This PR improves statistics counting, as well as adds support for more of them, fixing #63. It does so in a iA Writer inspired way, meaning:
* The stats bar displays one stat, word count by default.
* The stats bar now contains a button that [displays all stats and allows toggling between them](https://cl.ly/a0ce3fad3d72/gnome-shell-screenshot-QRNG0Z.png).
* The default stat is saved between sessions.
* All the stats are objective and deterministic. For instance, I contemplated adding GhostWriter's "Pages" estimation, but it's outright broken in my testing, and I also think we should be strict about what too include. Too many things will make it less useful. Regardless, it's trivial to extend.
* Calculations are done on a worker thread, to prevent hogging the UI and allowing future extensibility without much consideration.
The new stats counter is able to count characters, words, sentences, and
reading time.
It does so more accurately than before, by leveraging Pandoc's plain
format, and a few simple regular expressions that besides accuracy, also
improve support for Asian languages. It's all done on a background
thread to avoid hogging the UI.
This PR includes various fixes and improvements, most of which I discussed with @somas95 a couple of weeks ago. It also includes some refactoring, mainly to improve encapsulation.
Fixes#17Fixes#75Fixes#90Fixes#120Fixes#122
Some considerations/questions follow.
**Commit messages**
I recommend reviewing each commit message carefully, as they explain the thinking behind each change. Not everything is small or linear, and hopefully the commit message explains the background and reasoning properly. If anything is missing, I'm happy to try to explain.
**Translations**
There are a few capitalization/copy fixes. I am unsure how this affects translations, or if there's any work I can to make the transition easier. For instance, how are the po files updated?
**Styling**
Styling is subjective, and although I claim to address #90, it's important to note that I'm a fan of UberWriter's simplistic style, reminiscent of iA Writer's approach. As such, I didn't introduce any sizing nor color changes, as I don't personally agree with this direction. Instead, the changes are subtle:
* For links, the link/syntax part is greyed out, without any further changes
* For code blocks, they are indented similarly to quotations, without any further changes
**UI changes**
There are (very minor) UI changes within the places that were touched, mainly preferences and the export dialog. Most of these are around improving small things, such as spacing (eg. multiples of 8), slightly broken alignments, etc.
The only exception would be the removal of ODT as one of the export options in the top bar. As before, subjective, but I find that a sub-window's top bar with 6 horizontal buttons is a little overwhelming, and considering that ODT is still available within the advanced tab, I propose that we remove it as a default option and have a more balanced top bar. I am assuming that PDF/HTML are the most used, but please let me know if that's not the case.
**Further work**
I have a few more tasks planned for the upcoming weeks, hopefully built on top of this codebase as it makes some of them much easier. [Here's a screenshot of my Todoist.](https://cl.ly/4160755d210d/gnome-shell-screenshot-3MMO0Z.png) Hopefully this helps knowing what to expect. 😊
Gonçalo Silva
