Nothing sat between the full-screen `RasterizedGradient` scrim and the
position-driven leaves, so `markNeedsPaint` from the timeline slider walked past
the gradient and re-rasterized the entire chrome -- top bar, button row,
timestamps, timeline -- on every 250 ms position tick. That also partly defeated
`RasterizedGradient`, which exists because Skia gradients cost ~10 ms per
full-screen pass on this GPU class.
Around that, four things drove root `setState` calls that only needed to change a
leaf:
- Held D-pad seek called a root `setState` per key repeat, even when the readout
was already visible in the same direction and only the accumulated seconds had
changed. The seek amount now flows through a `ValueNotifier` that
`DoubleTapFeedback` reads, so a burst updates one `Text`.
- `DoubleTapFeedback`'s drift chevron ran `..repeat()` with no stop condition, and
kept ticking at 60 Hz for the ~300 ms the readout spends at zero opacity after
every burst. The controller is now gated on visibility.
- The auto-skip countdown ran a 5 Hz timer that root-`setState`d the controls tree
for the whole intro/credits window, to animate one progress ring.
- The play-next and still-watching countdowns root-`setState`d the player screen
once a second, which re-created `PlexVideoControls` with its ~50 props and
rebuilt the entire chrome to change one digit. Prompt open/close deliberately
stays on the state path, because `playNextFocusNode` is threaded through those
props and D-pad focus depends on it.
Two of the four position subscribers existed only to recompute pointer-hover
tooltips that a D-pad viewer never sees, rebuilding a button subtree 4x/s and
rescanning the chapter list each time; the "ends at" readout reformatted a string
4x/s for a value that changes once a minute. All three now dedupe.
Finally, the buffer path did two sequential `copyWith` calls on a 15-field
`PlayerState` and handed `BufferRangePainter` a freshly allocated list every tick.
`List` has no value equality, so `shouldRepaint` was unconditionally true.
Measured on device during playback with the chrome raised: 6 of 344 UI frames over
budget, p50 4.39 ms, layout p90 1.09 ms. During a held D-pad seek -- the worst
frame-time window on the TV path, because the readout and the decoder flush land in
the same frames -- 1 of 354 frames over budget, p50 4.28 ms, zero raster frames over
budget.