Merge pull request #2526 from vector-im/feature/bca/fix_mxto

element:// support + basic peeking + fix join via server

CHANGES.md

@@ -11,11 +11,13 @@ Features ✨:
 Improvements 🙌:
  - Add Setting Item to Change PIN (#2462)
  - Improve room history visibility setting UX (#1579)
+ - Matrix.to deeplink custom scheme support
 
 Bugfix 🐛:
  - Fix cancellation of sending event (#2438)
  - Double bottomsheet effect after verify with passphrase
  - EditText cursor jumps to the start while typing fast (#2469)
+ - No known servers error is given when joining rooms on new Gitter bridge (#2516)
  - Show preview when sending attachment from the keyboard (#2440)
  - Do not compress GIFs (#1616, #1254)
 

matrix-sdk-android-rx/src/main/java/org/matrix/android/sdk/rx/RxSession.kt

@@ -47,6 +47,7 @@ import org.matrix.android.sdk.api.util.toOptional
 import org.matrix.android.sdk.internal.crypto.model.CryptoDeviceInfo
 import org.matrix.android.sdk.internal.crypto.model.rest.DeviceInfo
 import org.matrix.android.sdk.internal.crypto.store.PrivateKeysInfo
+import org.matrix.android.sdk.internal.session.room.alias.RoomAliasDescription
 
 class RxSession(private val session: Session) {
 
@@ -139,7 +140,7 @@ class RxSession(private val session: Session) {
     }
 
     fun getRoomIdByAlias(roomAlias: String,
-                         searchOnServer: Boolean): Single<Optional<String>> = singleBuilder {
+                         searchOnServer: Boolean): Single<Optional<RoomAliasDescription>> = singleBuilder {
         session.getRoomIdByAlias(roomAlias, searchOnServer, it)
     }
 

matrix-sdk-android/src/main/java/org/matrix/android/sdk/api/session/permalinks/PermalinkService.kt

@@ -25,6 +25,7 @@ interface PermalinkService {
 
     companion object {
         const val MATRIX_TO_URL_BASE = "https://matrix.to/#/"
+        const val MATRIX_TO_CUSTOM_SCHEME_URL_BASE = "element://"
     }
 
     /**

matrix-sdk-android/src/main/java/org/matrix/android/sdk/api/session/room/RoomService.kt

@@ -18,12 +18,15 @@ package org.matrix.android.sdk.api.session.room
 
 import androidx.lifecycle.LiveData
 import org.matrix.android.sdk.api.MatrixCallback
+import org.matrix.android.sdk.api.session.events.model.Event
 import org.matrix.android.sdk.api.session.room.members.ChangeMembershipState
 import org.matrix.android.sdk.api.session.room.model.RoomMemberSummary
 import org.matrix.android.sdk.api.session.room.model.RoomSummary
 import org.matrix.android.sdk.api.session.room.model.create.CreateRoomParams
+import org.matrix.android.sdk.api.session.room.peeking.PeekResult
 import org.matrix.android.sdk.api.util.Cancelable
 import org.matrix.android.sdk.api.util.Optional
+import org.matrix.android.sdk.internal.session.room.alias.RoomAliasDescription
 
 /**
  * This interface defines methods to get rooms. It's implemented at the session level.
@@ -120,7 +123,7 @@ interface RoomService {
      */
     fun getRoomIdByAlias(roomAlias: String,
                          searchOnServer: Boolean,
-                         callback: MatrixCallback<Optional<String>>): Cancelable
+                         callback: MatrixCallback<Optional<RoomAliasDescription>>): Cancelable
 
     /**
      * Delete a room alias
@@ -163,4 +166,16 @@ interface RoomService {
      * @return a LiveData of the optional found room member
      */
     fun getRoomMemberLive(userId: String, roomId: String): LiveData<Optional<RoomMemberSummary>>
+
+    /**
+     * Get some state events about a room
+     */
+    fun getRoomState(roomId: String, callback: MatrixCallback<List<Event>>)
+
+    /**
+     * Use this if you want to get information from a room that you are not yet in (or invited)
+     * It might be possible to get some information on this room if it is public or if guest access is allowed
+     * This call will try to gather some information on this room, but it could fail and get nothing more
+     */
+    fun peekRoom(roomIdOrAlias: String, callback: MatrixCallback<PeekResult>)
 }

matrix-sdk-android/src/main/java/org/matrix/android/sdk/api/session/room/peeking/PeekResult.kt

@@ -0,0 +1,37 @@
+/*
+ * Copyright 2020 The Matrix.org Foundation C.I.C.
+ *
+ * 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 org.matrix.android.sdk.api.session.room.peeking
+
+sealed class PeekResult {
+    data class Success(
+            val roomId: String,
+            val alias: String?,
+            val name: String?,
+            val topic: String?,
+            val avatarUrl: String?,
+            val numJoinedMembers: Int?,
+            val viaServers: List<String>
+    ) : PeekResult()
+
+    data class PeekingNotAllowed(
+            val roomId: String,
+            val alias: String?,
+            val viaServers: List<String>
+    ) : PeekResult()
+
+    object UnknownAlias : PeekResult()
+}

matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/session/room/DefaultRoomService.kt

