A11y renderer: handle nodes with alpha=0f or HideFromAccessibility #2094
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FrancoisBlavoet
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FrancoisBlavoet
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Sep 8, 2025
| private fun SemanticsNode.hasZeroAlpha(): Boolean { | ||
| // try to reflectively query internal SemanticsNode.isTransparent() by iterating on kotlin field mangled names: | ||
| val candidateGetterNames = arrayOf( | ||
| "isTransparent", |
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This is very ugly, unless there is an alternative way to get this info, we should get Compose to expose this property
FrancoisBlavoet
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TWiStErRob
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Sep 10, 2025
| "getIsTransparent", | ||
| "getIsTransparent\$ui_release" | ||
| ) | ||
| for (name in candidateGetterNames) { |
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Feels like this is near inner loop; executed on all nodes. I should be possible to cache this reflection filter query (companion object by lazy? because it's not dependent on any specific node) and only doing the invoke in hasZeroAlpha.
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fair enough, we now cache the resolved function
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Ugly fix for #2093
The current approach to check for
modifier == Modifier.alpha(0f)only works if you use this exact modifier.In particular,
Modifier.graphicsLayer { alpha = 0f }won't match this check.Unfortunately, Compose does not really expose anything that we could use to identify a transparent node.
There is however an internal function allowing us to detect this.
Ideally we would get the compose team to make it public (or otherwise expose this information another way), but in the mean time I have written this ugly reflective way to access this information
This also adds a check for
HideFromAccessibilitysince this is a new replacement forInvisibleToUser, we need to check for that one too.