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   // Internal class name.
  32   static const char kViewClassName[];
  33
  34   enum Alignment {
  35     LEADING = 0,
  36     CENTER,
  37     TRAILING
  38   };
  39
  40   ImageView();
  41   ~ImageView() override;
  42
  43   // Set the image that should be displayed.
  44   void SetImage(const gfx::ImageSkia& img);
  45
  46   // Set the image that should be displayed from a pointer. Reset the image
  47   // if the pointer is NULL. The pointer contents is copied in the receiver's
  48   // image.
  49   void SetImage(const gfx::ImageSkia* image_skia);
  50
  51   // Returns the image currently displayed or NULL of none is currently set.
  52   // The returned image is still owned by the ImageView.
  53   const gfx::ImageSkia& GetImage();
  54
  55   // Set the desired image size for the receiving ImageView.
  56   void SetImageSize(const gfx::Size& image_size);
  57
  58   // Return the preferred size for the receiving view. Returns false if the
  59   // preferred size is not defined, which means that the view uses the image
  60   // size.
  61   bool GetImageSize(gfx::Size* image_size) const;
  62
  63   // Returns the actual bounds of the visible image inside the view.
  64   gfx::Rect GetImageBounds() const;
  65
  66   // Reset the image size to the current image dimensions.
  67   void ResetImageSize();
  68
  69   // Set / Get the horizontal alignment.
  70   void SetHorizontalAlignment(Alignment ha);
  71   Alignment GetHorizontalAlignment() const;
  72
  73   // Set / Get the vertical alignment.
  74   void SetVerticalAlignment(Alignment va);
  75   Alignment GetVerticalAlignment() const;
  76
  77   // Set / Get the tooltip text.
  78   void SetTooltipText(const base::string16& tooltip);
  79   base::string16 GetTooltipText() const;
  80
  81   void set_interactive(bool interactive) { interactive_ = interactive; }
  82
  83   void SetFocusPainter(scoped_ptr<Painter> focus_painter);
  84
  85   // Overriden from View:
  86   gfx::Size GetPreferredSize() const override;
  87   void OnFocus() override;
  88   void OnBlur() override;
  89   void OnPaint(gfx::Canvas* canvas) override;
  90   void GetAccessibleState(ui::AXViewState* state) override;
  91   const char* GetClassName() const override;
  92   bool GetTooltipText(const gfx::Point& p,
  93                       base::string16* tooltip) const override;
  94   bool CanProcessEventsWithinSubtree() const override;
  95
  96  private:
  97   void OnPaintImage(gfx::Canvas* canvas);
  98
  99   // Returns true if |img| is the same as the last image we painted. This is
 100   // intended to be a quick check, not exhaustive. In other words it's possible
 101   // for this to return false even though the images are in fact equal.
 102   bool IsImageEqual(const gfx::ImageSkia& img) const;
 103
 104   // Compute the image origin given the desired size and the receiver alignment
 105   // properties.
 106   gfx::Point ComputeImageOrigin(const gfx::Size& image_size) const;
 107
 108   // Whether the image size is set.
 109   bool image_size_set_;
 110
 111   // The actual image size.
 112   gfx::Size image_size_;
 113
 114   // The underlying image.
 115   gfx::ImageSkia image_;
 116
 117   // Horizontal alignment.
 118   Alignment horiz_alignment_;
 119
 120   // Vertical alignment.
 121   Alignment vert_alignment_;
 122
 123   // The current tooltip text.
 124   base::string16 tooltip_text_;
 125
 126   // A flag controlling hit test handling for interactivity.
 127   bool interactive_;
 128
 129   // Scale last painted at.
 130   float last_paint_scale_;
 131
 132   // Address of bytes we last painted. This is used only for comparison, so its
 133   // safe to cache.
 134   void* last_painted_bitmap_pixels_;
 135
 136   scoped_ptr<views::Painter> focus_painter_;
 137
 138   DISALLOW_COPY_AND_ASSIGN(ImageView);
 139 };
 140
 141 }  // namespace views
 142
 143 #endif  // UI_VIEWS_CONTROLS_IMAGE_VIEW_H_