Experiments with a new tabstrip + animator

chrome/browser/views/tabs/tab_strip_2.h

+// Copyright (c) 2009 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 CHROME_BROWSER_VIEWS_TABS_TAB_STRIP_2_H_
+#define CHROME_BROWSER_VIEWS_TABS_TAB_STRIP_2_H_
+
+#include <vector>
+
+#include "base/task.h"
+#include "chrome/browser/views/tabs/tab_2.h"
+#include "views/animator.h"
+#include "views/view.h"
+
+namespace gfx {
+class Canvas;
+}
+
+// An interface implemented by an object that provides state for objects in the
+// TabStrip2. This object is never owned by the TabStrip2.
+// TODO(beng): maybe TabStrip2Delegate?
+class TabStrip2Model {
+ public:
+  // Get presentation state for a particular Tab2.
+  virtual string16 GetTitle(int index) const = 0;
+  virtual bool IsSelected(int index) const = 0;
+
+  // The Tab2 at the specified index has been selected.
+  virtual void SelectTabAt(int index) = 0;
+
+  // Returns true if Tab2s can be dragged.
+  virtual bool CanDragTabs() const = 0;
+
+  // The Tab2 at the specified source index has moved to the specified
+  // destination index.
+  virtual void MoveTabAt(int index, int to_index) = 0;
+
+  // The Tab2 at the specified index was detached. |window_bounds| are the
+  // screen bounds of the current window, and |tab_bounds| are the bounds of the
+  // Tab2 in screen coordinates.
+  virtual void DetachTabAt(int index,
+                           const gfx::Rect& window_bounds,
+                           const gfx::Rect& tab_bounds) = 0;
+};
+
+// A TabStrip view.
+class TabStrip2 : public views::View,
+                  public Tab2Model,
+                  public views::AnimatorDelegate {
+ public:
+  explicit TabStrip2(TabStrip2Model* model);
+  virtual ~TabStrip2();
+
+  // Returns true if the new TabStrip is enabled.
+  static bool Enabled();
+
+  // API for adding, removing, selecting and moving tabs around.
+  void AddTabAt(int index);
+  void RemoveTabAt(int index, Tab2Model* removing_model);
+  void SelectTabAt(int index);
+  void MoveTabAt(int index, int to_index);
+
+  int GetTabCount() const;
+  Tab2* GetTabAt(int index) const;
+  int GetTabIndex(Tab2* tab) const;
+
+  // Returns the index to insert an item into the TabStrip at for a drop at the
+  // specified point in TabStrip coordinates.
+  int GetInsertionIndexForPoint(const gfx::Point& point) const;
+
+  // Returns the bounds of the Tab2 under |screen_point| in screen coordinates.
+  gfx::Rect GetDraggedTabScreenBounds(const gfx::Point& screen_point);
+
+  // Sets the bounds of the Tab2 at the specified index to |tab_bounds|.
+  void SetDraggedTabBounds(int index, const gfx::Rect& tab_bounds);
+
+  // Animates the dragged Tab2 to the location implied by its index in the
+  // model.
+  void SendDraggedTabHome();
+
+  // Continue a drag operation on the Tab2 at the specified index.
+  void ResumeDraggingTab(int index, const gfx::Rect& tab_bounds);
+
+  // Returns true if the mouse pointer at the specified point (screen bounds)
+  // constitutes a rearrange rather than a detach.
+  static bool IsDragRearrange(TabStrip2* tabstrip,
+                              const gfx::Point& screen_point);
+
+  // Overridden from Tab2Model:
+  virtual string16 GetTitle(Tab2* tab) const;
+  virtual bool IsSelected(Tab2* tab) const;
+  virtual void SelectTab(Tab2* tab);
+  virtual void CaptureDragInfo(Tab2* tab, const views::MouseEvent& drag_event);
+  virtual bool DragTab(Tab2* tab, const views::MouseEvent& drag_event);
+  virtual void DragEnded(Tab2* tab);
+  virtual views::AnimatorDelegate* AsAnimatorDelegate();
+
+  // Overridden from views::View:
+  virtual gfx::Size GetPreferredSize();
+  virtual void Layout();
+  virtual void Paint(gfx::Canvas* canvas);
+
+ private:
+  virtual void PaintChildren(gfx::Canvas* canvas);
+
+  // Overridden from views::AnimatorDelegate:
+  virtual views::View* GetClampedView(views::View* host);
+  virtual void AnimationCompletedForHost(View* host);
+
+  // Specifies what kind of TabStrip2 operation initiated the Layout, so the
+  // heuristic can adapt accordingly.
+  enum LayoutSource {
+    LS_TAB_ADD,
+    LS_TAB_REMOVE,
+    LS_TAB_SELECT,
+    LS_TAB_DRAG_REORDER,
+    LS_TAB_DRAG_NORMALIZE,
+    LS_OTHER
+  };
+
+  // Returns the animation directions for the specified layout source event.
+  int GetAnimateFlagsForLayoutSource(LayoutSource source) const;
+
+  // Lays out the contents of the TabStrip2.
+  void LayoutImpl(LayoutSource source);
+
+  // Execute the tab detach operation after a return to the message loop.
+  void DragDetachTabImpl(Tab2* tab, int index);
+
+  // Execute the drag initiation operation after a return to the message loop.
+  void StartDragTabImpl(int index, const gfx::Rect& tab_bounds);
+
+  // Returns the index into |tabs_| that corresponds to a publicly visible
+  // index. The index spaces are different since when a tab is closed we retain
+  // the tab in the presentation (and this our tab vector) until the tab has
+  // animated itself out of existence, but the clients of our API expect that
+  // index to be synchronously removed.
+  int GetInternalIndex(int public_index) const;
+
+  TabStrip2Model* model_;
+
+  // A vector of our Tabs. Stored separately from the child views, the child
+  // view order does not map directly to the presentation order, and because
+  // we can have child views that aren't Tab2s.
+  std::vector<Tab2*> tabs_;
+
+  // The position of the mouse relative to the widget when drag information was
+  // captured.
+  gfx::Point mouse_tab_offset_;
+
+  // The last position of the mouse along the horizontal axis of the TabStrip
+  // prior to the current drag event. Used to determine that the mouse has moved
+  // beyond the minimum horizontal threshold to initiate a drag operation.
+  int last_move_screen_x_;
+
+  // Factories to help break up work and avoid nesting message loops.
+  ScopedRunnableMethodFactory<TabStrip2> detach_factory_;
+  ScopedRunnableMethodFactory<TabStrip2> drag_start_factory_;
+
+  DISALLOW_COPY_AND_ASSIGN(TabStrip2);
+};
+
+#endif  // #ifndef CHROME_BROWSER_VIEWS_TABS_TAB_STRIP_2_H_