DownloadNotificationService.java 文件源码

private Bitmap getLargeNotificationIcon(Bitmap bitmap) {
    Resources resources = mContext.getResources();
    int height = (int) resources.getDimension(android.R.dimen.notification_large_icon_height);
    int width = (int) resources.getDimension(android.R.dimen.notification_large_icon_width);
    final OvalShape circle = new OvalShape();
    circle.resize(width, height);
    final Paint paint = new Paint();
    paint.setColor(ApiCompatibilityUtils.getColor(resources, R.color.google_blue_grey_500));

    final Bitmap result = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
    Canvas canvas = new Canvas(result);
    circle.draw(canvas, paint);
    float leftOffset = (width - bitmap.getWidth()) / 2f;
    float topOffset = (height - bitmap.getHeight()) / 2f;
    if (leftOffset >= 0 && topOffset >= 0) {
        canvas.drawBitmap(bitmap, leftOffset, topOffset, null);
    } else {
        // Scale down the icon into the notification icon dimensions
        canvas.drawBitmap(bitmap,
                new Rect(0, 0, bitmap.getWidth(), bitmap.getHeight()),
                new Rect(0, 0, width, height),
                null);
    }
    return result;
}