Re: [gtkmm] Application Design Problem

[Ivan Popivanov <popivan gmx net>]

Resolved, my use of gtk was erroneous.

Ivan Popivanov wrote:

> Hi,
>
> Here is an outline of the hierarchy design that I came up with for my 
> application:
>
> Main Window: GtkWindow: main application window
>  GtkVBox: to hold the menu, toolbar, application client area
>     Client Area: not sure about the type of this object, see below
>        GtkFixed: to manage the coordinate of few widgets that will be 
> needed in the client area
>           MyObjects: see below
>
> For the client area I need something that I can draw on. My first 
> thought was GtkDrawingArea, however, I run into problems when I tried 
> to attach the GtkFixed child. GtkDrawingArea is not a container right? 
> Then I tried GtkWindow and it didn't work either (the name is kind of 
> misleading, isn't it). At the end I decided that probably the best 
> match is GtkBin, the reason, the client area is going to have a single 
> child, namely the GtkFixed.
>
> My objects I created as GtkMisc (after few other tries), because I 
> want them to be window less, like GtkLabel. I added function members 
> to handle EXPOSE events.
>
> THE PROBLEM is that I receive the expose event in the Client Area, so 
> I can draw the background etc, however, I don't get any expose events 
> in MyObjects. They are on the top of the client area, but they don't 
> receive any draw messages. It seems to me that in gtkmm a signal 
> (event) is propagated to only one widget.
>
> One more thing, although I'm using gtkmm, I'm suspisous that it's a 
> Gtk problem.
>
> Any idea/explanation about event propagation in gtkmm?
>
> TIA,
>
> Ivan
>
>
> ------------------------------------------------------------------------
>
> #include <gdkmm.h>
> #include <gtkmm.h>
>
> #define APP_TITLE "Blah"
>
> class HandView : public Gtk::Misc
> {
> public:
>   HandView( );
>
> protected:
>   virtual bool on_expose_event( GdkEventExpose *event );
>   virtual bool on_configure_event(	GdkEventConfigure *event );
> };
>
> class ViewWnd : public Gtk::Bin
> {
> public:
>   ViewWnd( );
>
> protected:
>   virtual bool on_expose_event( GdkEventExpose *event );
>
> private:
>   Gtk::Fixed fixed_;
>   HandView hand_view_;
> };
>
> class FrameWnd : public Gtk::Window
> {
> public:
>   FrameWnd( );
>
> private:
>   Gtk::VBox wnd_vbox_;
>   ViewWnd view_;
> };
>
> inline
> FrameWnd::FrameWnd( )
> {
>   set_title( APP_TITLE );
>   /*
>   view_.add_events( Gdk::EXPOSURE_MASK |
>                     Gdk::STRUCTURE_MASK |
>                     Gdk::BUTTON_PRESS_MASK |
>                     Gdk::POINTER_MOTION_MASK |
>                     Gdk::BUTTON_RELEASE_MASK );
>    */
>   wnd_vbox_.pack_start( view_ );
>   add( wnd_vbox_ );
>   show_all_children( );
> }
>
> inline
> ViewWnd::ViewWnd( )
> {
>   fixed_.put( hand_view_, 5, 5 );
>   add( fixed_ );
> }
>
> bool
> ViewWnd::on_configure_event(	GdkEventConfigure *event )
> {
>   printf( "ViewWnd: Configure: rect( x = %d, y = %d, w = %d, h = %d )\n",
>           event->x, event->y,
>           event->width, event->height );
>   return true;
> }
>
> bool
> ViewWnd::on_expose_event( GdkEventExpose *event )
> {
>   printf( "ViewWnd: Expose: rect( x = %d, y = %d, w = %d, h = %d )\n",
>           event->area.x, event->area.y,
>           event->area.width, event->area.height );
>
>   Glib::RefPtr<Gdk::Window> win = get_window( );
>   Glib::RefPtr<Gdk::GC> gc = Gdk::GC::create(win);
>   Glib::RefPtr<Gdk::Colormap> colormap = get_default_colormap( );
>
>   Gdk::Color color;
>   color.set_red( 0xffff );
>   color.set_green( 0 );
>   color.set_blue( 0xffff );
>   colormap->alloc_color( color );
>   gc->set_rgb_fg_color( color );
>
>   int x, y, w, h;
>   int depth;
>
>   win->get_geometry( x, y, w, h, depth );
>   win->draw_rectangle( gc, true, 0, 0, w, h );
>
>   return false;
> }
>
> inline
> HandView::HandView( )
> {
>   set_size_request( 100, 100 );
> }
>
> bool
> HandView::on_expose_event( GdkEventExpose *event )
> {
>   printf( "HandView: Expose: rect( x = %d, y = %d, w = %d, h = %d )\n",
>           event->area.x, event->area.y,
>           event->area.width, event->area.height );
>
>   return false;
> }
>
> int
> main( int argc, char **argv )
> {
>   Gtk::Main kit( argc, argv );
>   FrameWnd frame_wnd;
>   Gtk::Main::run( frame_wnd );
>   
>   return 0;
> }
>