Ubuntu – How to change GtkWidget background in GTK3

application-developmentgtk3python

I'm trying to use override_background_color on some GTK3 widgets but they still showing up with the default background color.

Best Answer

GTK+ 1.2

  GtkRcStyle *rc_style;
  GdkColor color;

  color.red = 65535;
  color.green = 0;
  color.blue = 0;

  rc_style = gtk_rc_style_new();

  rc_style->bg[GTK_STATE_NORMAL] = color;

  rc_style->color_flags[GTK_STATE_NORMAL] |= GTK_RC_BG;

  gtk_widget_modify_style (widget, rc_style);

  gtk_rc_style_unref (rc_style);

GTK+ 2.24

Using the GDK Library:

GtkWidget *widget; //your widget

  GdkColor color; 

  gdk_color_parse ("red", &color); //setting a color - you can also use RGB

  gtk_widget_modify_bg(widget, GTK_STATE_NORMAL, &color); //modifying the background color of the widget

Full reference about GdkColor can be found at GNOME'S Dev Documentation.

GTK 3.0

For gtk+3 you can use gtk_css_provider() .Full tutorials and examples can be found at the GTK+ Forums.

Related Solutions

Ubuntu – How to add vte terminal widget in GTK3

Here a basic example:

#!/usr/bin/env python

from gi.repository import Gtk, Vte
from gi.repository import GLib
import os

terminal     = Vte.Terminal()
terminal.spawn_sync(
    Vte.PtyFlags.DEFAULT,
    os.environ['HOME'],
    ["/bin/sh"],
    [],
    GLib.SpawnFlags.DO_NOT_REAP_CHILD,
    None,
    None,
    )

win = Gtk.Window()
win.connect('delete-event', Gtk.main_quit)
win.add(terminal)
win.show_all()

Gtk.main()

Ubuntu – How to apply gradient background to GtkWidget in GTK3

Sure you can!

ugly gradient widget

Gtk3 allows for theming using CSS. Here's a quick example I threw together in Python:

#!/usr/bin/python3
from gi.repository import Gtk, Gdk

button = Gtk.Button("Click Me")
grid = Gtk.Grid()
grid.add(button)
window = Gtk.Window()
window.set_size_request(200, 50)
window.add(grid)

css_provider = Gtk.CssProvider()
css = """
 .button {
      background-image: -gtk-gradient (linear,
                                       left top,
       left bottom,
       from (#d0e4f7),
       color-stop (0.5, darker (#d0e4f7)),
       to (#fdffff));
    }
"""

css_provider.load_from_data(css.encode('UTF-8'))
screen = Gdk.Screen.get_default()
style_context = window.get_style_context()
style_context.add_provider_for_screen(screen, css_provider,
                                          Gtk.STYLE_PROVIDER_PRIORITY_APPLICATION)

window.connect('delete-event', Gtk.main_quit)
window.show_all()
Gtk.main()

Carlos Garnacho has a great article on GNOME Journal that gets into the specifics.