The GTK+ Reference Manual provides beginners with a simple introduction to the basics, and experts will find advanced details they need.
In this you will see the following things below.
Table of Contents
I. GTK+ Overview
II. GTK+ Core Reference
III. GTK+ Widgets and Objects
IV. Migrating from Previous Versions of GTK+
V. GTK+ Tools
You will find all this section offline without any internet connection and learn GTK+ easily anywhere and anytime.