@@ -20,6 +20,7 @@ import androidx.lifecycle.LiveData
 import androidx.lifecycle.Transformations
 import com.zhuinden.monarchy.Monarchy
 import org.matrix.android.sdk.api.MatrixCallback
+import org.matrix.android.sdk.api.session.events.model.Event
 import org.matrix.android.sdk.api.session.room.Room
 import org.matrix.android.sdk.api.session.room.RoomService
 import org.matrix.android.sdk.api.session.room.RoomSummaryQueryParams
@@ -27,6 +28,7 @@ import org.matrix.android.sdk.api.session.room.members.ChangeMembershipState
 import org.matrix.android.sdk.api.session.room.model.RoomMemberSummary
 import org.matrix.android.sdk.api.session.room.model.RoomSummary
 import org.matrix.android.sdk.api.session.room.model.create.CreateRoomParams
+import org.matrix.android.sdk.api.session.room.peeking.PeekResult
 import org.matrix.android.sdk.api.util.Cancelable
 import org.matrix.android.sdk.api.util.Optional
 import org.matrix.android.sdk.api.util.toOptional
@@ -35,10 +37,13 @@ import org.matrix.android.sdk.internal.database.model.RoomMemberSummaryEntityFie
 import org.matrix.android.sdk.internal.di.SessionDatabase
 import org.matrix.android.sdk.internal.session.room.alias.DeleteRoomAliasTask
 import org.matrix.android.sdk.internal.session.room.alias.GetRoomIdByAliasTask
+import org.matrix.android.sdk.internal.session.room.alias.RoomAliasDescription
 import org.matrix.android.sdk.internal.session.room.create.CreateRoomTask
 import org.matrix.android.sdk.internal.session.room.membership.RoomChangeMembershipStateDataSource
 import org.matrix.android.sdk.internal.session.room.membership.RoomMemberHelper
 import org.matrix.android.sdk.internal.session.room.membership.joining.JoinRoomTask
+import org.matrix.android.sdk.internal.session.room.peeking.PeekRoomTask
+import org.matrix.android.sdk.internal.session.room.peeking.ResolveRoomStateTask
 import org.matrix.android.sdk.internal.session.room.read.MarkAllRoomsReadTask
 import org.matrix.android.sdk.internal.session.room.summary.RoomSummaryDataSource
 import org.matrix.android.sdk.internal.session.user.accountdata.UpdateBreadcrumbsTask
@@ -55,6 +60,8 @@ internal class DefaultRoomService @Inject constructor(
         private val updateBreadcrumbsTask: UpdateBreadcrumbsTask,
         private val roomIdByAliasTask: GetRoomIdByAliasTask,
         private val deleteRoomAliasTask: DeleteRoomAliasTask,
+        private val resolveRoomStateTask: ResolveRoomStateTask,
+        private val peekRoomTask: PeekRoomTask,
         private val roomGetter: RoomGetter,
         private val roomSummaryDataSource: RoomSummaryDataSource,
         private val roomChangeMembershipStateDataSource: RoomChangeMembershipStateDataSource,
@@ -119,7 +126,7 @@ internal class DefaultRoomService @Inject constructor(
                 .executeBy(taskExecutor)
     }
 
-    override fun getRoomIdByAlias(roomAlias: String, searchOnServer: Boolean, callback: MatrixCallback<Optional<String>>): Cancelable {
+    override fun getRoomIdByAlias(roomAlias: String, searchOnServer: Boolean, callback: MatrixCallback<Optional<RoomAliasDescription>>): Cancelable {
         return roomIdByAliasTask
                 .configureWith(GetRoomIdByAliasTask.Params(roomAlias, searchOnServer)) {
                     this.callback = callback
@@ -154,4 +161,20 @@ internal class DefaultRoomService @Inject constructor(
             results.firstOrNull().toOptional()
         }
     }
+
+    override fun getRoomState(roomId: String, callback: MatrixCallback<List<Event>>) {
+        resolveRoomStateTask
+                .configureWith(ResolveRoomStateTask.Params(roomId)) {
+                    this.callback = callback
+                }
+                .executeBy(taskExecutor)
+    }
+
+    override fun peekRoom(roomIdOrAlias: String, callback: MatrixCallback<PeekResult>) {
+        peekRoomTask
+                .configureWith(PeekRoomTask.Params(roomIdOrAlias)) {
+                    this.callback = callback
+                }
+                .executeBy(taskExecutor)
+    }
 }

matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/session/room/RoomAPI.kt

@@ -183,7 +183,7 @@ internal interface RoomAPI {
                    @Body body: ThreePidInviteBody): Call<Unit>
 
     /**
-     * Send a generic state events
+     * Send a generic state event
      *
      * @param roomId         the room id.
      * @param stateEventType the state event type
@@ -195,7 +195,7 @@ internal interface RoomAPI {
                        @Body params: JsonDict): Call<Unit>
 
     /**
-     * Send a generic state events
+     * Send a generic state event
      *
      * @param roomId         the room id.
      * @param stateEventType the state event type
@@ -208,6 +208,13 @@ internal interface RoomAPI {
                        @Path("state_key") stateKey: String,
                        @Body params: JsonDict): Call<Unit>
 
+    /**
+     * Get state events of a room
+     * Ref: https://matrix.org/docs/spec/client_server/r0.6.1#get-matrix-client-r0-rooms-roomid-state
+     */
+    @GET(NetworkConstants.URI_API_PREFIX_PATH_R0 + "rooms/{roomId}/state")
+    fun getRoomState(@Path("roomId") roomId: String) : Call<List<Event>>
+
     /**
      * Send a relation event to a room.
      *

matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/session/room/RoomModule.kt

