İnstall glade

I may become a Linuxcnc expert or even a developer in the future. Becoming a developer can be very difficult, but it is not impossible. I especially appreciate the Aciera. It takes a lot of effort and time. I want to be a useful person like him. I think I will work hard and make serious contributions to this forum in the future, I am currently in the learning phase. As a first step, I started making changes to gmoccapy. But there is a problem.
I installed Glade using the sudo apt-get glade command but I think this is a version issue, for example I can't see the jog keys as I should. Can you guide me on this issue? (Don't laugh at me, maybe I can succeed one day on how to become a developer with this inexperience)

On a locally built (RIP) installation open a terminal and navigate to your linuxcnc installation folder:
then to start glade:
once glade has started, check if the linuxcnc glade widgets have been imported (ie widgets named 'HAL_....')

 There are not all pages, there is only 1 page and it looks like the following. Do you think this is normal?  
   
 

Ah, yes that is normal. Those spaces get filled dynamically during run time.
You have to keep in mind that a complex GUI like Gmoccapy has a lot of python code in the background that  interacts with the glade panels.
[edit]
Which also means that quick changes to the glade panels can easily lead to errors from the python code because it may be missing glade objects.

Thank you very much. I understand very well. For example, can I place a box on this page where I can enter a decimal number? and a button
For example, the value I will write in this box will be saved in #100 in the g code file. Is this possible?

I would suggest creating a user panel which allows adding elements to various predefined areas of gmoccapy without actually modifying the gui code:
linuxcnc.org/docs/html/gui/gmoccapy.html...tabs-and-side-panels

Here is an example:
1. Unzip the attached folder and save the folder 'gladevcp' containing the files 'testpanel.hal' and 'testpanel.ui' into your machine config folder

2. Add this to the [DISPLAY] section of your ini file:

You should now see a custom panel and its halpins in Gmoccapy:
 

Forgot:
to access the values in Gcode (eg the value 9.2 above) you can use:
Important notice:
I strongly recommend to use a quebuster command like 'M66 E0 L0' right before reading a hal pin in Gcode otherwise the readahead may read the pin much before code execution gets to that line.

Thank you very much

With 2.9 I have problem to open glade files done in 2.8.4 version, they request 3.8 while 3.4 glade is available. 
In synaptic manager gladevcp is not available. 

thanks for any help

Usually you can simply click 'OK' and save the file.