How can I change canvas size programmatically?

PaintCode doesn’t allow to change the size of canvas programatically. You probably need this to match the size of your drawing to size of your view. Please consider using Frame (see Frame Tool) and variables instead. Please, check out the "Example.pcvd" document, particularly the "BlueRectFramed" canvas in the "Basic" tab. Also, take a look at the example project. For implementation details, check out the EXBasicViewOne subclass.