@@ -57,6 +57,10 @@ import org.matrix.android.sdk.internal.session.room.membership.leaving.DefaultLe
 import org.matrix.android.sdk.internal.session.room.membership.leaving.LeaveRoomTask
 import org.matrix.android.sdk.internal.session.room.membership.threepid.DefaultInviteThreePidTask
 import org.matrix.android.sdk.internal.session.room.membership.threepid.InviteThreePidTask
+import org.matrix.android.sdk.internal.session.room.peeking.DefaultPeekRoomTask
+import org.matrix.android.sdk.internal.session.room.peeking.DefaultResolveRoomStateTask
+import org.matrix.android.sdk.internal.session.room.peeking.PeekRoomTask
+import org.matrix.android.sdk.internal.session.room.peeking.ResolveRoomStateTask
 import org.matrix.android.sdk.internal.session.room.read.DefaultMarkAllRoomsReadTask
 import org.matrix.android.sdk.internal.session.room.read.DefaultSetReadMarkersTask
 import org.matrix.android.sdk.internal.session.room.read.MarkAllRoomsReadTask
@@ -223,4 +227,10 @@ internal abstract class RoomModule {
 
     @Binds
     abstract fun bindDeleteTagFromRoomTask(task: DefaultDeleteTagFromRoomTask): DeleteTagFromRoomTask
+
+    @Binds
+    abstract fun bindResolveRoomStateTask(task: DefaultResolveRoomStateTask): ResolveRoomStateTask
+
+    @Binds
+    abstract fun bindPeekRoomTask(task: DefaultPeekRoomTask): PeekRoomTask
 }

matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/session/room/alias/GetRoomIdByAliasTask.kt

@@ -29,7 +29,7 @@ import org.matrix.android.sdk.internal.session.directory.DirectoryAPI
 import org.matrix.android.sdk.internal.task.Task
 import javax.inject.Inject
 
-internal interface GetRoomIdByAliasTask : Task<GetRoomIdByAliasTask.Params, Optional<String>> {
+internal interface GetRoomIdByAliasTask : Task<GetRoomIdByAliasTask.Params, Optional<RoomAliasDescription>> {
     data class Params(
             val roomAlias: String,
             val searchOnServer: Boolean
@@ -42,21 +42,21 @@ internal class DefaultGetRoomIdByAliasTask @Inject constructor(
         private val eventBus: EventBus
 ) : GetRoomIdByAliasTask {
 
-    override suspend fun execute(params: GetRoomIdByAliasTask.Params): Optional<String> {
-        var roomId = Realm.getInstance(monarchy.realmConfiguration).use {
+    override suspend fun execute(params: GetRoomIdByAliasTask.Params): Optional<RoomAliasDescription> {
+        val roomId = Realm.getInstance(monarchy.realmConfiguration).use {
             RoomSummaryEntity.findByAlias(it, params.roomAlias)?.roomId
         }
         return if (roomId != null) {
-            Optional.from(roomId)
+            Optional.from(RoomAliasDescription(roomId))
         } else if (!params.searchOnServer) {
-            Optional.from<String>(null)
+            Optional.from(null)
         } else {
-            roomId = tryOrNull("## Failed to get roomId from alias") {
+            val description  = tryOrNull("## Failed to get roomId from alias") {
                 executeRequest<RoomAliasDescription>(eventBus) {
                     apiCall = directoryAPI.getRoomIdByAlias(params.roomAlias)
                 }
-            }?.roomId
-            Optional.from(roomId)
+            }
+            Optional.from(description)
         }
     }
 }

matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/session/room/alias/RoomAliasDescription.kt

@@ -20,7 +20,7 @@ import com.squareup.moshi.Json
 import com.squareup.moshi.JsonClass
 
 @JsonClass(generateAdapter = true)
-internal data class RoomAliasDescription(
+data class RoomAliasDescription(
         /**
          * The room ID for this alias.
          */

matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/session/room/peeking/PeekRoomTask.kt

