diff --git a/libs/WindowManager/Shell/src/com/android/wm/shell/dagger/WMShellModule.java b/libs/WindowManager/Shell/src/com/android/wm/shell/dagger/WMShellModule.java
index 4c25889..b700a54 100644
--- a/libs/WindowManager/Shell/src/com/android/wm/shell/dagger/WMShellModule.java
+++ b/libs/WindowManager/Shell/src/com/android/wm/shell/dagger/WMShellModule.java
@@ -67,7 +67,7 @@
 import com.android.wm.shell.desktopmode.CloseDesktopTaskTransitionHandler;
 import com.android.wm.shell.desktopmode.DefaultDragToDesktopTransitionHandler;
 import com.android.wm.shell.desktopmode.DesktopActivityOrientationChangeHandler;
-import com.android.wm.shell.desktopmode.DesktopFullImmersiveTransitionHandler;
+import com.android.wm.shell.desktopmode.DesktopImmersiveController;
 import com.android.wm.shell.desktopmode.DesktopMixedTransitionHandler;
 import com.android.wm.shell.desktopmode.DesktopModeDragAndDropTransitionHandler;
 import com.android.wm.shell.desktopmode.DesktopModeEventLogger;
@@ -397,12 +397,12 @@
             Context context,
             ShellInit shellInit,
             Transitions transitions,
-            Optional<DesktopFullImmersiveTransitionHandler> desktopImmersiveTransitionHandler,
+            Optional<DesktopImmersiveController> desktopImmersiveController,
             WindowDecorViewModel windowDecorViewModel,
             Optional<TaskChangeListener> taskChangeListener,
             FocusTransitionObserver focusTransitionObserver) {
         return new FreeformTaskTransitionObserver(
-                context, shellInit, transitions, desktopImmersiveTransitionHandler,
+                context, shellInit, transitions, desktopImmersiveController,
                 windowDecorViewModel, taskChangeListener, focusTransitionObserver);
     }
 
@@ -638,7 +638,7 @@
             ToggleResizeDesktopTaskTransitionHandler toggleResizeDesktopTaskTransitionHandler,
             DragToDesktopTransitionHandler dragToDesktopTransitionHandler,
             @DynamicOverride DesktopRepository desktopRepository,
-            Optional<DesktopFullImmersiveTransitionHandler> desktopFullImmersiveTransitionHandler,
+            Optional<DesktopImmersiveController> desktopImmersiveController,
             DesktopModeLoggerTransitionObserver desktopModeLoggerTransitionObserver,
             LaunchAdjacentController launchAdjacentController,
             RecentsTransitionHandler recentsTransitionHandler,
@@ -657,7 +657,7 @@
                 returnToDragStartAnimator, enterDesktopTransitionHandler,
                 exitDesktopTransitionHandler, desktopModeDragAndDropTransitionHandler,
                 toggleResizeDesktopTaskTransitionHandler,
-                dragToDesktopTransitionHandler, desktopFullImmersiveTransitionHandler.get(),
+                dragToDesktopTransitionHandler, desktopImmersiveController.get(),
                 desktopRepository,
                 desktopModeLoggerTransitionObserver, launchAdjacentController,
                 recentsTransitionHandler, multiInstanceHelper, mainExecutor, desktopTasksLimiter,
@@ -705,7 +705,7 @@
 
     @WMSingleton
     @Provides
-    static Optional<DesktopFullImmersiveTransitionHandler> provideDesktopImmersiveHandler(
+    static Optional<DesktopImmersiveController> provideDesktopImmersiveController(
             Context context,
             Transitions transitions,
             @DynamicOverride DesktopRepository desktopRepository,
@@ -713,7 +713,7 @@
             ShellTaskOrganizer shellTaskOrganizer) {
         if (DesktopModeStatus.canEnterDesktopMode(context)) {
             return Optional.of(
-                    new DesktopFullImmersiveTransitionHandler(
+                    new DesktopImmersiveController(
                             transitions,
                             desktopRepository,
                             displayController,
diff --git a/libs/WindowManager/Shell/src/com/android/wm/shell/desktopmode/DesktopFullImmersiveTransitionHandler.kt b/libs/WindowManager/Shell/src/com/android/wm/shell/desktopmode/DesktopImmersiveController.kt
similarity index 81%
rename from libs/WindowManager/Shell/src/com/android/wm/shell/desktopmode/DesktopFullImmersiveTransitionHandler.kt
rename to libs/WindowManager/Shell/src/com/android/wm/shell/desktopmode/DesktopImmersiveController.kt
index 19ffd96..d0bc5f0 100644
--- a/libs/WindowManager/Shell/src/com/android/wm/shell/desktopmode/DesktopFullImmersiveTransitionHandler.kt
+++ b/libs/WindowManager/Shell/src/com/android/wm/shell/desktopmode/DesktopImmersiveController.kt
@@ -36,20 +36,21 @@
 import com.android.wm.shell.protolog.ShellProtoLogGroup.WM_SHELL_DESKTOP_MODE
 import com.android.wm.shell.transition.Transitions
 import com.android.wm.shell.transition.Transitions.TransitionHandler
+import com.android.wm.shell.transition.Transitions.TransitionObserver
 import com.android.wm.shell.windowdecor.OnTaskResizeAnimationListener
 
