Create intermediary nanostores for values required by the event handlers. This allows the event handlers to be purely imperative, with no reactivity: instead of recreating/setting the handlers when a dependent piece of state changes, we use nanostores' imperative API to access dependent state.
For example, some handlers depend on brush size. If we used the standard declarative `useSelector` API, we'd need to recreate the event handler callback each time the brush size changed. This can be costly.
An intermediate `$brushSize` nanostore is set in a `useLayoutEffect()`, which responds to changes to the redux store. Then, in the event handler, we use the imperative API to access the brush size: `$brushSize.get()`.
This change allows the event handler logic to be shared with the pending canvas v2, and also more easily tested. It's a noticeable perf improvement, too, especially when changing brush size.
- Rects snap to stage edge when within a threshold (10 screen pixels)
- When mouse leaves stage, set last mousedown pos to null, preventing nonfunctional rect outlines
Partially addresses #6306.
There's a technical challenge to fully address the issue - mouse event are not fired when the mouse is outside the stage. While we could draw the rect even if the mouse leaves, we cannot update the rect's dimensions on mouse move, or complete the drawing on mouse up.
To fully address the issue, we'd need to a way to forward window events back to the stage, or at least handle window events. We can explore this later.
Firefox v125.0.3 and below has a bug where `mouseenter` events are fired continually during mouse moves. The issue isn't present on FF v126.0b6 Developer Edition. It's not clear if the issue is present on FF nightly, and we're not sure if it will actually be fixed in the stable v126 release.
The control layers drawing logic relied on on `mouseenter` events to create new lines, and `mousemove` to extend existing lines. On the affected version of FF, all line extensions are turned into new lines, resulting in very poor performance, noncontiguous lines, and way-too-big internal state.
To resolve this, the drawing handling was updated to not use `mouseenter` at all. As a bonus, resolving this issue has resulted in simpler logic for drawing on the canvas.
- Revise control adapter config types
- Recreate all control adapter mutations in control layers slice
- Bit of renaming along the way - typing 'RegionalGuidanceLayer' over and over again was getting tedious
