Make widget web view request system permissions for camera and microphone

Previously the widget web view prompted to grant the widget permissions but it didn't
actually request those permissions from the system. So if the web view requested, e.g.
the camera permission but the app hadn't previously been granted that permission, the
web view wouldn't get camera access even when the widget permission request had been
confirmed.

With this commit, the app will also request camera and microphone permissions from the
system when needed.

Signed-off-by: Johannes Marbach <johannesm@element.io>

vector/src/main/java/im/vector/app/features/webview/WebChromeEventListener.kt

@@ -0,0 +1,32 @@
+/*
+ * Copyright 2022 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 im.vector.app.features.webview
+
+import android.webkit.PermissionRequest
+
+interface WebChromeEventListener {
+
+    /**
+     * Triggered when the web view requests permissions.
+     *
+     * @param request The permission request.
+     */
+    fun onPermissionRequest(request: PermissionRequest) {
+        // NO-OP
+    }
+
+}

vector/src/main/java/im/vector/app/features/widgets/WidgetFragment.kt

@@ -26,6 +26,8 @@ import android.view.Menu
 import android.view.MenuItem
 import android.view.View
 import android.view.ViewGroup
+import android.webkit.PermissionRequest
+import androidx.activity.result.contract.ActivityResultContracts
 import androidx.core.view.isInvisible
 import androidx.core.view.isVisible
 import com.airbnb.mvrx.Fail
@@ -42,7 +44,9 @@ import im.vector.app.core.platform.OnBackPressed
 import im.vector.app.core.platform.VectorBaseFragment
 import im.vector.app.core.utils.openUrlInExternalBrowser
 import im.vector.app.databinding.FragmentRoomWidgetBinding
+import im.vector.app.features.webview.WebChromeEventListener
 import im.vector.app.features.webview.WebViewEventListener
+import im.vector.app.features.widgets.webview.WebviewPermissionUtils
 import im.vector.app.features.widgets.webview.clearAfterWidget
 import im.vector.app.features.widgets.webview.setupForWidget
 import kotlinx.parcelize.Parcelize
@@ -63,6 +67,7 @@ data class WidgetArgs(
 class WidgetFragment @Inject constructor() :
         VectorBaseFragment<FragmentRoomWidgetBinding>(),
         WebViewEventListener,
+        WebChromeEventListener,
         OnBackPressed {
 
     private val fragmentArgs: WidgetArgs by args()
@@ -75,7 +80,7 @@ class WidgetFragment @Inject constructor() :
     override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
         super.onViewCreated(view, savedInstanceState)
         setHasOptionsMenu(true)
-        views.widgetWebView.setupForWidget(this)
+        views.widgetWebView.setupForWidget(this, this)
         if (fragmentArgs.kind.isAdmin()) {
             viewModel.getPostAPIMediator().setWebView(views.widgetWebView)
         }
@@ -271,6 +276,19 @@ class WidgetFragment @Inject constructor() :
         viewModel.handle(WidgetAction.OnWebViewLoadingError(url, true, errorCode, description))
     }
 
+    private val permissionResultLauncher = registerForActivityResult(ActivityResultContracts.RequestMultiplePermissions()) { result ->
+        WebviewPermissionUtils.onPermissionResult(result)
+    }
+
+    override fun onPermissionRequest(request: PermissionRequest) {
+        WebviewPermissionUtils.promptForPermissions(
+                title = R.string.room_widget_resource_permission_title,
+                request = request,
+                context = requireContext(),
+                activity = requireActivity(),
+                activityResultLauncher = permissionResultLauncher)
+    }
+
     private fun displayTerms(displayTerms: WidgetViewEvents.DisplayTerms) {
         navigator.openTerms(
                 context = requireContext(),

vector/src/main/java/im/vector/app/features/widgets/webview/WebviewPermissionUtils.kt