 /**
- * A [TransitionHandler] to move a task in/out of desktop's full immersive state where the task
+ * A controller to move tasks in/out of desktop's full immersive state where the task
  * remains freeform while being able to take fullscreen bounds and have its App Header visibility
  * be transient below the status bar like in fullscreen immersive mode.
  */
-class DesktopFullImmersiveTransitionHandler(
+class DesktopImmersiveController(
     private val transitions: Transitions,
     private val desktopRepository: DesktopRepository,
     private val displayController: DisplayController,
     private val shellTaskOrganizer: ShellTaskOrganizer,
     private val transactionSupplier: () -> SurfaceControl.Transaction,
-) : TransitionHandler {
+) : TransitionHandler, TransitionObserver {
 
     constructor(
         transitions: Transitions,
@@ -67,7 +68,7 @@
     private var state: TransitionState? = null
 
     @VisibleForTesting
-    val pendingExternalExitTransitions = mutableSetOf<ExternalPendingExit>()
+    val pendingExternalExitTransitions = mutableListOf<ExternalPendingExit>()
 
     /** Whether there is an immersive transition that hasn't completed yet. */
     private val inProgress: Boolean
@@ -184,6 +185,17 @@
         return null
     }
 
+
+    /** Whether the [change] in the [transition] is a known immersive change. */
+    fun isImmersiveChange(
+        transition: IBinder,
+        change: TransitionInfo.Change,
+    ): Boolean {
+        return pendingExternalExitTransitions.any {
+            it.transition == transition && it.taskId == change.taskInfo?.taskId
+        }
+    }
+
     private fun addPendingImmersiveExit(taskId: Int, displayId: Int, transition: IBinder) {
         pendingExternalExitTransitions.add(
             ExternalPendingExit(
@@ -201,10 +213,11 @@
         finishTransaction: SurfaceControl.Transaction,
         finishCallback: Transitions.TransitionFinishCallback
     ): Boolean {
+        logD("startAnimation transition=%s", transition)
         val state = requireState()
         if (transition != state.transition) return false
         animateResize(
-            transitionState = state,
+            targetTaskId = state.taskId,
             info = info,
             startTransaction = startTransaction,
             finishTransaction = finishTransaction,
@@ -214,40 +227,55 @@
     }
 
     private fun animateResize(
-        transitionState: TransitionState,
+        targetTaskId: Int,
         info: TransitionInfo,
         startTransaction: SurfaceControl.Transaction,
         finishTransaction: SurfaceControl.Transaction,
         finishCallback: Transitions.TransitionFinishCallback
     ) {
+        logD("animateResize for task#%d", targetTaskId)
         val change = info.changes.first { c ->
             val taskInfo = c.taskInfo
-            return@first taskInfo != null && taskInfo.taskId == transitionState.taskId
+            return@first taskInfo != null && taskInfo.taskId == targetTaskId
         }
+        animateResizeChange(change, startTransaction, finishTransaction, finishCallback)
+    }
+
+    /**
+     *  Animate an immersive change.
+     *
+     *  As of now, both enter and exit transitions have the same animation, a veiled resize.
+     */
+    fun animateResizeChange(
+        change: TransitionInfo.Change,
+        startTransaction: SurfaceControl.Transaction,
+        finishTransaction: SurfaceControl.Transaction,
+        finishCallback: Transitions.TransitionFinishCallback,
+    ) {
+        val taskId = change.taskInfo!!.taskId
         val leash = change.leash
         val startBounds = change.startAbsBounds
         val endBounds = change.endAbsBounds
+        logD("Animating resize change for task#%d from %s to %s", taskId, startBounds, endBounds)
 
+        startTransaction
+            .setPosition(leash, startBounds.left.toFloat(), startBounds.top.toFloat())
+            .setWindowCrop(leash, startBounds.width(), startBounds.height())
+            .show(leash)
+        onTaskResizeAnimationListener
+            ?.onAnimationStart(taskId, startTransaction, startBounds)
+            ?: startTransaction.apply()
         val updateTransaction = transactionSupplier()
         ValueAnimator.ofObject(rectEvaluator, startBounds, endBounds).apply {
             duration = FULL_IMMERSIVE_ANIM_DURATION_MS
             interpolator = DecelerateInterpolator()
             addListener(
-                onStart = {
-                    startTransaction
-                        .setPosition(leash, startBounds.left.toFloat(), startBounds.top.toFloat())
-                        .setWindowCrop(leash, startBounds.width(), startBounds.height())
-                        .show(leash)
-                    onTaskResizeAnimationListener
-                        ?.onAnimationStart(transitionState.taskId, startTransaction, startBounds)
-                        ?: startTransaction.apply()
-                },
                 onEnd = {
                     finishTransaction
                         .setPosition(leash, endBounds.left.toFloat(), endBounds.top.toFloat())
                         .setWindowCrop(leash, endBounds.width(), endBounds.height())
                         .apply()
-                    onTaskResizeAnimationListener?.onAnimationEnd(transitionState.taskId)
+                    onTaskResizeAnimationListener?.onAnimationEnd(taskId)
                     finishCallback.onTransitionFinished(null /* wct */)
                     clearState()
                 }
@@ -259,7 +287,7 @@
                     .setWindowCrop(leash, rect.width(), rect.height())
                     .apply()
                 onTaskResizeAnimationListener
-                    ?.onBoundsChange(transitionState.taskId, updateTransaction, rect)
+                    ?.onBoundsChange(taskId, updateTransaction, rect)
                     ?: updateTransaction.apply()
             }
             start()
@@ -289,15 +317,20 @@
      * |onTransitionReady|, before this transition actually animates) because drawing decorations
      * depends on whether the task is in full immersive state or not.
      */
-    fun onTransitionReady(transition: IBinder, info: TransitionInfo) {
+    override fun onTransitionReady(
+        transition: IBinder,
+        info: TransitionInfo,
+        startTransaction: SurfaceControl.Transaction,
+        finishTransaction: SurfaceControl.Transaction,
+    ) {
+        logD("onTransitionReady transition=%s", transition)
         // Check if this is a pending external exit transition.
         val pendingExit = pendingExternalExitTransitions
             .firstOrNull { pendingExit -> pendingExit.transition == transition }
         if (pendingExit != null) {
-            pendingExternalExitTransitions.remove(pendingExit)
             if (info.hasTaskChange(taskId = pendingExit.taskId)) {
                 if (desktopRepository.isTaskInFullImmersiveState(pendingExit.taskId)) {
-                    logV("Pending external exit for task ${pendingExit.taskId} verified")
+                    logV("Pending external exit for task#%d verified", pendingExit.taskId)
                     desktopRepository.setTaskInFullImmersiveState(
                         displayId = pendingExit.displayId,
                         taskId = pendingExit.taskId,
@@ -316,7 +349,7 @@
             val state = requireState()
             val startBounds = info.changes.first { c -> c.taskInfo?.taskId == state.taskId }
                 .startAbsBounds
-            logV("Direct move for task ${state.taskId} in ${state.direction} direction verified")
+            logV("Direct move for task#%d in %s direction verified", state.taskId, state.direction)
             when (state.direction) {
                 Direction.ENTER -> {
                     desktopRepository.setTaskInFullImmersiveState(
@@ -348,7 +381,7 @@
             .filter { c -> desktopRepository.isTaskInFullImmersiveState(c.taskInfo!!.taskId) }
             .filter { c -> c.startRotation != c.endRotation }
             .forEach { c ->
-                logV("Detected immersive exit due to rotation for task: ${c.taskInfo!!.taskId}")
+                logV("Detected immersive exit due to rotation for task#%d", c.taskInfo!!.taskId)
                 desktopRepository.setTaskInFullImmersiveState(
                     displayId = c.taskInfo!!.displayId,
                     taskId = c.taskInfo!!.taskId,
@@ -357,6 +390,32 @@
             }
     }
 
