ThumbnailRequestHandler.java 文件源码

/**
 * Copy/Paste of com.squareup.picasso.RequestHandler.calculateInSampleSize()...
 */
static void calculateInSampleSize(int reqWidth, int reqHeight, int width, int height,
                                  BitmapFactory.Options options, Request request) {
    int sampleSize = 1;
    if (height > reqHeight || width > reqWidth) {
        final int heightRatio;
        final int widthRatio;
        if (reqHeight == 0) {
            sampleSize = (int) Math.floor((float) width / (float) reqWidth);
        } else if (reqWidth == 0) {
            sampleSize = (int) Math.floor((float) height / (float) reqHeight);
        } else {
            heightRatio = (int) Math.floor((float) height / (float) reqHeight);
            widthRatio = (int) Math.floor((float) width / (float) reqWidth);
            sampleSize = request.centerInside
                    ? Math.max(heightRatio, widthRatio)
                    : Math.min(heightRatio, widthRatio);
        }
    }
    options.inSampleSize = sampleSize;
    options.inJustDecodeBounds = false;
}