re: non-interactive drawing area

[carlos pehoe civil ist utl pt (Carlos Pereira)]

> I am new to GTK and I read the tutorial on www.gtk.org.
> I want to use an area in my program, where I can draw things on,
> e.g. rectangles or a diagram. It should be non-interactive,
> means, the user should not be able to modify the area in any way
> (no events). And the backgound should be white.

> In the tutorial are examples, but they are interactive and
> I don't know if I need the widgets like DrawingArea ...

> What widgets do I have to use and how can I draw things on?
> (you don't need to answer in detail, some hints and a link
> to a manual would be enough ...)

By default, a DrawingArea is non-interactive, it starts
to be interactive only when you connect signals. Usually 
you would connect a DrawingArea to the signals below 
(taken from my own code).

In your case, just remove the "motion_notify_event" and
the "button_press_event" signals, which handle mouse movements
and clicks. You still need "expose_event" and "configure_event",
to redraw the picture and resize it, when the window size changes
or parts of the image were hidden before, for example. You might
ignore "realize" , particularly if you have little experience.

If you need to draw 3D stuff, then use OpenGL on top of your
DrawingArea (as I do), otherwise just use plain drawingArea.
For plain DrawingArea examples, I suggest the scribble example 
that comes with Gtk, and if you need something more elaborated,
you could look into Eric Harlow's example of a analog watch
made with DrawingArea, the code is free and you should be able
to find it with Google (perhaps it is at www.gtk.org, I don't
know).

Carlos
http://www.gamgi.org/

/*************************************
 * Redraw image when window exposed. *
 *************************************/

gtk_signal_connect (GTK_OBJECT (gl_area), "expose_event",
GTK_SIGNAL_FUNC (gamgi_mesa_gl_area_expose), window);

/**************************************
 * Handle mouse motion in the gl_area *
 **************************************/

gtk_signal_connect (GTK_OBJECT (gl_area), "motion_notify_event",
GTK_SIGNAL_FUNC (gamgi_mesa_gl_area_notify), window);

/*************************************
 * Handle mouse press in the gl_area *
 *************************************/

gtk_signal_connect (GTK_OBJECT (gl_area), "button_press_event",
GTK_SIGNAL_FUNC (gamgi_mesa_gl_area_press), window);

/*************************************************************
 * When window is resized viewport needs to be resized also. *
 *************************************************************/

gtk_signal_connect (GTK_OBJECT (gl_area), "configure_event",
GTK_SIGNAL_FUNC (gamgi_mesa_gl_area_configure), window);

/****************************************************
 * Do initialization when widget has been realized. *
 ****************************************************/

gtk_signal_connect(GTK_OBJECT (gl_area), "realize",
GTK_SIGNAL_FUNC (gamgi_mesa_gl_area_start), window);