+    override fun onTransitionMerged(merged: IBinder, playing: IBinder) {
+        logD("onTransitionMerged merged=%s playing=%s", merged, playing)
+        val pendingExit = pendingExternalExitTransitions
+            .firstOrNull { pendingExit -> pendingExit.transition == merged }
+        if (pendingExit != null) {
+            logV(
+                "Pending exit transition %s for task#%s merged into %s",
+                merged, pendingExit.taskId, playing
+            )
+            pendingExit.transition = playing
+        }
+    }
+
+    override fun onTransitionFinished(transition: IBinder, aborted: Boolean) {
+        logD("onTransitionFinished transition=%s aborted=%b", transition, aborted)
+        val pendingExit = pendingExternalExitTransitions
+            .firstOrNull { pendingExit -> pendingExit.transition == transition }
+        if (pendingExit != null) {
+            logV(
+                "Pending exit transition %s for task#%s finished",
+                transition, pendingExit
+            )
+            pendingExternalExitTransitions.remove(pendingExit)
+        }
+    }
+
     private fun clearState() {
         state = null
     }
@@ -399,7 +458,7 @@
     data class ExternalPendingExit(
         val taskId: Int,
         val displayId: Int,
-        val transition: IBinder,
+        var transition: IBinder,
     )
 
     private enum class Direction {
@@ -410,6 +469,10 @@
         ProtoLog.v(WM_SHELL_DESKTOP_MODE, "%s: $msg", TAG, *arguments)
     }
 
+    private fun logD(msg: String, vararg arguments: Any?) {
+        ProtoLog.d(WM_SHELL_DESKTOP_MODE, "%s: $msg", TAG, *arguments)
+    }
+
     private companion object {
         private const val TAG = "DesktopImmersive"
 
diff --git a/libs/WindowManager/Shell/src/com/android/wm/shell/desktopmode/DesktopTasksController.kt b/libs/WindowManager/Shell/src/com/android/wm/shell/desktopmode/DesktopTasksController.kt
index 18cf1f2..781aee0 100644
--- a/libs/WindowManager/Shell/src/com/android/wm/shell/desktopmode/DesktopTasksController.kt
+++ b/libs/WindowManager/Shell/src/com/android/wm/shell/desktopmode/DesktopTasksController.kt
@@ -48,6 +48,7 @@
 import android.view.KeyEvent
 import android.view.MotionEvent
 import android.view.SurfaceControl
+import android.view.SurfaceControl.Transaction
 import android.view.WindowManager.TRANSIT_CHANGE
 import android.view.WindowManager.TRANSIT_CLOSE
 import android.view.WindowManager.TRANSIT_NONE
@@ -59,6 +60,7 @@
 import android.window.DesktopModeFlags.ENABLE_WINDOWING_DYNAMIC_INITIAL_BOUNDS
 import android.window.RemoteTransition
 import android.window.TransitionInfo
+import android.window.TransitionInfo.Change
 import android.window.TransitionRequestInfo
 import android.window.WindowContainerTransaction
 import androidx.annotation.BinderThread
@@ -115,6 +117,7 @@
 import com.android.wm.shell.transition.FocusTransitionObserver
 import com.android.wm.shell.transition.OneShotRemoteHandler
 import com.android.wm.shell.transition.Transitions
+import com.android.wm.shell.transition.Transitions.TransitionFinishCallback
 import com.android.wm.shell.windowdecor.DragPositioningCallbackUtility
 import com.android.wm.shell.windowdecor.MoveToDesktopAnimator
 import com.android.wm.shell.windowdecor.OnTaskRepositionAnimationListener
@@ -146,7 +149,7 @@
     private val desktopModeDragAndDropTransitionHandler: DesktopModeDragAndDropTransitionHandler,
     private val toggleResizeDesktopTaskTransitionHandler: ToggleResizeDesktopTaskTransitionHandler,
     private val dragToDesktopTransitionHandler: DragToDesktopTransitionHandler,
-    private val immersiveTransitionHandler: DesktopFullImmersiveTransitionHandler,
+    private val desktopImmersiveController: DesktopImmersiveController,
     private val taskRepository: DesktopRepository,
     private val desktopModeLoggerTransitionObserver: DesktopModeLoggerTransitionObserver,
     private val launchAdjacentController: LaunchAdjacentController,
@@ -252,7 +255,7 @@
         toggleResizeDesktopTaskTransitionHandler.setOnTaskResizeAnimationListener(listener)
         enterDesktopTaskTransitionHandler.setOnTaskResizeAnimationListener(listener)
         dragToDesktopTransitionHandler.onTaskResizeAnimationListener = listener
-        immersiveTransitionHandler.onTaskResizeAnimationListener = listener
+        desktopImmersiveController.onTaskResizeAnimationListener = listener
     }
 
