Merge pull request #2490 from vector-im/feature/bma/url_preview

Url preview

CHANGES.md

@@ -4,6 +4,7 @@ Changes in Element 1.0.12 (2020-XX-XX)
 Features ✨:
  - Add room aliases management, and room directory visibility management in a dedicated screen (#1579, #2428)
  - Room setting: update join rules and guest access (#2442)
+ - Url preview (#481)
  - Store encrypted file in cache and cleanup decrypted file at each app start (#2512)
  - Emoji Keyboard (#2520)
 
@@ -22,6 +23,7 @@ Translations 🗣:
  -
 
 SDK API changes ⚠️:
+ - RawCacheStrategy has been moved and renamed to CacheStrategy
  - FileService: remove useless FileService.DownloadMode
 
 Build 🧱:

matrix-sdk-android/src/androidTest/java/org/matrix/android/sdk/internal/crypto/keysbackup/KeysBackupTest.kt

@@ -264,7 +264,7 @@ class KeysBackupTest : InstrumentedTest {
         assertNotNull(decryption)
         // - Check decryptKeyBackupData() returns stg
         val sessionData = keysBackup
-                .decryptKeyBackupData(keyBackupData!!,
+                .decryptKeyBackupData(keyBackupData,
                         session.olmInboundGroupSession!!.sessionIdentifier(),
                         cryptoTestData.roomId,
                         decryption!!)

matrix-sdk-android/src/androidTest/java/org/matrix/android/sdk/internal/crypto/keysbackup/KeysBackupTestHelper.kt

@@ -111,7 +111,7 @@ class KeysBackupTestHelper(
         Assert.assertTrue(keysBackup.isEnabled)
 
         stateObserver.stopAndCheckStates(null)
-        return PrepareKeysBackupDataResult(megolmBackupCreationInfo, keysVersion.version!!)
+        return PrepareKeysBackupDataResult(megolmBackupCreationInfo, keysVersion.version)
     }
 
     /**

matrix-sdk-android/src/androidTest/java/org/matrix/android/sdk/internal/session/media/UrlsExtractorTest.kt

@@ -0,0 +1,108 @@
+/*
+ * 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.media
+
+import androidx.test.ext.junit.runners.AndroidJUnit4
+import org.amshove.kluent.shouldBeEqualTo
+import org.junit.Test
+import org.junit.runner.RunWith
+import org.matrix.android.sdk.InstrumentedTest
+import org.matrix.android.sdk.api.session.events.model.Event
+import org.matrix.android.sdk.api.session.events.model.EventType
+import org.matrix.android.sdk.api.session.events.model.toContent
+import org.matrix.android.sdk.api.session.room.model.message.MessageTextContent
+import org.matrix.android.sdk.api.session.room.model.message.MessageType
+
+@RunWith(AndroidJUnit4::class)
+internal class UrlsExtractorTest : InstrumentedTest {
+
+    private val urlsExtractor = UrlsExtractor()
+
+    @Test
+    fun wrongEventTypeTest() {
+        createEvent(body = "https://matrix.org")
+                .copy(type = EventType.STATE_ROOM_GUEST_ACCESS)
+                .let { urlsExtractor.extract(it) }
+                .size shouldBeEqualTo 0
+    }
+
+    @Test
+    fun oneUrlTest() {
+        createEvent(body = "https://matrix.org")
+                .let { urlsExtractor.extract(it) }
+                .let { result ->
+                    result.size shouldBeEqualTo 1
+                    result[0] shouldBeEqualTo "https://matrix.org"
+                }
+    }
+
+    @Test
+    fun withoutProtocolTest() {
+        createEvent(body = "www.matrix.org")
+                .let { urlsExtractor.extract(it) }
+                .size shouldBeEqualTo 0
+    }
+
+    @Test
+    fun oneUrlWithParamTest() {
+        createEvent(body = "https://matrix.org?foo=bar")
+                .let { urlsExtractor.extract(it) }
+                .let { result ->
+                    result.size shouldBeEqualTo 1
+                    result[0] shouldBeEqualTo "https://matrix.org?foo=bar"
+                }
+    }
+
+    @Test
+    fun oneUrlWithParamsTest() {
+        createEvent(body = "https://matrix.org?foo=bar&bar=foo")
+                .let { urlsExtractor.extract(it) }
+                .let { result ->
+                    result.size shouldBeEqualTo 1
+                    result[0] shouldBeEqualTo "https://matrix.org?foo=bar&bar=foo"
+                }
+    }
+
+    @Test
+    fun oneUrlInlinedTest() {
+        createEvent(body = "Hello https://matrix.org, how are you?")
+                .let { urlsExtractor.extract(it) }
+                .let { result ->
+                    result.size shouldBeEqualTo 1
+                    result[0] shouldBeEqualTo  "https://matrix.org"
+                }
+    }
+
+    @Test
+    fun twoUrlsTest() {
+        createEvent(body = "https://matrix.org https://example.org")
+                .let { urlsExtractor.extract(it) }
+                .let { result ->
+                    result.size shouldBeEqualTo 2
+                    result[0] shouldBeEqualTo "https://matrix.org"
+                    result[1] shouldBeEqualTo "https://example.org"
+                }
+    }
+
+    private fun createEvent(body: String): Event = Event(
+            type = EventType.MESSAGE,
+            content = MessageTextContent(
+                    msgType = MessageType.MSGTYPE_TEXT,
+                    body = body
+            ).toContent()
+    )
+}

matrix-sdk-android/src/main/java/org/matrix/android/sdk/api/cache/CacheStrategy.kt

@@ -14,16 +14,16 @@
  * limitations under the License.
  */
 
-package org.matrix.android.sdk.api.raw
+package org.matrix.android.sdk.api.cache
 
-sealed class RawCacheStrategy {
+sealed class CacheStrategy {
     // Data is always fetched from the server
-    object NoCache : RawCacheStrategy()
+    object NoCache : CacheStrategy()
 
     // Once data is retrieved, it is stored for the provided amount of time.
     // In case of error, and if strict is set to false, the cache can be returned if available
-    data class TtlCache(val validityDurationInMillis: Long, val strict: Boolean) : RawCacheStrategy()
+    data class TtlCache(val validityDurationInMillis: Long, val strict: Boolean) : CacheStrategy()
 
     // Once retrieved, the data is stored in cache and will be always get from the cache
-    object InfiniteCache : RawCacheStrategy()
+    object InfiniteCache : CacheStrategy()
 }

matrix-sdk-android/src/main/java/org/matrix/android/sdk/api/raw/RawService.kt

@@ -16,6 +16,8 @@
 
 package org.matrix.android.sdk.api.raw
 
+import org.matrix.android.sdk.api.cache.CacheStrategy
+
 /**
  * Useful methods to fetch raw data from the server. The access token will not be used to fetched the data
  */
@@ -23,7 +25,7 @@ interface RawService {
     /**
      * Get a URL, either from cache or from the remote server, depending on the cache strategy
      */
-    suspend fun getUrl(url: String, rawCacheStrategy: RawCacheStrategy): String
+    suspend fun getUrl(url: String, cacheStrategy: CacheStrategy): String
 
     /**
      * Specific case for the well-known file. Cache validity is 8 hours

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

@@ -35,6 +35,7 @@ import org.matrix.android.sdk.api.session.group.GroupService
 import org.matrix.android.sdk.api.session.homeserver.HomeServerCapabilitiesService
 import org.matrix.android.sdk.api.session.identity.IdentityService
 import org.matrix.android.sdk.api.session.integrationmanager.IntegrationManagerService
+import org.matrix.android.sdk.api.session.media.MediaService
 import org.matrix.android.sdk.api.session.permalinks.PermalinkService
 import org.matrix.android.sdk.api.session.profile.ProfileService
 import org.matrix.android.sdk.api.session.pushers.PushersService
@@ -181,6 +182,11 @@ interface Session :
      */
     fun widgetService(): WidgetService
 
+    /**
+     * Returns the media service associated with the session
+     */
+    fun mediaService(): MediaService
+
     /**
      * Returns the integration manager service associated with the session
      */

matrix-sdk-android/src/main/java/org/matrix/android/sdk/api/session/media/MediaService.kt

@@ -0,0 +1,50 @@
+/*
+ * 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.media
+
+import org.matrix.android.sdk.api.cache.CacheStrategy
+import org.matrix.android.sdk.api.session.events.model.Event
+import org.matrix.android.sdk.api.util.JsonDict
+
+interface MediaService {
+    /**
+     * Extract URLs from an Event.
+     * @return the list of URLs contains in the body of the Event. It does not mean that URLs in this list have UrlPreview data
+     */
+    fun extractUrls(event: Event): List<String>
+
+    /**
+     * Get Raw Url Preview data from the homeserver. There is no cache management for this request
+     * @param url The url to get the preview data from
+     * @param timestamp The optional timestamp
+     */
+    suspend fun getRawPreviewUrl(url: String, timestamp: Long?): JsonDict
+
+    /**
+     * Get Url Preview data from the homeserver, or from cache, depending on the cache strategy
+     * @param url The url to get the preview data from
+     * @param timestamp The optional timestamp. Note that this parameter is not taken into account
+     * if the data is already in cache and the cache strategy allow to use it
+     * @param cacheStrategy the cache strategy, see the type for more details
+     */
+    suspend fun getPreviewUrl(url: String, timestamp: Long?, cacheStrategy: CacheStrategy): PreviewUrlData
+
+    /**
+     * Clear the cache of all retrieved UrlPreview data
+     */
+    suspend fun clearCache()
+}

matrix-sdk-android/src/main/java/org/matrix/android/sdk/api/session/media/PreviewUrlData.kt

