cancel transitions when scene root has detached

commit_hash:db2fa3bb7d4d0861d219cb6b8978d9ad61bf8391

.mapping.json

@@ -1210,6 +1210,7 @@
   "client/android/div/src/main/java/com/yandex/div/core/view2/animations/Fade.kt":"divkit/public/client/android/div/src/main/java/com/yandex/div/core/view2/animations/Fade.kt",
   "client/android/div/src/main/java/com/yandex/div/core/view2/animations/OutlineAwareVisibility.kt":"divkit/public/client/android/div/src/main/java/com/yandex/div/core/view2/animations/OutlineAwareVisibility.kt",
   "client/android/div/src/main/java/com/yandex/div/core/view2/animations/Scale.kt":"divkit/public/client/android/div/src/main/java/com/yandex/div/core/view2/animations/Scale.kt",
+  "client/android/div/src/main/java/com/yandex/div/core/view2/animations/SceneRootWatcher.kt":"divkit/public/client/android/div/src/main/java/com/yandex/div/core/view2/animations/SceneRootWatcher.kt",
   "client/android/div/src/main/java/com/yandex/div/core/view2/animations/Slide.kt":"divkit/public/client/android/div/src/main/java/com/yandex/div/core/view2/animations/Slide.kt",
   "client/android/div/src/main/java/com/yandex/div/core/view2/animations/Transitions.kt":"divkit/public/client/android/div/src/main/java/com/yandex/div/core/view2/animations/Transitions.kt",
   "client/android/div/src/main/java/com/yandex/div/core/view2/animations/Utils.kt":"divkit/public/client/android/div/src/main/java/com/yandex/div/core/view2/animations/Utils.kt",

CHANGELOG.md

@@ -3,6 +3,7 @@
 # Android Client:
 * Added API to force specific `Div2View` to use canvas clipping.
 * Fixed optional expression resolving when default value is defined.
+* Fixed running transition behavior when scene root is detached.
 
 # iOS Client:
 * Add `isEmpty()` method to dict and array.

client/android/div/src/main/java/com/yandex/div/core/state/DivStateChangeListener.kt

@@ -6,6 +6,7 @@ import androidx.transition.TransitionManager
 import com.yandex.div.core.animation.SpringInterpolator
 import com.yandex.div.core.annotations.PublicApi
 import com.yandex.div.core.view2.Div2View
+import com.yandex.div.core.view2.animations.SceneRootWatcher
 import javax.inject.Provider
 
 @PublicApi
@@ -37,6 +38,7 @@ class DefaultDivStateChangeListener @JvmOverloads constructor(
         val rootView = rootViewProvider.get() ?: return
         val transition = DivStateTransition(divView).setInterpolator(interpolator)
         TransitionManager.endTransitions(rootView)
+        SceneRootWatcher.watchFor(rootView, transition)
         TransitionManager.beginDelayedTransition(rootView, transition)
     }
 }

client/android/div/src/main/java/com/yandex/div/core/view2/Div2View.kt

@@ -45,6 +45,7 @@ import com.yandex.div.core.util.SingleTimeOnAttachCallback
 import com.yandex.div.core.util.walk
 import com.yandex.div.core.view2.animations.DivComparator
 import com.yandex.div.core.view2.animations.DivTransitionHandler
+import com.yandex.div.core.view2.animations.SceneRootWatcher
 import com.yandex.div.core.view2.animations.allowsTransitionsOnDataChange
 import com.yandex.div.core.view2.animations.doOnEnd
 import com.yandex.div.core.view2.divs.DivLayoutProviderVariablesHolder
@@ -877,8 +878,9 @@ class Div2View private constructor(
         }
 
         if (transition != null) {
-            val newStateScene = Scene(this, newStateView)
             TransitionManager.endTransitions(this)
+            val newStateScene = Scene(this, newStateView)
+            SceneRootWatcher.watchFor(newStateScene, transition)
             TransitionManager.go(newStateScene, transition)
         } else {
             addView(newStateView)

client/android/div/src/main/java/com/yandex/div/core/view2/animations/SceneRootWatcher.kt

@@ -0,0 +1,33 @@
+package com.yandex.div.core.view2.animations
+
+import android.view.View
+import android.view.View.OnAttachStateChangeListener
+import android.view.ViewGroup
+import androidx.transition.Scene
+import androidx.transition.Transition
+import androidx.transition.TransitionManager
+
+internal object SceneRootWatcher {
+
+    fun watchFor(scene: Scene, transition: Transition) {
+        watchFor(scene.sceneRoot, transition)
+    }
+
+    fun watchFor(sceneRoot: ViewGroup, transition: Transition) {
+        val detachListener = OnDetachListener(sceneRoot)
+        sceneRoot.addOnAttachStateChangeListener(detachListener)
+        transition.doOnEnd { sceneRoot.removeOnAttachStateChangeListener(detachListener) }
+    }
+
+    private class OnDetachListener(
+        private val sceneRoot: ViewGroup
+    ) : OnAttachStateChangeListener {
+
+        override fun onViewAttachedToWindow(view: View) = Unit
+
+        override fun onViewDetachedFromWindow(view: View) {
+            sceneRoot.removeOnAttachStateChangeListener(this)
+            TransitionManager.endTransitions(sceneRoot)
+        }
+    }
+}

client/android/div/src/main/java/com/yandex/div/core/view2/divs/DivStateBinder.kt

@@ -32,6 +32,7 @@ import com.yandex.div.core.view2.DivVisibilityActionTracker
 import com.yandex.div.core.view2.animations.DivComparator
 import com.yandex.div.core.view2.animations.Fade
 import com.yandex.div.core.view2.animations.Scale
+import com.yandex.div.core.view2.animations.SceneRootWatcher
 import com.yandex.div.core.view2.animations.VerticalTranslation
 import com.yandex.div.core.view2.animations.allowsTransitionsOnStateChange
 import com.yandex.div.core.view2.divs.widgets.DivStateLayout
@@ -132,6 +133,7 @@ internal class DivStateBinder @Inject constructor(
 
             if (transition != null) {
                 TransitionManager.endTransitions(layout)
+                SceneRootWatcher.watchFor(layout, transition)
                 TransitionManager.beginDelayedTransition(layout, transition)
             }
             layout.releaseAndRemoveChildren(divView)