Closes #3680: Synchronize thumbnails between browser-store and session

components/browser/session/src/main/java/mozilla/components/browser/session/Session.kt

@@ -11,10 +11,12 @@ import mozilla.components.browser.session.engine.request.LoadRequestOption
 import mozilla.components.browser.session.ext.syncDispatch
 import mozilla.components.browser.session.ext.toSecurityInfoState
 import mozilla.components.browser.session.tab.CustomTabConfig
+import mozilla.components.browser.state.action.ContentAction.RemoveThumbnailAction
 import mozilla.components.browser.state.action.ContentAction.UpdateLoadingStateAction
 import mozilla.components.browser.state.action.ContentAction.UpdateProgressAction
 import mozilla.components.browser.state.action.ContentAction.UpdateSecurityInfo
 import mozilla.components.browser.state.action.ContentAction.UpdateSearchTermsAction
+import mozilla.components.browser.state.action.ContentAction.UpdateThumbnailAction
 import mozilla.components.browser.state.action.ContentAction.UpdateTitleAction
 import mozilla.components.browser.state.action.ContentAction.UpdateUrlAction
 import mozilla.components.browser.state.store.BrowserStore
@@ -332,6 +334,9 @@ class Session(
      */
     var thumbnail: Bitmap? by Delegates.observable<Bitmap?>(null) { _, _, new ->
         notifyObservers { onThumbnailChanged(this@Session, new) }
+
+        val action = if (new != null) UpdateThumbnailAction(id, new) else RemoveThumbnailAction(id)
+        store?.syncDispatch(action)
     }
 
     /**

components/browser/session/src/test/java/mozilla/components/browser/session/SessionTest.kt

@@ -676,6 +676,24 @@ class SessionTest {
         verify(observer, never()).onThumbnailChanged(session, emptyThumbnail)
     }
 
+    @Test
+    fun `action is dispatched when thumbnail changes`() {
+        val store: BrowserStore = mock()
+        `when`(store.dispatch(any())).thenReturn(mock())
+
+        val session = Session("https://www.mozilla.org")
+        session.store = store
+
+        val emptyThumbnail = spy(Bitmap::class.java)
+        session.thumbnail = emptyThumbnail
+        verify(store).dispatch(ContentAction.UpdateThumbnailAction(session.id, emptyThumbnail))
+
+        session.thumbnail = null
+        verify(store).dispatch(ContentAction.RemoveThumbnailAction(session.id))
+
+        verifyNoMoreInteractions(store)
+    }
+
     @Test
     fun `session observer has default methods`() {
         val session = Session("")

components/browser/state/src/main/java/mozilla/components/browser/state/action/BrowserAction.kt

@@ -4,6 +4,7 @@
 
 package mozilla.components.browser.state.action
 
+import android.graphics.Bitmap
 import mozilla.components.browser.state.state.BrowserState
 import mozilla.components.browser.state.state.ContentState
 import mozilla.components.browser.state.state.SecurityInfoState
@@ -98,6 +99,11 @@ sealed class CustomTabListAction : BrowserAction() {
  * [BrowserState].
  */
 sealed class ContentAction : BrowserAction() {
+    /**
+     * Removes the thumbnail of the [ContentState] with the given [sessionId].
+     */
+    data class RemoveThumbnailAction(val sessionId: String) : ContentAction()
+
     /**
      * Updates the URL of the [ContentState] with the given [sessionId].
      */
@@ -127,4 +133,9 @@ sealed class ContentAction : BrowserAction() {
      * Updates the [SecurityInfoState] of the [ContentState] with the given [sessionId].
      */
     data class UpdateSecurityInfo(val sessionId: String, val securityInfo: SecurityInfoState) : ContentAction()
+
+    /**
+     * Updates the thumbnail of the [ContentState] with the given [sessionId].
+     */
+    data class UpdateThumbnailAction(val sessionId: String, val thumbnail: Bitmap) : ContentAction()
 }

components/browser/state/src/main/java/mozilla/components/browser/state/reducer/ContentStateReducer.kt

