This commit standardizes the various todos around the code a bit in a manner recognized by LDoc.
Besides drawing more attention by being displayed in the developer docs, they're also extractable with LDoc on the command line:
```sh
ldoc --tags todo,fixme *.lua
```
However, whether that particular usage offers any advantage over other search tools is questionable at best.
* and some random beautification
Multiswipes consisting of mixed straight and diagonal strokes are not dependable and too easy to mess up, but making them mutually exclusive seems to work out quite well.
When multiswipes are enabled, this fixes the long-standing complaint that swiping to open the menu could unintentionally trigger some light panning. With the introduction of multiswipes, this problem has become more noticeable.
Reported by @poire-z, cf. https://github.com/koreader/koreader/pull/4640#issuecomment-466544922
Apparently it's natural for me to make the second swipe slightly longer than the first, so I never noticed a logic issue. I did notice that it seemed slightly harder to make 4-swipe multiswipes than I expected it to be, but those are not necessarily easy gestures to make.
The problem was that I needed to prevent obviously silly gestures like west west west east. In ignoring such duplication, what I accidentally did was to ignore any further movement west after the first multiswipe direction was detected, meaning that the following swipe east could still end up as a relatively western movement overall.
By simply updating the current multiswipe slot in case of the same direction, both problems are prevented. We'll never get the same direction twice, and X moves over to where it's supposed to be on the left.
The basic idea is that you gain an infinite amount of extra gestures,
although in practice you're probably mostly limited to your 16 basic
two swipe combinations and maybe a few three swipe ones.
Touch zone decouples screen size from gesture event registration.
The win here is each individual widget does not need to update
gesture range on screen rotate/resize anymore.
Another advantage is we now have a centralized ordered array to handle
all registered touch event listeners, makes it much easier to resolve
gesture range conflicts between multiple widgets.
This patch also includes the following changes:
* migrate readerpaging to use readerui's touch zone
* migrate readerfooter to use readerui's touch zone
* move inverse read direction setting to touch menu's setting tab
* moved kobolight widget from readerview into readerui
* various dead code cleanups and comments
This is a major overhaul of the hardware abstraction layer.
A few notes:
General platform distinction happens in
frontend/device.lua
which will delegate everything else to
frontend/device/<platform_name>/device.lua
which should extend
frontend/device/generic/device.lua
Screen handling is implemented in
frontend/device/screen.lua
which includes the *functionality* to support device specifics.
Actually setting up the device specific functionality, however,
is done in the device specific setup code in the relevant
device.lua file.
The same goes for input handling.
