`Tasks` held an `Arc<Window>` only to call `request_redraw` when a task
finished, which made the task queue -- and so `DefaultRsc` -- impossible
to build without a window. It now takes an `Arc<dyn WakeTaskQueue>`, and
`Window` implements it.
Waking moves from "the task ended" to "an update was sent", which is when
there is something for the host to apply: a task that keeps running after
sending one no longer holds its update until it finishes, and a task that
sends none no longer asks for a frame it does not need.
`iris::harness` is what that buys. `UiRenderState` already does layout,
hit testing and primitive building with no surface, so a test can build a
tree, run frames, move a pointer and read back where widgets landed.
`tests/harness.rs` does each of those; none of them could be written
before, since the only entry point to layout was a window.
It does not draw. A claim about pixels still needs a real surface.
`update` redrew everything when `resized` was set, but `needs_redraw` --
which is what decides whether to request a frame at all -- did not know
about `resized`. A condition in one and not the other is a frame nobody
asks for and a stale window. The two share one `needs_redraw_all` now.
Latent on Wayland, because winit requests a redraw after a resize by
itself; a resize changes neither the root nor any widget, so nothing else
here would have asked. It stops being latent on Android, where the
surface work will not have winit underneath it and every rotation and
keyboard open is a resize.
This is not a fix for the startup defect recorded in RUST.md, where the
window keeps its pre-configure layout: that reproduces with this change
in place, and the frame it needs is requested and drawn.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>