FocusObserverModifier.kt
/*
* Copyright 2020 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package androidx.compose.ui
import androidx.compose.ui.focus.ExperimentalFocus
import androidx.compose.ui.focus.FocusState
/**
* A [modifier][Modifier.Element] that can be used to observe focus state changes.
*/
@ExperimentalFocus
interface FocusObserverModifier : Modifier.Element {
/**
* A callback that is called whenever focus state changes.
*/
val onFocusChange: (FocusState) -> Unit
}
@OptIn(ExperimentalFocus::class)
internal class FocusObserverModifierImpl(
override val onFocusChange: (FocusState) -> Unit
) : FocusObserverModifier
/**
* Add this modifier to a component to observe focus state changes.
*/
@ExperimentalFocus
fun Modifier.focusObserver(onFocusChange: (FocusState) -> Unit): Modifier = composed {
FocusObserverModifierImpl(onFocusChange)
}