Re: Setting the colour of the button

[Olexiy Avramchenko <ath beast stu cn ua>]

Chris Garrett wrote:

> Hi,
>
> I want to have a button that shows the current colour (for a drawing 
> package).  It needs to be able to use rgb values.  What is the best 
> way of doing this?

GnomeColorPicker widget from gnomeui library, unless you dont use gnome 
libraries.

> My current approach is to use a GdkPixbuf, but I am getting errors 
> when I try to add it to the drawing area which I have added to the 
> button.  The code looks like this:
>
> colorbutton = gtk_button_new();
> colordarea = gtk_drawing_area_new();
> gtk_widget_set_size_request(colordarea, 40, 40);
> gtk_container_add(GTK_CONTAINER(colorbutton), colordarea);
> colorpixbuf = gdk_pixbuf_new(GDK_COLORSPACE_RGB, FALSE,
>                     8, 40, 40);
> gdk_pixbuf_render_to_drawable(colorpixbuf,
>                     colordarea->window,
>                     colordarea->style->fg_gc[GTK_STATE_NORMAL],
>                     0, 0, 0, 0, 40, 40,
>                     GDK_RGB_DITHER_MAX, 0, 0);
>
> The error (at runtime) looks like this:
>
> (draw:2715): Gdk-CRITICAL **: file ../../gdk/gdkpixbuf-render.c: line 
> 182 (gdk_pixbuf_render_to_drawable): assertion `drawable != NULL' failed
>
>
> I am sure that I initialised the drawing area, so why am I getting the 
> error?

Your drawing area is not realized before gdk_pixbuf_render*. Use 
callback on "configure_event*, when it pops up - area is realized for sure.

Olexiy