Fix item hitbox ignoring transparency - #25
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Replace the pointer-event filter approach with a proper HitTestCore override so transparent pixels fail Avalonia's visual hit-test walk. When HitTestCore returns false, Avalonia continues searching elements below in z-order, allowing clicks on transparent areas to fall through to the item underneath. The previous OnPointerPressed/Moved/Released filtering still consumed the event even on transparent pixels, preventing sibling elements at lower z-order from receiving it. Fixes #8 Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
PointHitTestParameters does not exist in Avalonia — it is a WPF type. The correct Avalonia 11 API for per-pixel hit testing is implementing the ICustomHitTest interface (Avalonia.Rendering), whose HitTest(Point) method is called by the compositor instead of the default bounding-box check. Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
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Summary
InputMaskingImagewas using pointer-event filtering (OnPointerPressedetc.) to suppress clicks on transparent pixels, but this approach doesn't work for items stacked in z-order. Avalonia's hit-test walk picks the front-most element that passesHitTestCore(which defaulted to the full bounding box), routes the event there, and stops — so the transparent area of one item would consume clicks intended for the item below it.Fix: Replace the event-filter approach with a proper
HitTestCoreoverride. WhenHitTestCorereturnsfalse, Avalonia continues its hit-test walk to the next element in z-order, so transparent pixels cleanly pass through to whatever is beneath them.Test plan
Closes #8
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