Add support for link generated by matrix.to website.

app/src/main/AndroidManifest.xml

@@ -87,7 +87,7 @@
                 <data android:host="*.element.io" />
             </intent-filter>
             <!--
-              matrix.to  links
+              matrix.to links
               Note: On Android 12 and higher clicking a web link (that is not an Android App Link) always shows content in a web browser
               https://developer.android.com/training/app-links#web-links
             -->
@@ -100,6 +100,17 @@
                 <data android:scheme="https" />
                 <data android:host="matrix.to" />
             </intent-filter>
+            <!--
+              links from matrix.to website
+            -->
+            <intent-filter>
+                <action android:name="android.intent.action.VIEW" />
+                <category android:name="android.intent.category.DEFAULT" />
+
+                <data android:scheme="element" />
+                <data android:host="user" />
+                <data android:host="room" />
+            </intent-filter>
         </activity>
 
         <provider

libraries/core/src/main/kotlin/io/element/android/libraries/core/extensions/BasicExtensions.kt

@@ -58,3 +58,15 @@ fun String.ellipsize(length: Int): String {
 
     return "${this.take(length)}…"
 }
+
+/**
+ * Replace the old prefix with the new prefix.
+ * If the string does not start with the old prefix, the string is returned as is.
+ */
+fun String.replacePrefix(oldPrefix: String, newPrefix: String): String {
+    return if (startsWith(oldPrefix)) {
+        newPrefix + substring(oldPrefix.length)
+    } else {
+        this
+    }
+}

libraries/matrix/impl/src/main/kotlin/io/element/android/libraries/matrix/impl/permalink/DefaultMatrixToConverter.kt

@@ -19,6 +19,7 @@ package io.element.android.libraries.matrix.impl.permalink
 import android.net.Uri
 import com.squareup.anvil.annotations.ContributesBinding
 import io.element.android.appconfig.MatrixConfiguration
+import io.element.android.libraries.core.extensions.replacePrefix
 import io.element.android.libraries.di.AppScope
 import io.element.android.libraries.matrix.api.permalink.MatrixToConverter
 import javax.inject.Inject
@@ -35,9 +36,14 @@ class DefaultMatrixToConverter @Inject constructor() : MatrixToConverter {
      * - https://riot.im/develop/#/room/#element-android:matrix.org  ->  https://matrix.to/#/#element-android:matrix.org
      * - https://app.element.io/#/room/#element-android:matrix.org   ->  https://matrix.to/#/#element-android:matrix.org
      * - https://www.example.org/#/room/#element-android:matrix.org  ->  https://matrix.to/#/#element-android:matrix.org
+     * Also convert links coming from the matrix.to website:
+     * - element://room/#element-android:matrix.org                  ->  https://matrix.to/#/#element-android:matrix.org
+     * - element://user/@alice:matrix.org                            ->  https://matrix.to/#/@alice:matrix.org
      */
     override fun convert(uri: Uri): Uri? {
         val uriString = uri.toString()
+            // Handle links coming from the matrix.to website.
+            .replacePrefix(MATRIX_TO_CUSTOM_SCHEME_BASE_URL, "https://app.element.io/#/")
         val baseUrl = MatrixConfiguration.MATRIX_TO_PERMALINK_BASE_URL
 
         return when {
@@ -54,7 +60,8 @@ class DefaultMatrixToConverter @Inject constructor() : MatrixToConverter {
     }
 
     companion object {
-        val SUPPORTED_PATHS = listOf(
+        private const val MATRIX_TO_CUSTOM_SCHEME_BASE_URL = "element://"
+        private val SUPPORTED_PATHS = listOf(
             "/#/room/",
             "/#/user/",
             "/#/group/"

libraries/matrix/impl/src/test/kotlin/io/element/android/libraries/matrix/impl/permalink/DefaultMatrixToConverterTest.kt

@@ -53,4 +53,16 @@ class DefaultMatrixToConverterTest {
         val url = Uri.parse("https://element.io/")
         assertThat(DefaultMatrixToConverter().convert(url)).isNull()
     }
+
+    @Test
+    fun `converting url coming from the matrix-to website returns a matrix-to url for room case`() {
+        val url = Uri.parse("element://room/#element-android:matrix.org")
+        assertThat(DefaultMatrixToConverter().convert(url)).isEqualTo(Uri.parse("https://matrix.to/#/#element-android:matrix.org"))
+    }
+
+    @Test
+    fun `converting url coming from the matrix-to website returns a matrix-to url for user case`() {
+        val url = Uri.parse("element://user/@alice:matrix.org")
+        assertThat(DefaultMatrixToConverter().convert(url)).isEqualTo(Uri.parse("https://matrix.to/#/@alice:matrix.org"))
+    }
 }

tools/adb/deeplink_matrixto.sh

@@ -0,0 +1,19 @@
+#! /bin/bash
+#
+# Copyright (c) 2024 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.
+#
+
+adb shell am start -a android.intent.action.VIEW \
+   -d "element://room/%23element-android%3Amatrix.org"