| /* |
| * Copyright 2021 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.platform |
| |
| import androidx.compose.runtime.Composable |
| import androidx.compose.runtime.ExperimentalComposeApi |
| import androidx.compose.runtime.LaunchedEffect |
| import androidx.compose.runtime.Stable |
| import androidx.compose.runtime.mutableStateOf |
| import androidx.compose.runtime.rememberUpdatedState |
| import androidx.compose.runtime.snapshots.snapshotFlow |
| import kotlinx.coroutines.flow.collect |
| |
| /** |
| * Provides information about the Window that is hosting this compose hierarchy. |
| */ |
| @Stable |
| interface WindowInfo { |
| /** |
| * Indicates whether the window hosting this compose hierarchy is in focus. |
| * |
| * When there are multiple windows visible, either in a multi-window environment or if a |
| * popup or dialog is visible, this property can be used to determine if the current window |
| * is in focus. |
| */ |
| val isWindowFocused: Boolean |
| } |
| |
| @OptIn(ExperimentalComposeApi::class) |
| @Composable |
| internal fun WindowFocusObserver(onWindowFocusChanged: (isWindowFocused: Boolean) -> Unit) { |
| val windowInfo = AmbientWindowInfo.current |
| val callback = rememberUpdatedState(onWindowFocusChanged) |
| LaunchedEffect(windowInfo) { |
| snapshotFlow { windowInfo.isWindowFocused }.collect { callback.value(it) } |
| } |
| } |
| |
| internal class WindowInfoImpl : WindowInfo { |
| private val _isWindowFocused = mutableStateOf(false) |
| override var isWindowFocused: Boolean |
| set(value) { _isWindowFocused.value = value } |
| get() = _isWindowFocused.value |
| } |