     fun setOnTaskRepositionAnimationListener(listener: OnTaskRepositionAnimationListener) {
@@ -372,7 +375,7 @@
         // TODO(342378842): Instead of using default display, support multiple displays
         val taskToMinimize = bringDesktopAppsToFrontBeforeShowingNewTask(
             DEFAULT_DISPLAY, wct, taskId)
-        val runOnTransit = immersiveTransitionHandler.exitImmersiveIfApplicable(
+        val runOnTransit = desktopImmersiveController.exitImmersiveIfApplicable(
             wct = wct,
             displayId = DEFAULT_DISPLAY,
             excludeTaskId = taskId,
@@ -403,7 +406,7 @@
         }
         logV("moveRunningTaskToDesktop taskId=%d", task.taskId)
         exitSplitIfApplicable(wct, task)
-        val runOnTransit = immersiveTransitionHandler.exitImmersiveIfApplicable(
+        val runOnTransit = desktopImmersiveController.exitImmersiveIfApplicable(
             wct = wct,
             displayId = task.displayId,
             excludeTaskId = task.taskId,
@@ -452,7 +455,7 @@
         val taskToMinimize =
             bringDesktopAppsToFrontBeforeShowingNewTask(taskInfo.displayId, wct, taskInfo.taskId)
         addMoveToDesktopChanges(wct, taskInfo)
-        val runOnTransit = immersiveTransitionHandler.exitImmersiveIfApplicable(
+        val runOnTransit = desktopImmersiveController.exitImmersiveIfApplicable(
             wct, taskInfo.displayId)
         val transition = dragToDesktopTransitionHandler.finishDragToDesktopTransition(wct)
         transition?.let {
@@ -499,7 +502,7 @@
                 taskId
             )
         )
-        return immersiveTransitionHandler.exitImmersiveIfApplicable(wct, taskInfo)
+        return desktopImmersiveController.exitImmersiveIfApplicable(wct, taskInfo)
     }
 
     fun minimizeTask(taskInfo: RunningTaskInfo) {
@@ -512,7 +515,7 @@
             removeWallpaperActivity(wct)
         }
         // Notify immersive handler as it might need to exit immersive state.
-        val runOnTransit = immersiveTransitionHandler.exitImmersiveIfApplicable(wct, taskInfo)
+        val runOnTransit = desktopImmersiveController.exitImmersiveIfApplicable(wct, taskInfo)
 
         wct.reorder(taskInfo.token, false)
         val transition = freeformTaskTransitionStarter.startMinimizedModeTransition(wct)
@@ -616,7 +619,7 @@
         logV("moveBackgroundTaskToFront taskId=%s", taskId)
         val wct = WindowContainerTransaction()
         // TODO: b/342378842 - Instead of using default display, support multiple displays
-        val runOnTransit = immersiveTransitionHandler.exitImmersiveIfApplicable(
+        val runOnTransit = desktopImmersiveController.exitImmersiveIfApplicable(
             wct = wct,
             displayId = DEFAULT_DISPLAY,
             excludeTaskId = taskId,
@@ -642,7 +645,7 @@
         logV("moveTaskToFront taskId=%s", taskInfo.taskId)
         val wct = WindowContainerTransaction()
         wct.reorder(taskInfo.token, true /* onTop */, true /* includingParents */)
-        val runOnTransit = immersiveTransitionHandler.exitImmersiveIfApplicable(
+        val runOnTransit = desktopImmersiveController.exitImmersiveIfApplicable(
             wct = wct,
             displayId = taskInfo.displayId,
             excludeTaskId = taskInfo.taskId,
@@ -749,12 +752,12 @@
 
     private fun moveDesktopTaskToFullImmersive(taskInfo: RunningTaskInfo) {
         check(taskInfo.isFreeform) { "Task must already be in freeform" }
-        immersiveTransitionHandler.moveTaskToImmersive(taskInfo)
+        desktopImmersiveController.moveTaskToImmersive(taskInfo)
     }
 
     private fun exitDesktopTaskFromFullImmersive(taskInfo: RunningTaskInfo) {
         check(taskInfo.isFreeform) { "Task must already be in freeform" }
-        immersiveTransitionHandler.moveTaskToNonImmersive(taskInfo)
+        desktopImmersiveController.moveTaskToNonImmersive(taskInfo)
     }
 
