The 'autodraw' property

Boolean scalar

Valid for: All visible controls and windows

The autodraw property is a boolean scalar which determines whether commands issued using the Draw method are stored and automatically replayed when the window needs updating. The default is true (1).

If autodraw is 1, each time the window needs updating (for example, if you have resized it or uncovered it), the Draw commands stored with the object are re-run to update the window. This means that, once you have issued one or more Draw commands, you do not need to handle update events in your APL code.

Occasionally, however, you may not want this to happen, and you may want to handle re-drawing yourself. In this case you can set autodraw to 0, and use the onPaint callback to program the re-drawing in APL.

Any Draw commands issued while autodraw is set to 0 are not entered into the list of saved drawing commands associated with the object.