Merge "Update Bitmap#prepareToDraw doc" into oc-dev

    }

    /**

     * Rebuilds any caches associated with the bitmap that are used for

     * drawing it. In the case of purgeable bitmaps, this call will attempt to

     * ensure that the pixels have been decoded.

     * If this is called on more than one bitmap in sequence, the priority is

     * given in LRU order (i.e. the last bitmap called will be given highest

     * priority).

     *

     * For bitmaps with no associated caches, this call is effectively a no-op,

     * and therefore is harmless.

     * Builds caches associated with the bitmap that are used for drawing it.

     *

     * <p>Starting in {@link android.os.Build.VERSION_CODES#N}, this call initiates an asynchronous

     * upload to the GPU on RenderThread, if the Bitmap is not already uploaded. With Hardware

     * Acceleration, Bitmaps must be uploaded to the GPU in order to be rendered. This is done by

     * default the first time a Bitmap is drawn, but the process can take several milliseconds,

     * depending on the size of the Bitmap. Each time a Bitmap is modified and drawn again, it must

     * be re-uploaded.</p>

     *

     * <p>Calling this method in advance can save time in the first frame it's used. For example, it

     * is recommended to call this on an image decoding worker thread when a decoded Bitmap is about

     * to be displayed. It is recommended to make any pre-draw modifications to the Bitmap before

     * calling this method, so the cached, uploaded copy may be reused without re-uploading.</p>

     *

     * In {@link android.os.Build.VERSION_CODES#KITKAT} and below, for purgeable bitmaps, this call

     * would attempt to ensure that the pixels have been decoded.

     */

    public void prepareToDraw() {

        checkRecycled("Can't prepareToDraw on a recycled bitmap!");