@@ -0,0 +1,51 @@
+/*
+ * 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.media
+
+/**
+ * Facility data class to get the common field of a PreviewUrl response form the server
+ *
+ * Example of return data for the url `https://matrix.org`:
+ * <pre>
+ * {
+ *     "matrix:image:size": 112805,
+ *     "og:description": "Matrix is an open standard for interoperable, decentralised, real-time communication",
+ *     "og:image": "mxc://matrix.org/2020-12-03_uFqjagCCTJbaaJxb",
+ *     "og:image:alt": "Matrix is an open standard for interoperable, decentralised, real-time communication",
+ *     "og:image:height": 467,
+ *     "og:image:type": "image/jpeg",
+ *     "og:image:width": 911,
+ *     "og:locale": "en_US",
+ *     "og:site_name": "Matrix.org",
+ *     "og:title": "Matrix.org",
+ *     "og:type": "website",
+ *     "og:url": "https://matrix.org"
+ * }
+ * </pre>
+ */
+data class PreviewUrlData(
+        // Value of field "og:url". If not provided, this is the value passed in parameter
+        val url: String,
+        // Value of field "og:site_name"
+        val siteName: String?,
+        // Value of field "og:title"
+        val title: String?,
+        // Value of field "og:description"
+        val description: String?,
+        // Value of field "og:image"
+        val mxcUrl: String?
+)

matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/database/RealmSessionStoreMigration.kt

@@ -20,6 +20,7 @@ import io.realm.DynamicRealm
 import io.realm.RealmMigration
 import org.matrix.android.sdk.internal.database.model.HomeServerCapabilitiesEntityFields
 import org.matrix.android.sdk.internal.database.model.PendingThreePidEntityFields
+import org.matrix.android.sdk.internal.database.model.PreviewUrlCacheEntityFields
 import org.matrix.android.sdk.internal.database.model.RoomSummaryEntityFields
 import timber.log.Timber
 import javax.inject.Inject
@@ -27,7 +28,7 @@ import javax.inject.Inject
 class RealmSessionStoreMigration @Inject constructor() : RealmMigration {
 
     companion object {
-        const val SESSION_STORE_SCHEMA_VERSION = 5L
+        const val SESSION_STORE_SCHEMA_VERSION = 6L
     }
 
     override fun migrate(realm: DynamicRealm, oldVersion: Long, newVersion: Long) {
@@ -38,6 +39,7 @@ class RealmSessionStoreMigration @Inject constructor() : RealmMigration {
         if (oldVersion <= 2) migrateTo3(realm)
         if (oldVersion <= 3) migrateTo4(realm)
         if (oldVersion <= 4) migrateTo5(realm)
+        if (oldVersion <= 5) migrateTo6(realm)
     }
 
     private fun migrateTo1(realm: DynamicRealm) {
@@ -89,4 +91,18 @@ class RealmSessionStoreMigration @Inject constructor() : RealmMigration {
                 ?.removeField("adminE2EByDefault")
                 ?.removeField("preferredJitsiDomain")
     }
+
+    private fun migrateTo6(realm: DynamicRealm) {
+        Timber.d("Step 5 -> 6")
+        realm.schema.create("PreviewUrlCacheEntity")
+                .addField(PreviewUrlCacheEntityFields.URL, String::class.java)
+                .setRequired(PreviewUrlCacheEntityFields.URL, true)
+                .addPrimaryKey(PreviewUrlCacheEntityFields.URL)
+                .addField(PreviewUrlCacheEntityFields.URL_FROM_SERVER, String::class.java)
+                .addField(PreviewUrlCacheEntityFields.SITE_NAME, String::class.java)
+                .addField(PreviewUrlCacheEntityFields.TITLE, String::class.java)
+                .addField(PreviewUrlCacheEntityFields.DESCRIPTION, String::class.java)
+                .addField(PreviewUrlCacheEntityFields.MXC_URL, String::class.java)
+                .addField(PreviewUrlCacheEntityFields.LAST_UPDATED_TIMESTAMP, Long::class.java)
+    }
 }

matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/database/model/PreviewUrlCacheEntity.kt

@@ -0,0 +1,36 @@
+/*
+ * 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.database.model
+
+import io.realm.RealmObject
+import io.realm.annotations.PrimaryKey
+
+internal open class PreviewUrlCacheEntity(
+        @PrimaryKey
+        var url: String = "",
+
+        var urlFromServer: String? = null,
+        var siteName: String? = null,
+        var title: String? = null,
+        var description: String? = null,
+        var mxcUrl: String? = null,
+
+        var lastUpdatedTimestamp: Long = 0L
+) : RealmObject() {
+
+    companion object
+}

matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/database/model/SessionRealmModule.kt

@@ -48,6 +48,7 @@ import io.realm.annotations.RealmModule
             PushRulesEntity::class,
             PushRuleEntity::class,
             PushConditionEntity::class,
+            PreviewUrlCacheEntity::class,
             PusherEntity::class,
             PusherDataEntity::class,
             ReadReceiptsSummaryEntity::class,

matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/database/query/PreviewUrlCacheEntityQueries.kt

@@ -0,0 +1,39 @@
+/*
+ * 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.database.query
+
+import io.realm.Realm
+import io.realm.kotlin.createObject
+import io.realm.kotlin.where
+import org.matrix.android.sdk.internal.database.model.PreviewUrlCacheEntity
+import org.matrix.android.sdk.internal.database.model.PreviewUrlCacheEntityFields
+
+/**
+ * Get the current PreviewUrlCacheEntity, return null if it does not exist
+ */
+internal fun PreviewUrlCacheEntity.Companion.get(realm: Realm, url: String): PreviewUrlCacheEntity? {
+    return realm.where<PreviewUrlCacheEntity>()
+            .equalTo(PreviewUrlCacheEntityFields.URL, url)
+            .findFirst()
+}
+
+/**
+ * Get the current PreviewUrlCacheEntity, create one if it does not exist
+ */
+internal fun PreviewUrlCacheEntity.Companion.getOrCreate(realm: Realm, url: String): PreviewUrlCacheEntity {
+    return get(realm, url) ?: realm.createObject(url)
+}

matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/raw/DefaultRawService.kt

@@ -16,7 +16,7 @@
 
 package org.matrix.android.sdk.internal.raw
 
-import org.matrix.android.sdk.api.raw.RawCacheStrategy
+import org.matrix.android.sdk.api.cache.CacheStrategy
 import org.matrix.android.sdk.api.raw.RawService
 import java.util.concurrent.TimeUnit
 import javax.inject.Inject
@@ -25,15 +25,15 @@ internal class DefaultRawService @Inject constructor(
         private val getUrlTask: GetUrlTask,
         private val cleanRawCacheTask: CleanRawCacheTask
 ) : RawService {
-    override suspend fun getUrl(url: String, rawCacheStrategy: RawCacheStrategy): String {
+    override suspend fun getUrl(url: String, cacheStrategy: CacheStrategy): String {
-        return getUrlTask.execute(GetUrlTask.Params(url, rawCacheStrategy))
+        return getUrlTask.execute(GetUrlTask.Params(url, cacheStrategy))
     }
 
     override suspend fun getWellknown(userId: String): String {
         val homeServerDomain = userId.substringAfter(":")
         return getUrl(
                 "https://$homeServerDomain/.well-known/matrix/client",
-                RawCacheStrategy.TtlCache(TimeUnit.HOURS.toMillis(8), false)
+                CacheStrategy.TtlCache(TimeUnit.HOURS.toMillis(8), false)
         )
     }
 

matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/raw/GetUrlTask.kt

@@ -18,7 +18,7 @@ package org.matrix.android.sdk.internal.raw
 
 import com.zhuinden.monarchy.Monarchy
 import okhttp3.ResponseBody
-import org.matrix.android.sdk.api.raw.RawCacheStrategy
+import org.matrix.android.sdk.api.cache.CacheStrategy
 import org.matrix.android.sdk.internal.database.model.RawCacheEntity
 import org.matrix.android.sdk.internal.database.query.get
 import org.matrix.android.sdk.internal.database.query.getOrCreate
@@ -32,7 +32,7 @@ import javax.inject.Inject
 internal interface GetUrlTask : Task<GetUrlTask.Params, String> {
     data class Params(
             val url: String,
-            val rawCacheStrategy: RawCacheStrategy
+            val cacheStrategy: CacheStrategy
     )
 }
 
@@ -42,14 +42,14 @@ internal class DefaultGetUrlTask @Inject constructor(
 ) : GetUrlTask {
 
     override suspend fun execute(params: GetUrlTask.Params): String {
-        return when (params.rawCacheStrategy) {
+        return when (params.cacheStrategy) {
-            RawCacheStrategy.NoCache       -> doRequest(params.url)
+            CacheStrategy.NoCache       -> doRequest(params.url)
-            is RawCacheStrategy.TtlCache   -> doRequestWithCache(
+            is CacheStrategy.TtlCache   -> doRequestWithCache(
                     params.url,
-                    params.rawCacheStrategy.validityDurationInMillis,
+                    params.cacheStrategy.validityDurationInMillis,
-                    params.rawCacheStrategy.strict
+                    params.cacheStrategy.strict
             )
-            RawCacheStrategy.InfiniteCache -> doRequestWithCache(
+            CacheStrategy.InfiniteCache -> doRequestWithCache(
                     params.url,
                     Long.MAX_VALUE,
                     true

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

@@ -43,6 +43,7 @@ import org.matrix.android.sdk.api.session.file.FileService
 import org.matrix.android.sdk.api.session.group.GroupService
 import org.matrix.android.sdk.api.session.homeserver.HomeServerCapabilitiesService
 import org.matrix.android.sdk.api.session.integrationmanager.IntegrationManagerService
+import org.matrix.android.sdk.api.session.media.MediaService
 import org.matrix.android.sdk.api.session.permalinks.PermalinkService
 import org.matrix.android.sdk.api.session.profile.ProfileService
 import org.matrix.android.sdk.api.session.pushers.PushersService
@@ -102,6 +103,7 @@ internal class DefaultSession @Inject constructor(
         private val permalinkService: Lazy<PermalinkService>,
         private val secureStorageService: Lazy<SecureStorageService>,
         private val profileService: Lazy<ProfileService>,
+        private val mediaService: Lazy<MediaService>,
         private val widgetService: Lazy<WidgetService>,
         private val syncThreadProvider: Provider<SyncThread>,
         private val contentUrlResolver: ContentUrlResolver,
@@ -263,6 +265,8 @@ internal class DefaultSession @Inject constructor(
 
     override fun widgetService(): WidgetService = widgetService.get()
 
+    override fun mediaService(): MediaService = mediaService.get()
+
     override fun integrationManagerService() = integrationManagerService
 
     override fun callSignalingService(): CallSignalingService = callSignalingService.get()

