Implemented transparent gradients

src/pdf/SkPDFShader.h

 
 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 
 #ifndef SkPDFShader_DEFINED
@@ skipping 39 matching lines @@
     public:
         ShaderCanonicalEntry(SkPDFObject* pdfShader, const State* state);
         bool operator==(const ShaderCanonicalEntry& b) const;
 
         SkPDFObject* fPDFShader;
         const State* fState;
     };
     // This should be made a hash table if performance is a problem.
     static SkTDArray<ShaderCanonicalEntry>& CanonicalShaders();
     static SkBaseMutex& CanonicalShadersMutex();
+
+    static SkPDFObject* GetPDFShaderByState(State* shaderState);

[vandebo (ex-Chrome), 2013/07/12 21:41:44]

At the least this should document that it consumes the state that's passed in. 
But it'd probably be better if it didn't - that may be counter to what I've said
before, sorry if so.

[ducky, 2013/07/12 23:32:34]

It would be cleaner if it didn't, but it needs to be able to transfer ownership
of the shaderState from GetPDFShaderByState(...) to the newly created
SkPDFShader.

Otherwise, either:
- each SkPDFShader instantiation would need to copy the state, which is probably
bad from a performance standpoint and having extra code.
- or SkPDFShader::State would need to be reference-counted, so that an
additional ref() can be done if it is part of a new SkPDFShader object.

Thoughts?

     static void RemoveShader(SkPDFObject* shader);
 
     SkPDFShader();
     virtual ~SkPDFShader() {};
 
     virtual bool isValid() = 0;
 };
 
 #endif