On 6 Feb 2009, at 17:44, Fabio Bracci wrote: > Indeed what I am aiming for is to print/screen capture/etc a whole > widgets hierarchy contained in a Fl_Scroll (so a Fl_Group); I > already was thinking about providing a draw() function to a derived > class and enclose the Fl_Scroll::draw() with the offscreen > operations, thanx for the example! > > The problem I am facing now is that I have generated with fluid a > window with a scroll with a group; the group is the one holding the > complex widget structure.
Yes, that was what I had inferred from your previous comments, so that was what I tried to illustrate in my example. Was I right? > In my case I should wrap the group's draw() call with the offscreen > code ... but I can't! > /usr/include/FL/Fl_Group.H:56: error: ‘virtual void Fl_Group::draw > ()’ is protected > Is there a way to trigger the draw() method of a group from the > outside? > The alternative would be again deriving Fl_Group to customize draw > (), but fluid doesn't know anything about my custom widgets, so I > will not be able to use a Group with offscreen code from fluid. This is exactly what I would do, though. It is very easy to make a derived version of Fl_Group (as per my example) and then tell fluid to use that class for the container group. All you have to do is: - Construct your widget hierarchy in fluid as usual - Construct your derived group, and store it in a .cxx/.h pair of files with the text editor of your choice (just cut 'n paste from my example as a starting point!) - add a #include for the .h file to the top of the fluid tree (using the fluid New->Code->Declaration menu entry) - select the properties of your enclosing Fl_Group, go to the C++ tab and fill in the CLASS entry with the name of your derived class. Thereafter, fluid will use your derived class for that widget, rather than a "regular" Fl_Group, thereby making access to its draw method for custom effects straightforward. > In short: how is it possible to trigger the protected draw() of the > inner Group without dismantling the complex widget (built with fluid)? See above. I use this approach fairly often, and it is very straightforward, providing a flexible and powerful way to "tweak" any existing widget. -- Ian _______________________________________________ fltk mailing list [email protected] http://lists.easysw.com/mailman/listinfo/fltk
