| /* |
| * 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.input.key |
| |
| import androidx.compose.ui.ExperimentalComposeUiApi |
| import androidx.compose.ui.Modifier |
| import androidx.compose.ui.node.DelegatableNode |
| import androidx.compose.ui.node.modifierElementOf |
| |
| /** |
| * Implement this interface to create a [Modifier.Node] that can intercept hardware Key events. |
| * |
| * The event is routed to the focused item. Before reaching the focused item, [onPreKeyEvent]() is |
| * called for parents of the focused item. If the parents don't consume the event, [onPreKeyEvent]() |
| * is called for the focused item. If the event is still not consumed, [onKeyEvent]() is called on |
| * the focused item's parents. |
| */ |
| @ExperimentalComposeUiApi |
| interface KeyInputModifierNode : DelegatableNode { |
| |
| /** |
| * This function is called when a [KeyEvent] is received by this node during the upward |
| * pass. While implementing this callback, return true to stop propagation of this event. If you |
| * return false, the key event will be sent to this [KeyInputModifierNode]'s parent. |
| */ |
| fun onKeyEvent(event: KeyEvent): Boolean |
| |
| /** |
| * This function is called when a [KeyEvent] is received by this node during the |
| * downward pass. It gives ancestors of a focused component the chance to intercept an event. |
| * Return true to stop propagation of this event. If you return false, the event will be sent |
| * to this [KeyInputModifierNode]'s child. If none of the children consume the event, |
| * it will be sent back up to the root using the [onKeyEvent] function. |
| */ |
| fun onPreKeyEvent(event: KeyEvent): Boolean |
| } |
| |
| @ExperimentalComposeUiApi |
| internal class KeyInputInputModifierNodeImpl( |
| var onEvent: ((KeyEvent) -> Boolean)?, |
| var onPreEvent: ((KeyEvent) -> Boolean)? |
| ) : KeyInputModifierNode, Modifier.Node() { |
| override fun onKeyEvent(event: KeyEvent): Boolean = this.onEvent?.invoke(event) ?: false |
| override fun onPreKeyEvent(event: KeyEvent): Boolean = this.onPreEvent?.invoke(event) ?: false |
| } |
| |
| /** |
| * Adding this [modifier][Modifier] to the [modifier][Modifier] parameter of a component will |
| * allow it to intercept hardware key events when it (or one of its children) is focused. |
| * |
| * @param onKeyEvent This callback is invoked when the user interacts with the hardware keyboard. |
| * While implementing this callback, return true to stop propagation of this event. If you return |
| * false, the key event will be sent to this [onKeyEvent]'s parent. |
| * |
| * @sample androidx.compose.ui.samples.KeyEventSample |
| */ |
| @OptIn(ExperimentalComposeUiApi::class) |
| @Suppress("ModifierInspectorInfo") // b/251831790. |
| fun Modifier.onKeyEvent(onKeyEvent: (KeyEvent) -> Boolean): Modifier = this.then( |
| modifierElementOf( |
| key = onKeyEvent, |
| create = { KeyInputInputModifierNodeImpl(onEvent = onKeyEvent, onPreEvent = null) }, |
| update = { it.onEvent = onKeyEvent }, |
| definitions = { |
| name = "onKeyEvent" |
| properties["onKeyEvent"] = onKeyEvent |
| } |
| ) |
| ) |
| |
| /** |
| * Adding this [modifier][Modifier] to the [modifier][Modifier] parameter of a component will |
| * allow it to intercept hardware key events when it (or one of its children) is focused. |
| * |
| * @param onPreviewKeyEvent This callback is invoked when the user interacts with the hardware |
| * keyboard. It gives ancestors of a focused component the chance to intercept a [KeyEvent]. |
| * Return true to stop propagation of this event. If you return false, the key event will be sent |
| * to this [onPreviewKeyEvent]'s child. If none of the children consume the event, it will be |
| * sent back up to the root [KeyInputModifierNode] using the onKeyEvent callback. |
| * |
| * @sample androidx.compose.ui.samples.KeyEventSample |
| */ |
| @OptIn(ExperimentalComposeUiApi::class) |
| @Suppress("ModifierInspectorInfo") // b/251831790. |
| fun Modifier.onPreviewKeyEvent(onPreviewKeyEvent: (KeyEvent) -> Boolean): Modifier = this.then( |
| modifierElementOf( |
| key = onPreviewKeyEvent, |
| create = { KeyInputInputModifierNodeImpl(onEvent = null, onPreEvent = onPreviewKeyEvent) }, |
| update = { it.onPreEvent = onPreviewKeyEvent }, |
| definitions = { |
| name = "onPreviewKeyEvent" |
| properties["onPreviewKeyEvent"] = onPreviewKeyEvent |
| } |
| ) |
| ) |