Drawing in color in PyGTK

I’ve been playing with drawing on your own widgets in PyGTK on Windows, and I found it incredibly difficult to figure out how to draw something in color on a gtk.gdk.Drawable object using draw_line, draw_rectangle, etc. You can’t just set the color using the semi-obvious mechanism:

    gc = widget.window.new_gc()
    gc.set_foreground(gtk.gdk.Color(255,0,0))

I think the reason it doesn’t work is because if the color isn’t in the device-specific colormap, then GTK will ignore whatever color you set without bothering to warn you that something is wrong. However, I’ve finally hit on something that works. In your expose event (or elsewhere), you can put in something like the following:

    def on_expose_event(self, widget, event):

        gc = widget.window.new_gc()
        colormap = self.gc.get_colormap()
        color = colormap.alloc_color('yellow')
        gc.set_foreground(color)

        # whatever gtk.gdk.Drawable draw_* functions you call here
        # will use that color

Hope you find this useful!

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