     /**
@@ -1233,6 +1236,67 @@
         return result
     }
 
+    /** Whether the given [change] in the [transition] is a known desktop change. */
+    fun isDesktopChange(
+        transition: IBinder,
+        change: TransitionInfo.Change,
+    ): Boolean {
+        // Only the immersive controller is currently involved in mixed transitions.
+        return Flags.enableFullyImmersiveInDesktop()
+                && desktopImmersiveController.isImmersiveChange(transition, change)
+    }
+
+    /**
+     * Whether the given transition [info] will potentially include a desktop change, in which
+     * case the transition should be treated as mixed so that the change is in part animated by
+     * one of the desktop transition handlers.
+     */
+    fun shouldPlayDesktopAnimation(info: TransitionRequestInfo): Boolean {
+        // Only immersive mixed transition are currently supported.
+        if (!Flags.enableFullyImmersiveInDesktop()) return false
+        val triggerTask = info.triggerTask ?: return false
+        if (!isDesktopModeShowing(triggerTask.displayId)) {
+            return false
+        }
+        if (!TransitionUtil.isOpeningType(info.type)) {
+            return false
+        }
+        taskRepository.getTaskInFullImmersiveState(displayId = triggerTask.displayId)
+            ?: return false
+        return when {
+            triggerTask.isFullscreen -> {
+                // Trigger fullscreen task will enter desktop, so any existing immersive task
+                // should exit.
+                shouldFullscreenTaskLaunchSwitchToDesktop(triggerTask)
+            }
+            triggerTask.isFreeform -> {
+                // Trigger freeform task will enter desktop, so any existing immersive task should
+                // exit.
+                !shouldFreeformTaskLaunchSwitchToFullscreen(triggerTask)
+            }
+            else -> false
+        }
+    }
+
+    /** Animate a desktop change found in a mixed transitions. */
+    fun animateDesktopChange(
+        transition: IBinder,
+        change: Change,
+        startTransaction: Transaction,
+        finishTransaction: Transaction,
+        finishCallback: TransitionFinishCallback,
+    ) {
+        if (!desktopImmersiveController.isImmersiveChange(transition, change)) {
+            throw IllegalStateException("Only immersive changes support desktop mixed transitions")
+        }
+        desktopImmersiveController.animateResizeChange(
+            change,
+            startTransaction,
+            finishTransaction,
+            finishCallback
+        )
+    }
+
     private fun taskContainsDragAndDropCookie(taskInfo: RunningTaskInfo?) =
         taskInfo?.launchCookies?.any { it == dragAndDropFullscreenCookie } ?: false
 
@@ -1279,7 +1343,7 @@
             wct.startTask(requestedTaskId, options.toBundle())
             val taskToMinimize = bringDesktopAppsToFrontBeforeShowingNewTask(
                 callingTask.displayId, wct, requestedTaskId)
-            val runOnTransit = immersiveTransitionHandler.exitImmersiveIfApplicable(
+            val runOnTransit = desktopImmersiveController.exitImmersiveIfApplicable(
                 wct = wct,
                 displayId = callingTask.displayId,
                 excludeTaskId = requestedTaskId,
@@ -1392,7 +1456,7 @@
             return null
         }
         val wct = WindowContainerTransaction()
-        if (!isDesktopModeShowing(task.displayId)) {
+        if (shouldFreeformTaskLaunchSwitchToFullscreen(task)) {
             logD("Bring desktop tasks to front on transition=taskId=%d", task.taskId)
             if (taskRepository.isActiveTask(task.taskId) && !forceEnterDesktop(task.displayId)) {
                 // We are outside of desktop mode and already existing desktop task is being
@@ -1423,7 +1487,7 @@
         }
         // Desktop Mode is showing and we're launching a new Task:
         // 1) Exit immersive if needed.
-        immersiveTransitionHandler.exitImmersiveIfApplicable(transition, wct, task.displayId)
+        desktopImmersiveController.exitImmersiveIfApplicable(transition, wct, task.displayId)
         // 2) minimize a Task if needed.
         val taskToMinimize = addAndGetMinimizeChangesIfNeeded(task.displayId, wct, task.taskId)
         if (taskToMinimize != null) {
@@ -1438,7 +1502,7 @@
         transition: IBinder
     ): WindowContainerTransaction? {
         logV("handleFullscreenTaskLaunch")
-        if (isDesktopModeShowing(task.displayId) || forceEnterDesktop(task.displayId)) {
+        if (shouldFullscreenTaskLaunchSwitchToDesktop(task)) {
             logD("Switch fullscreen task to freeform on transition: taskId=%d", task.taskId)
             return WindowContainerTransaction().also { wct ->
                 addMoveToDesktopChanges(wct, task)
@@ -1454,7 +1518,7 @@
                 val taskToMinimize =
                     addAndGetMinimizeChangesIfNeeded(task.displayId, wct, task.taskId)
                 addPendingMinimizeTransition(transition, taskToMinimize)
-                immersiveTransitionHandler.exitImmersiveIfApplicable(
+                desktopImmersiveController.exitImmersiveIfApplicable(
                     transition, wct, task.displayId
                 )
             }
@@ -1462,6 +1526,12 @@
         return null
     }
 
