Cannot run brightness-controller after installing. Python error with index out of range. about brightness

[archisman-panigrahi]

See I2C Device Permissions section in https://www.ddcutil.com/config_steps/

[thardev]

Hi @archisman-panigrahi

I'm experiencing a similar problem and I think it might be a bug 🤔
This is the output that I get when I run the ddcutil detect command for the first time with the correct permissions.
And then, as you can see, the built-in display is no longer detected.

So after this happens, from what I understand of the implementation, xrandr is used to detect the number of displays, and when I run the xrandr --query command, as it is used here I correctly get two displays connected.

So, I suspect that during the init of the app, xrandr detects two displays but ddcutil only one, so when the following variable is filled, it contains two displays.

Brightness/brightness-controller-linux/brightness_controller_linux/init.py

Lines 50 to 52 in dab46e3

	self.displays = CDisplay.detect_display_devices()
	self.no_of_displays = len(self.displays)
	self.no_of_connected_dev = self.no_of_displays

Finally, when it reaches the following line, an error is thrown since the self.displayNames comes from ddcutil output not from xrandr.

Brightness/brightness-controller-linux/brightness_controller_linux/init.py

Lines 281 to 284 in dab46e3

	for i in range(self.no_of_connected_dev):
	self.ui.secondary_combo.addItem(self.displayNames[i])
	self.ui.primary_combobox.addItem(self.displayNames[i])
	pass

This is the error that I see on the logs.

If needed I can create a separate issue for this.
Thank you very much for your work!