GTK

Language: C

GUI

GTK was originally developed for the GIMP image editor and has evolved into a widely used toolkit for creating GUI applications on Linux, Windows, and macOS. PyGObject provides Python bindings for GTK 3 and GTK 4, enabling Python developers to create native-feeling desktop applications.

GTK (GIMP Toolkit) is a multi-platform toolkit for creating graphical user interfaces. In Python, GTK is accessible via the PyGObject library, allowing developers to build desktop applications with windows, dialogs, buttons, menus, and more.

Installation

pip: pip install PyGObject

conda: conda install -c conda-forge pygobject

Usage

GTK allows developers to build windows, buttons, labels, text entries, and complex layouts. It supports signals for event handling, CSS-like styling, and integration with OpenGL or Cairo for custom drawing.

Simple GTK Window

import gi
gi.require_version('Gtk', '3.0')
from gi.repository import Gtk

class MyWindow(Gtk.Window):
    def __init__(self):
        super().__init__(title='Hello GTK')
        self.set_default_size(300, 200)
        button = Gtk.Button(label='Click Me')
        button.connect('clicked', self.on_button_clicked)
        self.add(button)

    def on_button_clicked(self, widget):
        print('Button clicked!')

win = MyWindow()
win.connect('destroy', Gtk.main_quit)
win.show_all()
Gtk.main()

Creates a basic GTK window with a button that prints a message when clicked.

Adding multiple widgets

box = Gtk.Box(spacing=6)
win.add(box)
label = Gtk.Label(label='Hello')
entry = Gtk.Entry()
box.pack_start(label, True, True, 0)
box.pack_start(entry, True, True, 0)

Demonstrates adding multiple widgets (label and entry) to a GTK box layout.

Using TreeView to display data

store = Gtk.ListStore(str, int)
store.append(['Alice', 25])
store.append(['Bob', 30])
treeview = Gtk.TreeView(model=store)
renderer = Gtk.CellRendererText()
column = Gtk.TreeViewColumn('Name', renderer, text=0)
treeview.append_column(column)
column2 = Gtk.TreeViewColumn('Age', renderer, text=1)
treeview.append_column(column2)
win.add(treeview)

Displays tabular data in a GTK TreeView widget.

Using Dialogs

dialog = Gtk.MessageDialog(parent=win, flags=0, message_type=Gtk.MessageType.INFO, buttons=Gtk.ButtonsType.OK, text='Hello Dialog')
dialog.run()
dialog.destroy()

Creates and shows a simple information dialog.

Styling widgets with CSS

css_provider = Gtk.CssProvider()
css_provider.load_from_data(b'button { background-color: #3498db; color: white; }')
Gtk.StyleContext.add_provider_for_screen(Gdk.Screen.get_default(), css_provider, Gtk.STYLE_PROVIDER_PRIORITY_APPLICATION)

Applies CSS styling to GTK widgets.

Handling events and signals

button.connect('clicked', on_button_clicked)
window.connect('destroy', Gtk.main_quit)

Connects GTK signals to callback functions to handle events like clicks and window closing.

Error Handling

Gtk.main_quit not called: Ensure you connect the destroy signal to Gtk.main_quit to properly exit the application.

Widget not showing: Call `show()` or `show_all()` on the widget or parent container.

TypeError: cannot register type: Check PyGObject version compatibility with GTK version.

Best Practices

Use Gtk.Builder and .ui files for complex layouts to separate UI from code.

Always call `show_all()` on windows to display all widgets.

Connect signals carefully to avoid memory leaks.

Use containers like Box, Grid, or Paned for flexible layouts.

Follow GTK CSS conventions to style applications consistently.

Official Docs Github