Create an SkCodecImageGenerator

src/core/SkCodecImageGenerator.cpp

+/*
+ * Copyright 2015 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "SkCodec.h"
+#include "SkImageGenerator.h"
+
+class SkCodecImageGenerator : SkImageGenerator {
+public:
+    /*
+     * Takes ownership of codec
+     */
+    static SkImageGenerator* Create(SkCodec* codec);
+
+protected:
+
+    bool onGetPixels(const SkImageInfo& info, void* pixels, size_t rowBytes, SkPMColor ctable[],
+            int* ctableCount) override;
+
+private:
+    SkCodecImageGenerator(SkCodec* codec);
+
+    SkAutoTDelete<SkCodec> fCodec; // Owned

[scroggo, 2015/12/02 20:22:55]

nit: I think it's obvious that fCodec is owned, since it is held in an
SkAutoTDelete.

[msarett, 2015/12/02 22:56:01]

I think so too.  Removing the comment.

+
+    typedef SkImageGenerator INHERITED;
+};
+
+SkImageGenerator* SkCodecImageGenerator::Create(SkCodec* codec) {
+    if (nullptr == codec) {
+        return nullptr;
+    }
+
+    return new SkCodecImageGenerator(codec);
+}
+
+SkCodecImageGenerator::SkCodecImageGenerator(SkCodec* codec)
+    : INHERITED(codec->getInfo())
+    , fCodec(codec)
+{}
+
+bool SkCodecImageGenerator::onGetPixels(const SkImageInfo& info, void* pixels, size_t rowBytes,
+                                        SkPMColor ctable[], int* ctableCount) {
+
+    SkCodec::Result result = fCodec->getPixels(info, pixels, rowBytes, nullptr, ctable,
+            ctableCount);
+    switch (result) {
+        case SkCodec::kSuccess:
+        case SkCodec::kIncompleteInput:
+            return true;
+        default:
+            return false;
+    }
+}