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

@@ -40,6 +40,7 @@ import org.matrix.android.sdk.internal.session.group.GroupModule
 import org.matrix.android.sdk.internal.session.homeserver.HomeServerCapabilitiesModule
 import org.matrix.android.sdk.internal.session.identity.IdentityModule
 import org.matrix.android.sdk.internal.session.integrationmanager.IntegrationManagerModule
+import org.matrix.android.sdk.internal.session.media.MediaModule
 import org.matrix.android.sdk.internal.session.openid.OpenIdModule
 import org.matrix.android.sdk.internal.session.profile.ProfileModule
 import org.matrix.android.sdk.internal.session.pushers.AddHttpPusherWorker
@@ -75,6 +76,7 @@ import org.matrix.android.sdk.internal.util.MatrixCoroutineDispatchers
             GroupModule::class,
             ContentModule::class,
             CacheModule::class,
+            MediaModule::class,
             CryptoModule::class,
             PushersModule::class,
             OpenIdModule::class,

matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/session/homeserver/CapabilitiesAPI.kt

@@ -22,19 +22,12 @@ import retrofit2.Call
 import retrofit2.http.GET
 
 internal interface CapabilitiesAPI {
-
     /**
      * Request the homeserver capabilities
      */
     @GET(NetworkConstants.URI_API_PREFIX_PATH_R0 + "capabilities")
     fun getCapabilities(): Call<GetCapabilitiesResult>
 
-    /**
-     * Request the upload capabilities
-     */
-    @GET(NetworkConstants.URI_API_MEDIA_PREFIX_PATH_R0 + "config")
-    fun getUploadCapabilities(): Call<GetUploadCapabilitiesResult>
-
     /**
      * Request the versions
      */

matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/session/homeserver/GetHomeServerCapabilitiesTask.kt

@@ -29,6 +29,8 @@ import org.matrix.android.sdk.internal.di.SessionDatabase
 import org.matrix.android.sdk.internal.di.UserId
 import org.matrix.android.sdk.internal.network.executeRequest
 import org.matrix.android.sdk.internal.session.integrationmanager.IntegrationManagerConfigExtractor
+import org.matrix.android.sdk.internal.session.media.GetMediaConfigResult
+import org.matrix.android.sdk.internal.session.media.MediaAPI
 import org.matrix.android.sdk.internal.task.Task
 import org.matrix.android.sdk.internal.util.awaitTransaction
 import org.matrix.android.sdk.internal.wellknown.GetWellknownTask
@@ -40,6 +42,7 @@ internal interface GetHomeServerCapabilitiesTask : Task<Unit, Unit>
 
 internal class DefaultGetHomeServerCapabilitiesTask @Inject constructor(
         private val capabilitiesAPI: CapabilitiesAPI,
+        private val mediaAPI: MediaAPI,
         @SessionDatabase private val monarchy: Monarchy,
         private val eventBus: EventBus,
         private val getWellknownTask: GetWellknownTask,
@@ -67,9 +70,9 @@ internal class DefaultGetHomeServerCapabilitiesTask @Inject constructor(
             }
         }.getOrNull()
 
-        val uploadCapabilities = runCatching {
+        val mediaConfig = runCatching {
-            executeRequest<GetUploadCapabilitiesResult>(eventBus) {
+            executeRequest<GetMediaConfigResult>(eventBus) {
-                apiCall = capabilitiesAPI.getUploadCapabilities()
+                apiCall = mediaAPI.getMediaConfig()
             }
         }.getOrNull()
 
@@ -83,11 +86,11 @@ internal class DefaultGetHomeServerCapabilitiesTask @Inject constructor(
             getWellknownTask.execute(GetWellknownTask.Params(userId, homeServerConnectionConfig))
         }.getOrNull()
 
-        insertInDb(capabilities, uploadCapabilities, versions, wellknownResult)
+        insertInDb(capabilities, mediaConfig, versions, wellknownResult)
     }
 
     private suspend fun insertInDb(getCapabilitiesResult: GetCapabilitiesResult?,
-                                   getUploadCapabilitiesResult: GetUploadCapabilitiesResult?,
+                                   getMediaConfigResult: GetMediaConfigResult?,
                                    getVersionResult: Versions?,
                                    getWellknownResult: WellknownResult?) {
         monarchy.awaitTransaction { realm ->
@@ -97,8 +100,8 @@ internal class DefaultGetHomeServerCapabilitiesTask @Inject constructor(
                 homeServerCapabilitiesEntity.canChangePassword = getCapabilitiesResult.canChangePassword()
             }
 
-            if (getUploadCapabilitiesResult != null) {
+            if (getMediaConfigResult != null) {
-                homeServerCapabilitiesEntity.maxUploadFileSize = getUploadCapabilitiesResult.maxUploadSize
+                homeServerCapabilitiesEntity.maxUploadFileSize = getMediaConfigResult.maxUploadSize
                         ?: HomeServerCapabilities.MAX_UPLOAD_FILE_SIZE_UNKNOWN
             }
 

matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/session/media/ClearPreviewUrlCacheTask.kt

@@ -0,0 +1,40 @@
+/*
+ * 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.media
+
+import com.zhuinden.monarchy.Monarchy
+import io.realm.kotlin.where
+import org.matrix.android.sdk.internal.database.model.PreviewUrlCacheEntity
+import org.matrix.android.sdk.internal.di.SessionDatabase
+import org.matrix.android.sdk.internal.task.Task
+import org.matrix.android.sdk.internal.util.awaitTransaction
+import javax.inject.Inject
+
+internal interface ClearPreviewUrlCacheTask : Task<Unit, Unit>
+
+internal class DefaultClearPreviewUrlCacheTask @Inject constructor(
+        @SessionDatabase private val monarchy: Monarchy
+) : ClearPreviewUrlCacheTask {
+
+    override suspend fun execute(params: Unit) {
+        monarchy.awaitTransaction { realm ->
+            realm.where<PreviewUrlCacheEntity>()
+                    .findAll()
+                    .deleteAllFromRealm()
+        }
+    }
+}

matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/session/media/DefaultMediaService.kt

@@ -0,0 +1,55 @@
+/*
+ * 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.media
+
+import androidx.collection.LruCache
+import org.matrix.android.sdk.api.cache.CacheStrategy
+import org.matrix.android.sdk.api.session.events.model.Event
+import org.matrix.android.sdk.api.session.media.MediaService
+import org.matrix.android.sdk.api.session.media.PreviewUrlData
+import org.matrix.android.sdk.api.util.JsonDict
+import org.matrix.android.sdk.internal.util.getOrPut
+import javax.inject.Inject
+
+internal class DefaultMediaService @Inject constructor(
+        private val clearPreviewUrlCacheTask: ClearPreviewUrlCacheTask,
+        private val getPreviewUrlTask: GetPreviewUrlTask,
+        private val getRawPreviewUrlTask: GetRawPreviewUrlTask,
+        private val urlsExtractor: UrlsExtractor
+) : MediaService {
+    // Cache of extracted URLs
+    private val extractedUrlsCache = LruCache<String, List<String>>(1_000)
+
+    override fun extractUrls(event: Event): List<String> {
+        return extractedUrlsCache.getOrPut(event.cacheKey()) { urlsExtractor.extract(event) }
+    }
+
+    private fun Event.cacheKey() = "${eventId ?: ""}-${roomId ?: ""}"
+
+    override suspend fun getRawPreviewUrl(url: String, timestamp: Long?): JsonDict {
+        return getRawPreviewUrlTask.execute(GetRawPreviewUrlTask.Params(url, timestamp))
+    }
+
+    override suspend fun getPreviewUrl(url: String, timestamp: Long?, cacheStrategy: CacheStrategy): PreviewUrlData {
+        return getPreviewUrlTask.execute(GetPreviewUrlTask.Params(url, timestamp, cacheStrategy))
+    }
+
+    override suspend fun clearCache() {
+        extractedUrlsCache.evictAll()
+        clearPreviewUrlCacheTask.execute(Unit)
+    }
+}

matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/session/media/GetMediaConfigResult.kt

@@ -5,7 +5,7 @@
  * 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
+ *     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,
@@ -14,13 +14,13 @@
  * limitations under the License.
  */
 
-package org.matrix.android.sdk.internal.session.homeserver
+package org.matrix.android.sdk.internal.session.media
 
 import com.squareup.moshi.Json
 import com.squareup.moshi.JsonClass
 
 @JsonClass(generateAdapter = true)
-internal data class GetUploadCapabilitiesResult(
+internal data class GetMediaConfigResult(
         /**
          * The maximum size an upload can be in bytes. Clients SHOULD use this as a guide when uploading content.
          * If not listed or null, the size limit should be treated as unknown.

matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/session/media/GetPreviewUrlTask.kt

