I'm not sure exactly what caused this that other simpler cases were not,
but essentially nodes were already removed once by the time this loop is
evaluated, so we can skip adding them back to the list again.
Closes#138
This implementation works around most of the locking issues that arose
the first few times I tried fixing this. Unfortunately it's been just
long enough for me to forget how I triggered some catastrophic issues in
the past, but all of the current examples that would invoke this
behavior continue to work, and some of the side projects that have some
weird usages also still work.
While working on the changelog, I realized I didn't provide a type that
allowed a third party developer to provide a
PlatformWindowImplementation. This type now completes it.
Closes#98
This finishes my initial refactoring of the dynamic system to add
support for several dataflows including:
- Pure data sources that can be implemented using an `Owned<T>` at the
root of a graph of `Dynamic<U>`/`DynamicReader<U>`s.
- Read-only data sinks. I thought this would be more useful across other
widgets, but in general, Progress and Label seem like the only types
that this applies to currently.
- The ability to mix/match Dynamic/DynamicReader in tuple-based
for_each/map_each.
Refs #98
This refactor overhauls the reactive system to move all the reactive
methods to traits. The side effect of this change is that now
DynamicReader's API is the same as Dynamic's API, but because it only
implements Source<T>, DynamicReader does not offer any mutation
functions.
While it's unfortunate to have more traits to include to use Cushy, this
seems like the best option, and it offers a path to try to integrate
this into the tuple ForEach/MapEach traits. Unfortunately, my attempt at
doing those in this set of changes led to issues specifying generic
associated lifetimes for the DynamicGuard. But, I was also in the middle
of this larger refactoring, so it might be that a fresh attempt will
succeed.
After adding weak_clone, I realized that all map functions should use
weak references anyways. In the process of implementing this, I ran
tests a lot and found other edge cases where I hadn't properly reasoned
about Drop behavior.
While some of the state cleanup is a bit overkill at the moment, this is
in anticipation of wanting a WeakDynamicReader-like type.
There was a small window between when notify_all and the strong count
for the Arc is decreased that a DynamicReader could observe the strong
count still being greater than the reader count, but the drop thread
just hasn't proceeded far enough.
Now the on_disconnect is stored in an option, and its presence denotes
that the disconnect logic has not fired yet. DynamicReader now checks
on_disconnect in addition to the strong count.
This cascaded into a lot more work than expected. However, in general,
if one clones a `WidgetInstance` and shares it between two windows, it
should now work. Widget authors must ensure that when they cache
information, they do so with either a `WidgetCacheKey` or use a
`WindowLocal<T>` if per-window state is desired.
This is demonstrated in the debug-window example, where the counter of
open windows is next to a clone of the same button from the main window
that opens a new window.
While this was a workaround for a docs.rs issue (Px/Lp are not
linked), I decided having the shorter import path would look better in
the examples.
It probably wasn't necessary to update all of the references in the
internal code, but I decided it was worth the consistency.