@@ -15,6 +15,9 @@ internal object ContentStateReducer {
      */
     fun reduce(state: BrowserState, action: ContentAction): BrowserState {
         return when (action) {
+            is ContentAction.RemoveThumbnailAction -> updateContentState(state, action.sessionId) {
+                it.copy(thumbnail = null)
+            }
             is ContentAction.UpdateUrlAction -> updateContentState(state, action.sessionId) {
                 it.copy(url = action.url)
             }
@@ -33,6 +36,9 @@ internal object ContentStateReducer {
             is ContentAction.UpdateSecurityInfo -> updateContentState(state, action.sessionId) {
                 it.copy(securityInfo = action.securityInfo)
             }
+            is ContentAction.UpdateThumbnailAction -> updateContentState(state, action.sessionId) {
+                it.copy(thumbnail = action.thumbnail)
+            }
         }
     }
 }

components/browser/state/src/main/java/mozilla/components/browser/state/state/ContentState.kt

@@ -4,6 +4,8 @@
 
 package mozilla.components.browser.state.state
 
+import android.graphics.Bitmap
+
 /**
  * Value type that represents the state of the content within a [SessionState].
  *
@@ -14,8 +16,10 @@ package mozilla.components.browser.state.state
  * @property searchTerms the last used search terms, or an empty string if no
  * search was executed for this session.
  * @property securityInfo the security information as [SecurityInfoState],
- * describing whether or not the current session is for a secure URL, as well
+ * describing whether or not the this session is for a secure URL, as well
  * as the host and SSL certificate authority.
+ * @property thumbnail the last generated [Bitmap] of this session's content, to
+ * be used as a preview in e.g. a tab switcher.
  */
 data class ContentState(
     val url: String,
@@ -24,5 +28,6 @@ data class ContentState(
     val progress: Int = 0,
     val loading: Boolean = false,
     val searchTerms: String = "",
-    val securityInfo: SecurityInfoState = SecurityInfoState()
+    val securityInfo: SecurityInfoState = SecurityInfoState(),
+    val thumbnail: Bitmap? = null
 )

components/browser/state/src/test/java/mozilla/components/browser/state/action/ContentActionTest.kt

@@ -4,6 +4,7 @@
 
 package mozilla.components.browser.state.action
 
+import android.graphics.Bitmap
 import mozilla.components.browser.state.selector.findCustomTab
 import mozilla.components.browser.state.state.BrowserState
 import mozilla.components.browser.state.state.SecurityInfoState
@@ -15,9 +16,11 @@ import mozilla.components.support.test.ext.joinBlocking
 import org.junit.Assert.assertEquals
 import org.junit.Assert.assertFalse
 import org.junit.Assert.assertNotEquals
+import org.junit.Assert.assertNull
 import org.junit.Assert.assertTrue
 import org.junit.Before
 import org.junit.Test
+import org.mockito.Mockito.spy
 
 class ContentActionTest {
     private lateinit var store: BrowserStore
@@ -156,6 +159,40 @@ class ContentActionTest {
         assertEquals("The Mozilla Team", tab.content.securityInfo.issuer)
     }
 
+    @Test
+    fun `UpdateThumbnailAction updates thumbnail`() {
+        val thumbnail = spy(Bitmap::class.java)
+
+        assertNotEquals(thumbnail, tab.content.thumbnail)
+        assertNotEquals(thumbnail, otherTab.content.thumbnail)
+
+        store.dispatch(
+                ContentAction.UpdateThumbnailAction(tab.id, thumbnail)
+        ).joinBlocking()
+
+        assertEquals(thumbnail, tab.content.thumbnail)
+        assertNotEquals(thumbnail, otherTab.content.thumbnail)
+    }
+
+    @Test
+    fun `RemoveThumbnailAction removes thumbnail`() {
+        val thumbnail = spy(Bitmap::class.java)
+
+        assertNotEquals(thumbnail, tab.content.thumbnail)
+
+        store.dispatch(
+                ContentAction.UpdateThumbnailAction(tab.id, thumbnail)
+        ).joinBlocking()
+
+        assertEquals(thumbnail, tab.content.thumbnail)
+
+        store.dispatch(
+                ContentAction.RemoveThumbnailAction(tab.id)
+        ).joinBlocking()
+
+        assertNull(tab.content.thumbnail)
+    }
+
     @Test
     fun `Updating custom tab`() {
         val customTab = createCustomTab("https://getpocket.com")