[gtkmm] Can't compile tutorial example "Drawing Lines"

[Murray Cumming Comneon com]

The Drawing Area chapter has not been updated for gtkmm 2. Sorry.

However, most new widgets don't need to be drawn line by line. It's usually
enough to just arrange some pre-existing child widgets in a derived
container widget.

Murray Cumming
murrayc usa net
www.murrayc.com 

> -----Original Message-----
> From: Paul Scheremet [mailto:paul scheremet de] 
> Sent: Mittwoch, 12. März 2003 10:29
> To: gtkmm-list
> Subject: Re: Re: [gtkmm] Can't compile tutorial example 
> "Drawing Lines"
> 
> 
> I just updated the example from 
> http://www.gtkmm.org/gtkmm2/docs/tutorial/html/ch14s03.html
> 
> I started with Gtk/Gdk/Gtkmm yesterday, so please review the 
> code. I plan to 
> switch from Qt to Gtkmm, but I'm still quiet unsure, because 
> I need to 
> implement own widgets and it looks much more complicated than 
> with Qt, but I 
> hope it's worth the trouble...
> 
> Here's the code:
> (take care of new-lines from email-client...)
> 
> #include <gtkmm/main.h>
> #include <gtkmm/window.h>
> #include <gtkmm/drawingarea.h>
> #include <gdkmm/drawable.h>
> #include <gtkmm/style.h>
> 
> //Custom drawing area with modified expose_event.
> class cust_draw_area: public Gtk::DrawingArea
> {
>   int width, height;
>   Glib::RefPtr<Gdk::GC> gc_; // not needed, but code gets clearer
>   Gdk::Color blue_,red_; // needed for alloc_color(Gdk::Color &);
>   Glib::RefPtr<Gdk::Window> window_; // needed for clear();
>   
>   public:
>               cust_draw_area(int x_size = 0, int y_size = 0);
>          bool on_expose_event(GdkEventExpose*); // has to return bool 
>  virtual void on_realize();
> };
> 
> //Constructor.
> cust_draw_area::cust_draw_area(int x_size, int y_size)
> : DrawingArea(), width(x_size), height(y_size)
> {
>   Glib::RefPtr<Gdk::Colormap> colormap = get_default_colormap ();
> 
>   blue_ = Gdk::Color("blue");
>   red_ = Gdk::Color("red");
> 
>   colormap->alloc_color(blue_); // needed
>   colormap->alloc_color(red_);
>   
>   set_size_request(width, height);
> }
> 
> //Expose_event method.
> bool cust_draw_area::on_expose_event(GdkEventExpose *event)
> {
>   window_->clear(); 
>   get_window()->draw_line(this->get_style()->get_black_gc(), 
> 5, 2, 5, 20);
>   window_->draw_line(gc_, 5, 11, 10, 11); // much shorter ....
>   get_window()->draw_line(this->get_style()->get_black_gc(), 
> 10, 2, 10, 20);
>   get_window()->draw_line(this->get_style()->get_black_gc(), 
> 15, 2, 21, 2);
>   get_window()->draw_line(this->get_style()->get_black_gc(), 
> 18, 2, 18, 20);
>   get_window()->draw_line(this->get_style()->get_black_gc(), 
> 15, 20, 21, 20); }
> 
> void cust_draw_area::on_realize()
> {
>   // we need to do the default realize, else we'll get a 
> segmentation fault
>   Gtk::DrawingArea::on_realize();
> 
>   // Now we can allocate any additional resources we need
>   window_ = get_window();
>   Glib::RefPtr<Gdk::Drawable> drawable = window_; 
>   gc_ = Gdk::GC::create(drawable);
>   
>   window_->set_background(red_);
>   window_->clear();
>   
>   this->get_style()->get_black_gc()->set_foreground(blue_); 
>   gc_->set_foreground(blue_); // just another possiblity, not needed }
> 
> 
> class test_window : public Gtk::Window
> {
>   cust_draw_area some_draw_area;
>   public:
>     test_window();
> };
> 
> test_window::test_window()
> :  some_draw_area(50, 50)
> {
>   add(some_draw_area);
>   show_all();
> }
> 
> int main(int argc, char *argv[])
> {
>   Gtk::Main main_runner(argc, argv);
>   test_window foo;
>   main_runner.run();
>   return(0);
> }
> 
> 
> _______________________________________________
> gtkmm-list mailing list
> gtkmm-list gnome org http://mail.gnome.org/mailman/listinfo/gtkmm-list
>