Question

I am trying to set a different wallpaper for every home screen, but I get OutOfMemory issues. I have 5 Bitmaps which I am trying to overlay on a wallpaper Bitmap which is 5 times the display width. Using the code below I get OOM. The problem seems to be the first line of code which creates the large wallpaper Bitmap. My question is whether there is a way to do this (i.e. some way that takes up less memory, or someway to allocate more memory??). Thanks!

 Bitmap wallpaper = Bitmap.createBitmap(displayWidth*5,displayHeight, Config.ARGB_8888);
 Canvas canvas = new Canvas(wallpaper);
 Uri data = getIntent().getData();
 Bitmap bmp = getBitmap(data, imagePosition, displayWidth, displayHeight);
 canvas.drawBitmap(bmp, 0, 0,null);
 WallpaperManager wallpaperManager = (WallpaperManager) SetterActivity.this.getSystemService(Context.WALLPAPER_SERVICE);
 wallpaperManager.setBitmap(wallpaper);
 wallpaperManager.suggestDesiredDimensions(bmp.getWidth()*2, bmp.getHeight());

Answer 1

If you can’t get around having 5 screens worth of images loaded at a time, you could try only having one loaded at a time, and switch based on which home screen is currently being viewed.

That is, you have 2 bitmaps in memory, one is current and one is next. Load the current bitmap on first view. Use onOffsetsChanged to determine when a scroll is happening, and at that point load bitmap next based on which home screen will be showing next. You’ll need to do that interpolation from screen A to B on your own. when the scroll is finished, recycle current and save next as current.

I’m sure there are some gotchas in this implementation that I’m not thinking of right now, but you’ll only ever have 2 bitmaps allocated with this method. Good luck!