add SkCanvas::drawDRRect

include/core/SkCanvas.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 SkCanvas_DEFINED
 #define SkCanvas_DEFINED
 
@@ skipping 650 matching lines @@
 
     /**
      *  Draw the specified RRect using the specified paint The rrect will be filled or stroked
      *  based on the Style in the paint.
      *
      *  @param rrect    The round-rect to draw
      *  @param paint    The paint used to draw the round-rect
      */
     virtual void drawRRect(const SkRRect& rrect, const SkPaint& paint);
 
+    /**
+     *  Draw the annulus formed by the outer and inner rrects. The results
+     *  are undefined if the outer does not contain the inner.
+     */
+    void drawDRRect(const SkRRect& outer, const SkRRect& inner, const SkPaint&);
+
     /** Draw the specified circle using the specified paint. If radius is <= 0,
         then nothing will be drawn. The circle will be filled
         or framed based on the Style in the paint.
         @param cx       The x-coordinate of the center of the cirle to be drawn
         @param cy       The y-coordinate of the center of the cirle to be drawn
         @param radius   The radius of the cirle to be drawn
         @param paint    The paint used to draw the circle
     */
     void drawCircle(SkScalar cx, SkScalar cy, SkScalar radius,
                     const SkPaint& paint);
@@ skipping 373 matching lines @@
         bool              fDone;
     };
 
 protected:
     // default impl defers to getDevice()->newSurface(info)
     virtual SkSurface* onNewSurface(const SkImageInfo&);
 
     // default impl defers to its device
     virtual const void* onPeekPixels(SkImageInfo*, size_t* rowBytes);
 
+    virtual void onDrawDRRect(const SkRRect&, const SkRRect&, const SkPaint&);
+
     // Returns the canvas to be used by DrawIter. Default implementation
     // returns this. Subclasses that encapsulate an indirect canvas may
     // need to overload this method. The impl must keep track of this, as it
     // is not released or deleted by the caller.
     virtual SkCanvas* canvasForDrawIter();
 
     // Clip rectangle bounds. Called internally by saveLayer.
     // returns false if the entire rectangle is entirely clipped out
     // If non-NULL, The imageFilter parameter will be used to expand the clip
     // and offscreen bounds for any margin required by the filter DAG.
@@ skipping 209 matching lines @@
     bool asROBitmap(SkBitmap*) const;
 
 private:
     SkBitmap    fBitmap;    // used if peekPixels() fails
     const void* fAddr;      // NULL on failure
     SkImageInfo fInfo;
     size_t      fRowBytes;
 };
 
 #endif