+    private fun shouldFreeformTaskLaunchSwitchToFullscreen(task: RunningTaskInfo): Boolean =
+        !isDesktopModeShowing(task.displayId)
+
+    private fun shouldFullscreenTaskLaunchSwitchToDesktop(task: RunningTaskInfo): Boolean =
+        isDesktopModeShowing(task.displayId) || forceEnterDesktop(task.displayId)
+
     /**
      * If a task is not compatible with desktop mode freeform, it should always be launched in
      * fullscreen.
diff --git a/libs/WindowManager/Shell/src/com/android/wm/shell/freeform/FreeformTaskTransitionObserver.java b/libs/WindowManager/Shell/src/com/android/wm/shell/freeform/FreeformTaskTransitionObserver.java
index 771573d..7631ece 100644
--- a/libs/WindowManager/Shell/src/com/android/wm/shell/freeform/FreeformTaskTransitionObserver.java
+++ b/libs/WindowManager/Shell/src/com/android/wm/shell/freeform/FreeformTaskTransitionObserver.java
@@ -28,7 +28,7 @@
 import androidx.annotation.VisibleForTesting;
 
 import com.android.window.flags.Flags;
-import com.android.wm.shell.desktopmode.DesktopFullImmersiveTransitionHandler;
+import com.android.wm.shell.desktopmode.DesktopImmersiveController;
 import com.android.wm.shell.sysui.ShellInit;
 import com.android.wm.shell.transition.FocusTransitionObserver;
 import com.android.wm.shell.transition.Transitions;
@@ -48,7 +48,7 @@
  */
 public class FreeformTaskTransitionObserver implements Transitions.TransitionObserver {
     private final Transitions mTransitions;
-    private final Optional<DesktopFullImmersiveTransitionHandler> mImmersiveTransitionHandler;
+    private final Optional<DesktopImmersiveController> mDesktopImmersiveController;
     private final WindowDecorViewModel mWindowDecorViewModel;
     private final Optional<TaskChangeListener> mTaskChangeListener;
     private final FocusTransitionObserver mFocusTransitionObserver;
@@ -60,12 +60,12 @@
             Context context,
             ShellInit shellInit,
             Transitions transitions,
-            Optional<DesktopFullImmersiveTransitionHandler> immersiveTransitionHandler,
+            Optional<DesktopImmersiveController> desktopImmersiveController,
             WindowDecorViewModel windowDecorViewModel,
             Optional<TaskChangeListener> taskChangeListener,
             FocusTransitionObserver focusTransitionObserver) {
         mTransitions = transitions;
-        mImmersiveTransitionHandler = immersiveTransitionHandler;
+        mDesktopImmersiveController = desktopImmersiveController;
         mWindowDecorViewModel = windowDecorViewModel;
         mTaskChangeListener = taskChangeListener;
         mFocusTransitionObserver = focusTransitionObserver;
@@ -89,7 +89,8 @@
             // TODO(b/367268953): Remove when DesktopTaskListener is introduced and the repository
             //  is updated from there **before** the |mWindowDecorViewModel| methods are invoked.
             //  Otherwise window decoration relayout won't run with the immersive state up to date.
-            mImmersiveTransitionHandler.ifPresent(h -> h.onTransitionReady(transition, info));
+            mDesktopImmersiveController.ifPresent(h ->
+                    h.onTransitionReady(transition, info, startT, finishT));
         }
         // Update focus state first to ensure the correct state can be queried from listeners.
         // TODO(371503964): Remove this once the unified task repository is ready.
@@ -194,10 +195,20 @@
     }
 
     @Override
-    public void onTransitionStarting(@NonNull IBinder transition) {}
+    public void onTransitionStarting(@NonNull IBinder transition) {
+        if (Flags.enableFullyImmersiveInDesktop()) {
+            // TODO(b/367268953): Remove when DesktopTaskListener is introduced.
+            mDesktopImmersiveController.ifPresent(h -> h.onTransitionStarting(transition));
+        }
+    }
 
     @Override
     public void onTransitionMerged(@NonNull IBinder merged, @NonNull IBinder playing) {
+        if (Flags.enableFullyImmersiveInDesktop()) {
+            // TODO(b/367268953): Remove when DesktopTaskListener is introduced.
+            mDesktopImmersiveController.ifPresent(h -> h.onTransitionMerged(merged, playing));
+        }
+
         final List<ActivityManager.RunningTaskInfo> infoOfMerged =
                 mTransitionToTaskInfo.get(merged);
         if (infoOfMerged == null) {
@@ -218,6 +229,11 @@
 
     @Override
     public void onTransitionFinished(@NonNull IBinder transition, boolean aborted) {
+        if (Flags.enableFullyImmersiveInDesktop()) {
+            // TODO(b/367268953): Remove when DesktopTaskListener is introduced.
+            mDesktopImmersiveController.ifPresent(h -> h.onTransitionFinished(transition, aborted));
+        }
+
         final List<ActivityManager.RunningTaskInfo> taskInfo =
                 mTransitionToTaskInfo.getOrDefault(transition, Collections.emptyList());
         mTransitionToTaskInfo.remove(transition);
diff --git a/libs/WindowManager/Shell/src/com/android/wm/shell/transition/DefaultMixedHandler.java b/libs/WindowManager/Shell/src/com/android/wm/shell/transition/DefaultMixedHandler.java
index 766a6b3..0d89f75 100644
--- a/libs/WindowManager/Shell/src/com/android/wm/shell/transition/DefaultMixedHandler.java
+++ b/libs/WindowManager/Shell/src/com/android/wm/shell/transition/DefaultMixedHandler.java
@@ -83,8 +83,11 @@
         /** Both the display and split-state (enter/exit) is changing */
         static final int TYPE_DISPLAY_AND_SPLIT_CHANGE = 2;
 
-        /** Pip was entered while handling an intent with its own remoteTransition. */
-        static final int TYPE_OPTIONS_REMOTE_AND_PIP_CHANGE = 3;
+        /**
+         * While handling an intent with its own remoteTransition, a PIP enter or Desktop immersive
+         * exit change is found.
+         */
+        static final int TYPE_OPTIONS_REMOTE_AND_PIP_OR_DESKTOP_CHANGE = 3;
 
