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_BACKGROUND_H_ 6 #define UI_VIEWS_BACKGROUND_H_ 7 8 #include "build/build_config.h" 9 10 #if defined(OS_WIN) 11 #include <windows.h> 12 #endif // defined(OS_WIN) 13 14 #include "base/basictypes.h" 15 #include "third_party/skia/include/core/SkColor.h" 16 #include "ui/views/views_export.h" 17 18 namespace gfx { 19 class Canvas; 20 } 21 22 namespace views { 23 24 class Painter; 25 class View; 26 27 ///////////////////////////////////////////////////////////////////////////// 28 // 29 // Background class 30 // 31 // A background implements a way for views to paint a background. The 32 // background can be either solid or based on a gradient. Of course, 33 // Background can be subclassed to implement various effects. 34 // 35 // Any View can have a background. See View::SetBackground() and 36 // View::OnPaintBackground() 37 // 38 ///////////////////////////////////////////////////////////////////////////// 39 class VIEWS_EXPORT Background { 40 public: 41 Background(); 42 virtual ~Background(); 43 44 // Creates a background that fills the canvas in the specified color. 45 static Background* CreateSolidBackground(SkColor color); 46 47 // Creates a background that fills the canvas in the specified color. CreateSolidBackground(int r,int g,int b)48 static Background* CreateSolidBackground(int r, int g, int b) { 49 return CreateSolidBackground(SkColorSetRGB(r, g, b)); 50 } 51 52 // Creates a background that fills the canvas in the specified color. CreateSolidBackground(int r,int g,int b,int a)53 static Background* CreateSolidBackground(int r, int g, int b, int a) { 54 return CreateSolidBackground(SkColorSetARGB(a, r, g, b)); 55 } 56 57 // Creates a background that contains a vertical gradient that varies 58 // from |color1| to |color2| 59 static Background* CreateVerticalGradientBackground(SkColor color1, 60 SkColor color2); 61 62 // Creates a background that contains a vertical gradient. The gradient can 63 // have multiple |colors|. The |pos| array contains the relative positions of 64 // each corresponding color. |colors| and |pos| must be the same size. The 65 // first element in |pos| must be 0.0 and the last element must be 1.0. 66 // |count| contains the number of elements in |colors| and |pos|. 67 static Background* CreateVerticalMultiColorGradientBackground(SkColor* colors, 68 SkScalar* pos, 69 size_t count); 70 71 // Creates Chrome's standard panel background 72 static Background* CreateStandardPanelBackground(); 73 74 // Creates a Background from the specified Painter. If owns_painter is 75 // true, the Painter is deleted when the Border is deleted. 76 static Background* CreateBackgroundPainter(bool owns_painter, 77 Painter* painter); 78 79 // Render the background for the provided view 80 virtual void Paint(gfx::Canvas* canvas, View* view) const = 0; 81 82 // Set a solid, opaque color to be used when drawing backgrounds of native 83 // controls. Unfortunately alpha=0 is not an option. 84 void SetNativeControlColor(SkColor color); 85 86 // Returns the "background color". This is equivalent to the color set in 87 // SetNativeControlColor(). For solid backgrounds, this is the color; for 88 // gradient backgrounds, it's the midpoint of the gradient; for painter 89 // backgrounds, this is not useful (returns a default color). get_color()90 SkColor get_color() const { return color_; } 91 92 #if defined(OS_WIN) 93 // TODO(port): Make GetNativeControlBrush portable (currently uses HBRUSH). 94 95 // Get the brush that was specified by SetNativeControlColor 96 HBRUSH GetNativeControlBrush() const; 97 #endif // defined(OS_WIN) 98 99 private: 100 SkColor color_; 101 #if defined(OS_WIN) 102 // TODO(port): Create portable replacement for HBRUSH. 103 mutable HBRUSH native_control_brush_; 104 #endif // defined(OS_WIN) 105 106 DISALLOW_COPY_AND_ASSIGN(Background); 107 }; 108 109 } // namespace views 110 111 #endif // UI_VIEWS_BACKGROUND_H_ 112