@@ -0,0 +1,145 @@
+/*
+ * Copyright 2020 The Matrix.org Foundation C.I.C.
+ *
+ * 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 org.matrix.android.sdk.internal.session.room.peeking
+
+import org.matrix.android.sdk.api.MatrixPatterns
+import org.matrix.android.sdk.api.session.events.model.EventType
+import org.matrix.android.sdk.api.session.events.model.toModel
+import org.matrix.android.sdk.api.session.room.model.RoomAvatarContent
+import org.matrix.android.sdk.api.session.room.model.RoomCanonicalAliasContent
+import org.matrix.android.sdk.api.session.room.model.RoomDirectoryVisibility
+import org.matrix.android.sdk.api.session.room.model.RoomNameContent
+import org.matrix.android.sdk.api.session.room.model.RoomTopicContent
+import org.matrix.android.sdk.api.session.room.model.roomdirectory.PublicRoomsFilter
+import org.matrix.android.sdk.api.session.room.model.roomdirectory.PublicRoomsParams
+import org.matrix.android.sdk.api.session.room.peeking.PeekResult
+import org.matrix.android.sdk.internal.session.room.alias.GetRoomIdByAliasTask
+import org.matrix.android.sdk.internal.session.room.directory.GetPublicRoomTask
+import org.matrix.android.sdk.internal.session.room.directory.GetRoomDirectoryVisibilityTask
+import org.matrix.android.sdk.internal.task.Task
+import javax.inject.Inject
+
+internal interface PeekRoomTask : Task<PeekRoomTask.Params, PeekResult> {
+    data class Params(
+            val roomIdOrAlias: String
+    )
+}
+
+internal class DefaultPeekRoomTask @Inject constructor(
+        private val getRoomIdByAliasTask: GetRoomIdByAliasTask,
+        private val getRoomDirectoryVisibilityTask: GetRoomDirectoryVisibilityTask,
+        private val getPublicRoomTask: GetPublicRoomTask,
+        private val resolveRoomStateTask: ResolveRoomStateTask
+) : PeekRoomTask {
+
+    override suspend fun execute(params: PeekRoomTask.Params): PeekResult {
+        val roomId: String
+        val serverList: List<String>
+        val isAlias = MatrixPatterns.isRoomAlias(params.roomIdOrAlias)
+        if (isAlias) {
+            // get alias description
+            val aliasDescription = getRoomIdByAliasTask
+                    .execute(GetRoomIdByAliasTask.Params(params.roomIdOrAlias, true))
+                    .getOrNull()
+                    ?: return PeekResult.UnknownAlias
+
+            roomId = aliasDescription.roomId
+            serverList = aliasDescription.servers
+        } else {
+            roomId = params.roomIdOrAlias
+            serverList = emptyList()
+        }
+
+        // Is it a public room?
+        val publicRepoResult = when (getRoomDirectoryVisibilityTask.execute(GetRoomDirectoryVisibilityTask.Params(roomId))) {
+            RoomDirectoryVisibility.PRIVATE -> {
+                // We cannot resolve this room :/
+                null
+            }
+            RoomDirectoryVisibility.PUBLIC  -> {
+                // Try to find it in directory
+                val filter = if (isAlias) PublicRoomsFilter(searchTerm = params.roomIdOrAlias.substring(1))
+                else null
+
+                getPublicRoomTask.execute(GetPublicRoomTask.Params(
+                        server = serverList.firstOrNull(),
+                        publicRoomsParams = PublicRoomsParams(
+                                filter = filter,
+                                limit = 20.takeIf { filter != null } ?: 100
+                        )
+                )).chunk?.firstOrNull { it.roomId == roomId }
+            }
+        }
+
+        if (publicRepoResult != null) {
+            return PeekResult.Success(
+                    roomId = roomId,
+                    alias = publicRepoResult.getPrimaryAlias() ?: params.roomIdOrAlias.takeIf { isAlias },
+                    avatarUrl = publicRepoResult.avatarUrl,
+                    name = publicRepoResult.name,
+                    topic = publicRepoResult.topic,
+                    numJoinedMembers = publicRepoResult.numJoinedMembers,
+                    viaServers = serverList
+            )
+        }
+
+        // mm... try to peek state ? maybe the room is not public but yet allow guest to get events?
+        // this could be slow
+        try {
+            val stateEvents = resolveRoomStateTask.execute(ResolveRoomStateTask.Params(roomId))
+            val name = stateEvents
+                    .lastOrNull { it.type == EventType.STATE_ROOM_NAME && it.stateKey == "" }
+                    ?.let { it.content?.toModel<RoomNameContent>()?.name }
+
+            val topic = stateEvents
+                    .lastOrNull { it.type == EventType.STATE_ROOM_TOPIC && it.stateKey == "" }
+                    ?.let { it.content?.toModel<RoomTopicContent>()?.topic }
+
+            val avatarUrl = stateEvents
+                    .lastOrNull { it.type == EventType.STATE_ROOM_AVATAR }
+                    ?.let { it.content?.toModel<RoomAvatarContent>()?.avatarUrl }
+
+            val alias = stateEvents
+                    .lastOrNull { it.type == EventType.STATE_ROOM_CANONICAL_ALIAS }
+                    ?.let { it.content?.toModel<RoomCanonicalAliasContent>()?.canonicalAlias }
+
+            // not sure if it's the right way to do that :/
+            val memberCount = stateEvents
+                    .filter { it.type == EventType.STATE_ROOM_MEMBER && it.stateKey?.isNotEmpty() == true }
+                    .distinctBy { it.stateKey }
+                    .count()
+
+            return PeekResult.Success(
+                    roomId = roomId,
+                    alias = alias,
+                    avatarUrl = avatarUrl,
+                    name = name,
+                    topic = topic,
+                    numJoinedMembers = memberCount,
+                    viaServers = serverList
+            )
+        } catch (failure: Throwable) {
+            // Would be M_FORBIDDEN if cannot peek :/
+            // User XXX not in room !XXX, and room previews are disabled
+            return PeekResult.PeekingNotAllowed(
+                    roomId = roomId,
+                    alias = params.roomIdOrAlias.takeIf { isAlias },
+                    viaServers = serverList
+            )
+        }
+    }
+}

matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/session/room/peeking/ResolveRoomStateTask.kt

