Well, if panels can be transparent then I could use one main panel and add a canvas to draw the background and overlay it with the transparent panels (or use a message% with a bitmap label instead of the canvas if it is a fixed image). Then there is no need for the 'on-paint' for panels.
-----Original Message----- From: Matthew Flatt [mailto:mfl...@cs.utah.edu] Sent: vrijdag 25 februari 2011 13:55 To: Christophe Vandenberghe Cc: users@racket-lang.org Subject: RE: [racket] Graphical Toolkit change question Ok, but to be clear, you need both `on-paint' and transparency for panels, right? Transparent panels can group and hide controls, but you need `on-paint' to draw a background in the first place. It turns out that transparency more or less falls out of supporting `on-paint' for panels, so I'll work on both. At Fri, 25 Feb 2011 08:30:44 +0100, "Christophe Vandenberghe" wrote: > That is indeed my problem. I am using Win32 and panels take the same color as > their parent. That is why I could never make something like a background > panel > with another panel on top that is the same size as the background and only > contains for example one button centered in the middle (a.k.a a menu). This > would make it easy to be able to hide that "menu" and show another one when > the > button is clicked. But since the panels take the same color as their parent > (in > this case the frame), the overlaying panel hides the background panel. > > The only workaround I have found is to use a container panel for each of > these > "menus" that on their own contain the background and then a pane (as panes do > show transparent, but cannot be removed unless it's parent is removed) > containing the menu. That way I can always show and hide the container panel > and create a navigation between menus. The huge problem with this approach is > that the background has to be loaded and inserted for each of the menus > separately instead of just once in the main frame. > > -----Original Message----- > From: Matthew Flatt [mailto:mfl...@cs.utah.edu] > Sent: donderdag 24 februari 2011 15:11 > To: Christophe Vandenberghe > Cc: users@racket-lang.org > Subject: RE: [racket] Graphical Toolkit change question > > At Thu, 24 Feb 2011 09:30:26 +0100, "Christophe Vandenberghe" wrote: > > But then again like I said before. It would be easier to have > > transparency for panels, as it would resolve the need for panes > > inserted in panels to be able to hide or delete them when needed. > > That would also solve the background problem. Would that be easy to > > achieve with the new implementation? > > I'm not clear on the sense in which panels are currently opaque. > > Since siblings are not supposed to overlap, the only kind of window > that can be behind a panel is another panel or eventually a frame. > I'm relatively clear on what happens with Win32 and Cocoa: > > * Under Win32 (the way `racket/gui' currently uses it), all panels and > frames are the same color, so you can't really tell whether panels > are transparent (i.e., transparent and solid is all the same). > > * Under Cocoa, all panels are transparent, allowing a frame's texture > (if any) to show through. > > Is there a Gtk theme where frame content and/or panels can be textured > (as opposed to being all the same color), so that you can tell the > difference between an opaque panel and a transparent one? Or are you > talking about something else completely? _________________________________________________ For list-related administrative tasks: http://lists.racket-lang.org/listinfo/users
