1 /* 2 * Copyright 2011 Google Inc. 3 * 4 * Use of this source code is governed by a BSD-style license that can be 5 * found in the LICENSE file. 6 */ 7 8 #ifndef SkEmptyShader_DEFINED 9 #define SkEmptyShader_DEFINED 10 11 #include "SkShaderBase.h" 12 13 // TODO: move this to private, as there is a public factory on SkShader 14 15 /** 16 * \class SkEmptyShader 17 * A Shader that always draws nothing. Its createContext always returns nullptr. 18 */ 19 class SkEmptyShader : public SkShaderBase { 20 public: 21 SkEmptyShader() {} 22 23 SK_TO_STRING_OVERRIDE() 24 SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkEmptyShader) 25 26 protected: 27 Context* onMakeContext(const ContextRec&, SkArenaAlloc*) const override { 28 return nullptr; 29 } 30 31 void flatten(SkWriteBuffer& buffer) const override { 32 // Do nothing. 33 // We just don't want to fall through to SkShader::flatten(), 34 // which will write data we don't care to serialize or decode. 35 } 36 37 bool onAppendStages(const StageRec&) const override { 38 return false; 39 } 40 41 private: 42 typedef SkShaderBase INHERITED; 43 }; 44 45 #endif 46
