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      1 // Copyright (c) 2012 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_WORKSPACE_WINDOW_RESIZER_H_
      6 #define ASH_WM_WORKSPACE_WINDOW_RESIZER_H_
      7 
      8 #include <vector>
      9 
     10 #include "ash/wm/window_resizer.h"
     11 #include "ash/wm/workspace/magnetism_matcher.h"
     12 #include "base/compiler_specific.h"
     13 #include "base/gtest_prod_util.h"
     14 #include "base/memory/scoped_ptr.h"
     15 #include "ui/aura/window_tracker.h"
     16 
     17 namespace ash {
     18 namespace internal {
     19 
     20 class PhantomWindowController;
     21 class SnapSizer;
     22 class WindowSize;
     23 
     24 // WindowResizer implementation for workspaces. This enforces that windows are
     25 // not allowed to vertically move or resize outside of the work area. As windows
     26 // are moved outside the work area they are shrunk. We remember the height of
     27 // the window before it was moved so that if the window is again moved up we
     28 // attempt to restore the old height.
     29 class ASH_EXPORT WorkspaceWindowResizer : public WindowResizer {
     30  public:
     31   // When dragging an attached window this is the min size we'll make sure is
     32   // visible. In the vertical direction we take the max of this and that from
     33   // the delegate.
     34   static const int kMinOnscreenSize;
     35 
     36   // Min height we'll force on screen when dragging the caption.
     37   // TODO: this should come from a property on the window.
     38   static const int kMinOnscreenHeight;
     39 
     40   // Snap region when dragging close to the edges. That is, as the window gets
     41   // this close to an edge of the screen it snaps to the edge.
     42   static const int kScreenEdgeInset;
     43 
     44   virtual ~WorkspaceWindowResizer();
     45 
     46   static WorkspaceWindowResizer* Create(
     47       aura::Window* window,
     48       const gfx::Point& location_in_parent,
     49       int window_component,
     50       aura::client::WindowMoveSource source,
     51       const std::vector<aura::Window*>& attached_windows);
     52 
     53   // WindowResizer:
     54   virtual void Drag(const gfx::Point& location_in_parent,
     55                     int event_flags) OVERRIDE;
     56   virtual void CompleteDrag(int event_flags) OVERRIDE;
     57   virtual void RevertDrag() OVERRIDE;
     58   virtual aura::Window* GetTarget() OVERRIDE;
     59   virtual const gfx::Point& GetInitialLocation() const OVERRIDE;
     60 
     61  private:
     62   WorkspaceWindowResizer(const Details& details,
     63                          const std::vector<aura::Window*>& attached_windows);
     64 
     65  private:
     66   FRIEND_TEST_ALL_PREFIXES(WorkspaceWindowResizerTest, CancelSnapPhantom);
     67   FRIEND_TEST_ALL_PREFIXES(WorkspaceWindowResizerTest, PhantomSnapMaxSize);
     68 
     69   // Type of snapping.
     70   enum SnapType {
     71     // Snap to the left/right edge of the screen.
     72     SNAP_LEFT_EDGE,
     73     SNAP_RIGHT_EDGE,
     74 
     75     // No snap position.
     76     SNAP_NONE
     77   };
     78 
     79   // Returns the final bounds to place the window at. This differs from
     80   // the current when snapping.
     81   gfx::Rect GetFinalBounds(const gfx::Rect& bounds) const;
     82 
     83   // Lays out the attached windows. |bounds| is the bounds of the main window.
     84   void LayoutAttachedWindows(gfx::Rect* bounds);
     85 
     86   // Calculates the new sizes of the attached windows, given that the main
     87   // window has been resized (along the primary axis) by |delta|.
     88   // |available_size| is the maximum length of the space that the attached
     89   // windows are allowed to occupy (ie: the distance between the right/bottom
     90   // edge of the primary window and the right/bottom of the desktop area).
     91   // Populates |sizes| with the desired sizes of the attached windows, and
     92   // returns the number of pixels that couldn't be allocated to the attached
     93   // windows (due to min/max size constraints).
     94   // Note the return value can be positive or negative, a negative value
     95   // indicating that that many pixels couldn't be removed from the attached
     96   // windows.
     97   int CalculateAttachedSizes(
     98       int delta,
     99       int available_size,
    100       std::vector<int>* sizes) const;
    101 
    102   // Divides |amount| evenly between |sizes|. If |amount| is negative it
    103   // indicates how many pixels |sizes| should be shrunk by.
    104   // Returns how many pixels failed to be allocated/removed from |sizes|.
    105   int GrowFairly(int amount, std::vector<WindowSize>& sizes) const;
    106 
    107   // Calculate the ratio of pixels that each WindowSize in |sizes| should
    108   // receive when growing or shrinking.
