ReadingRuler

Description

Based on this script:
https://greasyfork.org/en/scripts/372448-reading-ruler/code

This reading ruler will aid you on reading texts on the internet
It will place a semi-transparent line on your screen, just hit the combination ctrl + r on windows and mac (not the command button but the control button) to activate the ruler, hit the same configuration to remove the ruler

This idea come from the reddit user /u/VectorLightning
And the thread can be found here: https://www.reddit.com/r/SomebodyMakeThis/comments/9huwbw/smt_a_firefox_addon_that_adds_a_horizontal/

I hope you find this extension useful

Releases Notes:
V3.1
Lots of improvements, extension should now always work and should not be invisible

- fix problem where ruler would not show on screen (for real this time!)
- new popup layout with 2 new options
- you now can choose a color for your ruler
- you can now set how visible you want your ruler to be
- update core code
- remove itself when its orphaned
- create functions to prevent references on event handlers
- remove unnecessary calls to background script
- overall improve code to work better

v3.0.1
- Avoid exceptions when extension is updated
- Increase z index of ruler to try to push to the foreground

v3.0
- Code rewrite to make extension function properly
- Update manifest to V3
- Fix extension so it should only show the ruler when active
- Drop support for Alt modifier key, you can now only combine CTRL, SHIFT and a keyboard key
- Drop badge text since it was not working anymore

v 2.2
- Fix issue with ruler not showing when pressing the toggle combination

v 2.1
- Add badge to extension icon to let you know the tool is active

v 2.0
- Add options page
- Allow user to choose from using CTRL, ALT and SHIFT plus a key
- Update and rewrite the entire code to be more OOP