FocusRequesterModifier.kt
/*
* Copyright 2023 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.focus
import androidx.compose.ui.ExperimentalComposeUiApi
import androidx.compose.ui.Modifier
import androidx.compose.ui.node.ModifierNodeElement
import androidx.compose.ui.platform.InspectorInfo
/**
* A [modifier][Modifier.Element] that is used to pass in a [FocusRequester] that can be used to
* request focus state changes.
*
* @sample androidx.compose.ui.samples.RequestFocusSample
*
* @see FocusRequester
* @see Modifier.focusRequester
*/
@Deprecated("Use FocusRequesterModifierNode instead")
@JvmDefaultWithCompatibility
interface FocusRequesterModifier : Modifier.Element {
/**
* An instance of [FocusRequester], that can be used to request focus state changes.
*
* @sample androidx.compose.ui.samples.RequestFocusSample
*/
val focusRequester: FocusRequester
}
/**
* Add this modifier to a component to request changes to focus.
*
* @sample androidx.compose.ui.samples.RequestFocusSample
*/
fun Modifier.focusRequester(focusRequester: FocusRequester): Modifier =
this then FocusRequesterElement(focusRequester)
@OptIn(ExperimentalComposeUiApi::class)
private data class FocusRequesterElement(
val focusRequester: FocusRequester
) : ModifierNodeElement<FocusRequesterModifierNodeImpl>() {
override fun create() = FocusRequesterModifierNodeImpl(focusRequester)
override fun update(node: FocusRequesterModifierNodeImpl) = node.apply {
focusRequester.focusRequesterNodes -= this
focusRequester = this@FocusRequesterElement.focusRequester
focusRequester.focusRequesterNodes += this
}
override fun InspectorInfo.inspectableProperties() {
name = "focusRequester"
properties["focusRequester"] = focusRequester
}
}
@OptIn(ExperimentalComposeUiApi::class)
private class FocusRequesterModifierNodeImpl(
var focusRequester: FocusRequester
) : FocusRequesterModifierNode, Modifier.Node() {
override fun onAttach() {
super.onAttach()
focusRequester.focusRequesterNodes += this
}
override fun onDetach() {
focusRequester.focusRequesterNodes -= this
super.onDetach()
}
}