DisplayUi

True until the first successful render, or after visible widget/state changes.

Clears capture before notifying widgets; call when rebinding or abandoning a display.

Click-only compatibility: one hit leaf blocks the click, even if passive or disabled.

Down captures one topmost leaf for this gesture. Drag/Up use that leaf's local coordinates, including outside its rectangle. Up/Cancel release capture before invoking callbacks. Handler failures drop that gesture and propagate. No polling or drawing occurs here.

Clipped drawing in bounds; does not clear, publish a frame or invoke input handlers.

Repaint only the damaged region, including overlapping widgets in their original order. Owns the background in bounds. An unchanged UI makes no display calls and opens no frame. Custom animations call their widget's invalidate(); failures leave damage pending for retry. Use draw() instead when the caller owns a larger composition and its frame lifecycle.