It is time.

ui/views/controls/single_split_view.h

-// Copyright (c) 2011 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_SINGLE_SPLIT_VIEW_H_
-#define UI_VIEWS_CONTROLS_SINGLE_SPLIT_VIEW_H_
-
-#include "base/gtest_prod_util.h"
-#include "ui/views/view.h"
-
-namespace views {
-
-class SingleSplitViewListener;
-
-// SingleSplitView lays out two views next to each other, either horizontally
-// or vertically. A splitter exists between the two views that the user can
-// drag around to resize the views.
-// SingleSplitViewListener's SplitHandleMoved notification helps to monitor user
-// initiated layout changes.
-class VIEWS_EXPORT SingleSplitView : public View {
- public:
-  enum Orientation {
-    HORIZONTAL_SPLIT,
-    VERTICAL_SPLIT
-  };
-
-  static const char kViewClassName[];
-
-  SingleSplitView(View* leading,
-                  View* trailing,
-                  Orientation orientation,
-                  SingleSplitViewListener* listener);
-
-  virtual void Layout() override;
-  virtual const char* GetClassName() const override;
-
-  virtual void GetAccessibleState(ui::AXViewState* state) override;
-
-  // SingleSplitView's preferred size is the sum of the preferred widths
-  // and the max of the heights.
-  virtual gfx::Size GetPreferredSize() const override;
-
-  // Overriden to return a resize cursor when over the divider.
-  virtual gfx::NativeCursor GetCursor(const ui::MouseEvent& event) override;
-
-  Orientation orientation() const {
-    return is_horizontal_ ? HORIZONTAL_SPLIT : VERTICAL_SPLIT;
-  }
-
-  void set_orientation(Orientation orientation) {
-    is_horizontal_ = orientation == HORIZONTAL_SPLIT;
-  }
-
-  void set_divider_offset(int divider_offset) {
-    divider_offset_ = divider_offset;
-  }
-  int divider_offset() const { return divider_offset_; }
-
-  int GetDividerSize() const;
-
-  void set_resize_disabled(bool resize_disabled) {
-    resize_disabled_ = resize_disabled;
-  }
-  bool is_resize_disabled() const { return resize_disabled_; }
-
-  // Sets whether the leading component is resized when the split views size
-  // changes. The default is true. A value of false results in the trailing
-  // component resizing on a bounds change.
-  void set_resize_leading_on_bounds_change(bool resize) {
-    resize_leading_on_bounds_change_ = resize;
-  }
-
-  // Calculates ideal leading and trailing view bounds according to the given
-  // split view |bounds|, current divider offset and children visiblity.
-  // Does not change children view bounds.
-  void CalculateChildrenBounds(const gfx::Rect& bounds,
-                               gfx::Rect* leading_bounds,
-                               gfx::Rect* trailing_bounds) const;
-
-  void SetAccessibleName(const base::string16& name);
-
- protected:
-  // View overrides.
-  virtual bool OnMousePressed(const ui::MouseEvent& event) override;
-  virtual bool OnMouseDragged(const ui::MouseEvent& event) override;
-  virtual void OnMouseCaptureLost() override;
-  virtual void OnBoundsChanged(const gfx::Rect& previous_bounds) override;
-
- private:
-  // This test calls OnMouse* functions.
-  FRIEND_TEST_ALL_PREFIXES(SingleSplitViewTest, MouseDrag);
-
-  // Returns true if |x| or |y| is over the divider.
-  bool IsPointInDivider(const gfx::Point& p);
-
-  // Calculates the new |divider_offset| based on the changes of split view
-  // bounds.
-  int CalculateDividerOffset(int divider_offset,
-                             const gfx::Rect& previous_bounds,
-                             const gfx::Rect& new_bounds) const;
-
-  // Returns divider offset within primary axis size range for given split
-  // view |bounds|.
-  int NormalizeDividerOffset(int divider_offset, const gfx::Rect& bounds) const;
-
-  // Returns width in case of horizontal split and height otherwise.
-  int GetPrimaryAxisSize() const {
-    return GetPrimaryAxisSize(width(), height());
-  }
-
-  int GetPrimaryAxisSize(int h, int v) const {
-    return is_horizontal_ ? h : v;
-  }
-
-  // Used to track drag info.
-  struct DragInfo {
-    // The initial coordinate of the mouse when the user started the drag.
-    int initial_mouse_offset;
-    // The initial position of the divider when the user started the drag.
-    int initial_divider_offset;
-  };
-
-  DragInfo drag_info_;
-
-  // Orientation of the split view.
-  bool is_horizontal_;
-
-  // Position of the divider.
-  int divider_offset_;
-
-  bool resize_leading_on_bounds_change_;
-
-  // Whether resizing is disabled.
-  bool resize_disabled_;
-
-  // Listener to notify about user initiated handle movements. Not owned.
-  SingleSplitViewListener* listener_;
-
-  // The accessible name of this view.
-  base::string16 accessible_name_;
-
-  DISALLOW_COPY_AND_ASSIGN(SingleSplitView);
-};
-
-}  // namespace views
-
-#endif  // UI_VIEWS_CONTROLS_SINGLE_SPLIT_VIEW_H_