Closes #4979 - Support Fennec web apps (PWAs).

app/src/main/AndroidManifest.xml

@@ -59,6 +59,15 @@
             android:exported="true">
         </activity-alias>
 
+        <!-- Activity alias from Fennec used by PWA launchers on the home screen -->
+        <activity-alias
+            android:name="org.mozilla.gecko.LauncherActivity"
+            android:targetActivity=".IntentReceiverActivity">
+            <intent-filter>
+                <action android:name="org.mozilla.gecko.WEBAPP" />
+            </intent-filter>
+        </activity-alias>
+
         <activity
             android:name=".HomeActivity"
             android:configChanges="keyboard|keyboardHidden|mcc|mnc|orientation|screenSize|layoutDirection|smallestScreenSize|screenLayout"

app/src/main/java/org/mozilla/fenix/components/Components.kt

@@ -54,7 +54,8 @@ class Components(private val context: Context) {
             useCases.searchUseCases,
             core.client,
             core.customTabsStore,
-            migrationStore
+            migrationStore,
+            core.webAppManifestStorage
         )
     }
 

app/src/main/java/org/mozilla/fenix/components/IntentProcessors.kt

@@ -11,13 +11,14 @@ import mozilla.components.feature.customtabs.CustomTabIntentProcessor
 import mozilla.components.feature.customtabs.store.CustomTabsServiceStore
 import mozilla.components.feature.intent.processing.TabIntentProcessor
 import mozilla.components.feature.pwa.ManifestStorage
-import mozilla.components.feature.pwa.intent.WebAppIntentProcessor
 import mozilla.components.feature.pwa.intent.TrustedWebActivityIntentProcessor
+import mozilla.components.feature.pwa.intent.WebAppIntentProcessor
 import mozilla.components.feature.search.SearchUseCases
 import mozilla.components.feature.session.SessionUseCases
 import mozilla.components.support.migration.MigrationIntentProcessor
 import mozilla.components.support.migration.state.MigrationStore
 import org.mozilla.fenix.BuildConfig
+import org.mozilla.fenix.customtabs.FennecWebAppIntentProcessor
 import org.mozilla.fenix.home.intent.FennecBookmarkShortcutsIntentProcessor
 import org.mozilla.fenix.test.Mockable
 
@@ -32,7 +33,8 @@ class IntentProcessors(
     private val searchUseCases: SearchUseCases,
     private val httpClient: Client,
     private val customTabsStore: CustomTabsServiceStore,
-    private val migrationStore: MigrationStore
+    private val migrationStore: MigrationStore,
+    private val manifestStorage: ManifestStorage
 ) {
     /**
      * Provides intent processing functionality for ACTION_VIEW and ACTION_SEND intents.
@@ -66,8 +68,9 @@ class IntentProcessors(
                 apiKey = BuildConfig.DIGITAL_ASSET_LINKS_TOKEN,
                 store = customTabsStore
             ),
-            WebAppIntentProcessor(sessionManager, sessionUseCases.loadUrl, ManifestStorage(context)),
-            FennecBookmarkShortcutsIntentProcessor(sessionManager, sessionUseCases.loadUrl)
+            WebAppIntentProcessor(sessionManager, sessionUseCases.loadUrl, manifestStorage),
+            FennecBookmarkShortcutsIntentProcessor(sessionManager, sessionUseCases.loadUrl),
+            FennecWebAppIntentProcessor(sessionManager, sessionUseCases.loadUrl, manifestStorage)
         )
     }
 

app/src/main/java/org/mozilla/fenix/customtabs/FennecWebAppIntentProcessor.kt

@@ -0,0 +1,91 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+package org.mozilla.fenix.customtabs
+
+import android.content.Intent
+import android.content.Intent.FLAG_ACTIVITY_NEW_DOCUMENT
+import androidx.annotation.VisibleForTesting
+import mozilla.components.browser.session.Session
+import mozilla.components.browser.session.Session.Source
+import mozilla.components.browser.session.SessionManager
+import mozilla.components.concept.engine.EngineSession
+import mozilla.components.concept.engine.manifest.WebAppManifest
+import mozilla.components.concept.engine.manifest.WebAppManifestParser
+import mozilla.components.concept.engine.manifest.getOrNull
+import mozilla.components.feature.intent.ext.putSessionId
+import mozilla.components.feature.intent.processing.IntentProcessor
+import mozilla.components.feature.pwa.ManifestStorage
+import mozilla.components.feature.pwa.ext.putWebAppManifest
+import mozilla.components.feature.pwa.ext.toCustomTabConfig
+import mozilla.components.feature.session.SessionUseCases
+import mozilla.components.support.utils.toSafeIntent
+import org.json.JSONObject
+import java.io.File
+
+/**
+ * Legacy processor for Progressive Web App shortcut intents created by Fennec.
+ */
+class FennecWebAppIntentProcessor(
+    private val sessionManager: SessionManager,
+    private val loadUrlUseCase: SessionUseCases.DefaultLoadUrlUseCase,
+    private val storage: ManifestStorage
+) : IntentProcessor {
+
+    /**
+     * Returns true if this intent should launch a progressive web app created in Fennec.
+     */
+    override fun matches(intent: Intent) =
+        intent.toSafeIntent().action == ACTION_FENNEC_WEBAPP
+
+    /**
+     * Processes the given [Intent] by creating a [Session] with a corresponding web app manifest.
+     *
+     * A custom tab config is also set so a custom tab toolbar can be shown when the user leaves
+     * the scope defined in the manifest.
+     */
+    override suspend fun process(intent: Intent): Boolean {
+        val safeIntent = intent.toSafeIntent()
+        val url = safeIntent.dataString
+
+        return if (!url.isNullOrEmpty() && matches(intent)) {
+            val webAppManifest = storage.loadManifest(url)
+                ?: fromFile(safeIntent.getStringExtra(EXTRA_FENNEC_MANIFEST_PATH))?.also {
+                    storage.saveManifest(it)
+                }
+                ?: return false
+
+            val session = Session(url, private = false, source = Source.HOME_SCREEN)
+            session.webAppManifest = webAppManifest
+            session.customTabConfig = webAppManifest.toCustomTabConfig()
+
+            sessionManager.add(session)
+            loadUrlUseCase(url, session, EngineSession.LoadUrlFlags.external())
+            intent.flags = FLAG_ACTIVITY_NEW_DOCUMENT
+            intent.putSessionId(session.id)
+            intent.putWebAppManifest(webAppManifest)
+
+            true
+        } else {
+            false
+        }
+    }
+
+    @VisibleForTesting
+    internal fun fromFile(path: String?): WebAppManifest? {
+        if (path.isNullOrEmpty()) return null
+
+        // Gecko in Fennec added some add some additional data, such as cached_icon, in
+        // the toplevel object. The actual web app manifest is in the "manifest" field.
+        val manifest = JSONObject(File(path).readText())
+        val manifestField = manifest.getJSONObject("manifest")
+
+        return WebAppManifestParser().parse(manifestField).getOrNull()
+    }
+
+    companion object {
+        const val ACTION_FENNEC_WEBAPP = "org.mozilla.gecko.WEBAPP"
+        const val EXTRA_FENNEC_MANIFEST_PATH = "MANIFEST_PATH"
+    }
+}