This should really be titled "Hooking it All Together with the main() function" because that's where it's all tied together. Yes, there are other important subroutines, such as the message handlers, but we'll get to them shortly. First, let's look at the key portions of main() which, as you know, is the heart of any and all C programs.

Now it's time to store pointers to all the widgets you build in your GLADE displays

Here's one way to end the program. (The other is in the display menu.)

I mentioned various display callbacks above. Here they get implemented.

Next, show data acquisition & update indicators in main window

Next, add layout diagram to main window

Read raw data every 300 milliseconds

Show layout display & status display, update every 5 seconds

Initialize wiringPi and use BCM pin numbering (maybe later, for powerpack control)

display the window

Now enter the main loop, processing messages, until quit signal

End gracefully

Actually, that wasn't so bad. Once it's hooked up, the "gtk_main" loop takes care of what people are used to knowing as a windowing and messaging system. We'll next have a look at the message handling routines. wherein a few tricks lie.

Click here to see the details about Message Handling functions.