add SkDrawPictureCallback optional parameter to drawPicture(), which can abort the picture drawing.

src/core/SkPicturePlayback.cpp

 
 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 #include "SkPicturePlayback.h"
 #include "SkPictureRecord.h"
 #include "SkTypeface.h"
@@ skipping 638 matching lines @@
         *size = 0;
     } else {
         UNPACK_8_24(temp, op, *size);
         if (MASK_24 == *size) {
             *size = reader->readInt();
         }
     }
     return (DrawType) op;
 }
 
-void SkPicturePlayback::draw(SkCanvas& canvas) {
+void SkPicturePlayback::draw(SkCanvas& canvas, SkDrawPictureCallback* callback) {
 #ifdef ENABLE_TIME_DRAW
     SkAutoTime  at("SkPicture::draw", 50);
 #endif
 
 #ifdef SPEW_CLIP_SKIPPING
     SkipClipRec skipRect, skipRRect, skipRegion, skipPath;
 #endif
 
 #ifdef SK_BUILD_FOR_ANDROID
     SkAutoMutexAcquire autoMutex(fDrawMutex);
@@ skipping 29 matching lines @@
     if (it.isValid()) {
         uint32_t skipTo = it.draw();
         if (kDrawComplete == skipTo) {
             return;
         }
         reader.setOffset(skipTo);
     }
 
     // Record this, so we can concat w/ it if we encounter a setMatrix()
     SkMatrix initialMatrix = canvas.getTotalMatrix();
+    int originalSaveCount = canvas.getSaveCount();
 
 #ifdef SK_BUILD_FOR_ANDROID
     fAbortCurrentPlayback = false;
 #endif
 
     while (!reader.eof()) {
+        if (callback && callback->abortDrawing()) {
+            canvas.restoreToCount(originalSaveCount);
+            return;
+        }
 #ifdef SK_BUILD_FOR_ANDROID

[robertphillips, 2013/05/16 15:04:23]

can this be folded into the new system?

         if (fAbortCurrentPlayback) {
             return;
         }
 #endif
 
         size_t curOffset = reader.offset();
         uint32_t size;
         DrawType op = read_op_and_size(&reader, &size);
         size_t skipTo = 0;
 #ifdef SK_DEVELOPER
@@ skipping 861 matching lines @@
     for (index = 0; index < fRegionCount; index++)
         bufferPtr += snprintf(bufferPtr, DUMP_BUFFER_SIZE - (bufferPtr - pBuffer),
             "region%p, ", &fRegions[index]);
     if (fRegionCount > 0)
         SkDebugf("%s0};\n", pBuffer);
 
     const_cast<SkPicturePlayback*>(this)->dumpStream();
 }
 
 #endif