Add SkImageGeneratorWIC

src/ports/SkImageGeneratorWIC.h

+/*
+ * Copyright 2016 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "SkTypes.h"
+
+#if defined(SK_BUILD_FOR_WIN)
+
+#include "SkData.h"
+#include "SkImageGenerator.h"
+#include "SkTemplates.h"
+#include "SkTScopedComPtr.h"
+
+#include <wincodec.h>
+
+/*
+ * Any Windows program that uses COM must initialize the COM library by calling
+ * the CoInitializeEx function.  In addition, each thread that uses a COM
+ * interface must make a separate call to this function.
+ *
+ * For every successful call to CoInitializeEx, the thread must call
+ * CoUninitialize before it exits.
+ *
+ * SkImageGeneratorWIC requires the COM library and leaves it to the client to
+ * initialize COM for their application.
+ *
+ * For more information on initializing COM, please see:
+ * https://msdn.microsoft.com/en-us/library/windows/desktop/ff485844.aspx
+ */
+class SkImageGeneratorWIC : public SkImageGenerator {
+public:
+    /*
+     * Refs the data if an image generator can be returned.  Otherwise does
+     * not affect the data.
+     */
+    static SkImageGenerator* NewFromEncodedWIC(SkData* data);
+
+protected:
+    SkData* onRefEncodedData(SK_REFENCODEDDATA_CTXPARAM) override;
+
+    bool onGetPixels(const SkImageInfo& info, void* pixels, size_t rowBytes, SkPMColor ctable[],
+            int* ctableCount) override;
+
+private:
+    /*
+     * Takes ownership of the imagingFactory
+     * Takes ownership of the imageSource
+     * Refs the data
+     */
+    SkImageGeneratorWIC(const SkImageInfo& info, IWICImagingFactory* imagingFactory,
+            IWICBitmapSource* imageSource, SkData* data);
+
+    SkTScopedComPtr<IWICImagingFactory> fImagingFactory;
+    SkTScopedComPtr<IWICBitmapSource>   fImageSource;
+    SkAutoTUnref<SkData>                fData;
+    
+    typedef SkImageGenerator INHERITED;
+};
+
+#endif // SK_BUILD_FOR_WIN