Focusable.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.foundation
import androidx.compose.runtime.getValue
import androidx.compose.runtime.mutableStateOf
import androidx.compose.runtime.onCommit
import androidx.compose.runtime.onDispose
import androidx.compose.runtime.remember
import androidx.compose.runtime.setValue
import androidx.compose.ui.Modifier
import androidx.compose.ui.composed
import androidx.compose.ui.focus
import androidx.compose.ui.focus.isFocused
import androidx.compose.ui.focus.onFocusChanged
import androidx.compose.ui.platform.debugInspectorInfo
import androidx.compose.ui.semantics.focused
import androidx.compose.ui.semantics.semantics
/**
* Configure component to be focusable via focus system or accessibility "focus" event.
*
* Add this modifier to the element to make it focusable within its bounds.
*
* @sample androidx.compose.foundation.samples.FocusableSample
*
* @param enabled Controls the enabled state. When `false`, element won't participate in the focus
* @param interactionState [InteractionState] that will be updated to contain [Interaction.Focused]
* when this focusable is focused
*/
fun Modifier.focusable(
enabled: Boolean = true,
interactionState: InteractionState? = null,
) = composed(
inspectorInfo = debugInspectorInfo {
name = "focusable"
properties["enabled"] = enabled
properties["interactionState"] = interactionState
}
) {
var isFocused by remember { mutableStateOf(false) }
onDispose {
interactionState?.removeInteraction(Interaction.Focused)
}
onCommit(enabled) {
if (!enabled) {
interactionState?.removeInteraction(Interaction.Focused)
}
}
if (enabled) {
Modifier
.semantics {
this.focused = isFocused
}
.onFocusChanged {
isFocused = it.isFocused
if (isFocused) {
interactionState?.addInteraction(Interaction.Focused)
} else {
interactionState?.removeInteraction(Interaction.Focused)
}
}
.focus()
} else {
Modifier
}
}