@@ -0,0 +1,122 @@
+/*
+ * 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.media
+
+import com.zhuinden.monarchy.Monarchy
+import org.greenrobot.eventbus.EventBus
+import org.matrix.android.sdk.api.cache.CacheStrategy
+import org.matrix.android.sdk.api.session.media.PreviewUrlData
+import org.matrix.android.sdk.api.util.JsonDict
+import org.matrix.android.sdk.internal.database.model.PreviewUrlCacheEntity
+import org.matrix.android.sdk.internal.database.query.get
+import org.matrix.android.sdk.internal.database.query.getOrCreate
+import org.matrix.android.sdk.internal.di.SessionDatabase
+import org.matrix.android.sdk.internal.network.executeRequest
+import org.matrix.android.sdk.internal.task.Task
+import org.matrix.android.sdk.internal.util.awaitTransaction
+import java.util.Date
+import javax.inject.Inject
+
+internal interface GetPreviewUrlTask : Task<GetPreviewUrlTask.Params, PreviewUrlData> {
+    data class Params(
+            val url: String,
+            val timestamp: Long?,
+            val cacheStrategy: CacheStrategy
+    )
+}
+
+internal class DefaultGetPreviewUrlTask @Inject constructor(
+        private val mediaAPI: MediaAPI,
+        private val eventBus: EventBus,
+        @SessionDatabase private val monarchy: Monarchy
+) : GetPreviewUrlTask {
+
+    override suspend fun execute(params: GetPreviewUrlTask.Params): PreviewUrlData {
+        return when (params.cacheStrategy) {
+            CacheStrategy.NoCache -> doRequest(params.url, params.timestamp)
+            is CacheStrategy.TtlCache -> doRequestWithCache(
+                    params.url,
+                    params.timestamp,
+                    params.cacheStrategy.validityDurationInMillis,
+                    params.cacheStrategy.strict
+            )
+            CacheStrategy.InfiniteCache -> doRequestWithCache(
+                    params.url,
+                    params.timestamp,
+                    Long.MAX_VALUE,
+                    true
+            )
+        }
+    }
+
+    private suspend fun doRequest(url: String, timestamp: Long?): PreviewUrlData {
+        return executeRequest<JsonDict>(eventBus) {
+            apiCall = mediaAPI.getPreviewUrlData(url, timestamp)
+        }
+                .toPreviewUrlData(url)
+    }
+
+    private fun JsonDict.toPreviewUrlData(url: String): PreviewUrlData {
+        return PreviewUrlData(
+                url = (get("og:url") as? String) ?: url,
+                siteName = get("og:site_name") as? String,
+                title = get("og:title") as? String,
+                description = get("og:description") as? String,
+                mxcUrl = get("og:image") as? String
+        )
+    }
+
+    private suspend fun doRequestWithCache(url: String, timestamp: Long?, validityDurationInMillis: Long, strict: Boolean): PreviewUrlData {
+        // Get data from cache
+        var dataFromCache: PreviewUrlData? = null
+        var isCacheValid = false
+        monarchy.doWithRealm { realm ->
+            val entity = PreviewUrlCacheEntity.get(realm, url)
+            dataFromCache = entity?.toDomain()
+            isCacheValid = entity != null && Date().time < entity.lastUpdatedTimestamp + validityDurationInMillis
+        }
+
+        val finalDataFromCache = dataFromCache
+        if (finalDataFromCache != null && isCacheValid) {
+            return finalDataFromCache
+        }
+
+        // No cache or outdated cache
+        val data = try {
+            doRequest(url, timestamp)
+        } catch (throwable: Throwable) {
+            // In case of error, we can return value from cache even if outdated
+            return finalDataFromCache
+                    ?.takeIf { !strict }
+                    ?: throw throwable
+        }
+
+        // Store cache
+        monarchy.awaitTransaction { realm ->
+            val previewUrlCacheEntity = PreviewUrlCacheEntity.getOrCreate(realm, url)
+            previewUrlCacheEntity.urlFromServer = data.url
+            previewUrlCacheEntity.siteName = data.siteName
+            previewUrlCacheEntity.title = data.title
+            previewUrlCacheEntity.description = data.description
+            previewUrlCacheEntity.mxcUrl = data.mxcUrl
+
+            previewUrlCacheEntity.lastUpdatedTimestamp = Date().time
+        }
+
+        return data
+    }
+}

matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/session/media/GetRawPreviewUrlTask.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.media
+
+import org.greenrobot.eventbus.EventBus
+import org.matrix.android.sdk.api.util.JsonDict
+import org.matrix.android.sdk.internal.network.executeRequest
+import org.matrix.android.sdk.internal.task.Task
+import javax.inject.Inject
+
+internal interface GetRawPreviewUrlTask : Task<GetRawPreviewUrlTask.Params, JsonDict> {
+    data class Params(
+            val url: String,
+            val timestamp: Long?
+    )
+}
+
+internal class DefaultGetRawPreviewUrlTask @Inject constructor(
+        private val mediaAPI: MediaAPI,
+        private val eventBus: EventBus
+) : GetRawPreviewUrlTask {
+
+    override suspend fun execute(params: GetRawPreviewUrlTask.Params): JsonDict {
+        return executeRequest(eventBus) {
+            apiCall = mediaAPI.getPreviewUrlData(params.url, params.timestamp)
+        }
+    }
+}

matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/session/media/MediaAPI.kt

@@ -0,0 +1,43 @@
+/*
+ * 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.media
+
+import org.matrix.android.sdk.api.util.JsonDict
+import org.matrix.android.sdk.internal.network.NetworkConstants
+import retrofit2.Call
+import retrofit2.http.GET
+import retrofit2.http.Query
+
+internal interface MediaAPI {
+    /**
+     * Retrieve the configuration of the content repository
+     * Ref: https://matrix.org/docs/spec/client_server/r0.6.1#get-matrix-media-r0-config
+     */
+    @GET(NetworkConstants.URI_API_MEDIA_PREFIX_PATH_R0 + "config")
+    fun getMediaConfig(): Call<GetMediaConfigResult>
+
+    /**
+     * Get information about a URL for the client. Typically this is called when a client
+     * sees a URL in a message and wants to render a preview for the user.
+     * Ref: https://matrix.org/docs/spec/client_server/r0.6.1#get-matrix-media-r0-preview-url
+     * @param url Required. The URL to get a preview of.
+     * @param ts The preferred point in time to return a preview for. The server may return a newer version
+     * if it does not have the requested version available.
+     */
+    @GET(NetworkConstants.URI_API_MEDIA_PREFIX_PATH_R0 + "preview_url")
+    fun getPreviewUrlData(@Query("url") url: String, @Query("ts") ts: Long?): Call<JsonDict>
+}

matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/session/media/MediaModule.kt

@@ -0,0 +1,50 @@
+/*
+ * 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.media
+
+import dagger.Binds
+import dagger.Module
+import dagger.Provides
+import org.matrix.android.sdk.api.session.media.MediaService
+import org.matrix.android.sdk.internal.session.SessionScope
+import retrofit2.Retrofit
+
+@Module
+internal abstract class MediaModule {
+
+    @Module
+    companion object {
+        @Provides
+        @JvmStatic
+        @SessionScope
+        fun providesMediaAPI(retrofit: Retrofit): MediaAPI {
+            return retrofit.create(MediaAPI::class.java)
+        }
+    }
+
+    @Binds
+    abstract fun bindMediaService(service: DefaultMediaService): MediaService
+
+    @Binds
+    abstract fun bindGetRawPreviewUrlTask(task: DefaultGetRawPreviewUrlTask): GetRawPreviewUrlTask
+
+    @Binds
+    abstract fun bindGetPreviewUrlTask(task: DefaultGetPreviewUrlTask): GetPreviewUrlTask
+
+    @Binds
+    abstract fun bindClearMediaCacheTask(task: DefaultClearPreviewUrlCacheTask): ClearPreviewUrlCacheTask
+}

matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/session/media/PreviewUrlMapper.kt

@@ -0,0 +1,31 @@
+/*
+ * 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.media
+
+import org.matrix.android.sdk.api.session.media.PreviewUrlData
+import org.matrix.android.sdk.internal.database.model.PreviewUrlCacheEntity
+
+/**
+ * PreviewUrlCacheEntity -> PreviewUrlData
+ */
+internal fun PreviewUrlCacheEntity.toDomain() = PreviewUrlData(
+        url = urlFromServer ?: url,
+        siteName = siteName,
+        title = title,
+        description = description,
+        mxcUrl = mxcUrl
+)

matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/session/media/UrlsExtractor.kt

@@ -0,0 +1,44 @@
+/*
+ * 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.media
+
+import android.util.Patterns
+import org.matrix.android.sdk.api.session.events.model.Event
+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.message.MessageContent
+import org.matrix.android.sdk.api.session.room.model.message.MessageType
+import javax.inject.Inject
+
+internal class UrlsExtractor @Inject constructor() {
+    // Sadly Patterns.WEB_URL_WITH_PROTOCOL is not public so filter the protocol later
+    private val urlRegex = Patterns.WEB_URL.toRegex()
+
+    fun extract(event: Event): List<String> {
+        return event.takeIf { it.getClearType() == EventType.MESSAGE }
+                ?.getClearContent()
+                ?.toModel<MessageContent>()
+                ?.takeIf { it.msgType == MessageType.MSGTYPE_TEXT || it.msgType == MessageType.MSGTYPE_EMOTE }
+                ?.body
+                ?.let { urlRegex.findAll(it) }
+                ?.map { it.value }
+                ?.filter { it.startsWith("https://") || it.startsWith("http://") }
+                ?.distinct()
+                ?.toList()
+                .orEmpty()
+    }
+}

matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/util/LruCache.kt

@@ -0,0 +1,24 @@
+/*
+ * 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.util
+
+import androidx.collection.LruCache
+
+@Suppress("NULLABLE_TYPE_PARAMETER_AGAINST_NOT_NULL_TYPE_PARAMETER")
+internal inline fun <K, V> LruCache<K, V>.getOrPut(key: K, defaultValue: () -> V): V {
+    return get(key) ?: defaultValue().also { put(key, it) }
+}

vector/src/main/java/im/vector/app/core/ui/views/JumpToReadMarkerView.kt

@@ -1,19 +1,17 @@
 /*
-
+ * Copyright 2019 New Vector Ltd
-  * Copyright 2019 New Vector Ltd
+ *
-  *
+ * Licensed under the Apache License, Version 2.0 (the "License");
-  * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
-  * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
-  * You may obtain a copy of the License at
+ *
-  *
+ *     http://www.apache.org/licenses/LICENSE-2.0
-  *     http://www.apache.org/licenses/LICENSE-2.0
+ *
-  *
+ * Unless required by applicable law or agreed to in writing, software
-  * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
-  * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
-  * See the License for the specific language governing permissions and
+ * limitations under the License.
-  * limitations under the License.
-
  */
 
 package im.vector.app.core.ui.views

vector/src/main/java/im/vector/app/core/utils/Debouncer.kt

@@ -1,19 +1,17 @@
 /*
-
+ * Copyright 2019 New Vector Ltd
-  * Copyright 2019 New Vector Ltd
+ *
-  *
+ * Licensed under the Apache License, Version 2.0 (the "License");
-  * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
-  * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
-  * You may obtain a copy of the License at
+ *
-  *
+ *     http://www.apache.org/licenses/LICENSE-2.0
-  *     http://www.apache.org/licenses/LICENSE-2.0
+ *
-  *
+ * Unless required by applicable law or agreed to in writing, software
-  * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
-  * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
-  * See the License for the specific language governing permissions and
+ * limitations under the License.
-  * limitations under the License.
-
  */
 package im.vector.app.core.utils
 

vector/src/main/java/im/vector/app/core/utils/Handler.kt

@@ -1,19 +1,17 @@
 /*
-
+ * Copyright 2019 New Vector Ltd
-  * Copyright 2019 New Vector Ltd
+ *
-  *
+ * Licensed under the Apache License, Version 2.0 (the "License");
-  * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
-  * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
-  * You may obtain a copy of the License at
+ *
-  *
+ *     http://www.apache.org/licenses/LICENSE-2.0
-  *     http://www.apache.org/licenses/LICENSE-2.0
+ *
-  *
+ * Unless required by applicable law or agreed to in writing, software
-  * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
-  * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
-  * See the License for the specific language governing permissions and
+ * limitations under the License.
-  * limitations under the License.
-
  */
 
 package im.vector.app.core.utils

vector/src/main/java/im/vector/app/features/home/room/detail/RoomDetailAction.kt

@@ -98,4 +98,7 @@ sealed class RoomDetailAction : VectorViewModelAction {
     data class SetAvatarAction(val newAvatarUri: Uri, val newAvatarFileName: String) : RoomDetailAction()
     object QuickActionSetTopic : RoomDetailAction()
     data class ShowRoomAvatarFullScreen(val matrixItem: MatrixItem?, val transitionView: View?) : RoomDetailAction()
+
+    // Preview URL
+    data class DoNotShowPreviewUrlFor(val eventId: String, val url: String) : RoomDetailAction()
 }

vector/src/main/java/im/vector/app/features/home/room/detail/RoomDetailFragment.kt

