ui/views/controls/button/image_button.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_BUTTON_IMAGE_BUTTON_H_
   6 #define UI_VIEWS_CONTROLS_BUTTON_IMAGE_BUTTON_H_
   7
   8 #include "base/gtest_prod_util.h"
   9 #include "base/memory/scoped_ptr.h"
  10 #include "ui/base/layout.h"
  11 #include "ui/gfx/image/image_skia.h"
  12 #include "ui/views/controls/button/custom_button.h"
  13
  14 namespace views {
  15
  16 class Painter;
  17
  18 // An image button.
  19
  20 // Note that this type of button is not focusable by default and will not be
  21 // part of the focus chain.  Call SetFocusable(true) to make it part of the
  22 // focus chain.
  23
  24 class VIEWS_EXPORT ImageButton : public CustomButton {
  25  public:
  26   static const char kViewClassName[];
  27
  28   enum HorizontalAlignment {
  29     ALIGN_LEFT = 0,
  30     ALIGN_CENTER,
  31     ALIGN_RIGHT
  32   };
  33
  34   enum VerticalAlignment {
  35     ALIGN_TOP = 0,
  36     ALIGN_MIDDLE,
  37     ALIGN_BOTTOM
  38   };
  39
  40   explicit ImageButton(ButtonListener* listener);
  41   ~ImageButton() override;
  42
  43   // Returns the image for a given |state|.
  44   virtual const gfx::ImageSkia& GetImage(ButtonState state) const;
  45
  46   // Set the image the button should use for the provided state.
  47   virtual void SetImage(ButtonState state, const gfx::ImageSkia* image);
  48
  49   // Set the background details.
  50   void SetBackground(SkColor color,
  51                      const gfx::ImageSkia* image,
  52                      const gfx::ImageSkia* mask);
  53
  54   // Sets how the image is laid out within the button's bounds.
  55   void SetImageAlignment(HorizontalAlignment h_align,
  56                          VerticalAlignment v_align);
  57
  58   void SetFocusPainter(scoped_ptr<Painter> focus_painter);
  59
  60   // The minimum size of the contents (not including the border). The contents
  61   // will be at least this size, but may be larger if the image itself is
  62   // larger.
  63   const gfx::Size& minimum_image_size() const { return minimum_image_size_; }
  64   void SetMinimumImageSize(const gfx::Size& size);
  65
  66   // Whether we should draw our images resources horizontally flipped.
  67   void SetDrawImageMirrored(bool mirrored) {
  68     draw_image_mirrored_ = mirrored;
  69   }
  70
  71   // Overridden from View:
  72   gfx::Size GetPreferredSize() const override;
  73   const char* GetClassName() const override;
  74   void OnPaint(gfx::Canvas* canvas) override;
  75
  76  protected:
  77   // Overridden from View:
  78   void OnFocus() override;
  79   void OnBlur() override;
  80
  81   // Returns the image to paint. This is invoked from paint and returns a value
  82   // from images.
  83   virtual gfx::ImageSkia GetImageToPaint();
  84
  85   // Updates button background for |scale_factor|.
  86   void UpdateButtonBackground(ui::ScaleFactor scale_factor);
  87
  88   Painter* focus_painter() { return focus_painter_.get(); }
  89
  90   // The images used to render the different states of this button.
  91   gfx::ImageSkia images_[STATE_COUNT];
  92
  93   gfx::ImageSkia background_image_;
  94
  95  private:
  96   FRIEND_TEST_ALL_PREFIXES(ImageButtonTest, Basics);
  97   FRIEND_TEST_ALL_PREFIXES(ImageButtonTest, ImagePositionWithBorder);
  98   FRIEND_TEST_ALL_PREFIXES(ImageButtonTest, LeftAlignedMirrored);
  99   FRIEND_TEST_ALL_PREFIXES(ImageButtonTest, RightAlignedMirrored);
 100
 101   // Returns the correct position of the image for painting.
 102   gfx::Point ComputeImagePaintPosition(const gfx::ImageSkia& image);
 103
 104   // Image alignment.
 105   HorizontalAlignment h_alignment_;
 106   VerticalAlignment v_alignment_;
 107   gfx::Size minimum_image_size_;
 108
 109   // Whether we draw our resources horizontally flipped. This can happen in the
 110   // linux titlebar, where image resources were designed to be flipped so a
 111   // small curved corner in the close button designed to fit into the frame
 112   // resources.
 113   bool draw_image_mirrored_;
 114
 115   scoped_ptr<Painter> focus_painter_;
 116
 117   DISALLOW_COPY_AND_ASSIGN(ImageButton);
 118 };
 119
 120 ////////////////////////////////////////////////////////////////////////////////
 121 //
 122 // ToggleImageButton
 123 //
 124 // A toggle-able ImageButton.  It swaps out its graphics when toggled.
 125 //
 126 ////////////////////////////////////////////////////////////////////////////////
 127 class VIEWS_EXPORT ToggleImageButton : public ImageButton {
 128  public:
 129   explicit ToggleImageButton(ButtonListener* listener);
 130   ~ToggleImageButton() override;
 131
 132   // Change the toggled state.
 133   void SetToggled(bool toggled);
 134
 135   // Like ImageButton::SetImage(), but to set the graphics used for the
 136   // "has been toggled" state.  Must be called for each button state
 137   // before the button is toggled.
 138   void SetToggledImage(ButtonState state, const gfx::ImageSkia* image);
 139
 140   // Set the tooltip text displayed when the button is toggled.
 141   void SetToggledTooltipText(const base::string16& tooltip);
 142
 143   // Overridden from ImageButton:
 144   const gfx::ImageSkia& GetImage(ButtonState state) const override;
 145   void SetImage(ButtonState state, const gfx::ImageSkia* image) override;
 146
 147   // Overridden from View:
 148   bool GetTooltipText(const gfx::Point& p,
 149                       base::string16* tooltip) const override;
 150   void GetAccessibleState(ui::AXViewState* state) override;
 151
 152  private:
 153   // The parent class's images_ member is used for the current images,
 154   // and this array is used to hold the alternative images.
 155   // We swap between the two when toggling.
 156   gfx::ImageSkia alternate_images_[STATE_COUNT];
 157
 158   // True if the button is currently toggled.
 159   bool toggled_;
 160
 161   // The parent class's tooltip_text_ is displayed when not toggled, and
 162   // this one is shown when toggled.
 163   base::string16 toggled_tooltip_text_;
 164
 165   DISALLOW_COPY_AND_ASSIGN(ToggleImageButton);
 166 };
 167
 168 }  // namespace views
 169
 170 #endif  // UI_VIEWS_CONTROLS_BUTTON_IMAGE_BUTTON_H_