@@ -0,0 +1,42 @@
+/*
+ * Copyright 2020 The Matrix.org Foundation C.I.C.
+ *
+ * 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 org.matrix.android.sdk.internal.session.room.peeking
+
+import org.greenrobot.eventbus.EventBus
+import org.matrix.android.sdk.api.session.events.model.Event
+import org.matrix.android.sdk.internal.network.executeRequest
+import org.matrix.android.sdk.internal.session.room.RoomAPI
+import org.matrix.android.sdk.internal.task.Task
+import javax.inject.Inject
+
+internal interface ResolveRoomStateTask : Task<ResolveRoomStateTask.Params, List<Event>> {
+    data class Params(
+            val roomId: String
+    )
+}
+
+internal class DefaultResolveRoomStateTask @Inject constructor(
+        private val roomAPI: RoomAPI,
+        private val eventBus: EventBus
+) : ResolveRoomStateTask {
+
+    override suspend fun execute(params: ResolveRoomStateTask.Params): List<Event> {
+        return executeRequest(eventBus) {
+            apiCall = roomAPI.getRoomState(params.roomId)
+        }
+    }
+}

tools/check/forbidden_strings_in_code.txt

@@ -164,7 +164,7 @@ Formatter\.formatShortFileSize===1
 # android\.text\.TextUtils
 
 ### This is not a rule, but a warning: the number of "enum class" has changed. For Json classes, it is mandatory that they have `@JsonClass(generateAdapter = false)`. If the enum is not used as a Json class, change the value in file forbidden_strings_in_code.txt
-enum class===83
+enum class===84
 
 ### Do not import temporary legacy classes
 import org.matrix.android.sdk.internal.legacy.riot===3

vector/src/main/AndroidManifest.xml

@@ -81,8 +81,9 @@
                 android:resource="@xml/shortcuts" />
         </activity-alias>
 
-        <activity android:name=".features.home.HomeActivity"
-            android:launchMode="singleTask"/>
+        <activity
+            android:name=".features.home.HomeActivity"
+            android:launchMode="singleTask" />
         <activity
             android:name=".features.login.LoginActivity"
             android:launchMode="singleTask"
@@ -190,15 +191,25 @@
         <activity
             android:name=".features.signout.soft.SoftLogoutActivity"
             android:windowSoftInputMode="adjustResize" />
-        <activity android:name=".features.permalink.PermalinkHandlerActivity" android:launchMode="singleTask">
+        <activity
+            android:name=".features.permalink.PermalinkHandlerActivity"
+            android:launchMode="singleTask">
             <intent-filter>
                 <action android:name="android.intent.action.VIEW" />
+
                 <category android:name="android.intent.category.DEFAULT" />
                 <category android:name="android.intent.category.BROWSABLE" />
 
                 <data android:scheme="http" />
                 <data android:scheme="https" />
                 <data android:host="matrix.to" />
+                <data
+                    android:host="user"
+                    android:scheme="element" />
+                <data
+                    android:host="room"
+                    android:scheme="element" />
+
             </intent-filter>
         </activity>
 

vector/src/main/java/im/vector/app/features/home/HomeActivity.kt

@@ -162,11 +162,27 @@ class HomeActivity : VectorBaseActivity(), ToolbarConfigurable, UnknownDeviceDet
 
     private fun handleIntent(intent: Intent?) {
         intent?.dataString?.let { deepLink ->
-            if (!deepLink.startsWith(PermalinkService.MATRIX_TO_URL_BASE)) return@let
+            val resolvedLink = when {
+                deepLink.startsWith(PermalinkService.MATRIX_TO_URL_BASE)               -> deepLink
+                deepLink.startsWith(PermalinkService.MATRIX_TO_CUSTOM_SCHEME_URL_BASE) -> {
+                    // This is a bit ugly, but for now just convert to matrix.to link for compatibility
+                    when {
+                        deepLink.startsWith(USER_LINK_PREFIX) -> deepLink.substring(USER_LINK_PREFIX.length)
+                        deepLink.startsWith(ROOM_LINK_PREFIX) -> deepLink.substring(ROOM_LINK_PREFIX.length)
+                        else                                  -> null
+                    }?.let {
+                        activeSessionHolder.getSafeActiveSession()?.permalinkService()?.createPermalink(it)
+                    }
+                }
+                else                                                                   -> null
+            }
 
-            permalinkHandler.launch(this, deepLink,
+            permalinkHandler.launch(
+                    context = this,
+                    deepLink = resolvedLink,
                     navigationInterceptor = this,
-                    buildTask = true)
+                    buildTask = true
+            )
                     // .delay(500, TimeUnit.MILLISECONDS)
                     .observeOn(AndroidSchedulers.mainThread())
                     .subscribe { isHandled ->
@@ -345,11 +361,11 @@ class HomeActivity : VectorBaseActivity(), ToolbarConfigurable, UnknownDeviceDet
                 bugReporter.openBugReportScreen(this, false)
                 return true
             }
-            R.id.menu_home_filter -> {
+            R.id.menu_home_filter     -> {
                 navigator.openRoomsFiltering(this)
                 return true
             }
-            R.id.menu_home_setting -> {
+            R.id.menu_home_setting    -> {
                 navigator.openSettings(this)
                 return true
             }
@@ -390,5 +406,8 @@ class HomeActivity : VectorBaseActivity(), ToolbarConfigurable, UnknownDeviceDet
                         putExtra(MvRx.KEY_ARG, args)
                     }
         }
+
+        private const val ROOM_LINK_PREFIX = "${PermalinkService.MATRIX_TO_CUSTOM_SCHEME_URL_BASE}room/"
+        private const val USER_LINK_PREFIX = "${PermalinkService.MATRIX_TO_CUSTOM_SCHEME_URL_BASE}user/"
     }
 }

vector/src/main/java/im/vector/app/features/permalink/PermalinkHandler.kt

@@ -31,6 +31,7 @@ import org.matrix.android.sdk.api.session.permalinks.PermalinkData
 import org.matrix.android.sdk.api.session.permalinks.PermalinkParser
 import org.matrix.android.sdk.api.session.room.model.Membership
 import org.matrix.android.sdk.api.util.Optional
+import org.matrix.android.sdk.api.util.toOptional
 import org.matrix.android.sdk.rx.rx
 import javax.inject.Inject
 
