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#compose
Title
# compose
n
Nat Strangerweather
12/12/2020, 9:11 AMDoes anybody know where I can find out how to pass a variable from one Composable to another?
j
jaqxues
12/12/2020, 9:16 AMA variable? Wym pass a variable? You are probably looking for state I think
n
Nat Strangerweather
12/12/2020, 9:17 AMBasically, I have a color that changes depending on which button is selected. I want to use that same color in another composable.
j
jaqxues
12/12/2020, 9:19 AMWell, you should have state in the lowest common parent of both child compose views, and then pass that down
There should be some information about this in the tutorials, one sec
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Nat Strangerweather
12/12/2020, 9:21 AMThank you! 🙂
a
Archie
12/12/2020, 10:09 AMComposable functions are just functions, so if you need to pass-in a value just would call a (Composable) function passing in a parameter.
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Nat Strangerweather
12/12/2020, 10:10 AMYes, the problem is I can't because parameters only take val and not var.
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Archie
12/12/2020, 10:14 AM Copy code
@Composable
fun Parent() {
var color by remember { mutableStateOf(myColor) }
...
Child(color)
}
@Composable
fun Child(color: Color) {
...
}j
jaqxues
12/12/2020, 10:16 AMTbh if you have nested childs, it would probably be smarter to pass down the color as a state. Otherwise, if you are using
byBy having the state passed down and not the value, it should only recompose the children I think, which is a bit more efficient
a
Archie
12/12/2020, 10:19 AMIf you are using the state value on the parent as well, then that doesn't matter as it would need to recompose when value changes as well.
n
Nat Strangerweather
12/12/2020, 10:26 AMThanks guys, I'll give this a try!
Hi again @jaqxues and @Archie. So if I understand correctly, my way of setting content in my Scaffold is not the recommended way? Instead I need to nest my Composables within each other?
Copy code
bodyContent = {
ScrollableColumn(horizontalAlignment = CenterHorizontally) {
Spacer(modifier = Modifier.height(20.dp))
Text(text = "Quick Settings")
Spacer(modifier = Modifier.height(20.dp))
QuickOptions(context)
Spacer(modifier = Modifier.height(40.dp))
Text(text = "Sound Options")
Spacer(modifier = Modifier.height(20.dp))
SoundOptions()
Spacer(modifier = Modifier.height(30.dp))
}
},a
Archie
12/12/2020, 12:23 PMThe structure of your composables depends on your usecase. There is no right or wrong way of doing it.
👍 1
n
Nat Strangerweather
12/12/2020, 6:15 PMok, I just can't work it out in spite of your kind help. I made a post in StackOverflow with more code. Maybe it makes more sense than my initial question?
a
Archie
12/16/2020, 1:26 PMFor the question you posted, the first question you should be asking is where your
indexindexState<T>2 Views