Overridden from View:
   gfx::Size GetPreferredSize() const override;
   const char* GetClassName() const override;
 
  private:
+  friend class FocusTraversalTest;
+  friend class Tab;
   friend class TabStrip;
+  FRIEND_TEST_ALL_PREFIXES(TabbedPaneTest, AddAndSelect);
+  FRIEND_TEST_ALL_PREFIXES(TabbedPaneTest, ArrowKeyBindings);
 
   // Get the Tab (the tabstrip view, not its content) at the valid |index|.
   Tab* GetTabAt(int index);
 
+  // Get the Tab (the tabstrip view, not its content) at the selected index.
+  Tab* GetSelectedTab();
+
+  // Returns the content View of the currently selected Tab.
+  View* GetSelectedTabContentView();
+
+  // Moves the selection by |delta| tabs, where negative delta means leftwards
+  // and positive delta means rightwards. Returns whether the selection could be
+  // moved by that amount; the only way this can fail is if there is only one
+  // tab.
+  bool MoveSelectionBy(int delta);
+
   // Overridden from View:
   void Layout() override;
   void ViewHierarchyChanged(
       const ViewHierarchyChangedDetails& details) override;
   bool AcceleratorPressed(const ui::Accelerator& accelerator) override;
-  void OnFocus() override;
   void GetAccessibleState(ui::AXViewState* state) override;
 
   // A listener notified when tab selection changes. Weak, not owned.
   TabbedPaneListener* listener_;
 
   // The tab strip and contents container. The child indices of these members
   // correspond to match each Tab with its respective content View.
   TabStrip* tab_strip_;
   View* contents_;
 
   // The selected tab index or -1 if invalid.
   int selected_tab_index_;
 
   DISALLOW_COPY_AND_ASSIGN(TabbedPane);
 };
 
+// The tab view shown in the tab strip.
+class Tab : public View {
+ public:
+  // Internal class name.
+  static const char kViewClassName[];
+
+  Tab(TabbedPane* tabbed_pane, const base::string16& title, View* contents);
+  ~Tab() override;
+
+  View* contents() const { return contents_; }
+
+  bool selected() const { return contents_->visible(); }
+  void SetSelected(bool selected);
+
+  // Overridden from View:
+  bool OnMousePressed(const ui::MouseEvent& event) override;
+  void OnMouseEntered(const ui::MouseEvent& event) override;
+  void OnMouseExited(const ui::MouseEvent& event) override;
+  void OnGestureEvent(ui::GestureEvent* event) override;
+  gfx::Size GetPreferredSize() const override;
+  void Layout() override;
+  const char* GetClassName() const override;
+  void OnFocus() override;
+  void OnBlur() override;
+  bool OnKeyPressed(const ui::KeyEvent& event) override;
+
+ protected:
+  Label* title() { return title_; }
+
+  // Called whenever |tab_state_| changes.
+  virtual void OnStateChanged();
+
+  // Returns whether the containing TabStrip has focus.
+  bool ContainerHasFocus();
+
+ private:
+  enum TabState {
+    TAB_INACTIVE,
+    TAB_ACTIVE,
+    TAB_HOVERED,
+  };
+
+  void SetState(TabState tab_state);
+
+  TabbedPane* tabbed_pane_;
+  Label* title_;
+  gfx::Size preferred_title_size_;
+  TabState tab_state_;
+  // The content view associated with this tab.
+  View* contents_;
+
+  DISALLOW_COPY_AND_ASSIGN(Tab);
+};
+
 }  // namespace views
 
 #endif  // UI_VIEWS_CONTROLS_TABBED_PANE_TABBED_PANE_H_