IssueTracker

Description: Right now once you've consumed an event, but then realized that that event can't be used for your gesture, it's impossible to pass the next events (all events until all pointers are up) to child composables that listen to pointer events. So if you have a draggable child composable it will stop receiving pointer events until all the pointers are up (awaitAllPointersUp() inside of the forEachGesture {})

Use Case: Let's say I have a composable with Modifier.pointerInput {} which is a parent of a HorizontalPager. I want to implement a special horizontal left-to-right drag gesture that will instead of scrolling the HorizontalPager do something else (drag the drawer for example). That gesture will only be possible in some part of the screen (let's say a rect 300x300 px at bottom left of the screen). So basically when the finger is inside of that zone I want to do the next steps:

1. Listen to the first pointer event (PointerEventPass.Initial) and check whether it hits the special zone (300x300px).
2. If it does not then skip it, if it does then consume it and start detecting the touch slop (If I don't consume it then the HorizontalPager's draggable modifier will get triggered and HorizontalPager will start being dragged).
3. When the gesture reaches the touch slop calculate the direction the pointer is moving towards.
4. If it's moving from left to right I want to execute my own gesture, otherwise I want to emulate a POINTER_DOWN event and send it into the HorizontalPager (I don't necessary have to know who I'm sending the event to, the API may just send it to all the children and they will figure it out on their own). Then I want to pass all the subsequent POINTER_MOVE events into the HorizontalPager as well until the pointer is up or canceled.

Right now it's impossible to do this without relying on hacks like using NestedScrollConnection (to block the HorizontalPager's scrolling until the touch slop is reached) or emulating gestures by sending them via LocalView.current.dispatchTouchEvent().

It would be really nice to have an API which would allow sending PointerInputChanges to children composables. This would make gesture handling in Jetpack Compose even more convenient. Maybe you already have something like this planned but it's just not public yet.