- Fix tab order bug by removing switchTab call in notifyStackItemAdd.

medusalib/src/main/java/com/trendyol/medusalib/navigator/FragmentStackState.kt

@@ -4,10 +4,9 @@ import com.trendyol.medusalib.common.extensions.insertToBottom
 import com.trendyol.medusalib.common.extensions.moveToTop
 import com.trendyol.medusalib.navigator.data.StackItem
 import java.util.*
-import kotlin.collections.ArrayList
 
 data class FragmentStackState constructor(
-    val fragmentTagStack: MutableList<Stack<StackItem>> = ArrayList(),
+    val fragmentTagStack: MutableList<Stack<StackItem>> = mutableListOf(),
     val tabIndexStack: Stack<Int> = Stack()
 ) {
 
@@ -17,18 +16,19 @@ data class FragmentStackState constructor(
 
     fun isTabEmpty(index: Int) = fragmentTagStack[index].isEmpty()
 
-    fun addStackItem(tabIndex: Int, stackItem: StackItem) {
-        val stack = fragmentTagStack.getOrElse(tabIndex) {
-            Stack<StackItem>().apply {
-                fragmentTagStack.add(tabIndex, this)
-            }
-        }
+    fun notifyStackItemAdd(tabIndex: Int, stackItem: StackItem) {
+        val stack = fragmentTagStack.get(tabIndex)
         stack.push(stackItem)
-        switchTab(tabIndex)
     }
 
-    fun addStackItemToSelectedTab(stackItem: StackItem) {
-        addStackItem(getSelectedTabIndex(), stackItem)
+    fun notifyStackItemAddToCurrentTab(stackItem: StackItem) {
+        notifyStackItemAdd(getSelectedTabIndex(), stackItem)
+    }
+
+    fun setStackCount(size: Int) {
+        for (index in 0 until size) {
+            fragmentTagStack.add(Stack())
+        }
     }
 
     fun clear() {
@@ -50,11 +50,12 @@ data class FragmentStackState constructor(
 
     fun hasSelectedTabOnlyRoot() = fragmentTagStack[getSelectedTabIndex()].size <= 1
 
-    fun peekItemFromSelectedTab() = fragmentTagStack[getSelectedTabIndex()].peek()
+    fun peekItemFromSelectedTab() =
+        fragmentTagStack[getSelectedTabIndex()].takeIf { it.isNotEmpty() }?.peek()
 
     fun popItem(tabIndex: Int): StackItem {
         val item = fragmentTagStack.get(tabIndex).pop()
-        if(fragmentTagStack.get(tabIndex).isEmpty()) {
+        if (isTabEmpty(tabIndex) && tabIndex == getSelectedTabIndex() && tabIndexStack.size > 1 ) {
             popSelectedTab()
         }
         return item
@@ -102,10 +103,6 @@ data class FragmentStackState constructor(
         tabIndexStack.addAll(stackState.tabIndexStack)
     }
 
-    fun peekRootItems(): List<StackItem> {
-        return fragmentTagStack.map { it.get(0) }
-    }
-
     fun peekItem(tabIndex: Int) = fragmentTagStack.get(tabIndex).peek()
     fun popItemFromSelectedTab() = popItem(getSelectedTabIndex())
     fun popSelectedTab(): Int {

medusalib/src/main/java/com/trendyol/medusalib/navigator/MultipleStackNavigator.kt

@@ -70,7 +70,7 @@ open class MultipleStackNavigator(
         } else {
             fragmentManagerController.disableAndStartFragment(getCurrentFragmentTag(), fragmentData)
         }
-        fragmentStackState.addStackItemToSelectedTab(
+        fragmentStackState.notifyStackItemAddToCurrentTab(
             StackItem(
                 fragmentTag = createdTag,
                 groupName = fragmentGroupName
@@ -128,12 +128,6 @@ open class MultipleStackNavigator(
         }
 
         clearAllFragments(tabIndex, resetRootFragment)
-
-        if (resetRootFragment) {
-            val rootFragment = getRootFragment(tabIndex)
-            val createdTag = tagCreator.create(rootFragment)
-            fragmentStackState.addStackItem(tabIndex, StackItem(createdTag))
-        }
     }
 
     override fun resetCurrentTab(resetRootFragment: Boolean) {
@@ -144,10 +138,11 @@ open class MultipleStackNavigator(
             val rootFragment = getRootFragment(currentTabIndex)
             val createdTag = tagCreator.create(rootFragment)
             val rootFragmentData = FragmentData(rootFragment, createdTag)
-            fragmentStackState.addStackItem(currentTabIndex, StackItem(fragmentTag = createdTag))
+            fragmentStackState.switchTab(currentTabIndex)
+            fragmentStackState.notifyStackItemAdd(currentTabIndex, StackItem(fragmentTag = createdTag))
             fragmentManagerController.addFragment(rootFragmentData)
         } else {
-            val upperFragmentTag = fragmentStackState.peekItemFromSelectedTab().fragmentTag
+            val upperFragmentTag = getCurrentFragmentTag()
             fragmentManagerController.enableFragment(upperFragmentTag)
         }
     }
@@ -182,7 +177,7 @@ open class MultipleStackNavigator(
     }
 
     override fun getCurrentFragment(): Fragment? {
-        val visibleFragmentTag = fragmentStackState.peekItemFromSelectedTab().fragmentTag
+        val visibleFragmentTag = getCurrentFragmentTag()
         return fragmentManagerController.getFragment(visibleFragmentTag)
     }
 
