For #167: Adds browser -> home animation

app/src/main/java/org/mozilla/fenix/browser/BaseBrowserFragment.kt

@@ -168,7 +168,7 @@ abstract class BaseBrowserFragment : Fragment(), UserInteractionHandler, Session
             swipeRefresh = WeakReference(swipeRefresh),
             arguments = arguments!!
         ).apply {
-            beginAnimationIfNecessary()
+            beginAnimateInIfNecessary()
         }
 
         return getSessionById()?.also { session ->

app/src/main/java/org/mozilla/fenix/browser/BrowserAnimator.kt

@@ -41,17 +41,34 @@ class BrowserAnimator(
     private val unwrappedSwipeRefresh: View?
         get() = swipeRefresh.get()
 
+    private val browserInValueAnimator = ValueAnimator.ofFloat(0f, END_ANIMATOR_VALUE).apply {
+        addUpdateListener {
+            unwrappedSwipeRefresh?.scaleX = STARTING_XY_SCALE + XY_SCALE_MULTIPLIER * it.animatedFraction
+            unwrappedSwipeRefresh?.scaleY = STARTING_XY_SCALE + XY_SCALE_MULTIPLIER * it.animatedFraction
+            unwrappedSwipeRefresh?.alpha = it.animatedFraction
+        }
+
+        doOnEnd {
+            unwrappedEngineView?.asView()?.visibility = View.VISIBLE
+            unwrappedSwipeRefresh?.background = null
+            arguments.putBoolean(SHOULD_ANIMATE_FLAG, false)
+        }
+
+        interpolator = DecelerateInterpolator()
+        duration = ANIMATION_DURATION
+    }
+
     /**
-     * Triggers the browser animation to run if necessary (based on the SHOULD_ANIMATE_FLAG). Also
+     * Triggers the *in* browser animation to run if necessary (based on the SHOULD_ANIMATE_FLAG). Also
      * removes the flag from the bundle so it is not played on future entries into the fragment.
      */
-    fun beginAnimationIfNecessary() {
+    fun beginAnimateInIfNecessary() {
         val shouldAnimate = arguments.getBoolean(SHOULD_ANIMATE_FLAG, false)
         if (shouldAnimate) {
             viewLifeCycleScope?.launch(Dispatchers.Main) {
                 delay(ANIMATION_DELAY)
                 captureEngineViewAndDrawStatically {
-                    animateBrowserEngine(unwrappedSwipeRefresh)
+                    browserInValueAnimator.start()
                 }
             }
         } else {
@@ -62,26 +79,15 @@ class BrowserAnimator(
     }
 
     /**
-     * Details exactly how the browserEngine animation should look and plays it.
+     * Triggers the *out* browser animation to run.
      */
-    private fun animateBrowserEngine(browserEngine: View?) {
+    fun beginAnimateOut() {
-        val valueAnimator = ValueAnimator.ofFloat(0f, END_ANIMATOR_VALUE)
+        viewLifeCycleScope?.launch(Dispatchers.Main) {
-
+            captureEngineViewAndDrawStatically {
-        valueAnimator.addUpdateListener {
+                unwrappedEngineView?.asView()?.visibility = View.GONE
-            browserEngine?.scaleX = STARTING_XY_SCALE + XY_SCALE_MULTIPLIER * it.animatedFraction
+                browserInValueAnimator.reverse()
-            browserEngine?.scaleY = STARTING_XY_SCALE + XY_SCALE_MULTIPLIER * it.animatedFraction
+            }
-            browserEngine?.alpha = it.animatedFraction
         }
-
-        valueAnimator.doOnEnd {
-            unwrappedEngineView?.asView()?.visibility = View.VISIBLE
-            unwrappedSwipeRefresh?.background = null
-            arguments.putBoolean(SHOULD_ANIMATE_FLAG, false)
-        }
-
-        valueAnimator.interpolator = DecelerateInterpolator()
-        valueAnimator.duration = ANIMATION_DURATION
-        valueAnimator.start()
     }
 
     /**

app/src/main/java/org/mozilla/fenix/components/toolbar/BrowserToolbarController.kt

@@ -14,6 +14,7 @@ import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.ExperimentalCoroutinesApi
 import kotlinx.coroutines.MainScope
+import kotlinx.coroutines.delay
 import kotlinx.coroutines.launch
 import mozilla.components.browser.session.Session
 import mozilla.components.browser.session.SessionManager
@@ -300,7 +301,11 @@ class DefaultBrowserToolbarController(
     }
 
     private fun animateTabAndNavigateHome() {
-        browserAnimator.captureEngineViewAndDrawStatically {
+        scope.launch {
+            browserAnimator.beginAnimateOut()
+            // Delay for a short amount of time so the browser has time to start animating out
+            // before we transition the fragment. This makes the animation feel smoother
+            delay(ANIMATION_DELAY)
             if (!navController.popBackStack(R.id.homeFragment, false)) {
                 val directions = BrowserFragmentDirections.actionBrowserFragmentToHomeFragment()
                 navController.nav(
@@ -356,8 +361,7 @@ class DefaultBrowserToolbarController(
     }
 
     companion object {
-        @VisibleForTesting
+        const val ANIMATION_DELAY = 50L
-        const val TAB_ITEM_TRANSITION_NAME = "tab_item"
         internal const val TELEMETRY_BROWSER_IDENTIFIER = "browserMenu"
     }
 }

app/src/main/res/anim/zoom_out_fade.xml

@@ -0,0 +1,19 @@
+<!-- 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/. -->
+
+<set xmlns:android="http://schemas.android.com/apk/res/android">
+    <alpha
+        android:interpolator="@android:interpolator/decelerate_cubic"
+        android:fromAlpha="0" android:toAlpha="1"
+        android:duration="175" />
+    <scale
+        android:interpolator="@android:interpolator/decelerate_cubic"
+        android:pivotX="50%"
+        android:pivotY="50%"
+        android:fromXScale="108%"
+        android:toXScale="100%"
+        android:fromYScale="108%"
+        android:toYScale="100%"
+        android:duration="175" />
+</set>

app/src/main/res/navigation/nav_graph.xml

@@ -58,6 +58,7 @@
     <fragment
         android:id="@+id/homeFragment"
         android:name="org.mozilla.fenix.home.HomeFragment"
+        app:enterAnim="@anim/zoom_out_fade"
         tools:layout="@layout/fragment_home">
         <action
             android:id="@+id/action_homeFragment_to_turnOnSyncFragment"
@@ -76,7 +77,7 @@
             android:id="@+id/action_homeFragment_to_browserFragment"
             app:destination="@id/browserFragment"
             app:exitAnim="@anim/zoom_in_fade"
-            app:popEnterAnim="@anim/fade_in" />
+            app:popEnterAnim="@anim/zoom_out_fade" />
         <action
             android:id="@+id/action_homeFragment_to_libraryFragment"
             app:destination="@id/libraryFragment" />