[fltk.general] R: Re: R: Bargraph object with Fl_Group
Hi Ian, thanks for your answer. I am writing to you directly, Best not - I very seldom reply to off-list posts... Sorry, will post to the list. OK: Then you need to composite the bar graph on top of the image. Fltk does not provide support for transparent widgets (yet) as it is a hard thing to do in a consistent cross-platform way, so the best bet may be for you to just blit the image into the box, then render the bar on top of it. This is easy and cheap to do, if you are rendering the graph on top of an image your app owns. If you want to render the graph transparently on top of (for example) the desktop then you are on your own out there, since fltk can't really do that without a lot of platform specific code...! Hope that made sense! FWIW, I think Greg's cheat pages have examples of doing some of this, so it would be worth a look... http://www.seriss.com/people/erco/fltk/ I need a bit of thinking. I am writing an app for creating supervision screens on an embedded platform. All is ruled by a configuration text file : it is parsed from my program which then creates all the pages, the buttons for page jumps, the graphics objects and so on. In general I do not know what there will be under my bargraph : maybe a picture, maybe a filled background. The situation is more similar to the desktop you mentioned. For now the simplest solution I can imagine is to redraw the whole parent of my object. Thanks a lot for your observations, regards Lucio ___ fltk mailing list fltk@easysw.com http://lists.easysw.com/mailman/listinfo/fltk
Re: [fltk.general] R: Re: R: Bargraph object with Fl_Group
On 03/15/13 08:02, memoryl...@tin.it wrote: I need a bit of thinking. I am writing an app for creating supervision screens on an embedded platform. All is ruled by a configuration text file : it is parsed from my program which then creates all the pages, the buttons for page jumps, the graphics objects and so on. In general I do not know what there will be under my bargraph : maybe a picture, maybe a filled background. The situation is more similar to the desktop you mentioned. For now the simplest solution I can imagine is to redraw the whole parent of my object. Thanks a lot for your observations, If the image is assigned to the bargraph's group, then just telling the bargraph widget to redraw() will do it. But if the image is assigned to the parent window, then you'll have to tell the parent window to redraw. Be sure to use an Fl_Double_Window to prevent flickering during redraws. ___ fltk mailing list fltk@easysw.com http://lists.easysw.com/mailman/listinfo/fltk
Re: [fltk.general] R: Re: R: Bargraph object with Fl_Group
On 15 Mar 2013, at 15:02, memoryl...@tin.it wrote: In general I do not know what there will be under my bargraph : maybe a picture, maybe a filled background. The situation is more similar to the desktop you mentioned. So long as the background is drawn by your app, then it is feasible to composite the bar graphs and etc on top of it. But: If the background is drawn by some other app, or is otherwise outside the control of your app windows, then compositing the graphs and so forth on top becomes Very Tricky. For now the simplest solution I can imagine is to redraw the whole parent of my object. Quite possibly: I think we need to understand more about the nature of the backgrounds, how they are drawn etc, and from there we can figure out how to render the graphs on top of them... ___ fltk mailing list fltk@easysw.com http://lists.easysw.com/mailman/listinfo/fltk
