Am 21.06.2005 um 18:52 schrieb Himanshu Garg:

> Hello,
>
>       I have subclassed Morph and overridden its drawOn. I found that
> it doesn't get called when the main Squeak window is maximized after
> minimization or when it becomes visible after an overlapping window
> moves away.
>
>       What is the function that I must override so that redrawing
> takes place even on unminimization or movement of overlapping window.
>
>       I am drawing text using an external dll with FFI which directly
> draws in the Squeak window. Any suggestions/pointers would be a great
> help. It isn't necessary that I use Morphic if it is not possible with
> it.

In normal drawing it is not necessary to redraw portions of of the  
display because the whole screen bitmap is cached. When the Squeak  
window needs to be redrawn, just the right bits from that bitmap  
(which is called Display) are copied to the screen. Morphic just  
draws into the bitmap and tells the system to update the changed  
portions.

If you draw yourself via FFI, you also need to get hold of the redraw  
events yourself. There is no support for this in regular Squeak.

- Bert -