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fix: android - Pinch gesture handler when one finger is lifted #1799

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fix: android - Pinch gesture handler when one finger is lifted #1799

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bb16311
fix: android single finger behaviour in pinch
intergalacticspacehighway Jan 2, 2022
aad9c87
fix: android single finger behaviour in pinch
intergalacticspacehighway Jan 2, 2022
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10 changes: 5 additions & 5 deletions android/lib/src/main/java/com/swmansion/gesturehandler/PinchGestureHandler.kt
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Original file line number Diff line number Diff line change
Expand Up @@ -59,12 +59,12 @@ class PinchGestureHandler : GestureHandler<PinchGestureHandler>() {
spanSlop = configuration.scaledTouchSlop.toFloat()
begin()
}
scaleGestureDetector?.onTouchEvent(event)
var activePointers = event.pointerCount
if (event.actionMasked == MotionEvent.ACTION_POINTER_UP) {
activePointers -= 1

if(event.actionMasked != MotionEvent.ACTION_POINTER_UP){
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@intergalacticspacehighway intergalacticspacehighway Jan 2, 2022 •
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This surely appears weird, but I am not sure If there's a better way to achieve this. This is done due to the below scenario.

User has 2 fingers and performing pinch -> One finger is lifted -> ACTION_POINTER_UP is fired -> event.pointerCount is still 2 -> scale detector sets the focal values to single finger -> the event received has new focus but the pointer count is still 2.

However, this again makes it consistent with iOS. iOS Pinch handler doesn't send events in case of a finger is lifted. Only when a single pointer is moved, it starts sending the event. (practically tested, it would be great if someone can find it documented somewhere)

scaleGestureDetector?.onTouchEvent(event)
}
if (state == STATE_ACTIVE && activePointers < 2) {

if (state == STATE_ACTIVE && event.actionMasked == MotionEvent.ACTION_UP) {
end()
} else if (event.actionMasked == MotionEvent.ACTION_UP) {
fail()
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