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_GFX_SHADOW_VALUE_H_ 6 #define UI_GFX_SHADOW_VALUE_H_ 7 8 #include <string> 9 #include <tuple> 10 #include <vector> 11 12 #include "third_party/skia/include/core/SkColor.h" 13 #include "ui/gfx/geometry/vector2d.h" 14 #include "ui/gfx/gfx_export.h" 15 16 namespace gfx { 17 18 class Insets; 19 20 class ShadowValue; 21 typedef std::vector<ShadowValue> ShadowValues; 22 23 // ShadowValue encapsulates parameters needed to define a shadow, including the 24 // shadow's offset, blur amount and color. 25 class GFX_EXPORT ShadowValue { 26 public: 27 constexpr ShadowValue() = default; ShadowValue(const gfx::Vector2d & offset,double blur,SkColor color)28 constexpr ShadowValue(const gfx::Vector2d& offset, double blur, SkColor color) 29 : offset_(offset), blur_(blur), color_(color) {} 30 x()31 constexpr int x() const { return offset_.x(); } y()32 constexpr int y() const { return offset_.y(); } offset()33 constexpr const gfx::Vector2d& offset() const { return offset_; } blur()34 constexpr double blur() const { return blur_; } color()35 constexpr SkColor color() const { return color_; } 36 37 constexpr bool operator==(const ShadowValue& other) const { 38 return offset_ == other.offset_ && blur_ == other.blur_ && 39 color_ == other.color_; 40 } 41 42 ShadowValue Scale(float scale) const; 43 44 std::string ToString() const; 45 46 // Gets margin space needed for shadows. Note that values in returned Insets 47 // are negative because shadow margins are outside a boundary. 48 static Insets GetMargin(const ShadowValues& shadows); 49 50 // Gets the area inside a rectangle that would be affected by shadow blur. 51 // This is similar to the margin except it's positive (the blur region is 52 // inside a hypothetical rectangle) and it accounts for the blur both inside 53 // and outside the bounding box. The region inside the "blur region" would be 54 // a uniform color. 55 static Insets GetBlurRegion(const ShadowValues& shadows); 56 57 // Makes ShadowValues matching MD or Refresh shadows for the given elevation 58 // and color. 59 static ShadowValues MakeRefreshShadowValues(int elevation, SkColor color); 60 static ShadowValues MakeMdShadowValues(int elevation, 61 SkColor color = SK_ColorBLACK); 62 63 private: 64 gfx::Vector2d offset_; 65 66 // Blur amount of the shadow in pixels. If underlying implementation supports 67 // (e.g. Skia), it can have fraction part such as 0.5 pixel. The value 68 // defines a range from full shadow color at the start point inside the 69 // shadow to fully transparent at the end point outside it. The range is 70 // perpendicular to and centered on the shadow edge. For example, a blur 71 // amount of 4.0 means to have a blurry shadow edge of 4 pixels that 72 // transitions from full shadow color to fully transparent and with 2 pixels 73 // inside the shadow and 2 pixels goes beyond the edge. 74 double blur_ = 0.; 75 76 SkColor color_ = SK_ColorTRANSPARENT; 77 }; 78 79 } // namespace gfx 80 81 #endif // UI_GFX_SHADOW_VALUE_H_ 82