@@ -140,6 +140,7 @@ import im.vector.app.features.home.room.detail.timeline.item.MessageInformationD
 import im.vector.app.features.home.room.detail.timeline.item.MessageTextItem
 import im.vector.app.features.home.room.detail.timeline.item.ReadReceiptData
 import im.vector.app.features.home.room.detail.timeline.reactions.ViewReactionsBottomSheet
+import im.vector.app.features.home.room.detail.timeline.url.PreviewUrlRetriever
 import im.vector.app.features.home.room.detail.widget.RoomWidgetsBottomSheet
 import im.vector.app.features.html.EventHtmlRenderer
 import im.vector.app.features.html.PillImageSpan
@@ -1615,6 +1616,10 @@ class RoomDetailFragment @Inject constructor(
         roomDetailViewModel.handle(itemAction)
     }
 
+    override fun getPreviewUrlRetriever(): PreviewUrlRetriever {
+        return roomDetailViewModel.previewUrlRetriever
+    }
+
     override fun onRoomCreateLinkClicked(url: String) {
         permalinkHandler
                 .launch(requireContext(), url, object : NavigationInterceptor {
@@ -1637,6 +1642,14 @@ class RoomDetailFragment @Inject constructor(
         roomDetailViewModel.handle(RoomDetailAction.EnterTrackingUnreadMessagesState)
     }
 
+    override fun onPreviewUrlClicked(url: String) {
+        onUrlClicked(url, url)
+    }
+
+    override fun onPreviewUrlCloseClicked(eventId: String, url: String) {
+        roomDetailViewModel.handle(RoomDetailAction.DoNotShowPreviewUrlFor(eventId, url))
+    }
+
     private fun onShareActionClicked(action: EventSharedAction.Share) {
         if (action.messageContent is MessageTextContent) {
             shareText(requireContext(), action.messageContent.body)

vector/src/main/java/im/vector/app/features/home/room/detail/RoomDetailViewModel.kt

@@ -40,6 +40,7 @@ import im.vector.app.features.home.room.detail.composer.rainbow.RainbowGenerator
 import im.vector.app.features.home.room.detail.sticker.StickerPickerActionHandler
 import im.vector.app.features.home.room.detail.timeline.helper.RoomSummaryHolder
 import im.vector.app.features.home.room.detail.timeline.helper.TimelineSettingsFactory
+import im.vector.app.features.home.room.detail.timeline.url.PreviewUrlRetriever
 import im.vector.app.features.home.room.typing.TypingHelper
 import im.vector.app.features.powerlevel.PowerLevelsObservableFactory
 import im.vector.app.features.raw.wellknown.getElementWellknown
@@ -125,6 +126,9 @@ class RoomDetailViewModel @AssistedInject constructor(
     private var timelineEvents = PublishRelay.create<List<TimelineEvent>>()
     val timeline = room.createTimeline(eventId, timelineSettings)
 
+    // Same lifecycle than the ViewModel (survive to screen rotation)
+    val previewUrlRetriever = PreviewUrlRetriever(session)
+
     // Slot to keep a pending action during permission request
     var pendingAction: RoomDetailAction? = null
 
@@ -277,9 +281,14 @@ class RoomDetailViewModel @AssistedInject constructor(
                         RoomDetailViewEvents.ShowRoomAvatarFullScreen(action.matrixItem, action.transitionView)
                 )
             }
+            is RoomDetailAction.DoNotShowPreviewUrlFor           -> handleDoNotShowPreviewUrlFor(action)
         }.exhaustive
     }
 
+    private fun handleDoNotShowPreviewUrlFor(action: RoomDetailAction.DoNotShowPreviewUrlFor) {
+        previewUrlRetriever.doNotShowPreviewUrlFor(action.eventId, action.url)
+    }
+
     private fun handleSetNewAvatar(action: RoomDetailAction.SetAvatarAction) {
         viewModelScope.launch(Dispatchers.IO) {
             try {
@@ -1336,6 +1345,17 @@ class RoomDetailViewModel @AssistedInject constructor(
 
     override fun onTimelineUpdated(snapshot: List<TimelineEvent>) {
         timelineEvents.accept(snapshot)
+
+        // PreviewUrl
+        if (vectorPreferences.showUrlPreviews()) {
+            withState { state ->
+                snapshot
+                        .takeIf { state.asyncRoomSummary.invoke()?.isEncrypted == false }
+                        ?.forEach {
+                            previewUrlRetriever.getPreviewUrl(it.root, viewModelScope)
+                        }
+            }
+        }
     }
 
     override fun onTimelineFailure(throwable: Throwable) {

vector/src/main/java/im/vector/app/features/home/room/detail/timeline/TimelineEventController.kt

@@ -48,6 +48,7 @@ import im.vector.app.features.home.room.detail.timeline.item.DaySeparatorItem_
 import im.vector.app.features.home.room.detail.timeline.item.MessageInformationData
 import im.vector.app.features.home.room.detail.timeline.item.ReadReceiptData
 import im.vector.app.features.home.room.detail.timeline.item.TimelineReadMarkerItem_
+import im.vector.app.features.home.room.detail.timeline.url.PreviewUrlRetriever
 import im.vector.app.features.media.ImageContentRenderer
 import im.vector.app.features.media.VideoContentRenderer
 import im.vector.app.features.settings.VectorPreferences
@@ -76,7 +77,13 @@ class TimelineEventController @Inject constructor(private val dateFormatter: Vec
                                                   private val backgroundHandler: Handler
 ) : EpoxyController(backgroundHandler, backgroundHandler), Timeline.Listener, EpoxyController.Interceptor {
 
-    interface Callback : BaseCallback, ReactionPillCallback, AvatarCallback, UrlClickCallback, ReadReceiptsCallback {
+    interface Callback :
+            BaseCallback,
+            ReactionPillCallback,
+            AvatarCallback,
+            UrlClickCallback,
+            ReadReceiptsCallback,
+            PreviewUrlCallback {
         fun onLoadMore(direction: Timeline.Direction)
         fun onEventInvisible(event: TimelineEvent)
         fun onEventVisible(event: TimelineEvent)
@@ -91,6 +98,8 @@ class TimelineEventController @Inject constructor(private val dateFormatter: Vec
 
         // TODO move all callbacks to this?
         fun onTimelineItemAction(itemAction: RoomDetailAction)
+
+        fun getPreviewUrlRetriever(): PreviewUrlRetriever
     }
 
     interface ReactionPillCallback {
@@ -118,6 +127,11 @@ class TimelineEventController @Inject constructor(private val dateFormatter: Vec
         fun onUrlLongClicked(url: String): Boolean
     }
 
+    interface PreviewUrlCallback {
+        fun onPreviewUrlClicked(url: String)
+        fun onPreviewUrlCloseClicked(eventId: String, url: String)
+    }
+
     // Map eventId to adapter position
     private val adapterPositionMapping = HashMap<String, Int>()
     private val modelCache = arrayListOf<CacheItemData?>()

vector/src/main/java/im/vector/app/features/home/room/detail/timeline/factory/MessageItemFactory.kt

