Add support for UiMediaScope in iOS (test, do not merge)

compose/ui/ui/src/iosMain/kotlin/androidx/compose/ui/platform/MediaEnvironment.ios.kt

@@ -0,0 +1,285 @@
+/*
+ * Copyright 2026 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.
+ */
+
+@file:OptIn(ExperimentalMediaQueryApi::class)
+
+package androidx.compose.ui.platform
+
+import androidx.compose.runtime.MutableState
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.ui.ExperimentalMediaQueryApi
+import androidx.compose.ui.UiMediaScope
+import androidx.compose.ui.uikit.InterfaceOrientation
+import androidx.compose.ui.uikit.density
+import androidx.compose.ui.unit.Density
+import androidx.compose.ui.unit.Dp
+import org.jetbrains.skiko.SystemTheme
+import androidx.compose.ui.uikit.utils.CMPKeyValueObserver
+import androidx.compose.ui.uikit.utils.CMPUIWindowSceneUtils
+import androidx.compose.ui.window.KeyboardVisibilityListener
+import androidx.compose.ui.window.KeyboardVisibilitySubscriber
+import kotlinx.cinterop.BetaInteropApi
+import kotlinx.cinterop.CPointed
+import kotlinx.cinterop.CPointer
+import kotlinx.cinterop.CValue
+import kotlinx.cinterop.ObjCAction
+import kotlinx.cinterop.useContents
+import platform.AVFoundation.AVCaptureDevice
+import platform.AVFoundation.AVCaptureDeviceWasConnectedNotification
+import platform.AVFoundation.AVCaptureDeviceWasDisconnectedNotification
+import platform.AVFoundation.AVMediaTypeAudio
+import platform.AVFoundation.AVMediaTypeVideo
+import platform.CoreGraphics.CGRect
+import platform.Foundation.NSKeyValueObservingOptionNew
+import platform.Foundation.NSNotification
+import platform.Foundation.NSNotificationCenter
+import platform.Foundation.NSSelectorFromString
+import platform.Foundation.addObserver
+import platform.Foundation.removeObserver
+import platform.darwin.NSObject
+import platform.UIKit.UIUserInterfaceStyle
+import platform.UIKit.UIViewAnimationOptions
+import platform.UIKit.UIWindow
+import platform.UIKit.UIWindowScene
+
+internal class MediaEnvironment(val windowInfo: WindowInfo) : UiMediaScope, KeyboardVisibilitySubscriber {
+
+    private var window: UIWindow? = null
+    /*
+     * Initial value is arbitrarily chosen to avoid propagating invalid value logic
+     * It's never the case in the real usage scenario to reflect that in type system
+     */
+    internal val interfaceOrientationState: MutableState<InterfaceOrientation> = mutableStateOf(
+        InterfaceOrientation.Portrait
+    )
+    private val systemThemeState: MutableState<SystemTheme> = mutableStateOf(SystemTheme.UNKNOWN)
+
+    private val systemDensityState: MutableState<Density> = mutableStateOf(window?.density ?: Density(1f))
+
+    private val isImeShowing = mutableStateOf(KeyboardVisibilityListener.keyboardFrame.useContents { size.height > 0 })
+    private val pointerPrecisionState: MutableState<UiMediaScope.PointerPrecision> = mutableStateOf(
+        UiMediaScope.PointerPrecision.Coarse
+    )
+
+    private val hasMicrophoneState: MutableState<Boolean> = mutableStateOf(detectHasMicrophone())
+    private val hasCameraState: MutableState<Boolean> = mutableStateOf(detectHasCamera())
+
+    private fun detectHasMicrophone(): Boolean =
+        AVCaptureDevice.defaultDeviceWithMediaType(AVMediaTypeAudio) != null
+
+    private fun detectHasCamera(): Boolean =
+        AVCaptureDevice.defaultDeviceWithMediaType(AVMediaTypeVideo) != null
+
+
+    private fun updateCaptureDeviceAvailabilityState() {
+        hasMicrophoneState.value = detectHasMicrophone()
+        hasCameraState.value = detectHasCamera()
+    }
+
+    private val captureDeviceAvailabilityObserver = CaptureDeviceAvailabilityObserver(::updateCaptureDeviceAvailabilityState)
+
+    fun updateInterfaceOrientationState() {
+        currentInterfaceOrientation?.let {
+            interfaceOrientationState.value = it
+        }
+    }
+    fun updateUserInterfaceStyle(style: UIUserInterfaceStyle) {
+        systemThemeState.value = style.asComposeSystemTheme()
+    }
+    fun updatePointerPrecision(precision: UiMediaScope.PointerPrecision) {
+        pointerPrecisionState.value = precision
+    }
+
+    private val currentInterfaceOrientation: InterfaceOrientation?
