Here is some progress with what I have done so far. I have added the following things:
- Ability to change what “mode” you are in: painting, panning, color picking
- Picking a color you want to clear the canvas with
- Loading and saving an image for reference
- The scratchpad size is dynamic, so you can resize the window and you kind of have an “infinite” canvas

My file dialog was gigantic for some reason, so sorry with that going off the screen with the loading and saving options.