Thanks Albrecht for your very detailed explanation and thanks everybody for answering. Calling init_sizes() resolved the problem. The other issues in the code were due it was just a draft to expose the resizing problem.
David > David Lopez wrote: > > Hi, I'm sorry to disturb you with a so basic question. > > This is not a basic question. Understanding FLTK's resizing strategies is not > trivial. > > > The posted source code implements a rough button moving by drag and drop in > > a resizable window. > > If I move the button and then I maximize or resize the window, the buttton > > is moved and scaled as expected. > > But if I first maximize the window and and then I move the button and after > > that I restore the window size, the button appears on its original location. > > This is not the whole story. Just for understanding what happens, try this > after > you start the program: > > (1) drag the button (optional, try with and without) > (2) resize the window only by a small amount > (3) drag the button (again) > (4) now maximize the window. > > Do you see the difference? The button should jump back to the (relative) > position after the _first_ window resize. > > > What am I missing? How can I preserve the changes done during the maximized > > state? > > As Ian suspected in his reply, you need init_sizes() to *save* the positions > of > your widgets internally after moving them. This can be done in the FL_RELEASE > case, see below. > > From the docs > <http://www.fltk.org/doc-1.1/Fl_Group.html#Fl_Group.init_sizes>: > > The Fl_Group widget keeps track of the original widget sizes and positions > when > resizing occurs [...]. If you rearrange the widgets in your group, call this > method to register the new arrangement with the Fl_Group that contains them. > > > case FL_DRAG: > > drag = 1; > > fl_cursor (FL_CURSOR_MOVE); > > Try adding position() and redraw() here too to see the effect *while* > dragging. > > > break; > > case FL_RELEASE: > > if (drag) //It's the end of a dragging > > { > > fl_cursor (FL_CURSOR_DEFAULT); > > position (x() + Fl::event_x(), y() + > > Fl::event_y()); //Move object > > you'd better use: > position (Fl::event_x(), Fl::event_y()); //Move object > > And add this here: > parent()->init_sizes(); // *save* positions and sizes > > > drag = 0; > > this->parent()->redraw (); > > } > > break; > > After you've fixed this: your dragging is "suboptimal" (there's always a jump > of > the widget such that the top left corner is at the cursor position). The next > step would be to make it smooth by saving coordinates and using relative > (delta > x, delta y) movement, but this is just another story. > > And, btw, your handle() always returns 1, which is probably not what you would > want in a real application, and it doesn't call the base class handle() > method. > You should read the docs about event handling in the subclassing chapter, > there > is also a good example how to do it the right way. > > http://www.fltk.org/doc-1.1/subclassing.html#handle > > If you do it this way, you'll probably see that you must also return 1 on > FL_PUSH events and maybe some more to make it work again. > > HTH > > Albrecht _______________________________________________ fltk mailing list [email protected] http://lists.easysw.com/mailman/listinfo/fltk