@@ -146,16 +146,16 @@ class MessageItemFactory @Inject constructor(
 //        val all = event.root.toContent()
 //        val ev = all.toModel<Event>()
         return when (messageContent) {
-            is MessageEmoteContent -> buildEmoteMessageItem(messageContent, informationData, highlight, callback, attributes)
+            is MessageEmoteContent               -> buildEmoteMessageItem(messageContent, informationData, highlight, callback, attributes)
-            is MessageTextContent -> buildItemForTextContent(messageContent, informationData, highlight, callback, attributes)
+            is MessageTextContent                -> buildItemForTextContent(messageContent, informationData, highlight, callback, attributes)
-            is MessageImageInfoContent -> buildImageMessageItem(messageContent, informationData, highlight, callback, attributes)
+            is MessageImageInfoContent           -> buildImageMessageItem(messageContent, informationData, highlight, callback, attributes)
-            is MessageNoticeContent -> buildNoticeMessageItem(messageContent, informationData, highlight, callback, attributes)
+            is MessageNoticeContent              -> buildNoticeMessageItem(messageContent, informationData, highlight, callback, attributes)
-            is MessageVideoContent -> buildVideoMessageItem(messageContent, informationData, highlight, callback, attributes)
+            is MessageVideoContent               -> buildVideoMessageItem(messageContent, informationData, highlight, callback, attributes)
-            is MessageFileContent -> buildFileMessageItem(messageContent, highlight, attributes)
+            is MessageFileContent                -> buildFileMessageItem(messageContent, highlight, attributes)
-            is MessageAudioContent -> buildAudioMessageItem(messageContent, informationData, highlight, attributes)
+            is MessageAudioContent               -> buildAudioMessageItem(messageContent, informationData, highlight, attributes)
             is MessageVerificationRequestContent -> buildVerificationRequestMessageItem(messageContent, informationData, highlight, callback, attributes)
-            is MessageOptionsContent -> buildOptionsMessageItem(messageContent, informationData, highlight, callback, attributes)
+            is MessageOptionsContent             -> buildOptionsMessageItem(messageContent, informationData, highlight, callback, attributes)
-            is MessagePollResponseContent -> noticeItemFactory.create(event, highlight, roomSummaryHolder.roomSummary, callback)
+            is MessagePollResponseContent        -> noticeItemFactory.create(event, highlight, roomSummaryHolder.roomSummary, callback)
             else                                 -> buildNotHandledMessageItem(messageContent, informationData, highlight, callback, attributes)
         }
     }
@@ -166,7 +166,7 @@ class MessageItemFactory @Inject constructor(
                                         callback: TimelineEventController.Callback?,
                                         attributes: AbsMessageItem.Attributes): VectorEpoxyModel<*>? {
         return when (messageContent.optionType) {
-            OPTION_TYPE_POLL -> {
+            OPTION_TYPE_POLL    -> {
                 MessagePollItem_()
                         .attributes(attributes)
                         .callback(callback)
@@ -378,7 +378,7 @@ class MessageItemFactory @Inject constructor(
             val codeVisitor = CodeVisitor()
             codeVisitor.visit(localFormattedBody)
             when (codeVisitor.codeKind) {
-                CodeVisitor.Kind.BLOCK -> {
+                CodeVisitor.Kind.BLOCK  -> {
                     val codeFormattedBlock = htmlRenderer.get().render(localFormattedBody)
                     if (codeFormattedBlock == null) {
                         buildFormattedTextItem(messageContent, informationData, highlight, callback, attributes)
@@ -394,7 +394,7 @@ class MessageItemFactory @Inject constructor(
                         buildMessageTextItem(codeFormatted, false, informationData, highlight, callback, attributes)
                     }
                 }
-                CodeVisitor.Kind.NONE -> {
+                CodeVisitor.Kind.NONE   -> {
                     buildFormattedTextItem(messageContent, informationData, highlight, callback, attributes)
                 }
             }
@@ -431,6 +431,9 @@ class MessageItemFactory @Inject constructor(
         }
                 .useBigFont(linkifiedBody.length <= MAX_NUMBER_OF_EMOJI_FOR_BIG_FONT * 2 && containsOnlyEmojis(linkifiedBody.toString()))
                 .searchForPills(isFormatted)
+                .previewUrlRetriever(callback?.getPreviewUrlRetriever())
+                .imageContentRenderer(imageContentRenderer)
+                .previewUrlCallback(callback)
                 .leftGuideline(avatarSizeProvider.leftGuideline)
                 .attributes(attributes)
                 .highlighted(highlight)
@@ -536,6 +539,9 @@ class MessageItemFactory @Inject constructor(
                     }
                 }
                 .leftGuideline(avatarSizeProvider.leftGuideline)
+                .previewUrlRetriever(callback?.getPreviewUrlRetriever())
+                .imageContentRenderer(imageContentRenderer)
+                .previewUrlCallback(callback)
                 .attributes(attributes)
                 .highlighted(highlight)
                 .movementMethod(createLinkMovementMethod(callback))

vector/src/main/java/im/vector/app/features/home/room/detail/timeline/helper/MessageInformationDataFactory.kt

@@ -1,19 +1,17 @@
 /*
-
+ * Copyright 2019 New Vector Ltd
-  * Copyright 2019 New Vector Ltd
+ *
-  *
+ * Licensed under the Apache License, Version 2.0 (the "License");
-  * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
-  * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
-  * You may obtain a copy of the License at
+ *
-  *
+ *     http://www.apache.org/licenses/LICENSE-2.0
-  *     http://www.apache.org/licenses/LICENSE-2.0
+ *
-  *
+ * Unless required by applicable law or agreed to in writing, software
-  * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
-  * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
-  * See the License for the specific language governing permissions and
+ * limitations under the License.
-  * limitations under the License.
-
  */
 
 package im.vector.app.features.home.room.detail.timeline.helper

vector/src/main/java/im/vector/app/features/home/room/detail/timeline/helper/MessageItemAttributesFactory.kt

@@ -1,19 +1,17 @@
 /*
-
+ * Copyright 2019 New Vector Ltd
-  * Copyright 2019 New Vector Ltd
+ *
-  *
+ * Licensed under the Apache License, Version 2.0 (the "License");
-  * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
-  * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
-  * You may obtain a copy of the License at
+ *
-  *
+ *     http://www.apache.org/licenses/LICENSE-2.0
-  *     http://www.apache.org/licenses/LICENSE-2.0
+ *
-  *
+ * Unless required by applicable law or agreed to in writing, software
-  * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
-  * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
-  * See the License for the specific language governing permissions and
+ * limitations under the License.
-  * limitations under the License.
-
  */
 package im.vector.app.features.home.room.detail.timeline.helper
 

vector/src/main/java/im/vector/app/features/home/room/detail/timeline/item/MessageTextItem.kt

@@ -23,7 +23,12 @@ import androidx.core.widget.TextViewCompat
 import com.airbnb.epoxy.EpoxyAttribute
 import com.airbnb.epoxy.EpoxyModelClass
 import im.vector.app.R
+import im.vector.app.features.home.room.detail.timeline.TimelineEventController
 import im.vector.app.features.home.room.detail.timeline.tools.findPillsAndProcess
+import im.vector.app.features.home.room.detail.timeline.url.PreviewUrlRetriever
+import im.vector.app.features.home.room.detail.timeline.url.PreviewUrlUiState
+import im.vector.app.features.home.room.detail.timeline.url.PreviewUrlView
+import im.vector.app.features.media.ImageContentRenderer
 
 @EpoxyModelClass(layout = R.layout.item_timeline_event_base)
 abstract class MessageTextItem : AbsMessageItem<MessageTextItem.Holder>() {
@@ -37,10 +42,27 @@ abstract class MessageTextItem : AbsMessageItem<MessageTextItem.Holder>() {
     @EpoxyAttribute
     var useBigFont: Boolean = false
 
+    @EpoxyAttribute
+    var previewUrlRetriever: PreviewUrlRetriever? = null
+
+    @EpoxyAttribute
+    var previewUrlCallback: TimelineEventController.PreviewUrlCallback? = null
+
+    @EpoxyAttribute
+    var imageContentRenderer: ImageContentRenderer? = null
+
     @EpoxyAttribute(EpoxyAttribute.Option.DoNotHash)
     var movementMethod: MovementMethod? = null
 
+    private val previewUrlViewUpdater = PreviewUrlViewUpdater()
+
     override fun bind(holder: Holder) {
+        // Preview URL
+        previewUrlViewUpdater.previewUrlView = holder.previewUrlView
+        previewUrlViewUpdater.imageContentRenderer = imageContentRenderer
+        previewUrlRetriever?.addListener(attributes.informationData.eventId, previewUrlViewUpdater)
+        holder.previewUrlView.delegate = previewUrlCallback
+
         if (useBigFont) {
             holder.messageView.textSize = 44F
         } else {
@@ -65,12 +87,29 @@ abstract class MessageTextItem : AbsMessageItem<MessageTextItem.Holder>() {
         holder.messageView.setTextFuture(textFuture)
     }
 
+    override fun unbind(holder: Holder) {
+        super.unbind(holder)
+        previewUrlViewUpdater.previewUrlView = null
+        previewUrlViewUpdater.imageContentRenderer = null
+        previewUrlRetriever?.removeListener(attributes.informationData.eventId, previewUrlViewUpdater)
+    }
+
     override fun getViewType() = STUB_ID
 
     class Holder : AbsMessageItem.Holder(STUB_ID) {
         val messageView by bind<AppCompatTextView>(R.id.messageTextView)
+        val previewUrlView by bind<PreviewUrlView>(R.id.messageUrlPreview)
     }
 
+    inner class PreviewUrlViewUpdater : PreviewUrlRetriever.PreviewUrlRetrieverListener {
+        var previewUrlView: PreviewUrlView? = null
+        var imageContentRenderer: ImageContentRenderer? = null
+
+        override fun onStateUpdated(state: PreviewUrlUiState) {
+            val safeImageContentRenderer = imageContentRenderer ?: return
+            previewUrlView?.render(state, safeImageContentRenderer)
+        }
+    }
     companion object {
         private const val STUB_ID = R.id.messageContentTextStub
     }

vector/src/main/java/im/vector/app/features/home/room/detail/timeline/url/PreviewUrlRetriever.kt

@@ -0,0 +1,127 @@
+/*
+ * 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.home.room.detail.timeline.url
+
+import im.vector.app.BuildConfig
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.launch
+import org.matrix.android.sdk.api.cache.CacheStrategy
+import org.matrix.android.sdk.api.session.Session
+import org.matrix.android.sdk.api.session.events.model.Event
+
+class PreviewUrlRetriever(session: Session) {
+    private val mediaService = session.mediaService()
+
+    private val data = mutableMapOf<String, PreviewUrlUiState>()
+    private val listeners = mutableMapOf<String, MutableSet<PreviewUrlRetrieverListener>>()
+
+    // In memory list
+    private val blockedUrl = mutableSetOf<String>()
+
+    fun getPreviewUrl(event: Event, coroutineScope: CoroutineScope) {
+        val eventId = event.eventId ?: return
+
+        synchronized(data) {
+            if (data[eventId] == null) {
+                // Keep only the first URL for the moment
+                val url = mediaService.extractUrls(event)
+                        .firstOrNull()
+                        ?.takeIf { it !in blockedUrl }
+                if (url == null) {
+                    updateState(eventId, PreviewUrlUiState.NoUrl)
+                } else {
+                    updateState(eventId, PreviewUrlUiState.Loading)
+                }
+                url
+            } else {
+                // Already handled
+                null
+            }
+        }?.let { urlToRetrieve ->
+            coroutineScope.launch {
+                runCatching {
+                    mediaService.getPreviewUrl(
+                            url = urlToRetrieve,
+                            timestamp = null,
+                            cacheStrategy = if (BuildConfig.DEBUG) CacheStrategy.NoCache else CacheStrategy.TtlCache(CACHE_VALIDITY, false)
+                    )
+                }.fold(
+                        {
+                            synchronized(data) {
+                                // Blocked after the request has been sent?
+                                if (urlToRetrieve in blockedUrl) {
+                                    updateState(eventId, PreviewUrlUiState.NoUrl)
+                                } else {
+                                    updateState(eventId, PreviewUrlUiState.Data(eventId, urlToRetrieve, it))
+                                }
+                            }
+                        },
+                        {
+                            synchronized(data) {
+                                updateState(eventId, PreviewUrlUiState.Error(it))
+                            }
+                        }
+                )
+            }
+        }
+    }
+
+    fun doNotShowPreviewUrlFor(eventId: String, url: String) {
+        blockedUrl.add(url)
+
+        // Notify the listener
+        synchronized(data) {
+            data[eventId]
+                    ?.takeIf { it is PreviewUrlUiState.Data && it.url == url }
+                    ?.let {
+                        updateState(eventId, PreviewUrlUiState.NoUrl)
+                    }
+        }
+    }
+
+    private fun updateState(eventId: String, state: PreviewUrlUiState) {
+        data[eventId] = state
+        // Notify the listener
+        listeners[eventId].orEmpty().forEach {
+            it.onStateUpdated(state)
+        }
+    }
+
+    // Called by the Epoxy item during binding
+    fun addListener(key: String, listener: PreviewUrlRetrieverListener) {
+        listeners.getOrPut(key) { mutableSetOf() }.add(listener)
+
+        // Give the current state if any
+        synchronized(data) {
+            listener.onStateUpdated(data[key] ?: PreviewUrlUiState.Unknown)
+        }
+    }
+
+    // Called by the Epoxy item during unbinding
+    fun removeListener(key: String, listener: PreviewUrlRetrieverListener) {
+        listeners[key]?.remove(listener)
+    }
+
+    interface PreviewUrlRetrieverListener {
+        fun onStateUpdated(state: PreviewUrlUiState)
+    }
+
+    companion object {
+        // One week in millis
+        private const val CACHE_VALIDITY: Long = 7 * 24 * 3_600 * 1_000
+    }
+}