+        get() {
+            return InterfaceOrientation.getByRawValue(
+                CMPUIWindowSceneUtils.interfaceOrientationForWindowScene(window?.windowScene)
+            )
+        }
+
+    private val interfaceOrientationObserver = SceneGeometryObserver {
+        updateInterfaceOrientationState()
+    }
+    fun onDidMoveToWindow(window: UIWindow?) {
+        this.window = window
+        interfaceOrientationObserver.windowScene = window?.windowScene
+        window ?: return
+
+        systemDensityState.value = window.density
+        updateInterfaceOrientationState()
+
+    }
+
+    val systemTheme: SystemTheme
+        get() = systemThemeState.value
+    val systemDensity: Density
+        get() = systemDensityState.value
+
+    fun startObserving() {
+        interfaceOrientationObserver.isObservingEnabled = true
+        captureDeviceAvailabilityObserver.isObservingEnabled = true
+        KeyboardVisibilityListener.addSubscriber(this)
+    }
+
+    fun stopObserving() {
+        interfaceOrientationObserver.isObservingEnabled = false
+        captureDeviceAvailabilityObserver.isObservingEnabled = false
+        KeyboardVisibilityListener.removeSubscriber(this)
+    }
+
+    override val windowPosture: UiMediaScope.Posture
+        get() = UiMediaScope.Posture.Flat //iOS doesn't have foldables yet!
+    override val windowWidth: Dp
+        get() = windowInfo.containerDpSize.width
+    override val windowHeight: Dp
+        get() = windowInfo.containerDpSize.height
+    override val pointerPrecision: UiMediaScope.PointerPrecision
+        get() = pointerPrecisionState.value
+    override val keyboardKind: UiMediaScope.KeyboardKind
+        get() = when {
+            isImeShowing.value -> UiMediaScope.KeyboardKind.Virtual
+            else -> UiMediaScope.KeyboardKind.None
+        }
+    override val hasMicrophone: Boolean
+        get() = hasMicrophoneState.value
+    override val hasCamera: Boolean
+        get() = hasCameraState.value
+    override val viewingDistance: UiMediaScope.ViewingDistance
+        get() = UiMediaScope.ViewingDistance.Near
+
+    override fun keyboardWillShow(
+        targetFrame: CValue<CGRect>,
+        duration: Double,
+        animationOptions: UIViewAnimationOptions
+    ) {
+        isImeShowing.value = targetFrame.useContents { size.height > 0 }
+    }
+
+    override fun keyboardWillHide(
+        targetFrame: CValue<CGRect>,
+        duration: Double,
+        animationOptions: UIViewAnimationOptions
+    ) {
+        isImeShowing.value = false //targetFrame is CGRectZero.readValue()
+    }
+
+    override fun keyboardWillChangeFrame(
+        targetFrame: CValue<CGRect>,
+        duration: Double,
+        animationOptions: UIViewAnimationOptions
+    ) {
+        isImeShowing.value = targetFrame.useContents { size.height > 0 }
+    }
+}
+
+
+private class SceneGeometryObserver(
+    val onGeometryChanged: () -> Unit
+) : CMPKeyValueObserver() {
+    private val observingKey = "effectiveGeometry"
+
+    var windowScene: UIWindowScene? = null
+        set(value) {
+            if (field == value) return
+            removeObserverIfNeeded()
+            field = value
+            addObserverIfNeeded()
+        }
+
+    var isObservingEnabled = false
+        set(value) {
+            if (field == value) return
+            field = value
+            if (value) {
+                addObserverIfNeeded()
+            } else {
+                removeObserverIfNeeded()
+            }
+        }
+
+    private var isObservingAdded = false
+
+    private fun addObserverIfNeeded() {
+        if (isObservingEnabled && !isObservingAdded) {
+            isObservingAdded = true
+            windowScene?.addObserver(this, observingKey, NSKeyValueObservingOptionNew, null)
+        }
+    }
+
+    private fun removeObserverIfNeeded() {
+        windowScene?.removeObserver(this, observingKey)
+        isObservingAdded = false
+    }
+
+    override fun observeValueForKeyPath(
+        keyPath: String?,
+        ofObject: Any?,
+        change: Map<Any?, *>?,
+        context: CPointer<out CPointed>?
+    ) {
+        onGeometryChanged()
+    }
+}
+
+private class CaptureDeviceAvailabilityObserver(
+    val onDeviceAvailabilityChanged: () -> Unit,
+    private val notificationCenter: NSNotificationCenter = NSNotificationCenter.defaultCenter
+) : NSObject() {
+
+    var isObservingEnabled = false
+        set(value) {
+            if (field == value) return
+            field = value
+            if (value) {
+                addObservers()
+            } else {
+                removeObservers()
+            }
+        }
+
+    private fun addObservers() {
+        notificationCenter.addObserver(
+            observer = this,
+            selector = NSSelectorFromString(::deviceAvailabilityDidChange.name + ":"),
+            name = AVCaptureDeviceWasConnectedNotification,
+            `object` = null
+        )
+        notificationCenter.addObserver(
+            observer = this,
+            selector = NSSelectorFromString(::deviceAvailabilityDidChange.name + ":"),
+            name = AVCaptureDeviceWasDisconnectedNotification,
+            `object` = null
+        )
+    }
+
+    private fun removeObservers() {
+        notificationCenter.removeObserver(this)
+    }
+
+    @OptIn(BetaInteropApi::class)
+    @ObjCAction
+    fun deviceAvailabilityDidChange(arg: NSNotification) {
+        onDeviceAvailabilityChanged()
+    }
+}
+
+private fun UIUserInterfaceStyle.asComposeSystemTheme(): SystemTheme {
+    return when (this) {
+        UIUserInterfaceStyle.UIUserInterfaceStyleLight -> SystemTheme.LIGHT
+        UIUserInterfaceStyle.UIUserInterfaceStyleDark -> SystemTheme.DARK
+        else -> SystemTheme.UNKNOWN
+    }
+}