@@ -15,17 +15,30 @@
  */
 package im.vector.app.features.widgets.webview
 
+import android.Manifest
 import android.annotation.SuppressLint
 import android.content.Context
 import android.webkit.PermissionRequest
+import androidx.activity.result.ActivityResultLauncher
 import androidx.annotation.StringRes
+import androidx.fragment.app.FragmentActivity
 import com.google.android.material.dialog.MaterialAlertDialogBuilder
 import im.vector.app.R
+import im.vector.app.core.utils.checkPermissions
 
 object WebviewPermissionUtils {
 
+    private var permissionRequest: PermissionRequest? = null
+    private var selectedPermissions = listOf<String>()
+
     @SuppressLint("NewApi")
-    fun promptForPermissions(@StringRes title: Int, request: PermissionRequest, context: Context) {
+    fun promptForPermissions(
+            @StringRes title: Int,
+            request: PermissionRequest,
+            context: Context,
+            activity: FragmentActivity,
+            activityResultLauncher: ActivityResultLauncher<Array<String>>
+    ) {
         val allowedPermissions = request.resources.map {
             it to false
         }.toMutableList()
@@ -37,9 +50,21 @@ object WebviewPermissionUtils {
                     allowedPermissions[which] = allowedPermissions[which].first to isChecked
                 }
                 .setPositiveButton(R.string.room_widget_resource_grant_permission) { _, _ ->
-                    request.grant(allowedPermissions.mapNotNull { perm ->
+                    permissionRequest = request
+                    selectedPermissions = allowedPermissions.mapNotNull { perm ->
                         perm.first.takeIf { perm.second }
-                    }.toTypedArray())
+                    }
+
+                    val requiredAndroidPermissions = selectedPermissions.mapNotNull { permission ->
+                        webPermissionToAndroidPermission(permission)
+                    }
+
+                    // When checkPermissions returns false, some of the required Android permissions will
+                    // have to be requested and the flow completes asynchronously via onPermissionResult
+                    if (checkPermissions(requiredAndroidPermissions, activity, activityResultLauncher)) {
+                        request.grant(selectedPermissions.toTypedArray())
+                        reset()
+                    }
                 }
                 .setNegativeButton(R.string.room_widget_resource_decline_permission) { _, _ ->
                     request.deny()
@@ -47,6 +72,28 @@ object WebviewPermissionUtils {
                 .show()
     }
 
+    fun onPermissionResult(result: Map<String, Boolean>) {
+        permissionRequest?.let { request ->
+            val grantedPermissions = selectedPermissions.filter { webPermission ->
+                val androidPermission = webPermissionToAndroidPermission(webPermission)
+                        ?: return@filter true // No corresponding Android permission exists
+                return@filter result[androidPermission]
+                        ?: return@filter true // Android permission already granted before
+            }
+            if (grantedPermissions.isNotEmpty()) {
+                request.grant(grantedPermissions.toTypedArray())
+            } else {
+                request.deny()
+            }
+            reset()
+        }
+    }
+
+    private fun reset() {
+        permissionRequest = null
+        selectedPermissions = listOf()
+    }
+
     private fun webPermissionToHumanReadable(permission: String, context: Context): String {
         return when (permission) {
             PermissionRequest.RESOURCE_AUDIO_CAPTURE      -> context.getString(R.string.room_widget_webview_access_microphone)
@@ -55,4 +102,12 @@ object WebviewPermissionUtils {
             else                                          -> permission
         }
     }
+
+    private fun webPermissionToAndroidPermission(permission: String): String? {
+        return when (permission) {
+            PermissionRequest.RESOURCE_AUDIO_CAPTURE -> Manifest.permission.RECORD_AUDIO
+            PermissionRequest.RESOURCE_VIDEO_CAPTURE -> Manifest.permission.CAMERA
+            else                                     -> null
+        }
+    }
 }

vector/src/main/java/im/vector/app/features/widgets/webview/WidgetWebView.kt

@@ -25,10 +25,11 @@ import android.webkit.WebView
 import im.vector.app.R
 import im.vector.app.features.themes.ThemeUtils
 import im.vector.app.features.webview.VectorWebViewClient
+import im.vector.app.features.webview.WebChromeEventListener
 import im.vector.app.features.webview.WebViewEventListener
 
 @SuppressLint("NewApi")
-fun WebView.setupForWidget(webViewEventListener: WebViewEventListener) {
+fun WebView.setupForWidget(webViewEventListener: WebViewEventListener, webChromeEventListener: WebChromeEventListener) {
     // xml value seems ignored
     setBackgroundColor(ThemeUtils.getColor(context, R.attr.colorSurface))
 
@@ -59,7 +60,7 @@ fun WebView.setupForWidget(webViewEventListener: WebViewEventListener) {
     // Permission requests
     webChromeClient = object : WebChromeClient() {
         override fun onPermissionRequest(request: PermissionRequest) {
-            WebviewPermissionUtils.promptForPermissions(R.string.room_widget_resource_permission_title, request, context)
+            webChromeEventListener.onPermissionRequest(request)
         }
     }
     webViewClient = VectorWebViewClient(webViewEventListener)