Cancel predictive back gesture when stack changed (experimental anima…

…tion API)
arkivanov · Nov 7, 2024 · e4c0d00 · e4c0d00
1 parent 00bf7ee
commit e4c0d00
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Showing 2 changed files with 29 additions and 2 deletions.
diff --git a/...ivanov/decompose/extensions/compose/experimental/stack/animation/DefaultStackAnimation.kt b/...ivanov/decompose/extensions/compose/experimental/stack/animation/DefaultStackAnimation.kt
@@ -69,7 +69,7 @@ internal class DefaultStackAnimation<C : Any, T : Any>(
 
             if (updateItems) {
                 val newItems = getAnimationItems(newStack = currentStack, oldStack = oldStack)
-                if (items.size == 1) {
+                if ((items.size == 1) || items.values.last().transitionState.isSeekable()) {
                     items = newItems
                 } else {
                     nextItems = newItems
@@ -401,3 +401,6 @@ private fun TransitionState<*>.isIdle(): Boolean =
         is SeekableTransitionState -> false
         else -> false
     }
+
+private fun TransitionState<*>.isSeekable(): Boolean =
+    this is SeekableTransitionState
diff --git a/...ov/decompose/extensions/compose/experimental/stack/animation/PredictiveBackGestureTest.kt b/...ov/decompose/extensions/compose/experimental/stack/animation/PredictiveBackGestureTest.kt
@@ -213,6 +213,29 @@ class PredictiveBackGestureTest {
         composeRule.onNodeWithText("3").assertDoesNotExist()
     }
 
+    @Test
+    fun GIVEN_gesture_started_WHEN_stack_popped_THEN_gesture_cancelled() {
+        var stack by mutableStateOf(stack("1", "2"))
+        val animation = DefaultStackAnimation(animator = fade(), onBack = { stack = stack.dropLast() },)
+
+        composeRule.setContent {
+            animation(stack, Modifier) {
+                Text(text = it.configuration)
+            }
+        }
+
+        backDispatcher.startPredictiveBack(BackEvent(progress = 0F))
+        composeRule.waitForIdle()
+        backDispatcher.progressPredictiveBack(BackEvent(progress = 0.5F))
+        composeRule.waitForIdle()
+
+        stack = stack.dropLast()
+        composeRule.mainClock.autoAdvance = false
+        composeRule.mainClock.advanceTimeByFrame()
+
+        composeRule.onNodeWithText("2").assertTestTagToRootDoesNotExist { it.startsWith(TEST_TAG_PREFIX) }
+    }
+
     @Test
     fun GIVEN_gesture_started_WHEN_stack_pushed_and_back_THEN_new_child_popped_and_gesture_finished() {
         var stack by mutableStateOf(stack("1", "2"))
@@ -471,6 +494,7 @@ class PredictiveBackGestureTest {
 
     private fun DefaultStackAnimation(
         predictiveBackAnimatable: (initialBackEvent: BackEvent) -> PredictiveBackAnimatable? = ::TestAnimatable,
+        animator: StackAnimator? = null,
         onBack: () -> Unit,
     ): DefaultStackAnimation<String, String> =
         DefaultStackAnimation(
@@ -482,7 +506,7 @@ class PredictiveBackGestureTest {
                     animatable = predictiveBackAnimatable,
                 )
             },
-            selector = { _, _, _ -> null },
+            selector = { _, _, _ -> animator },
         )
 
     private fun stack(configs: List<String>): ChildStack<String, String> =