1 2 /* 3 * Copyright 2011 Google Inc. 4 * 5 * Use of this source code is governed by a BSD-style license that can be 6 * found in the LICENSE file. 7 */ 8 9 10 11 #ifndef SkEmptyShader_DEFINED 12 #define SkEmptyShader_DEFINED 13 14 #include "SkShader.h" 15 16 /** 17 * \class SkEmptyShader 18 * A Shader that always draws nothing. Its setContext always returns false, 19 * so it never expects that its shadeSpan() methods will get called. 20 */ 21 class SK_API SkEmptyShader : public SkShader { 22 public: SkEmptyShader()23 SkEmptyShader() {} 24 25 virtual uint32_t getFlags() SK_OVERRIDE; 26 virtual uint8_t getSpan16Alpha() const SK_OVERRIDE; 27 virtual bool setContext(const SkBitmap&, const SkPaint&, 28 const SkMatrix&) SK_OVERRIDE; 29 virtual void shadeSpan(int x, int y, SkPMColor span[], int count) SK_OVERRIDE; 30 virtual void shadeSpan16(int x, int y, uint16_t span[], int count) SK_OVERRIDE; 31 virtual void shadeSpanAlpha(int x, int y, uint8_t alpha[], int count) SK_OVERRIDE; 32 33 protected: 34 SkEmptyShader(SkFlattenableReadBuffer&); 35 36 virtual Factory getFactory() SK_OVERRIDE; 37 virtual void flatten(SkFlattenableWriteBuffer&) SK_OVERRIDE; 38 39 private: 40 typedef SkShader INHERITED; 41 }; 42 43 #endif 44