Is there anything that can detect drag gesture started and stopped I am currently using it like this:

Modifier.pointerInput(Unit) {
    detectTransformGestures { centroid, pan, zoom, rotation ->
        offset += pan
        scale *= zoom
    }
}

I am zooming the image and I need to know when the zoom drag is ended like we removed the fingers? Further info 👇

You can use both. See my implementation.

I stumbled over the same issue some time ago and I think it is an omission in the API which makes things unnecessarily complicated.

@Michael Paus yeah I think so 😄, but there are some things to look in the above repo

IMO current API with coroutines integrated is much better compared to touch event handling in the view system as it allows you to separate logics of handling different gestures while in the view system you have to mix all the logics. If you want to detect multiple gestures, just use multiple

detect*Gestures

functions. Nothing counterintuitive.

I tried using it like

Modifier.pointerInput(Unit) {
    detectTransformGestures { centroid, pan, zoom, rotation ->
        offset += pan
        scale *= zoom
    }
    detectDragGestures {
       // used onDragEnd() something here
    }
}

But this thing didn't work and only the lambda fun used first was working only

As those are suspend functions, you need to use

coroutineScope

and

launch

as shown here. If you are familiar with coroutines, there’s nothing special here.

@Vivek Sharma Somewhere else here in kotlinlang I was told that putting multiple detect*s into a single pointerInput is wrong. One should always do it like this:

Modifier
.pointerInput(Unit) {
    detectTransformGestures { centroid, pan, zoom, rotation ->
        offset += pan
        scale *= zoom
    }
}
.pointerInput(Unit) {
    detectDragGestures {
       // used onDragEnd() something here
    }
}

But this won’t change anything here because

detectTransformGestures

and

detectDragGestures

are mutually exclusive.

I also tried using this before asking here! And I found that they don't behave as we want and here only one thing was working , other was not

That’s why I’m using

Modifier.transformable()

instead of

detectTransformGestures

.

But can we control

onDragEnd

something like that in

Modifier.transformable()

?

You can't so I said you can use both.

@Albert Chang This contradicts the following answer here https://kotlinlang.slack.com/archives/CJLTWPH7S/p1639070958379400?thread_ts=1638996490.330900&cid=CJLTWPH7S and also this issue in the issue tracker: https://issuetracker.google.com/issues/209937353?pli=1