How about adding -onPaint and -onEraseBkGnd just to windows and not all controls? An alternative would be to make the Graphic control more flexible, adding scroll bar support etc.
jez. ----- Original Message ----- From: "Laurent ROCHER" <[EMAIL PROTECTED]> To: "Jez White" <[EMAIL PROTECTED]> Cc: "guihackers" <perl-win32-gui-hackers@lists.sourceforge.net> Sent: Tuesday, May 18, 2004 4:55 PM Subject: Re: [perl-win32-gui-hackers] GUI.xs (BeginPaint and EndPaint) > Hi, > > Graphic control it's a specialized window for painting issue. > Graphic was created only for provide Paint event for user wanted to draw > specific stuff. > Paint event, it's not usefull for standard/common control (button, > listbox, ...). And, for doing owner draw control, it's not WM_PAINT event to > use but WM_DRAWITEM/NM_CUSTOMDRAW. > > For me, it's not a good idea to add this event for all control. > If you really need this event for a special case, it's better to use > HookEvent. > > For performance, WM_PAINT it's a frequent event so adding it to every > control can slowdown application. > > But, It's a good idea to add -onEraseBkGnd event to Graphic control. > > Laurent. > > > > > I had assumed that the Graphic control was some sort of windows thing. > It's > > not, its a perl thing. A graphic is simply a window, with XS code to call > > the paint and interactive events in perl. I must admit that other than the > > paint handler, I'm a bit stumped to come up with a reason why the Graphic > > control exits, other than in older versions of Win32::GUI normal windows > did > > not have the events associated with an "interactive" Graphic (mousemove > > etc). So if a normal window had a paint handler, why use a graphic > control? > > > > It also turns out there is an alternatives to using Windows > > BeginPaint/EndPaint - use ValidateRect and GetUpdateRect which is how > > painting works for Graphic controls (ValidateRect is Validate in Perl > > speak). There are subtle differences to BeginPaint/EndPaint and > > ValidateRect/GetUpdateRect but I'll have to play to see what the effects > are > > in reality. You can use the Validate method on a DC for a hooked paint > > event. > > > > If adding an -onPaint event is a sensible thing (I think it is) I also > > suggest adding the event -onEraseBkGnd (WM_ERASEBKGND). Having this event > > would give more control in how the background is erased (that annoying > > flicker on resize). My only concern is would this effect the performance > of > > windows who do not explicitly use these events? > > >
