Symptom: a test (test_click_to_create_drawing) started randomly failing
after I inserted a `return` 2 commits ago.
Cause: my tests call edit.draw, but button handlers only get cleared in
app.draw. So my tests weren't clearing button handlers, and every call
to edit.draw was accumulating states. Still unclear why those were going
to different state objects after the `return`, but anyway. I'm not going
to understand every last thing that happens when things go wrong, just
guarantee they can't go wrong. And the way to do that is to decentralize
button handlers to each state that receives them.
The State object in buttons.lua doesn't have to be Editor_state. It just
has to be some table that provides a Schelling Point for shared state.
Still lots to do, but the eventual hope is that this will make this
project's code easier to reuse from other LÖVE projects.
One gotcha: even as we start putting code more aggressively into nested
tables, tests must remain at the top-level. Otherwise they won't run.
I have a set of changes that passes all tests, but I'm going to commit
them very carefully to ensure I don't miss any call-sites. In this
commit I'm adding the args to:
- Text.draw
- Text.tweak_screen_top_and_cursor
But calls within them don't yet pass them where they should. In this
manner I'm going to progress systematically from the top down.
This has been broken since commit b544e8c357 on May 17 :/
I'm just undoing that commit, which turns out to be completely
unnecessary. And adding a test.
I can't believe I didn't catch this until now. All I had to do is open
MobyDick.markdown from https://www.hogbaysoftware.com/posts/moby-dick-workout,
press page-down and click on the top screen line (or any screen line
containing the same line as the top screen line). Easy to catch with any
file containing lots of overly long lines, as happens in particular at
the start of Moby Dick.
I _had_ seen this problem before, but it seemed to disappear after
unrelated changes, and I convinced myself I'd fixed it as a side-effect.
The bug just failed to manifest if the top line happened to start at the
top of the screen. Scroll down a few pages in Moby Dick and the dialogue
starts and line length drops precipitously.
We just need to ensure textinput events never make use of selection
state.
All tests are passing, but I'm aware of a couple of issues. But now we
can keep all the special cases in one place.
Bugfix: we want selections to persist even when we lift up the shift
key.
This requires hoisting some code inside every case inside the whole
keypress hierarchy, to ensure we never clear selections before
textinput events can handle them.
Current cross-cutting concerns we're explicitly scattering code for.
- autosave
- undo
- selection management
To reproduce:
click to position cursor at end of a line
hit enter
press any key
before:
newline got erased and key got added to previous line
now:
newline is preserved
The new test checks a generalization of this.
It might reduce wear and tear on disk, and losing 3 seconds of data
doesn't feel catastrophic (short of a C-z rampage).
Thanks to the love2d.org community for the suggestion:
https://love2d.org/forums/viewtopic.php?f=14&t=93173
Not sure where that idiom comes from or why strings work in some places
(auto-coercion?). I picked it up off some example apps. But
https://love2d.org/wiki/love.mouse.isDown says it should be an integer.
manifestation: clicking past end of a long, wrapping line containing
non-ASCII would cause the cursor to disappear rather than position past
end of screen line. Hitting enter would then throw an assertion with the
following stack trace:
Error: text.lua:381: bad argument #2 to 'sub' (number expected, got nil)
stack traceback:
[love "boot.lua"]:345: in function <[love "boot.lua"]:341>
[C]: in function 'sub'
text.lua:381: in function 'insert_return'
text.lua:179: in function 'keychord_pressed'
main.lua:495: in function 'keychord_pressed'
keychord.lua:10: in function <keychord.lua:5>
app.lua:34: in function <app.lua:25>
[C]: in function 'xpcall'
cause: the click caused a call to Text.to_pos_on_line whose result was
not on a UTF-8 character boundary.
fix: make to_pos_on_line utf8-aware.
Any time I press a ctrl- chord LÖVE actually sees two key chords:
C-lctrl
C-... (the real one)
But it's not just that. There's also a lot in the codebase that's just
habit-based. I need more tests.
All signs so far seem to be that CPU is cheap for this application, but
memory is expensive. It's easy to get sluggish if the GC comes on.
After some experiments using https://github.com/yaukeywang/LuaMemorySnapshotDump,
one source of memory leaks is rendered fragments (https://love2d.org/wiki/Text
objects). I need to render text in approximately word-sized fragments to
mostly break lines more intelligently at word boundaries.
I've attached the files I used for my experiments (suffixed with a '.')
There's definitely still a leak in fragments. The longer I edit, the
more memory goes to them.
I've tried to keep the time period of the blinking similar to my
terminal.
Honestly I'm no longer sure if any of my experiments are showing a
statistically significant result. Let's see how it feels over a period
of time.
This still isn't ideal. On my Linux laptop for some reason the window
receives a signal to maximize itself soon after (but sometime after) the
program starts.
I'm being unprincipled at the moment between pos and x,y coordinates.
Whatever is more convenient. Perhaps a cleaner approach will come to me
over time.
It's still a bit simple-minded. Most software will keep the first bound
fixed and move the second. Lines currently has the bounds in a queue of
sorts. But I have a test to indicate the behavior that is definitely
desired. We'll see if we need it to get more complex.
Mouse stuff is pretty strenuous. For the first time I have to be careful
not to recompute too often. And I ran into a race condition for the
first time where resetting line.y within App.draw meant mouse clicks
were extremely unlikely to see line.y set.
Incredibly inefficient, but I don't yet know how to efficiently encode
undo mutations that can span multiple lines.
There seems to be one bug related to creating new drawings; they're not
spawning events and undoing past drawing creation has some weird
artifacts. Redo seems to consistently work, though.
I've written a few tests for delete_selection, but the way different
operations initialize the selection seems fairly standard and not worth
testing so far.