vector/src/main/java/im/vector/app/features/home/room/detail/timeline/url/PreviewUrlUiState.kt

@@ -0,0 +1,41 @@
+/*
+ * 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.home.room.detail.timeline.url
+
+import org.matrix.android.sdk.api.session.media.PreviewUrlData
+
+/**
+ * The state representing a preview url UI state for an Event
+ */
+sealed class PreviewUrlUiState {
+    // No info
+    object Unknown : PreviewUrlUiState()
+
+    // The event does not contain any URLs
+    object NoUrl : PreviewUrlUiState()
+
+    // Loading
+    object Loading : PreviewUrlUiState()
+
+    // Error
+    data class Error(val throwable: Throwable) : PreviewUrlUiState()
+
+    // PreviewUrl data
+    data class Data(val eventId: String,
+                    val url: String,
+                    val previewUrlData: PreviewUrlData) : PreviewUrlUiState()
+}

vector/src/main/java/im/vector/app/features/home/room/detail/timeline/url/PreviewUrlView.kt

@@ -0,0 +1,141 @@
+/*
+ * 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.home.room.detail.timeline.url
+
+import android.content.Context
+import android.util.AttributeSet
+import android.view.View
+import android.widget.ImageView
+import android.widget.TextView
+import androidx.constraintlayout.widget.ConstraintLayout
+import androidx.core.view.isVisible
+import butterknife.BindView
+import butterknife.ButterKnife
+import im.vector.app.R
+import im.vector.app.core.extensions.setTextOrHide
+import im.vector.app.features.home.room.detail.timeline.TimelineEventController
+import im.vector.app.features.media.ImageContentRenderer
+import org.matrix.android.sdk.api.extensions.orFalse
+import org.matrix.android.sdk.api.session.media.PreviewUrlData
+
+/**
+ * A View to display a PreviewUrl and some other state
+ */
+class PreviewUrlView @JvmOverloads constructor(
+        context: Context,
+        attrs: AttributeSet? = null,
+        defStyleAttr: Int = 0
+) : ConstraintLayout(context, attrs, defStyleAttr), View.OnClickListener {
+
+    @BindView(R.id.url_preview_title)
+    lateinit var titleView: TextView
+
+    @BindView(R.id.url_preview_image)
+    lateinit var imageView: ImageView
+
+    @BindView(R.id.url_preview_description)
+    lateinit var descriptionView: TextView
+
+    @BindView(R.id.url_preview_site)
+    lateinit var siteView: TextView
+
+    @BindView(R.id.url_preview_close)
+    lateinit var closeView: View
+
+    var delegate: TimelineEventController.PreviewUrlCallback? = null
+
+    init {
+        setupView()
+    }
+
+    private var state: PreviewUrlUiState = PreviewUrlUiState.Unknown
+
+    /**
+     * This methods is responsible for rendering the view according to the newState
+     *
+     * @param newState the newState representing the view
+     */
+    fun render(newState: PreviewUrlUiState,
+               imageContentRenderer: ImageContentRenderer,
+               force: Boolean = false) {
+        if (newState == state && !force) {
+            return
+        }
+
+        state = newState
+
+        hideAll()
+        when (newState) {
+            PreviewUrlUiState.Unknown,
+            PreviewUrlUiState.NoUrl    -> renderHidden()
+            PreviewUrlUiState.Loading  -> renderLoading()
+            is PreviewUrlUiState.Error -> renderHidden()
+            is PreviewUrlUiState.Data  -> renderData(newState.previewUrlData, imageContentRenderer)
+        }
+    }
+
+    override fun onClick(v: View?) {
+        when (val finalState = state) {
+            is PreviewUrlUiState.Data -> delegate?.onPreviewUrlClicked(finalState.url)
+            else                      -> Unit
+        }
+    }
+
+    private fun onCloseClick() {
+        when (val finalState = state) {
+            is PreviewUrlUiState.Data -> delegate?.onPreviewUrlCloseClicked(finalState.eventId, finalState.url)
+            else                      -> Unit
+        }
+    }
+
+    // PRIVATE METHODS ****************************************************************************************************************************************
+
+    private fun setupView() {
+        inflate(context, R.layout.url_preview, this)
+        ButterKnife.bind(this)
+
+        setOnClickListener(this)
+        closeView.setOnClickListener { onCloseClick() }
+    }
+
+    private fun renderHidden() {
+        isVisible = false
+    }
+
+    private fun renderLoading() {
+        // Just hide for the moment
+        isVisible = false
+    }
+
+    private fun renderData(previewUrlData: PreviewUrlData, imageContentRenderer: ImageContentRenderer) {
+        isVisible = true
+        titleView.setTextOrHide(previewUrlData.title)
+        imageView.isVisible = previewUrlData.mxcUrl?.let { imageContentRenderer.render(it, imageView) }.orFalse()
+        descriptionView.setTextOrHide(previewUrlData.description)
+        siteView.setTextOrHide(previewUrlData.siteName.takeIf { it != previewUrlData.title })
+    }
+
+    /**
+     * Hide all views that are not visible in all state
+     */
+    private fun hideAll() {
+        titleView.isVisible = false
+        imageView.isVisible = false
+        descriptionView.isVisible = false
+        siteView.isVisible = false
+    }
+}

vector/src/main/java/im/vector/app/features/media/ImageContentRenderer.kt

@@ -84,6 +84,19 @@ class ImageContentRenderer @Inject constructor(private val activeSessionHolder:
         STICKER
     }
 
+    /**
+     * For url preview
+     */
+    fun render(mxcUrl: String, imageView: ImageView): Boolean {
+        val contentUrlResolver = activeSessionHolder.getActiveSession().contentUrlResolver()
+        val imageUrl = contentUrlResolver.resolveFullSize(mxcUrl) ?: return false
+
+        GlideApp.with(imageView)
+                .load(imageUrl)
+                .into(imageView)
+        return true
+    }
+
     /**
      * For gallery
      */
@@ -232,7 +245,7 @@ class ImageContentRenderer @Inject constructor(private val activeSessionHolder:
             val contentUrlResolver = activeSessionHolder.getActiveSession().contentUrlResolver()
             val resolvedUrl = when (mode) {
                 Mode.FULL_SIZE,
-                Mode.STICKER   -> resolveUrl(data)
+                Mode.STICKER -> resolveUrl(data)
                 Mode.THUMBNAIL -> contentUrlResolver.resolveThumbnail(data.url, size.width, size.height, ContentUrlResolver.ThumbnailMethod.SCALE)
             }
             // Fallback to base url
@@ -300,7 +313,7 @@ class ImageContentRenderer @Inject constructor(private val activeSessionHolder:
                     finalHeight = min(maxImageWidth * height / width, maxImageHeight)
                     finalWidth = finalHeight * width / height
                 }
-                Mode.STICKER   -> {
+                Mode.STICKER -> {
                     // limit on width
                     val maxWidthDp = min(dimensionConverter.dpToPx(120), maxImageWidth / 2)
                     finalWidth = min(dimensionConverter.dpToPx(width), maxWidthDp)

vector/src/main/java/im/vector/app/features/settings/VectorPreferences.kt

@@ -783,6 +783,15 @@ class VectorPreferences @Inject constructor(private val context: Context) {
         return defaultPrefs.getBoolean(SETTINGS_USE_ANALYTICS_KEY, false)
     }
 
+    /**
+     * Tells if the user wants to see URL previews in the timeline
+     *
+     * @return true if the user wants to see URL previews in the timeline
+     */
+    fun showUrlPreviews(): Boolean {
+        return defaultPrefs.getBoolean(SETTINGS_SHOW_URL_PREVIEW_KEY, true)
+    }
+
     /**
      * Enable or disable the analytics tracking.
      *

vector/src/main/java/im/vector/app/features/settings/VectorSettingsPreferencesFragment.kt

@@ -22,7 +22,6 @@ import android.widget.CheckedTextView
 import android.widget.LinearLayout
 import androidx.appcompat.app.AlertDialog
 import androidx.preference.Preference
-import androidx.preference.SwitchPreference
 import im.vector.app.R
 import im.vector.app.core.extensions.restart
 import im.vector.app.core.preference.VectorListPreference
@@ -64,9 +63,9 @@ class VectorSettingsPreferencesFragment @Inject constructor(
         }
 
