The GTK+ 3 Reference Manual can be viewed locally on a Linux computer in a program called Devhelp. When developing GTK+ 3 applications a local copy of the documentation can be very helpful.
A previous article explained how to get on-line and off-line help for GTK+ using a web browser. Devhelp is an alternative application to using a web browser to view help files.
With Devhelp it is not necessary to navigate to the folder that contains the off-line documentation, the documentation is accessed in the left pane of Devhelp as shown in the above image.
The Devhelp application can be installed in a Linux terminal window with the following command:
sudo apt-get install devhelp
After installation Devhelp can be found on the main menu of a Linux Mint computer under Menu → Programming → Devhelp.
Installing Off-line GTK+ 3 Reference Manual
The GTK+ 3 reference manual will not appear in Devhelp until it is installed on the system. To install the GTK+ 3 reference manual enter the following in a terminal window:
sudo apt-get install libgtk-3-doc
Now the next time that you open Devhelp, the GTK+ 3 manual will appear along with the GDK 3 reference manual.