@@ -196,28 +191,21 @@ open class MultipleStackNavigator(
     }
 
     private fun initializeStackState() {
-        val providedRootFragments = rootFragmentProvider.map { it.invoke() }
-        addRootFragmentsToStackState(providedRootFragments)
-
         val initialTabIndex = navigatorConfiguration.initialTabIndex
-        fragmentStackState.switchTab(initialTabIndex)
+        val rootFragment = rootFragmentProvider.get(initialTabIndex).invoke()
+        val createdTag = tagCreator.create(rootFragment)
+        val stackItem = StackItem(fragmentTag = createdTag)
 
+        fragmentStackState.setStackCount(rootFragmentProvider.size)
+        fragmentStackState.notifyStackItemAdd(tabIndex = initialTabIndex, stackItem = stackItem)
+        fragmentStackState.switchTab(initialTabIndex)
 
-        val rootFragment = getRootFragment(initialTabIndex)
         val rootFragmentTag = fragmentStackState.peekItem(initialTabIndex).fragmentTag
         val rootFragmentData = FragmentData(rootFragment, rootFragmentTag)
         fragmentManagerController.addFragment(rootFragmentData)
         navigatorListener?.onTabChanged(navigatorConfiguration.initialTabIndex)
     }
 
-    private fun addRootFragmentsToStackState(rootFragments: List<Fragment>) {
-        rootFragments.forEachIndexed { index: Int, fragment: Fragment ->
-            val createdTag = tagCreator.create(fragment)
-            val stackItem = StackItem(fragmentTag = createdTag)
-            fragmentStackState.addStackItem(index, stackItem)
-        }
-    }
-
     private fun loadStackStateFromSavedState(savedState: Bundle) {
         val stackState = fragmentStackStateMapper.fromBundle(savedState.getBundle(MEDUSA_STACK_STATE_KEY))
         fragmentStackState.setStackState(stackState)
@@ -232,17 +220,19 @@ open class MultipleStackNavigator(
     }
 
     private fun showUpperFragment() {
-        val upperFragmentTag = fragmentStackState.peekItemFromSelectedTab().fragmentTag
-        if (fragmentManagerController.isFragmentNull(upperFragmentTag)) {
+        val upperFragmentTag = fragmentStackState.peekItemFromSelectedTab()?.fragmentTag
+        if (upperFragmentTag == null || fragmentManagerController.isFragmentNull(upperFragmentTag)) {
             val rootFragment = getRootFragment(fragmentStackState.getSelectedTabIndex())
-            val rootFragmentData = FragmentData(rootFragment, upperFragmentTag)
+            val createdTag = tagCreator.create(rootFragment)
+            val rootFragmentData = FragmentData(rootFragment, createdTag)
+            fragmentStackState.notifyStackItemAdd(fragmentStackState.getSelectedTabIndex(), StackItem(createdTag))
             fragmentManagerController.addFragment(rootFragmentData)
         } else {
             fragmentManagerController.enableFragment(upperFragmentTag)
         }
     }
 
-    private fun getCurrentFragmentTag() = fragmentStackState.peekItemFromSelectedTab().fragmentTag
+    private fun getCurrentFragmentTag() = requireNotNull(fragmentStackState.peekItemFromSelectedTab()).fragmentTag
 
     private fun shouldExit(): Boolean {
         return fragmentStackState.hasTabStack() && fragmentStackState.hasSelectedTabOnlyRoot()

medusalib/src/test/java/com/trendyol/medusalib/navigator/FragmentStackStateTest.kt

@@ -28,22 +28,4 @@ class FragmentStackStateTest {
 
         Truth.assertThat(stackState.fragmentTagStack).containsExactlyElementsIn(emptyStack)
     }
-
-    @Test
-    fun `given stackstate with tab index stack of (2, 1, 0), when addStackItem is called with tabIndex 1, then new tab index must be (2, 0, 1)`() {
-        val stackState = buildFragmentStackState(tabStack = buildTabStack(2, 1, 0))
-
-        stackState.addStackItem(1, buildStackItem())
-
-        Truth.assertThat(stackState.tabIndexStack).containsExactly(2, 0, 1).inOrder()
-    }
-
-    @Test
-    fun `given stackstate with tab index stack of (2, 1, 0), when addStackItem is called with tabIndex 0, then new tab index must be (2, 1, 0)`() {
-        val stackState = buildFragmentStackState(tabStack = buildTabStack(2, 1, 0))
-
-        stackState.addStackItem(0, buildStackItem())
-
-        Truth.assertThat(stackState.tabIndexStack).containsExactly(2, 1, 0).inOrder()
-    }
 }