Integrate Element Call with widget API (#1581)

* Integrate Element Call with widget API.

- Add `appconfig` module and extract constants that can be overridden in forks there.
- Add an Element Call feature flag, disabled by default.
- Refactor the whole `ElementCallActivity`, move most logic out of it.
- Integrate with the Rust Widget Driver API (note the Rust SDK version used in this PR lacks some needed changes to make the calls actually work).
- Handle calls differently based on `CallType`.
- Add UI to create/join a call.

---------

Co-authored-by: ElementBot <benoitm+elementbot@element.io>

libraries/matrix/impl/src/main/kotlin/io/element/android/libraries/matrix/impl/room/RustMatrixRoom.kt

@@ -40,6 +40,8 @@ import io.element.android.libraries.matrix.api.room.location.AssetType
 import io.element.android.libraries.matrix.api.room.roomMembers
 import io.element.android.libraries.matrix.api.room.roomNotificationSettings
 import io.element.android.libraries.matrix.api.timeline.MatrixTimeline
+import io.element.android.libraries.matrix.api.widget.MatrixWidgetDriver
+import io.element.android.libraries.matrix.api.widget.MatrixWidgetSettings
 import io.element.android.libraries.matrix.impl.core.toProgressWatcher
 import io.element.android.libraries.matrix.impl.media.MediaUploadHandlerImpl
 import io.element.android.libraries.matrix.impl.media.map
@@ -48,6 +50,8 @@ import io.element.android.libraries.matrix.impl.poll.toInner
 import io.element.android.libraries.matrix.impl.room.location.toInner
 import io.element.android.libraries.matrix.impl.timeline.RustMatrixTimeline
 import io.element.android.libraries.matrix.impl.util.destroyAll
+import io.element.android.libraries.matrix.impl.widget.RustWidgetDriver
+import io.element.android.libraries.matrix.impl.widget.generateWidgetWebViewUrl
 import io.element.android.libraries.sessionstorage.api.SessionData
 import io.element.android.services.toolbox.api.systemclock.SystemClock
 import kotlinx.coroutines.CancellationException
@@ -65,6 +69,8 @@ import org.matrix.rustcomponents.sdk.RoomListItem
 import org.matrix.rustcomponents.sdk.RoomMember
 import org.matrix.rustcomponents.sdk.RoomMessageEventContentWithoutRelation
 import org.matrix.rustcomponents.sdk.SendAttachmentJoinHandle
+import org.matrix.rustcomponents.sdk.WidgetPermissions
+import org.matrix.rustcomponents.sdk.WidgetPermissionsProvider
 import org.matrix.rustcomponents.sdk.messageEventContentFromHtml
 import org.matrix.rustcomponents.sdk.messageEventContentFromMarkdown
 import timber.log.Timber
@@ -478,6 +484,27 @@ class RustMatrixRoom(
         )
     }
 
+    override suspend fun generateWidgetWebViewUrl(
+        widgetSettings: MatrixWidgetSettings,
+        clientId: String,
+        languageTag: String?,
+        theme: String?,
+    ) = runCatching {
+        widgetSettings.generateWidgetWebViewUrl(innerRoom, clientId, languageTag, theme)
+    }
+
+    override fun getWidgetDriver(widgetSettings: MatrixWidgetSettings): Result<MatrixWidgetDriver> = runCatching {
+        RustWidgetDriver(
+            widgetSettings = widgetSettings,
+            room = innerRoom,
+            widgetPermissionsProvider = object : WidgetPermissionsProvider {
+                override fun acquirePermissions(permissions: WidgetPermissions): WidgetPermissions {
+                    return permissions
+                }
+           },
+        )
+    }
+
     private suspend fun sendAttachment(files: List<File>, handle: () -> SendAttachmentJoinHandle): Result<MediaUploadHandler> {
         return runCatching {
             MediaUploadHandlerImpl(files, handle())

libraries/matrix/impl/src/main/kotlin/io/element/android/libraries/matrix/impl/widget/DefaultCallWidgetSettingsProvider.kt

@@ -0,0 +1,46 @@
+/*
+ * Copyright (c) 2023 New Vector Ltd
+ *
+ * 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 io.element.android.libraries.matrix.impl.widget
+
+import com.squareup.anvil.annotations.ContributesBinding
+import io.element.android.libraries.di.AppScope
+import io.element.android.libraries.matrix.api.widget.CallWidgetSettingsProvider
+import io.element.android.libraries.matrix.api.widget.MatrixWidgetSettings
+import org.matrix.rustcomponents.sdk.VirtualElementCallWidgetOptions
+import org.matrix.rustcomponents.sdk.newVirtualElementCallWidget
+import javax.inject.Inject
+
+@ContributesBinding(AppScope::class)
+class DefaultCallWidgetSettingsProvider @Inject constructor() : CallWidgetSettingsProvider {
+    override fun provide(baseUrl: String, widgetId: String): MatrixWidgetSettings {
+        val options = VirtualElementCallWidgetOptions(
+            elementCallUrl = baseUrl,
+            widgetId = widgetId,
+            parentUrl = null,
+            hideHeader = null,
+            preload = null,
+            fontScale = null,
+            appPrompt = false,
+            skipLobby = true,
+            confineToRoom = true,
+            fonts = null,
+            analyticsId = null
+        )
+        val rustWidgetSettings = newVirtualElementCallWidget(options)
+        return MatrixWidgetSettings.fromRustWidgetSettings(rustWidgetSettings)
+    }
+}