@@ -111,7 +112,7 @@ class PermalinkHandler @Inject constructor(private val activeSessionHolder: Acti
     private fun PermalinkData.RoomLink.getRoomId(): Single<Optional<String>> {
         val session = activeSessionHolder.getSafeActiveSession()
         return if (isRoomAlias && session != null) {
-            session.rx().getRoomIdByAlias(roomIdOrAlias, true).subscribeOn(Schedulers.io())
+            session.rx().getRoomIdByAlias(roomIdOrAlias, true).map { it.getOrNull()?.roomId.toOptional() }.subscribeOn(Schedulers.io())
         } else {
             Single.just(Optional.from(roomIdOrAlias))
         }
@@ -149,16 +150,28 @@ class PermalinkHandler @Inject constructor(private val activeSessionHolder: Acti
                 navigator.openRoom(context, roomId, eventId, buildTask)
             }
             else                             -> {
-                val roomPreviewData = RoomPreviewData(
-                        roomId = roomId,
-                        eventId = eventId,
-                        roomAlias = roomAlias ?: roomSummary?.canonicalAlias,
-                        roomName = roomSummary?.displayName,
-                        avatarUrl = roomSummary?.avatarUrl,
-                        buildTask = buildTask,
-                        homeServers = permalinkData.viaParameters
-                )
-                navigator.openRoomPreview(context, roomPreviewData)
+                if (roomSummary == null) {
+                    // we don't know this room, try to peek
+                    val roomPreviewData = RoomPreviewData(
+                            roomId = roomId,
+                            roomAlias = roomAlias,
+                            peekFromServer = true,
+                            buildTask = buildTask,
+                            homeServers = permalinkData.viaParameters
+                    )
+                    navigator.openRoomPreview(context, roomPreviewData)
+                } else {
+                    val roomPreviewData = RoomPreviewData(
+                            roomId = roomId,
+                            eventId = eventId,
+                            roomAlias = roomAlias ?: roomSummary.canonicalAlias,
+                            roomName = roomSummary.displayName,
+                            avatarUrl = roomSummary.avatarUrl,
+                            buildTask = buildTask,
+                            homeServers = permalinkData.viaParameters
+                    )
+                    navigator.openRoomPreview(context, roomPreviewData)
+                }
             }
         }
     }

vector/src/main/java/im/vector/app/features/popup/PopupAlertManager.kt

@@ -130,7 +130,7 @@ class PopupAlertManager @Inject constructor(private val avatarRenderer: Lazy<Ava
 
     private fun displayNextIfPossible() {
         val currentActivity = weakCurrentActivity?.get()
-        if (Alerter.isShowing || currentActivity == null) {
+        if (Alerter.isShowing || currentActivity == null || currentActivity.isDestroyed) {
             // will retry later
             return
         }

vector/src/main/java/im/vector/app/features/roomdirectory/roompreview/PeekingState.kt

@@ -0,0 +1,23 @@
+/*
+ * Copyright (c) 2020 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.roomdirectory.roompreview
+
+enum class PeekingState {
+    FOUND,
+    NOT_FOUND,
+    NO_ACCESS
+}

vector/src/main/java/im/vector/app/features/roomdirectory/roompreview/RoomPreviewActivity.kt

@@ -40,6 +40,7 @@ data class RoomPreviewData(
         val worldReadable: Boolean = false,
         val avatarUrl: String? = null,
         val homeServers: List<String> = emptyList(),
+        val peekFromServer: Boolean = false,
         val buildTask: Boolean = false
 ) : Parcelable {
     val matrixItem: MatrixItem

vector/src/main/java/im/vector/app/features/roomdirectory/roompreview/RoomPreviewNoPreviewFragment.kt

@@ -20,6 +20,8 @@ import android.os.Bundle
 import android.view.View
 import androidx.core.view.isVisible
 import androidx.transition.TransitionManager
+import com.airbnb.mvrx.Loading
+import com.airbnb.mvrx.Success
 import com.airbnb.mvrx.args
 import com.airbnb.mvrx.fragmentViewModel
 import com.airbnb.mvrx.withState
@@ -30,6 +32,7 @@ import im.vector.app.core.platform.VectorBaseFragment
 import im.vector.app.features.home.AvatarRenderer
 import im.vector.app.features.roomdirectory.JoinState
 import kotlinx.android.synthetic.main.fragment_room_preview_no_preview.*
+import org.matrix.android.sdk.api.util.MatrixItem
 import javax.inject.Inject
 
