BitmapSource.java 文件源码

public TileImage getTileImage() {
    if (mIsGif) {
        return null;
    }

    InputStream inputStream = getInputStream();
    if (inputStream != null) {
        BitmapFactory.Options options = new BitmapFactory.Options();
        options.inJustDecodeBounds = true;
        BitmapFactory.decodeStream(inputStream, null, options);
        closeSilently(inputStream);
        int width = options.outWidth;
        int height = options.outHeight;

        if (width <= 0 || height <= 0) {
            return null;
        }

        inputStream = getInputStream();
        try {
            BitmapRegionDecoder bitmapRegionDecoder = BitmapRegionDecoder.newInstance(inputStream, false);
            closeSilently(inputStream);
            inputStream = getInputStream();
            int orientation = OrientationInfoUtility.getOrientation(inputStream);
            closeSilently(inputStream);
            return TileImage.newInstance(width, height, orientation, bitmapRegionDecoder);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
    return null;
}