libraries/matrix/impl/src/main/kotlin/io/element/android/libraries/matrix/impl/widget/MatrixWidgetSettings.kt

@@ -0,0 +1,50 @@
+/*
+ * Copyright (c) 2023 New Vector Ltd
+ *
+ * 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 io.element.android.libraries.matrix.impl.widget
+
+import io.element.android.libraries.matrix.api.widget.MatrixWidgetSettings
+import org.matrix.rustcomponents.sdk.ClientProperties
+import org.matrix.rustcomponents.sdk.Room
+import org.matrix.rustcomponents.sdk.WidgetSettings
+import org.matrix.rustcomponents.sdk.generateWebviewUrl
+
+fun MatrixWidgetSettings.toRustWidgetSettings() = WidgetSettings(
+    id = this.id,
+    initAfterContentLoad = this.initAfterContentLoad,
+    rawUrl = this.rawUrl,
+)
+
+fun MatrixWidgetSettings.Companion.fromRustWidgetSettings(widgetSettings: WidgetSettings) = MatrixWidgetSettings(
+    id = widgetSettings.id,
+    initAfterContentLoad = widgetSettings.initAfterContentLoad,
+    rawUrl = widgetSettings.rawUrl,
+)
+
+suspend fun MatrixWidgetSettings.generateWidgetWebViewUrl(
+    room: Room,
+    clientId: String,
+    languageTag: String? = null,
+    theme: String? = null
+) = generateWebviewUrl(
+    widgetSettings = this.toRustWidgetSettings(),
+    room = room,
+    props = ClientProperties(
+        clientId = clientId,
+        languageTag = languageTag,
+        theme = theme,
+    )
+)

libraries/matrix/impl/src/main/kotlin/io/element/android/libraries/matrix/impl/widget/RustWidgetDriver.kt

@@ -0,0 +1,78 @@
+/*
+ * Copyright (c) 2023 New Vector Ltd
+ *
+ * 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 io.element.android.libraries.matrix.impl.widget
+
+import io.element.android.libraries.matrix.api.widget.MatrixWidgetDriver
+import io.element.android.libraries.matrix.api.widget.MatrixWidgetSettings
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.Job
+import kotlinx.coroutines.flow.MutableSharedFlow
+import kotlinx.coroutines.isActive
+import kotlinx.coroutines.launch
+import org.matrix.rustcomponents.sdk.Room
+import org.matrix.rustcomponents.sdk.WidgetPermissionsProvider
+import org.matrix.rustcomponents.sdk.makeWidgetDriver
+import java.util.concurrent.atomic.AtomicBoolean
+import kotlin.coroutines.coroutineContext
+
+class RustWidgetDriver(
+    widgetSettings: MatrixWidgetSettings,
+    private val room: Room,
+    private val widgetPermissionsProvider: WidgetPermissionsProvider,
+): MatrixWidgetDriver {
+
+    override val incomingMessages = MutableSharedFlow<String>()
+
+    private val driverAndHandle = makeWidgetDriver(widgetSettings.toRustWidgetSettings())
+    private var receiveMessageJob: Job? = null
+
+    private var isRunning = AtomicBoolean(false)
+
+    override val id: String = widgetSettings.id
+
+    override suspend fun run() {
+        // Don't run the driver if it's already running
+        if (!isRunning.compareAndSet(false, true)) {
+            return
+        }
+
+        val coroutineScope = CoroutineScope(coroutineContext)
+        coroutineScope.launch {
+            // This call will suspend the coroutine while the driver is running, so it needs to be launched separately
+            driverAndHandle.driver.run(room, widgetPermissionsProvider)
+        }
+        receiveMessageJob = coroutineScope.launch(Dispatchers.IO) {
+            try {
+                while (isActive) {
+                    driverAndHandle.handle.recv()?.let { incomingMessages.emit(it) }
+                }
+            } finally {
+                driverAndHandle.handle.close()
+            }
+        }
+    }
+
+    override suspend fun send(message: String) {
+        driverAndHandle.handle.send(message)
+    }
+
+    override fun close() {
+        receiveMessageJob?.cancel()
+        driverAndHandle.driver.close()
+    }
+}