 /**
@@ -48,22 +51,6 @@ class RoomPreviewNoPreviewFragment @Inject constructor(
     override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
         super.onViewCreated(view, savedInstanceState)
         setupToolbar(roomPreviewNoPreviewToolbar)
-        val titleText = roomPreviewData.roomName ?: roomPreviewData.roomAlias ?: roomPreviewData.roomId
-
-        // Toolbar
-        avatarRenderer.render(roomPreviewData.matrixItem, roomPreviewNoPreviewToolbarAvatar)
-        roomPreviewNoPreviewToolbarTitle.text = titleText
-
-        // Screen
-        avatarRenderer.render(roomPreviewData.matrixItem, roomPreviewNoPreviewAvatar)
-        roomPreviewNoPreviewName.text = titleText
-        roomPreviewNoPreviewTopic.setTextOrHide(roomPreviewData.topic)
-
-        if (roomPreviewData.worldReadable) {
-            roomPreviewNoPreviewLabel.setText(R.string.room_preview_world_readable_room_not_supported_yet)
-        } else {
-            roomPreviewNoPreviewLabel.setText(R.string.room_preview_no_preview)
-        }
 
         roomPreviewNoPreviewJoin.callback = object : ButtonStateView.Callback {
             override fun onButtonClicked() {
@@ -100,7 +87,62 @@ class RoomPreviewNoPreviewFragment @Inject constructor(
             // Quit this screen
             requireActivity().finish()
             // Open room
-            navigator.openRoom(requireActivity(), roomPreviewData.roomId, roomPreviewData.eventId, roomPreviewData.buildTask)
+            navigator.openRoom(requireActivity(), state.roomId, roomPreviewData.eventId, roomPreviewData.buildTask)
+        }
+
+        val bestName = state.roomName ?: state.roomAlias ?: state.roomId
+        when (state.peekingState) {
+            is Loading -> {
+                roomPreviewPeekingProgress.isVisible = true
+                roomPreviewNoPreviewJoin.isVisible = false
+            }
+            is Success -> {
+                roomPreviewPeekingProgress.isVisible = false
+                when (state.peekingState.invoke()) {
+                    PeekingState.FOUND     -> {
+                        // show join buttons
+                        roomPreviewNoPreviewJoin.isVisible = true
+                        renderState(bestName, state.matrixItem(), state.roomTopic)
+                    }
+                    PeekingState.NO_ACCESS -> {
+                        roomPreviewNoPreviewJoin.isVisible = true
+                        roomPreviewNoPreviewLabel.isVisible = true
+                        roomPreviewNoPreviewLabel.setText(R.string.room_preview_no_preview_join)
+                        renderState(bestName, state.matrixItem().takeIf { state.roomAlias != null }, state.roomTopic)
+                    }
+                    else                   -> {
+                        roomPreviewNoPreviewJoin.isVisible = false
+                        roomPreviewNoPreviewLabel.isVisible = true
+                        roomPreviewNoPreviewLabel.setText(R.string.room_preview_not_found)
+                        renderState(bestName, null, state.roomTopic)
+                    }
+                }
+            }
+            else       -> {
+                // Render with initial state, no peeking
+                roomPreviewPeekingProgress.isVisible = false
+                roomPreviewNoPreviewJoin.isVisible = true
+                renderState(bestName, state.matrixItem(), state.roomTopic)
+                roomPreviewNoPreviewLabel.isVisible = false
+            }
         }
     }
+
+    private fun renderState(roomName: String, matrixItem: MatrixItem?, topic: String?) {
+        // Toolbar
+        if (matrixItem != null) {
+            roomPreviewNoPreviewToolbarAvatar.isVisible = true
+            roomPreviewNoPreviewAvatar.isVisible = true
+            avatarRenderer.render(matrixItem, roomPreviewNoPreviewToolbarAvatar)
+            avatarRenderer.render(matrixItem, roomPreviewNoPreviewAvatar)
+        } else {
+            roomPreviewNoPreviewToolbarAvatar.isVisible = false
+            roomPreviewNoPreviewAvatar.isVisible = false
+        }
+        roomPreviewNoPreviewToolbarTitle.text = roomName
+
+        // Screen
+        roomPreviewNoPreviewName.text = roomName
+        roomPreviewNoPreviewTopic.setTextOrHide(topic)
+    }
 }

vector/src/main/java/im/vector/app/features/roomdirectory/roompreview/RoomPreviewViewModel.kt

@@ -16,8 +16,11 @@
 
 package im.vector.app.features.roomdirectory.roompreview
 
+import androidx.lifecycle.viewModelScope
 import com.airbnb.mvrx.FragmentViewModelContext
+import com.airbnb.mvrx.Loading
 import com.airbnb.mvrx.MvRxViewModelFactory
+import com.airbnb.mvrx.Success
 import com.airbnb.mvrx.ViewModelContext
 import com.squareup.inject.assisted.Assisted
 import com.squareup.inject.assisted.AssistedInject
@@ -25,12 +28,17 @@ import im.vector.app.core.extensions.exhaustive
 import im.vector.app.core.platform.EmptyViewEvents
 import im.vector.app.core.platform.VectorViewModel
 import im.vector.app.features.roomdirectory.JoinState
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.launch
 import org.matrix.android.sdk.api.MatrixCallback
+import org.matrix.android.sdk.api.extensions.tryOrNull
 import org.matrix.android.sdk.api.query.QueryStringValue
 import org.matrix.android.sdk.api.session.Session
 import org.matrix.android.sdk.api.session.room.members.ChangeMembershipState
 import org.matrix.android.sdk.api.session.room.model.Membership
+import org.matrix.android.sdk.api.session.room.peeking.PeekResult
 import org.matrix.android.sdk.api.session.room.roomSummaryQueryParams
+import org.matrix.android.sdk.internal.util.awaitCallback
 import org.matrix.android.sdk.rx.rx
 import timber.log.Timber
 