    109   void CalculateGrowthRatios(const std::vector<WindowSize*>& sizes,
    110                              std::vector<float>* out_ratios) const;
    111 
    112   // Adds a WindowSize to |sizes| for each attached window.
    113   void CreateBucketsForAttached(std::vector<WindowSize>* sizes) const;
    114 
    115   // If possible snaps the window to a neary window. Updates |bounds| if there
    116   // was a close enough window.
    117   void MagneticallySnapToOtherWindows(gfx::Rect* bounds);
    118 
    119   // If possible snaps the resize to a neary window. Updates |bounds| if there
    120   // was a close enough window.
    121   void MagneticallySnapResizeToOtherWindows(gfx::Rect* bounds);
    122 
    123   // Finds the neareset window to magentically snap to. Updates
    124   // |magnetism_window_| and |magnetism_edge_| appropriately. |edges| is a
    125   // bitmask of the MagnetismEdges to match again. Returns true if a match is
    126   // found.
    127   bool UpdateMagnetismWindow(const gfx::Rect& bounds, uint32 edges);
    128 
    129   // Adjusts the bounds of the window: magnetically snapping, ensuring the
    130   // window has enough on screen... |snap_size| is the distance from an edge of
    131   // the work area before the window is snapped. A value of 0 results in no
    132   // snapping.
    133   void AdjustBoundsForMainWindow(int snap_size, gfx::Rect* bounds);
    134 
    135   // Stick the window bounds to the work area during a move.
    136   bool StickToWorkAreaOnMove(const gfx::Rect& work_area,
    137                              int sticky_size,
    138                              gfx::Rect* bounds) const;
    139 
    140   // Stick the window bounds to the work area during a resize.
    141   void StickToWorkAreaOnResize(const gfx::Rect& work_area,
    142                                int sticky_size,
    143                                gfx::Rect* bounds) const;
    144 
    145   // Returns a coordinate along the primary axis. Used to share code for
    146   // left/right multi window resize and top/bottom resize.
    147   int PrimaryAxisSize(const gfx::Size& size) const;
    148   int PrimaryAxisCoordinate(int x, int y) const;
    149 
    150   // Updates the bounds of the phantom window for window snapping.
    151   void UpdateSnapPhantomWindow(const gfx::Point& location,
    152                                const gfx::Rect& bounds);
    153 
    154   // Restacks the windows z-order position so that one of the windows is at the
    155   // top of the z-order, and the rest directly underneath it.
    156   void RestackWindows();
    157 
    158   // Returns the SnapType for the specified point. SNAP_NONE is used if no
    159   // snapping should be used.
    160   SnapType GetSnapType(const gfx::Point& location) const;
    161 
    162   aura::Window* window() const { return details_.window; }
    163 
    164   const Details details_;
    165 
    166   const std::vector<aura::Window*> attached_windows_;
    167 
    168   // Set to true once Drag() is invoked and the bounds of the window change.
    169   bool did_move_or_resize_;
    170 
    171   // The initial size of each of the windows in |attached_windows_| along the
    172   // primary axis.
    173   std::vector<int> initial_size_;
    174 
    175   // Sum of the minimum sizes of the attached windows.
    176   int total_min_;
    177 
    178   // Sum of the sizes in |initial_size_|.
    179   int total_initial_size_;
    180 
    181   // Gives a previews of where the the window will end up. Only used if there
    182   // is a grid and the caption is being dragged.
    183   scoped_ptr<PhantomWindowController> snap_phantom_window_controller_;
    184 
    185   // Used to determine the target position of a snap.
    186   scoped_ptr<SnapSizer> snap_sizer_;
    187 
    188   // Last SnapType.
    189   SnapType snap_type_;
    190 
    191   // Number of mouse moves since the last bounds change. Only used for phantom
    192   // placement to track when the mouse is moved while pushed against the edge of
    193   // the screen.
    194   int num_mouse_moves_since_bounds_change_;
    195 
    196   // The mouse location passed to Drag().
    197   gfx::Point last_mouse_location_;
    198 
    199   // Window the drag has magnetically attached to.
    200   aura::Window* magnetism_window_;
    201 
    202   // Used to verify |magnetism_window_| is still valid.
    203   aura::WindowTracker window_tracker_;
    204 
    205   // If |magnetism_window_| is non-NULL this indicates how the two windows
    206   // should attach.
    207   MatchedEdge magnetism_edge_;
    208 
    209   DISALLOW_COPY_AND_ASSIGN(WorkspaceWindowResizer);
    210 };
    211 
    212 }  // namespace internal
    213 }  // namespace ash
    214 
    215 #endif  // ASH_WM_WORKSPACE_WINDOW_RESIZER_H_
    216