implement isABitmap for imageshader, return localmatrix for bitmap's impl

include/core/SkShader.h

 /*
  * 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 SkShader_DEFINED
 #define SkShader_DEFINED
 
 #include "SkBitmap.h"
 #include "SkFlattenable.h"
 #include "SkImageInfo.h"
 #include "SkMask.h"
 #include "SkMatrix.h"
 #include "SkPaint.h"
 #include "../gpu/GrColor.h"
 
 class SkColorFilter;
 class SkColorSpace;
+class SkImage;
 class SkPath;
 class SkPicture;
 class SkXfermode;
 class GrContext;
 class GrFragmentProcessor;
 
 /** \class SkShader
  *
  *  Shaders specify the source color(s) for what is being drawn. If a paint
  *  has no shader, then the paint's color is used. If the paint has a
@@ skipping 204 matching lines @@
      */
     bool isABitmap(SkBitmap* outTexture, SkMatrix* outMatrix, TileMode xy[2]) const {
         return this->onIsABitmap(outTexture, outMatrix, xy);
     }
 
     bool isABitmap() const {
         return this->isABitmap(nullptr, nullptr, nullptr);
     }
 
     /**
+     *  Iff this shader is backed by a single SkImage, return its ptr (the caller must ref this
+     *  if they want to keep it longer than the lifetime of the shader). If not, return nullptr.
+     */
+    SkImage* isAImage(SkMatrix* localMatrix, TileMode xy[2]) const {
+        return this->onIsAImage(localMatrix, xy);
+    }
+
+    bool isAImage() const {
+        return this->isAImage(nullptr, nullptr) != nullptr;
+    }
+
+    /**
      *  If the shader subclass can be represented as a gradient, asAGradient
      *  returns the matching GradientType enum (or kNone_GradientType if it
      *  cannot). Also, if info is not null, asAGradient populates info with
      *  the relevant (see below) parameters for the gradient.  fColorCount
      *  is both an input and output parameter.  On input, it indicates how
      *  many entries in fColors and fColorOffsets can be used, if they are
      *  non-NULL.  After asAGradient has run, fColorCount indicates how
      *  many color-offset pairs there are in the gradient.  If there is
      *  insufficient space to store all of the color-offset pairs, fColors
      *  and fColorOffsets will not be altered.  fColorOffsets specifies
@@ skipping 250 matching lines @@
     virtual size_t onContextSize(const ContextRec&) const;
 
     virtual bool onAsLuminanceColor(SkColor*) const {
         return false;
     }
 
     virtual bool onIsABitmap(SkBitmap*, SkMatrix*, TileMode[2]) const {
         return false;
     }
 
+    virtual SkImage* onIsAImage(SkMatrix*, TileMode[2]) const {
+        return nullptr;
+    }
+
 private:
     // This is essentially const, but not officially so it can be modified in
     // constructors.
     SkMatrix fLocalMatrix;
 
     // So the SkLocalMatrixShader can whack fLocalMatrix in its SkReadBuffer constructor.
     friend class SkLocalMatrixShader;
     friend class SkBitmapProcShader;    // for computeTotalInverse()
 
     typedef SkFlattenable INHERITED;
 };
 
 #endif