hmos-multidevice-screen-window-window-size

To fix responsive layout issues in HarmonyOS, classify the screen anomaly by breakpoint mismatch or stale state, then apply GridRow/GridCol containers for structure switching and explicit window-change listeners with lifecycle cancellation.

Your breakpoint system fails during split-screen because runtime window size observation lacks explicit window-change listener logic with lifecycle cancellation, causing stale breakpoint state that prevents immediate layout refresh without breaking single-screen baseline.

The best way to handle font scale and display density adaptation is using a consistent breakpoint strategy alongside responsive containers like GridRow/GridCol, ensuring runtime window size synchronization updates breakpoint state and drives immediate layout refresh.

To validate multi-device UI adaptation, produce an objective verification matrix with required evidence including screenshots, layout dumps, and window size proofs, alongside a regression watchlist targeting truncation, offset, and overlap anomalies.

HarmonyOS prefers GridRow/GridCol for responsive container structure switching on 2-in-1 devices, applying rule-based fixes with guardrails for common anomalies like truncation, offset, and overlap while maintaining a consistent breakpoint strategy.

Breakpoint system limitations in HarmonyOS split mode include stale window-size state if listener lifecycle cancellation is missing, requiring explicit window-change listener logic to synchronize breakpoint state and drive immediate layout refresh without breaking single-screen baseline.