         // Url preview
+        /*
+        TODO Note: we keep the setting client side for now
         findPreference<SwitchPreference>(VectorPreferences.SETTINGS_SHOW_URL_PREVIEW_KEY)!!.let {
-            /*
-            TODO
             it.isChecked = session.isURLPreviewEnabled
 
             it.onPreferenceChangeListener = Preference.OnPreferenceChangeListener { _, newValue ->
@@ -100,8 +99,8 @@ class VectorSettingsPreferencesFragment @Inject constructor(
 
                 false
             }
-            */
         }
+        */
 
         // update keep medias period
         findPreference<VectorPreference>(VectorPreferences.SETTINGS_MEDIA_SAVING_PERIOD_KEY)!!.let {

vector/src/main/res/drawable/ic_close_24dp.xml

@@ -0,0 +1,10 @@
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    android:width="25dp"
+    android:height="24dp"
+    android:viewportWidth="25"
+    android:viewportHeight="24">
+    <path
+        android:fillColor="#000000"
+        android:fillType="evenOdd"
+        android:pathData="M17.7929,5.2929C18.1834,4.9024 18.8166,4.9024 19.2071,5.2929C19.5976,5.6834 19.5976,6.3166 19.2071,6.7071L13.9142,12L19.2071,17.2929C19.5976,17.6834 19.5976,18.3166 19.2071,18.7071C18.8166,19.0976 18.1834,19.0976 17.7929,18.7071L12.5,13.4142L7.2071,18.7071C6.8166,19.0976 6.1834,19.0976 5.7929,18.7071C5.4024,18.3166 5.4024,17.6834 5.7929,17.2929L11.0858,12L5.7929,6.7071C5.4024,6.3166 5.4024,5.6834 5.7929,5.2929C6.1834,4.9024 6.8166,4.9024 7.2071,5.2929L12.5,10.5858L17.7929,5.2929Z" />
+</vector>

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

@@ -87,7 +87,6 @@
             android:id="@+id/messageContentTextStub"
             style="@style/TimelineContentStubBaseParams"
             android:layout_height="wrap_content"
-            android:inflatedId="@id/messageTextView"
             android:layout="@layout/item_timeline_event_text_message_stub"
             tools:visibility="visible" />
 

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

@@ -1,9 +1,26 @@
 <?xml version="1.0" encoding="utf-8"?>
-<TextView xmlns:android="http://schemas.android.com/apk/res/android"
+<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:tools="http://schemas.android.com/tools"
-    android:id="@+id/messageTextView"
     android:layout_width="match_parent"
     android:layout_height="wrap_content"
-    android:textColor="?riotx_text_primary"
+    android:orientation="vertical">
-    android:textSize="14sp"
+
-    tools:text="@sample/matrix.json/data/message" />
+    <TextView
+        android:id="@+id/messageTextView"
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        android:textColor="?riotx_text_primary"
+        android:textSize="14sp"
+        tools:text="@sample/matrix.json/data/message" />
+
+    <im.vector.app.features.home.room.detail.timeline.url.PreviewUrlView
+        android:id="@+id/messageUrlPreview"
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        android:layout_marginTop="8dp"
+        android:layout_marginBottom="4dp"
+        android:foreground="?attr/selectableItemBackground"
+        android:visibility="gone"
+        tools:visibility="visible" />
+
+</LinearLayout>

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

@@ -0,0 +1,88 @@
+<?xml version="1.0" encoding="utf-8"?>
+<merge xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto"
+    xmlns:tools="http://schemas.android.com/tools"
+    android:id="@+id/informationUrlPreviewContainer"
+    android:layout_width="match_parent"
+    android:layout_height="wrap_content"
+    tools:parentTag="androidx.constraintlayout.widget.ConstraintLayout">
+
+    <View
+        android:id="@+id/url_preview_left_border"
+        android:layout_width="2dp"
+        android:layout_height="0dp"
+        android:background="?riotx_text_tertiary"
+        app:layout_constraintBottom_toBottomOf="parent"
+        app:layout_constraintStart_toStartOf="parent"
+        app:layout_constraintTop_toTopOf="parent" />
+
+    <TextView
+        android:id="@+id/url_preview_title"
+        android:layout_width="0dp"
+        android:layout_height="wrap_content"
+        android:layout_marginStart="7dp"
+        android:ellipsize="end"
+        android:maxLines="2"
+        android:textColor="?riotx_text_primary"
+        android:textSize="14sp"
+        android:textStyle="bold"
+        app:layout_constraintEnd_toStartOf="@+id/url_preview_close"
+        app:layout_constraintStart_toStartOf="@+id/url_preview_left_border"
+        app:layout_constraintTop_toTopOf="parent"
+        tools:text="Jo Malone denounces her former brand's John Boyega decision" />
+
+    <ImageView
+        android:id="@+id/url_preview_image"
+        android:layout_width="0dp"
+        android:layout_height="157dp"
+        android:layout_marginTop="16dp"
+        android:importantForAccessibility="no"
+        android:scaleType="fitStart"
+        app:layout_constraintEnd_toEndOf="parent"
+        app:layout_constraintStart_toStartOf="@+id/url_preview_title"
+        app:layout_constraintTop_toBottomOf="@+id/url_preview_title"
+        tools:src="@tools:sample/backgrounds/scenic" />
+
+    <TextView
+        android:id="@+id/url_preview_description"
+        android:layout_width="0dp"
+        android:layout_height="wrap_content"
+        android:layout_marginStart="7dp"
+        android:layout_marginTop="8dp"
+        android:ellipsize="end"
+        android:maxLines="4"
+        android:textColor="?riotx_text_secondary"
+        android:textSize="14sp"
+        app:layout_constraintEnd_toEndOf="parent"
+        app:layout_constraintStart_toStartOf="@+id/url_preview_left_border"
+        app:layout_constraintTop_toBottomOf="@+id/url_preview_image"
+        tools:text="The British perfumer says removing actor John Boyega from his own advert was “utterly despicable”." />
+
+    <TextView
+        android:id="@+id/url_preview_site"
+        android:layout_width="0dp"
+        android:layout_height="wrap_content"
+        android:layout_marginStart="7dp"
+        android:layout_marginTop="4dp"
+        android:ellipsize="end"
+        android:maxLines="1"
+        android:singleLine="true"
+        android:textColor="?riotx_text_tertiary"
+        android:textSize="14sp"
+        app:layout_constraintEnd_toEndOf="parent"
+        app:layout_constraintStart_toStartOf="@+id/url_preview_left_border"
+        app:layout_constraintTop_toBottomOf="@+id/url_preview_description"
+        tools:text="BBC News" />
+
+    <ImageView
+        android:id="@+id/url_preview_close"
+        android:layout_width="@dimen/layout_touch_size"
+        android:layout_height="@dimen/layout_touch_size"
+        android:scaleType="center"
+        android:src="@drawable/ic_close_24dp"
+        app:layout_constraintEnd_toEndOf="parent"
+        app:layout_constraintTop_toTopOf="parent"
+        app:tint="?riotx_text_secondary"
+        tools:ignore="MissingPrefix" />
+
+</merge>

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

@@ -107,6 +107,13 @@
     <color name="riotx_text_secondary_dark">#FFA1B2D1</color>
     <color name="riotx_text_secondary_black">#FFA1B2D1</color>
 
+    <attr name="riotx_text_tertiary" format="color" />
+    <color name="riotx_text_tertiary_light">#FF8D99A5</color>
+    <!-- TODO Pick color from Figma, I do not know where to find it -->
+    <color name="riotx_text_tertiary_dark">#FF8D99A5</color>
+    <!-- TODO Pick color from Figma, I do not know where to find it -->
+    <color name="riotx_text_tertiary_black">#FF8D99A5</color>
+
     <attr name="riotx_text_primary_body_contrast" format="color" />
     <color name="riotx_text_primary_body_contrast_light">#FF61708B</color>
     <color name="riotx_text_primary_body_contrast_dark">#FFA1B2D1</color>

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

@@ -18,6 +18,7 @@
         <item name="riotx_header_panel_text_secondary">@color/riotx_header_panel_text_secondary_black</item>
         <item name="riotx_text_primary">@color/riotx_text_primary_black</item>
         <item name="riotx_text_secondary">@color/riotx_text_secondary_black</item>
+        <item name="riotx_text_tertiary">@color/riotx_text_tertiary_black</item>
         <item name="riotx_text_primary_body_contrast">@color/riotx_text_primary_body_contrast_black</item>
         <item name="riotx_android_secondary">@color/riotx_android_secondary_black</item>
         <item name="riotx_search_placeholder">@color/riotx_search_placeholder_black</item>

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

@@ -16,6 +16,7 @@
         <item name="riotx_header_panel_text_secondary">@color/riotx_header_panel_text_secondary_dark</item>
         <item name="riotx_text_primary">@color/riotx_text_primary_dark</item>
         <item name="riotx_text_secondary">@color/riotx_text_secondary_dark</item>
+        <item name="riotx_text_tertiary">@color/riotx_text_tertiary_dark</item>
         <item name="riotx_text_primary_body_contrast">@color/riotx_text_primary_body_contrast_dark</item>
         <item name="riotx_android_secondary">@color/riotx_android_secondary_dark</item>
         <item name="riotx_search_placeholder">@color/riotx_search_placeholder_dark</item>

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

@@ -16,6 +16,7 @@
         <item name="riotx_header_panel_text_secondary">@color/riotx_header_panel_text_secondary_light</item>
         <item name="riotx_text_primary">@color/riotx_text_primary_light</item>
         <item name="riotx_text_secondary">@color/riotx_text_secondary_light</item>
+        <item name="riotx_text_tertiary">@color/riotx_text_tertiary_light</item>
         <item name="riotx_text_primary_body_contrast">@color/riotx_text_primary_body_contrast_light</item>
         <item name="riotx_android_secondary">@color/riotx_android_secondary_light</item>
         <item name="riotx_search_placeholder">@color/riotx_search_placeholder_light</item>

vector/src/main/res/xml/vector_settings_preferences.xml

@@ -57,8 +57,7 @@
             android:defaultValue="true"
             android:key="SETTINGS_SHOW_URL_PREVIEW_KEY"
             android:summary="@string/settings_inline_url_preview_summary"
-            android:title="@string/settings_inline_url_preview"
+            android:title="@string/settings_inline_url_preview" />
-            app:isPreferenceVisible="@bool/false_not_implemented" />
 
         <im.vector.app.core.preference.VectorSwitchPreference
             android:key="SETTINGS_ALWAYS_SHOW_TIMESTAMPS_KEY"