@@ -56,6 +64,56 @@ class RoomPreviewViewModel @AssistedInject constructor(@Assisted private val ini
         // Observe joined room (from the sync)
         observeRoomSummary()
         observeMembershipChanges()
+
+        if (initialState.shouldPeekFromServer) {
+            peekRoomFromServer()
+        }
+    }
+
+    private fun peekRoomFromServer() {
+        setState {
+            copy(peekingState = Loading())
+        }
+        viewModelScope.launch(Dispatchers.IO) {
+            val peekResult = tryOrNull {
+                awaitCallback<PeekResult> {
+                    session.peekRoom(initialState.roomAlias ?: initialState.roomId, it)
+                }
+            }
+
+            when (peekResult) {
+                is PeekResult.Success           -> {
+                    setState {
+                        copy(
+                                roomId = peekResult.roomId,
+                                avatarUrl = peekResult.avatarUrl,
+                                roomAlias = peekResult.alias ?: initialState.roomAlias,
+                                roomTopic = peekResult.topic,
+                                homeServers = peekResult.viaServers,
+                                peekingState = Success(PeekingState.FOUND)
+                        )
+                    }
+                }
+                is PeekResult.PeekingNotAllowed -> {
+                    setState {
+                        copy(
+                                roomId = peekResult.roomId,
+                                roomAlias = peekResult.alias ?: initialState.roomAlias,
+                                homeServers = peekResult.viaServers,
+                                peekingState = Success(PeekingState.NO_ACCESS)
+                        )
+                    }
+                }
+                PeekResult.UnknownAlias,
+                null                            -> {
+                    setState {
+                        copy(
+                                peekingState = Success(PeekingState.NOT_FOUND)
+                        )
+                    }
+                }
+            }
+        }
     }
 
     private fun observeRoomSummary() {

vector/src/main/java/im/vector/app/features/roomdirectory/roompreview/RoomPreviewViewState.kt

@@ -16,13 +16,23 @@
 
 package im.vector.app.features.roomdirectory.roompreview
 
+import com.airbnb.mvrx.Async
 import com.airbnb.mvrx.MvRxState
+import com.airbnb.mvrx.Uninitialized
 import im.vector.app.features.roomdirectory.JoinState
+import org.matrix.android.sdk.api.util.MatrixItem
 
 data class RoomPreviewViewState(
+        val peekingState: Async<PeekingState> = Uninitialized,
         // The room id
         val roomId: String = "",
         val roomAlias: String? = null,
+
+        val roomName: String? = null,
+        val roomTopic: String? = null,
+        val avatarUrl: String? = null,
+
+        val shouldPeekFromServer: Boolean = false,
         /**
          * Can be empty when the server is the current user's home server.
          */
@@ -36,6 +46,14 @@ data class RoomPreviewViewState(
     constructor(args: RoomPreviewData) : this(
             roomId = args.roomId,
             roomAlias = args.roomAlias,
-            homeServers = args.homeServers
+            homeServers = args.homeServers,
+            roomName = args.roomName,
+            roomTopic = args.topic,
+            avatarUrl = args.avatarUrl,
+            shouldPeekFromServer = args.peekFromServer
     )
+
+    fun matrixItem() : MatrixItem {
+        return MatrixItem.RoomItem(roomId, roomName ?: roomAlias, avatarUrl)
+    }
 }

vector/src/main/res/layout/fragment_room_preview_no_preview.xml

@@ -54,6 +54,14 @@
 
         </androidx.appcompat.widget.Toolbar>
 
+        <ProgressBar
+            android:id="@+id/roomPreviewPeekingProgress"
+            style="@style/Widget.AppCompat.ProgressBar.Horizontal"
+            android:layout_width="match_parent"
+            android:layout_height="14dp"
+            android:layout_gravity="center"
+            android:background="?riotx_header_panel_background"
+            android:indeterminate="true" />
 
         <androidx.core.widget.NestedScrollView
             android:layout_width="match_parent"
@@ -71,7 +79,7 @@
                     android:id="@+id/roomPreviewNoPreviewAvatar"
                     android:layout_width="128dp"
                     android:layout_height="128dp"
-                    android:layout_marginTop="123dp"
+                    android:layout_marginTop="60dp"
                     tools:src="@tools:sample/avatars" />
 
                 <TextView

vector/src/main/res/values/strings.xml

@@ -1711,7 +1711,8 @@
 
     <string name="room_preview_no_preview">"This room can't be previewed"</string>
     <string name="room_preview_world_readable_room_not_supported_yet">"The preview of world-readable room is not supported yet in Element"</string>
-
+    <string name="room_preview_not_found">This room is not accessible at this time.\nTry again later, or ask a room admin to check if you have access.</string>
+    <string name="room_preview_no_preview_join">"This room can't be previewed. Do you want to join it?"</string>
     <string name="fab_menu_create_room">"Rooms"</string>
     <string name="fab_menu_create_chat">"Direct Messages"</string>