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
11namespace gfx {
12class Canvas;
13}
14
15namespace views {
16
17class 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/////////////////////////////////////////////////////////////////////////////
29class 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);
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 string16& tooltip);
76  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() OVERRIDE;
84  virtual void OnFocus() OVERRIDE;
85  virtual void OnBlur() OVERRIDE;
86  virtual void OnPaint(gfx::Canvas* canvas) OVERRIDE;
87  virtual void GetAccessibleState(ui::AccessibleViewState* state) OVERRIDE;
88  virtual bool GetTooltipText(const gfx::Point& p,
89                              string16* tooltip) const OVERRIDE;
90  virtual bool HitTestRect(const gfx::Rect& rect) 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  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_
140