Sk_API for SkImageGenerator and SkInstallDiscardablePixelRef

src/lazy/SkDiscardablePixelRef.cpp

 /*
  * Copyright 2013 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkDiscardablePixelRef.h"
 #include "SkDiscardableMemory.h"
+#include "SkImageGenerator.h"
 
 SkDiscardablePixelRef::SkDiscardablePixelRef(SkImageGenerator* generator,
                                              const SkImageInfo& info,
                                              size_t size,
                                              size_t rowBytes,
                                              SkDiscardableMemory::Factory* fact)
     : fGenerator(generator)
     , fDMFactory(fact)
     , fInfo(info)
     , fSize(size)
@@ skipping 35 matching lines @@
         return NULL;  // TODO(halcanary) Find out correct thing to do.
     }
     return pixels;
 }
 void SkDiscardablePixelRef::onUnlockPixels() {
     if (fDiscardableMemory != NULL) {
         fDiscardableMemory->unlock();
     }
 }
 
-bool SkDiscardablePixelRef::Install(SkImageGenerator* generator,
-                                    SkBitmap* dst,
-                                    SkDiscardableMemory::Factory* factory) {
+bool SkInstallDiscardablePixelRef(SkImageGenerator* generator,
+                                  SkBitmap* dst,
+                                  SkDiscardableMemory::Factory* factory) {
     SkImageInfo info;
     SkASSERT(generator != NULL);
     if ((NULL == generator)
         || (!generator->getInfo(&info))
-        || (!dst->setConfig(info, 0))
-        || (0 == dst->getSize())) {  // dst->getSize=0 Probably a bad config
+        || (!dst->setConfig(info, 0))) {
         SkDELETE(generator);
         return false;
     }
+    SkASSERT(dst->config() != SkBitmap::kNo_Config);
+    if (dst->empty()) { // Use a normal pixelref.
+        SkDELETE(generator);  // Do not need this anymore.
+        return dst->allocPixels(NULL, NULL);
+    }
     SkAutoTUnref<SkDiscardablePixelRef> ref(SkNEW_ARGS(SkDiscardablePixelRef,
                                                    (generator, info,
                                                     dst->getSize(),
                                                     dst->rowBytes(),
                                                     factory)));
     dst->setPixelRef(ref);
     return true;
 }