make SkComposeShader.h private

BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1697523003

Review URL: https://codereview.chromium.org/1697523003

2 files changed, 90 insertions, 2 deletions

diff --git a/src/core/SkComposeShader.cpp b/src/core/SkComposeShader.cpp
index c49d8a48ae..9e5e2c6a49 100644
--- a/src/core/SkComposeShader.cpp
+++ b/src/core/SkComposeShader.cpp
@@ -1,4 +1,3 @@
-
 /*
  * Copyright 2006 The Android Open Source Project
  *
@@ -6,7 +5,6 @@
  * found in the LICENSE file.
  */
 
-
 #include "SkComposeShader.h"
 #include "SkColorFilter.h"
 #include "SkColorPriv.h"
diff --git a/src/core/SkComposeShader.h b/src/core/SkComposeShader.h
new file mode 100644
index 0000000000..bc9d932ee5
--- /dev/null
+++ b/src/core/SkComposeShader.h
@@ -0,0 +1,90 @@
+
+/*
+ * Copyright 2006 The Android Open Source Project
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+
+#ifndef SkComposeShader_DEFINED
+#define SkComposeShader_DEFINED
+
+#include "SkShader.h"
+
+class SkXfermode;
+
+///////////////////////////////////////////////////////////////////////////////////////////
+
+/** \class SkComposeShader
+    This subclass of shader returns the composition of two other shaders, combined by
+    a xfermode.
+*/
+class SK_API SkComposeShader : public SkShader {
+public:
+    /** Create a new compose shader, given shaders A, B, and a combining xfermode mode.
+        When the xfermode is called, it will be given the result from shader A as its
+        "dst", and the result from shader B as its "src".
+        mode->xfer32(sA_result, sB_result, ...)
+        @param shaderA  The colors from this shader are seen as the "dst" by the xfermode
+        @param shaderB  The colors from this shader are seen as the "src" by the xfermode
+        @param mode     The xfermode that combines the colors from the two shaders. If mode
+                        is null, then SRC_OVER is assumed.
+    */
+    SkComposeShader(SkShader* sA, SkShader* sB, SkXfermode* mode = NULL);
+    virtual ~SkComposeShader();
+
+    size_t contextSize() const override;
+
+#if SK_SUPPORT_GPU
+    const GrFragmentProcessor*  asFragmentProcessor(GrContext*,
+                                                    const SkMatrix& viewM,
+                                                    const SkMatrix* localMatrix,
+                                                    SkFilterQuality) const override;
+#endif
+
+    class ComposeShaderContext : public SkShader::Context {
+    public:
+        // When this object gets destroyed, it will call contextA and contextB's destructor
+        // but it will NOT free the memory.
+        ComposeShaderContext(const SkComposeShader&, const ContextRec&,
+                             SkShader::Context* contextA, SkShader::Context* contextB);
+
+        SkShader::Context* getShaderContextA() const { return fShaderContextA; }
+        SkShader::Context* getShaderContextB() const { return fShaderContextB; }
+
+        virtual ~ComposeShaderContext();
+
+        void shadeSpan(int x, int y, SkPMColor[], int count) override;
+
+    private:
+        SkShader::Context* fShaderContextA;
+        SkShader::Context* fShaderContextB;
+
+        typedef SkShader::Context INHERITED;
+    };
+
+#ifdef SK_DEBUG
+    SkShader* getShaderA() { return fShaderA; }
+    SkShader* getShaderB() { return fShaderB; }
+#endif
+
+    bool asACompose(ComposeRec* rec) const override;
+
+    SK_TO_STRING_OVERRIDE()
+    SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkComposeShader)
+
+protected:
+    SkComposeShader(SkReadBuffer& );
+    void flatten(SkWriteBuffer&) const override;
+    Context* onCreateContext(const ContextRec&, void*) const override;
+
+private:
+    SkShader*   fShaderA;
+    SkShader*   fShaderB;
+    SkXfermode* fMode;
+
+    typedef SkShader INHERITED;
+};
+
+#endif