ui/views/controls/image_view.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_VIEWS_CONTROLS_IMAGE_VIEW_H_
   6 #define UI_VIEWS_CONTROLS_IMAGE_VIEW_H_
   7
   8 #include "ui/gfx/image/image_skia.h"
   9 #include "ui/views/view.h"
  10
  11 namespace gfx {
  12 class Canvas;
  13 }
  14
  15 namespace views {
  16
  17 class Painter;
  18
  19 /////////////////////////////////////////////////////////////////////////////
  20 //
  21 // ImageView class.
  22 //
  23 // An ImageView can display an image from an ImageSkia. If a size is provided,
  24 // the ImageView will resize the provided image to fit if it is too big or will
  25 // center the image if smaller. Otherwise, the preferred size matches the
  26 // provided image size.
  27 //
  28 /////////////////////////////////////////////////////////////////////////////
  29 class VIEWS_EXPORT ImageView : public View {
  30  public:
  31   enum Alignment {
  32     LEADING = 0,
  33     CENTER,
  34     TRAILING
  35   };
  36
  37   ImageView();
  38   virtual ~ImageView();
  39
  40   // Set the image that should be displayed.
  41   void SetImage(const gfx::ImageSkia& img);
  42
  43   // Set the image that should be displayed from a pointer. Reset the image
  44   // if the pointer is NULL. The pointer contents is copied in the receiver's
  45   // image.
  46   void SetImage(const gfx::ImageSkia* image_skia);
  47
  48   // Returns the image currently displayed or NULL of none is currently set.
  49   // The returned image is still owned by the ImageView.
  50   const gfx::ImageSkia& GetImage();
  51
  52   // Set the desired image size for the receiving ImageView.
  53   void SetImageSize(const gfx::Size& image_size);
  54
  55   // Return the preferred size for the receiving view. Returns false if the
  56   // preferred size is not defined, which means that the view uses the image
  57   // size.
  58   bool GetImageSize(gfx::Size* image_size) const;
  59
  60   // Returns the actual bounds of the visible image inside the view.
  61   gfx::Rect GetImageBounds() const;
  62
  63   // Reset the image size to the current image dimensions.
  64   void ResetImageSize();
  65
  66   // Set / Get the horizontal alignment.
  67   void SetHorizontalAlignment(Alignment ha);
  68   Alignment GetHorizontalAlignment() const;
  69
  70   // Set / Get the vertical alignment.
  71   void SetVerticalAlignment(Alignment va);
  72   Alignment GetVerticalAlignment() const;
  73
  74   // Set / Get the tooltip text.
  75   void SetTooltipText(const base::string16& tooltip);
  76   base::string16 GetTooltipText() const;
  77
  78   void set_interactive(bool interactive) { interactive_ = interactive; }
  79
  80   void SetFocusPainter(scoped_ptr<Painter> focus_painter);
  81
  82   // Overriden from View:
  83   virtual gfx::Size GetPreferredSize() const OVERRIDE;
  84   virtual void OnFocus() OVERRIDE;
  85   virtual void OnBlur() OVERRIDE;
  86   virtual void OnPaint(gfx::Canvas* canvas) OVERRIDE;
  87   virtual void GetAccessibleState(ui::AXViewState* state) OVERRIDE;
  88   virtual bool GetTooltipText(const gfx::Point& p,
  89                               base::string16* tooltip) const OVERRIDE;
  90   virtual bool CanProcessEventsWithinSubtree() const OVERRIDE;
  91
  92  private:
  93   void OnPaintImage(gfx::Canvas* canvas);
  94
  95   // Returns true if |img| is the same as the last image we painted. This is
  96   // intended to be a quick check, not exhaustive. In other words it's possible
  97   // for this to return false even though the images are in fact equal.
  98   bool IsImageEqual(const gfx::ImageSkia& img) const;
  99
 100   // Compute the image origin given the desired size and the receiver alignment
 101   // properties.
 102   gfx::Point ComputeImageOrigin(const gfx::Size& image_size) const;
 103
 104   // Whether the image size is set.
 105   bool image_size_set_;
 106
 107   // The actual image size.
 108   gfx::Size image_size_;
 109
 110   // The underlying image.
 111   gfx::ImageSkia image_;
 112
 113   // Horizontal alignment.
 114   Alignment horiz_alignment_;
 115
 116   // Vertical alignment.
 117   Alignment vert_alignment_;
 118
 119   // The current tooltip text.
 120   base::string16 tooltip_text_;
 121
 122   // A flag controlling hit test handling for interactivity.
 123   bool interactive_;
 124
 125   // Scale last painted at.
 126   float last_paint_scale_;
 127
 128   // Address of bytes we last painted. This is used only for comparison, so its
 129   // safe to cache.
 130   void* last_painted_bitmap_pixels_;
 131
 132   scoped_ptr<views::Painter> focus_painter_;
 133
 134   DISALLOW_COPY_AND_ASSIGN(ImageView);
 135 };
 136
 137 }  // namespace views
 138
 139 #endif  // UI_VIEWS_CONTROLS_IMAGE_VIEW_H_