Check wallpaper visibility to determine if wallpaper is obscuring apps.

     * it may obscure windows behind it.

     */

    boolean isOpaqueDrawn() {

        return (mAttrs.format == PixelFormat.OPAQUE

                        || mAttrs.type == TYPE_WALLPAPER)

        // When there is keyguard, wallpaper could be placed over the secure app

        // window but invisible. We need to check wallpaper visibility explicitly

        // to determine if it's occluding apps.

        return ((!mIsWallpaper && mAttrs.format == PixelFormat.OPAQUE)

                || (mIsWallpaper && mWallpaperVisible))

                && isDrawnLw() && mWinAnimator.mAnimation == null

                && (mAppToken == null || mAppToken.mAppAnimator.animation == null);

    }