We want to show an error when the user tries to invoke an action that expects only
a single item to be selected.
We're using the GetDisabledReason field to enforce this (as well as DisabledReason
on menu items).
I've created a ListControllerTrait to store some shared convenience functions for this.
We're not fully standardising here: different contexts can store their range state however
they like. What we are standardising on is that now the view is always responsible for
highlighting the selected lines, meaning the context/controller needs to tell the view
where the range start is.
Two convenient benefits from this change:
1) we no longer need bespoke code in integration tests for asserting on selected lines because
we can just ask the view
2) line selection in staging/patch-building/merge-conflicts views now look the same as in
list views i.e. the highlight applies to the whole line (including trailing space)
I also noticed a bug with merge conflicts not rendering the selection on focus though I suspect
it wasn't a bug with any real consequences when the view wasn't displaying the selection.
I'm going to scrap the selectedRangeBgColor config and just let it use the single line
background color. Hopefully nobody cares, but there's really no need for an extra config.
We have not been good at consistent casing so far. Now we use 'Sentence case' everywhere. EVERYWHERE.
Also Removing 'Lc' prefix from i18n field names: the 'Lc' stood for lowercase but now that everything
is in 'Sentence case' there's no need for the distinction.
I've got a couple lower case things I've kept: namely, things that show up in parentheses.
This begins a big refactor of moving more code out of the Gui struct into contexts, controllers, and helpers. We also move some code into structs in the
gui package purely for the sake of better encapsulation
The "open" command is supposed to behave in the same way as double-clicking a
file in the Finder/Explorer. The concept of jumping to a specific line in the
file doesn't make sense for this; use "edit" instead.
