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 "third_party/skia/include/core/SkColor.h"
   9 #include "ui/gfx/image/image_skia.h"
  10 #include "ui/views/view.h"
  11
  12 namespace gfx {
  13 class Canvas;
  14 }
  15
  16 namespace views {
  17
  18 class Painter;
  19
  20 /////////////////////////////////////////////////////////////////////////////
  21 //
  22 // ImageView class.
  23 //
  24 // An ImageView can display an image from an ImageSkia. If a size is provided,
  25 // the ImageView will resize the provided image to fit if it is too big or will
  26 // center the image if smaller. Otherwise, the preferred size matches the
  27 // provided image size.
  28 //
  29 /////////////////////////////////////////////////////////////////////////////
  30 class VIEWS_EXPORT ImageView : public View {
  31  public:
  32   // Internal class name.
  33   static const char kViewClassName[];
  34
  35   enum Alignment {
  36     LEADING = 0,
  37     CENTER,
  38     TRAILING
  39   };
  40
  41   ImageView();
  42   ~ImageView() override;
  43
  44   // Set the image that should be displayed.
  45   void SetImage(const gfx::ImageSkia& img);
  46
  47   // Set the image that should be displayed from a pointer. Reset the image
  48   // if the pointer is NULL. The pointer contents is copied in the receiver's
  49   // image.
  50   void SetImage(const gfx::ImageSkia* image_skia);
  51
  52   // Returns the image currently displayed or NULL of none is currently set.
  53   // The returned image is still owned by the ImageView.
  54   const gfx::ImageSkia& GetImage();
  55
  56   // Set the desired image size for the receiving ImageView.
  57   void SetImageSize(const gfx::Size& image_size);
  58
  59   // Returns the actual bounds of the visible image inside the view.
  60   gfx::Rect GetImageBounds() const;
  61
  62   // Reset the image size to the current image dimensions.
  63   void ResetImageSize();
  64
  65   // Set / Get the horizontal alignment.
  66   void SetHorizontalAlignment(Alignment ha);
  67   Alignment GetHorizontalAlignment() const;
  68
  69   // Set / Get the vertical alignment.
  70   void SetVerticalAlignment(Alignment va);
  71   Alignment GetVerticalAlignment() const;
  72
  73   // Set / Get the tooltip text.
  74   void SetTooltipText(const base::string16& tooltip);
  75   base::string16 GetTooltipText() const;
  76
  77   void set_interactive(bool interactive) { interactive_ = interactive; }
  78
  79   void SetFocusPainter(scoped_ptr<Painter> focus_painter);
  80
  81   // Overriden from View:
  82   gfx::Size GetPreferredSize() const override;
  83   void OnFocus() override;
  84   void OnBlur() override;
  85   void OnPaint(gfx::Canvas* canvas) override;
  86   void GetAccessibleState(ui::AXViewState* state) override;
  87   const char* GetClassName() const override;
  88   bool GetTooltipText(const gfx::Point& p,
  89                       base::string16* tooltip) const override;
  90   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   // Returns the size the image will be painted.
 101   gfx::Size GetImageSize() const;
 102
 103   // Compute the image origin given the desired size and the receiver alignment
 104   // properties.
 105   gfx::Point ComputeImageOrigin(const gfx::Size& image_size) const;
 106
 107   // Whether the image size is set.
 108   bool image_size_set_;
 109
 110   // The actual image size.
 111   gfx::Size image_size_;
 112
 113   // The underlying image.
 114   gfx::ImageSkia image_;
 115
 116   // Horizontal alignment.
 117   Alignment horiz_alignment_;
 118
 119   // Vertical alignment.
 120   Alignment vert_alignment_;
 121
 122   // The current tooltip text.
 123   base::string16 tooltip_text_;
 124
 125   // A flag controlling hit test handling for interactivity.
 126   bool interactive_;
 127
 128   // Scale last painted at.
 129   float last_paint_scale_;
 130
 131   // Address of bytes we last painted. This is used only for comparison, so its
 132   // safe to cache.
 133   void* last_painted_bitmap_pixels_;
 134
 135   scoped_ptr<views::Painter> focus_painter_;
 136
 137   DISALLOW_COPY_AND_ASSIGN(ImageView);
 138 };
 139
 140 }  // namespace views
 141
 142 #endif  // UI_VIEWS_CONTROLS_IMAGE_VIEW_H_