ui/aura/window_delegate.h

   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 UI_AURA_WINDOW_DELEGATE_H_
   6 #define UI_AURA_WINDOW_DELEGATE_H_
   7
   8 #include "base/compiler_specific.h"
   9 #include "base/memory/ref_counted.h"
  10 #include "ui/aura/aura_export.h"
  11 #include "ui/events/event_constants.h"
  12 #include "ui/events/event_handler.h"
  13 #include "ui/gfx/native_widget_types.h"
  14
  15 namespace gfx {
  16 class Canvas;
  17 class Path;
  18 class Point;
  19 class Rect;
  20 class Size;
  21 }
  22
  23 namespace ui {
  24 class GestureEvent;
  25 class KeyEvent;
  26 class Layer;
  27 class MouseEvent;
  28 class Texture;
  29 class TouchEvent;
  30 }
  31
  32 namespace aura {
  33
  34 // Delegate interface for aura::Window.
  35 class AURA_EXPORT WindowDelegate : public ui::EventHandler {
  36  public:
  37   // Returns the window's minimum size, or size 0,0 if there is no limit.
  38   virtual gfx::Size GetMinimumSize() const = 0;
  39
  40   // Returns the window's maximum size, or size 0,0 if there is no limit.
  41   virtual gfx::Size GetMaximumSize() const = 0;
  42
  43   // Called when the Window's position and/or size changes.
  44   virtual void OnBoundsChanged(const gfx::Rect& old_bounds,
  45                                const gfx::Rect& new_bounds) = 0;
  46
  47   // Returns the native cursor for the specified point, in window coordinates,
  48   // or NULL for the default cursor.
  49   virtual gfx::NativeCursor GetCursor(const gfx::Point& point) = 0;
  50
  51   // Returns the non-client component (see hit_test.h) containing |point|, in
  52   // window coordinates.
  53   virtual int GetNonClientComponent(const gfx::Point& point) const = 0;
  54
  55   // Returns true if event handling should descend into |child|. |location| is
  56   // in terms of the Window.
  57   virtual bool ShouldDescendIntoChildForEventHandling(
  58       Window* child,
  59       const gfx::Point& location) = 0;
  60
  61   // Returns true of the window can be focused.
  62   virtual bool CanFocus() = 0;
  63
  64   // Invoked when mouse capture is lost on the window.
  65   virtual void OnCaptureLost() = 0;
  66
  67   // Asks the delegate to paint window contents into the supplied canvas.
  68   virtual void OnPaint(gfx::Canvas* canvas) = 0;
  69
  70   // Called when the window's device scale factor has changed.
  71   virtual void OnDeviceScaleFactorChanged(float device_scale_factor) = 0;
  72
  73   // Called from Window's destructor before OnWindowDestroyed and before the
  74   // children have been destroyed and the window has been removed from its
  75   // parent.
  76   // This method takes the window because the delegate implementation may no
  77   // longer have a route back to the window by the time this method is called.
  78   virtual void OnWindowDestroying(Window* window) = 0;
  79
  80   // Called when the Window has been destroyed (i.e. from its destructor). This
  81   // is called after OnWindowDestroying and after the children have been
  82   // deleted and the window has been removed from its parent.
  83   // The delegate can use this as an opportunity to delete itself if necessary.
  84   // This method takes the window because the delegate implementation may no
  85   // longer have a route back to the window by the time this method is called.
  86   virtual void OnWindowDestroyed(Window* window) = 0;
  87
  88   // Called when the TargetVisibility() of a Window changes. |visible|
  89   // corresponds to the target visibility of the window. See
  90   // Window::TargetVisibility() for details.
  91   virtual void OnWindowTargetVisibilityChanged(bool visible) = 0;
  92
  93   // Called from Window::HitTest to check if the window has a custom hit test
  94   // mask. It works similar to the views counterparts. That is, if the function
  95   // returns true, GetHitTestMask below will be called to get the mask.
  96   // Otherwise, Window will hit-test against its bounds.
  97   virtual bool HasHitTestMask() const = 0;
  98
  99   // Called from Window::HitTest to retrieve hit test mask when HasHitTestMask
 100   // above returns true.
 101   virtual void GetHitTestMask(gfx::Path* mask) const = 0;
 102
 103  protected:
 104   ~WindowDelegate() override {}
 105 };
 106
 107 }  // namespace aura
 108
 109 #endif  // UI_AURA_WINDOW_DELEGATE_H_