         /** Recents transition while split-screen foreground. */
         static final int TYPE_RECENTS_DURING_SPLIT = 4;
@@ -110,6 +113,9 @@
         /** The display changes when pip is entering. */
         static final int TYPE_ENTER_PIP_WITH_DISPLAY_CHANGE = 11;
 
+        /** Open transition during a desktop session. */
+        static final int TYPE_OPEN_IN_DESKTOP = 12;
+
         /** The default animation for this mixed transition. */
         static final int ANIM_TYPE_DEFAULT = 0;
 
@@ -296,7 +302,7 @@
                 return null;
             }
             final MixedTransition mixed = createDefaultMixedTransition(
-                    MixedTransition.TYPE_OPTIONS_REMOTE_AND_PIP_CHANGE, transition);
+                    MixedTransition.TYPE_OPTIONS_REMOTE_AND_PIP_OR_DESKTOP_CHANGE, transition);
             mixed.mLeftoversHandler = handler.first;
             mActiveTransitions.add(mixed);
             if (mixed.mLeftoversHandler != mPlayer.getRemoteTransitionHandler()) {
@@ -334,6 +340,20 @@
                         MixedTransition.TYPE_UNFOLD, transition));
             }
             return wct;
+        } else if (mDesktopTasksController != null
+                && mDesktopTasksController.shouldPlayDesktopAnimation(request)) {
+            final Pair<Transitions.TransitionHandler, WindowContainerTransaction> handler =
+                    mPlayer.dispatchRequest(transition, request, /* skip= */ this);
+            if (handler == null) {
+                return null;
+            }
+            ProtoLog.v(ShellProtoLogGroup.WM_SHELL_TRANSITIONS, " Got a desktop request, so"
+                    + " treat it as Mixed. handler=%s", handler.first);
+            final MixedTransition mixed = createDefaultMixedTransition(
+                    MixedTransition.TYPE_OPEN_IN_DESKTOP, transition);
+            mixed.mLeftoversHandler = handler.first;
+            mActiveTransitions.add(mixed);
+            return handler.second;
         }
         return null;
     }
@@ -341,7 +361,7 @@
     private DefaultMixedTransition createDefaultMixedTransition(int type, IBinder transition) {
         return new DefaultMixedTransition(
                 type, transition, mPlayer, this, mPipHandler, mSplitHandler, mKeyguardHandler,
-                mUnfoldHandler, mActivityEmbeddingController);
+                mUnfoldHandler, mActivityEmbeddingController, mDesktopTasksController);
     }
 
     @Override
diff --git a/libs/WindowManager/Shell/src/com/android/wm/shell/transition/DefaultMixedTransition.java b/libs/WindowManager/Shell/src/com/android/wm/shell/transition/DefaultMixedTransition.java
index c8921d2..3d3de88 100644
--- a/libs/WindowManager/Shell/src/com/android/wm/shell/transition/DefaultMixedTransition.java
+++ b/libs/WindowManager/Shell/src/com/android/wm/shell/transition/DefaultMixedTransition.java
@@ -30,6 +30,7 @@
 
 import com.android.internal.protolog.ProtoLog;
 import com.android.wm.shell.activityembedding.ActivityEmbeddingController;
+import com.android.wm.shell.desktopmode.DesktopTasksController;
 import com.android.wm.shell.keyguard.KeyguardTransitionHandler;
 import com.android.wm.shell.pip.PipTransitionController;
 import com.android.wm.shell.protolog.ShellProtoLogGroup;
@@ -39,15 +40,19 @@
 class DefaultMixedTransition extends DefaultMixedHandler.MixedTransition {
     private final UnfoldTransitionHandler mUnfoldHandler;
     private final ActivityEmbeddingController mActivityEmbeddingController;
+    @Nullable
+    private final DesktopTasksController mDesktopTasksController;
 
     DefaultMixedTransition(int type, IBinder transition, Transitions player,
             MixedTransitionHandler mixedHandler, PipTransitionController pipHandler,
             StageCoordinator splitHandler, KeyguardTransitionHandler keyguardHandler,
             UnfoldTransitionHandler unfoldHandler,
-            ActivityEmbeddingController activityEmbeddingController) {
+            ActivityEmbeddingController activityEmbeddingController,
+            @Nullable DesktopTasksController desktopTasksController) {
         super(type, transition, player, mixedHandler, pipHandler, splitHandler, keyguardHandler);
         mUnfoldHandler = unfoldHandler;
         mActivityEmbeddingController = activityEmbeddingController;
+        mDesktopTasksController = desktopTasksController;
 
         switch (type) {
             case TYPE_UNFOLD:
@@ -57,7 +62,8 @@
             case TYPE_ENTER_PIP_FROM_ACTIVITY_EMBEDDING:
             case TYPE_ENTER_PIP_FROM_SPLIT:
             case TYPE_KEYGUARD:
-            case TYPE_OPTIONS_REMOTE_AND_PIP_CHANGE:
+            case TYPE_OPTIONS_REMOTE_AND_PIP_OR_DESKTOP_CHANGE:
+            case TYPE_OPEN_IN_DESKTOP:
             default:
                 break;
         }
@@ -85,11 +91,14 @@
             case TYPE_KEYGUARD ->
                     animateKeyguard(this, info, startTransaction, finishTransaction, finishCallback,
                             mKeyguardHandler, mPipHandler);
-            case TYPE_OPTIONS_REMOTE_AND_PIP_CHANGE ->
-                    animateOpenIntentWithRemoteAndPip(transition, info, startTransaction,
+            case TYPE_OPTIONS_REMOTE_AND_PIP_OR_DESKTOP_CHANGE ->
+                    animateOpenIntentWithRemoteAndPipOrDesktop(transition, info, startTransaction,
                             finishTransaction, finishCallback);
             case TYPE_UNFOLD ->
                     animateUnfold(info, startTransaction, finishTransaction, finishCallback);
+            case TYPE_OPEN_IN_DESKTOP ->
+                    animateOpenInDesktop(
+                            transition, info, startTransaction, finishTransaction, finishCallback);
             default -> throw new IllegalStateException(
                     "Starting default mixed animation with unknown or illegal type: " + mType);
         };
@@ -146,31 +155,34 @@
         return true;
     }
 
