View.GONE alternative in Jetpack Compose?-CodePudding

I'll give an example of the problem, let's say I have two buttons within the Box

@Preview
@Composable
fun testView() {
    Box(modifier = Modifier
        .size(200.dp)
    ) {
        Button(onClick = {
            Log.e("HERE", "First btn")
        }) {
            Text(text = "Btn1")
        }

        Button(modifier = Modifier
            onClick = {
            Log.e("HERE", "Second btn")
        }) {
            Text(text = "Btn2")
        }
    }
}

When I run the app I see Btn2 (which is actually on the top of the Btn1) and when I click in the log I see Second btn as expected.

Let's say I need to hide Btn2 so the user can click Btn1, in order to do this in old way I would add View.GONE and it would work, however in JetpackCompose (as far as I understood) there is only alpha option, so I try to set it to 0f like this

...
Button(modifier = Modifier
            .alpha(0f),
            onClick = {
            Log.e("HERE", "Second btn")
        }) {
            Text(text = "Btn2")
        }
...

When I run the app I see (as expected) Btn1 on the screen, however, when I click I see in the log Second btn.

So, it is obvious that alpha is changing the visibility but the view itself is still there.

The question is there an alternative for View.GONE as it was before?

CodePudding user response：

The way to do that would be not to output the second button if you would want it GONE.

if( some_condition) {
    Button(modifier = Modifier
        onClick = {
        Log.e("HERE", "Second btn")
    }) {
        Text(text = "Btn2")
    }
}

If some_condition is false, it won't output the Button, and it won't appear.

CodePudding user response：

You need to create an object that triggers recombination,Recombination is triggered when state changes.

var isSplash by mutableStateOf(true)
if (isSplash) {
    SplashView()
    isSplash = false
} else {
    Main()
    //...
}