ash/wm/window_positioner.h

   1 // Copyright 2013 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef ASH_WM_WINDOW_POSITIONER_H_
   6 #define ASH_WM_WINDOW_POSITIONER_H_
   7
   8 #include "ash/ash_export.h"
   9 #include "base/basictypes.h"
  10 #include "ui/base/ui_base_types.h"
  11 #include "ui/gfx/rect.h"
  12
  13 namespace aura {
  14 class Window;
  15 class RootWindow;
  16 }
  17
  18 namespace gfx {
  19 class Display;
  20 class Rect;
  21 class Screen;
  22 }
  23
  24 namespace ash {
  25
  26 namespace test {
  27 class WindowPositionerTest;
  28 }
  29
  30 // WindowPositioner is used by the browser to move new popups automatically to
  31 // a usable position on the closest work area (of the active window).
  32 class ASH_EXPORT WindowPositioner {
  33  public:
  34   // When the screen resolution width is smaller then this size, The algorithm
  35   // will default to maximized.
  36   static int GetForceMaximizedWidthLimit();
  37
  38   // The number of pixels which are kept free top, left and right when a window
  39   // gets positioned to its default location.
  40   static const int kDesktopBorderSize;
  41
  42   // Maximum width of a window even if there is more room on the desktop.
  43   static const int kMaximumWindowWidth;
  44
  45   // Computes and returns the bounds and show state for new window
  46   // based on the parameter passed AND existing windows. |window| is
  47   // the one this function will generate a bounds for and used to
  48   // exclude the self window in making decision how to position the
  49   // window. |window| can be (and in most case) NULL.
  50   // |is_saved_bounds| indicates the |bounds_in_out| is the saved
  51   // bounds.
  52   static void GetBoundsAndShowStateForNewWindow(
  53       const gfx::Screen* screen,
  54       const aura::Window* new_window,
  55       bool is_saved_bounds,
  56       ui::WindowShowState show_state_in,
  57       gfx::Rect* bounds_in_out,
  58       ui::WindowShowState* show_state_out);
  59
  60   // Returns the default bounds for a window to be created in the |display|.
  61   static gfx::Rect GetDefaultWindowBounds(const gfx::Display& display);
  62
  63   // Check if after removal or hide of the given |removed_window| an
  64   // automated desktop location management can be performed and
  65   // rearrange accordingly.
  66   static void RearrangeVisibleWindowOnHideOrRemove(
  67       const aura::Window* removed_window);
  68
  69   // Turn the automatic positioning logic temporarily off. Returns the previous
  70   // state.
  71   static bool DisableAutoPositioning(bool ignore);
  72
  73   // Check if after insertion or showing of the given |added_window|
  74   // an automated desktop location management can be performed and
  75   // rearrange accordingly.
  76   static void RearrangeVisibleWindowOnShow(aura::Window* added_window);
  77
  78   WindowPositioner();
  79   ~WindowPositioner();
  80
  81   // Find a suitable screen position for a popup window and return it. The
  82   // passed input position is only used to retrieve the width and height.
  83   // The position is determined on the left / right / top / bottom first. If
  84   // no smart space is found, the position will follow the standard what other
  85   // operating systems do (default cascading style).
  86   gfx::Rect GetPopupPosition(const gfx::Rect& old_pos);
  87
  88   // Accessor to set a flag indicating whether the first window in ASH should
  89   // be maximized.
  90   static void SetMaximizeFirstWindow(bool maximize);
  91
  92  protected:
  93   friend class test::WindowPositionerTest;
  94
  95   // Find a smart way to position the popup window. If there is no space this
  96   // function will return an empty rectangle.
  97   gfx::Rect SmartPopupPosition(const gfx::Rect& old_pos,
  98                                const gfx::Rect& work_area,
  99                                int grid);
 100
 101   // Find the next available cascading popup position (on the given screen).
 102   gfx::Rect NormalPopupPosition(const gfx::Rect& old_pos,
 103                                 const gfx::Rect& work_area);
 104
 105   // Align the location to the grid / snap to the right / bottom corner.
 106   gfx::Rect AlignPopupPosition(const gfx::Rect &pos,
 107                                const gfx::Rect &work_area,
 108                                int grid);
 109
 110   // Constant exposed for unittest.
 111   static const int kMinimumWindowOffset;
 112
 113   // The offset in X and Y for the next popup which opens.
 114   int pop_position_offset_increment_x;
 115   int pop_position_offset_increment_y;
 116
 117   // The position on the screen for the first popup which gets shown if no
 118   // empty space can be found.
 119   int popup_position_offset_from_screen_corner_x;
 120   int popup_position_offset_from_screen_corner_y;
 121
 122   // The last used position.
 123   int last_popup_position_x_;
 124   int last_popup_position_y_;
 125
 126   DISALLOW_COPY_AND_ASSIGN(WindowPositioner);
 127 };
 128
 129 }  // namespace ash
 130
 131 #endif  // ASH_WM_WINDOW_POSITIONER_H_