DraggingItemDecorator.java 文件源码

private Bitmap createDraggingItemImage(View v, NinePatchDrawable shadow) {
    int width = v.getWidth() + mShadowPadding.left + mShadowPadding.right;
    int height = v.getHeight() + mShadowPadding.top + mShadowPadding.bottom;

    final Bitmap bitmap = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);

    final Canvas canvas = new Canvas(bitmap);

    if (shadow != null) {
        shadow.setBounds(0, 0, width, height);
        shadow.draw(canvas);
    }

    final int savedCount = canvas.save(Canvas.CLIP_SAVE_FLAG | Canvas.MATRIX_SAVE_FLAG);
    // NOTE: Explicitly set clipping rect. This is required on Gingerbread.
    canvas.clipRect(mShadowPadding.left, mShadowPadding.top, width - mShadowPadding.right, height - mShadowPadding.bottom);
    canvas.translate(mShadowPadding.left, mShadowPadding.top);
    v.draw(canvas);
    canvas.restoreToCount(savedCount);

    return bitmap;
}