Issue mozilla-mobile#7647: Add SessionFeature.release() to allow app …

…to stop rendering engine sessions and release the current one.

components/feature/session/src/main/java/mozilla/components/feature/session/SessionFeature.kt

@@ -56,4 +56,15 @@ class SessionFeature(
     override fun stop() {
         presenter.stop()
     }
+
+    /**
+     * Stops the feature from rendering sessions on the [EngineView] (until explicitly started again)
+     * and releases an already rendering session from the [EngineView].
+     */
+    fun release() {
+        // Once we fully migrated to BrowserStore we may be able to get rid of the need for cleanup().
+        // See https://github.com/mozilla-mobile/android-components/issues/7657
+        presenter.stop()
+        engineView.release()
+    }
 }

components/feature/session/src/test/java/mozilla/components/feature/session/SessionFeatureTest.kt

@@ -278,6 +278,56 @@ class SessionFeatureTest {
         verify(view).release()
     }
 
+    @Test
+    fun `release() stops observing and releases session from view`() {
+        val store = BrowserStore(BrowserState(
+            tabs = listOf(
+                createTab("https://www.mozilla.org", id = "A"),
+                createTab("https://getpocket.com", id = "B"),
+                createTab("https://www.firefox.com", id = "C")
+            ),
+            selectedTabId = "B"
+        ))
+
+        val view: EngineView = mock()
+        val useCases: EngineSessionUseCases = mock()
+        val getOrCreateUseCase: EngineSessionUseCases.GetOrCreateUseCase = mock()
+        doReturn(getOrCreateUseCase).`when`(useCases).getOrCreateEngineSession
+
+        val engineSession: EngineSession = mock()
+        doReturn(engineSession).`when`(getOrCreateUseCase).invoke(ArgumentMatchers.anyString())
+
+        val feature = SessionFeature(store, mock(), useCases, view)
+
+        verify(getOrCreateUseCase, never()).invoke(anyString())
+        verify(view, never()).render(any())
+
+        feature.start()
+
+        testDispatcher.advanceUntilIdle()
+        store.waitUntilIdle()
+
+        verify(getOrCreateUseCase).invoke("B")
+        verify(view).render(engineSession)
+
+        reset(view)
+        reset(getOrCreateUseCase)
+
+        val newEngineSession: EngineSession = mock()
+        doReturn(newEngineSession).`when`(getOrCreateUseCase).invoke(ArgumentMatchers.anyString())
+
+        feature.release()
+
+        verify(view).release()
+
+        store.dispatch(
+            TabListAction.SelectTabAction("A")
+        ).joinBlocking()
+
+        verify(getOrCreateUseCase, never()).invoke("A")
+        verify(view, never()).render(newEngineSession)
+    }
+
     @Test
     fun `Releases when custom tab gets removed`() {
         val store = BrowserStore(BrowserState(

docs/changelog.md

@@ -12,6 +12,9 @@ permalink: /changelog/
 * [Gecko](https://github.com/mozilla-mobile/android-components/blob/master/buildSrc/src/main/java/Gecko.kt)
 * [Configuration](https://github.com/mozilla-mobile/android-components/blob/master/buildSrc/src/main/java/Config.kt)
 
+* **feature-session**
+  * Added `SessionFeature.release()`: Calling this method stops the feature from rendering sessions on the `EngineView` (until explicitly started again) and releases an already rendering session from the `EngineView`.
+
 * **support-ktx**
   * Adds `Bundle.contentEquals` function to check if two bundles are equal.