-    private boolean animateOpenIntentWithRemoteAndPip(
+    private boolean animateOpenIntentWithRemoteAndPipOrDesktop(
             @NonNull IBinder transition, @NonNull TransitionInfo info,
             @NonNull SurfaceControl.Transaction startTransaction,
             @NonNull SurfaceControl.Transaction finishTransaction,
             @NonNull Transitions.TransitionFinishCallback finishCallback) {
         ProtoLog.v(ShellProtoLogGroup.WM_SHELL_TRANSITIONS, "Mixed transition for opening an intent"
-                + " with a remote transition and PIP #%d", info.getDebugId());
-        boolean handledToPip = tryAnimateOpenIntentWithRemoteAndPip(
+                + " with a remote transition and PIP or Desktop #%d", info.getDebugId());
+        boolean handledToPipOrDesktop = tryAnimateOpenIntentWithRemoteAndPipOrDesktop(
                 info, startTransaction, finishTransaction, finishCallback);
         // Consume the transition on remote handler if the leftover handler already handle this
         // transition. And if it cannot, the transition will be handled by remote handler, so don't
         // consume here.
-        // Need to check leftOverHandler as it may change in #animateOpenIntentWithRemoteAndPip
-        if (handledToPip && mHasRequestToRemote
+        // Need to check leftOverHandler as it may change in
+        // #animateOpenIntentWithRemoteAndPipOrDesktop
+        if (handledToPipOrDesktop && mHasRequestToRemote
                 && mLeftoversHandler != mPlayer.getRemoteTransitionHandler()) {
             mPlayer.getRemoteTransitionHandler().onTransitionConsumed(transition, false, null);
         }
-        return handledToPip;
+        return handledToPipOrDesktop;
     }
 
-    private boolean tryAnimateOpenIntentWithRemoteAndPip(
+    private boolean tryAnimateOpenIntentWithRemoteAndPipOrDesktop(
             @NonNull TransitionInfo info,
             @NonNull SurfaceControl.Transaction startTransaction,
             @NonNull SurfaceControl.Transaction finishTransaction,
             @NonNull Transitions.TransitionFinishCallback finishCallback) {
+        ProtoLog.v(ShellProtoLogGroup.WM_SHELL_TRANSITIONS,
+                "tryAnimateOpenIntentWithRemoteAndPipOrDesktop");
         TransitionInfo.Change pipChange = null;
         for (int i = info.getChanges().size() - 1; i >= 0; --i) {
             TransitionInfo.Change change = info.getChanges().get(i);
@@ -183,13 +195,31 @@
                 info.getChanges().remove(i);
             }
         }
+        TransitionInfo.Change desktopChange = null;
+        for (int i = info.getChanges().size() - 1; i >= 0; --i) {
+            TransitionInfo.Change change = info.getChanges().get(i);
+            if (mDesktopTasksController != null
+                    && mDesktopTasksController.isDesktopChange(mTransition, change)) {
+                if (desktopChange != null) {
+                    throw new IllegalStateException("More than 1 desktop changes in one"
+                            + " transition? " + info);
+                }
+                desktopChange = change;
+                info.getChanges().remove(i);
+            }
+        }
         Transitions.TransitionFinishCallback finishCB = (wct) -> {
             --mInFlightSubAnimations;
             joinFinishArgs(wct);
             if (mInFlightSubAnimations > 0) return;
             finishCallback.onTransitionFinished(mFinishWCT);
         };
-        if (pipChange == null) {
+        if ((pipChange == null && desktopChange == null)
+                || (pipChange != null && desktopChange != null)) {
+            // Don't split the transition. Let the leftovers handler handle it all.
+            // TODO: b/? - split the transition into three pieces when there's both a PIP and a
+            //  desktop change are present. For example, during remote intent open over a desktop
+            //  with both a PIP capable task and an immersive task.
             if (mLeftoversHandler != null) {
                 mInFlightSubAnimations = 1;
                 if (mLeftoversHandler.startAnimation(
@@ -198,27 +228,52 @@
                 }
             }
             return false;
-        }
-        ProtoLog.v(ShellProtoLogGroup.WM_SHELL_TRANSITIONS, "Splitting PIP into a separate"
-                + " animation because remote-animation likely doesn't support it #%d",
-                info.getDebugId());
-        // Split the transition into 2 parts: the pip part and the rest.
-        mInFlightSubAnimations = 2;
-        // make a new startTransaction because pip's startEnterAnimation "consumes" it so
-        // we need a separate one to send over to launcher.
-        SurfaceControl.Transaction otherStartT = new SurfaceControl.Transaction();
+        } else if (pipChange != null && desktopChange == null) {
+            ProtoLog.v(ShellProtoLogGroup.WM_SHELL_TRANSITIONS, "Splitting PIP into a separate"
+                            + " animation because remote-animation likely doesn't support it #%d",
+                    info.getDebugId());
+            // Split the transition into 2 parts: the pip part and the rest.
+            mInFlightSubAnimations = 2;
+            // make a new startTransaction because pip's startEnterAnimation "consumes" it so
+            // we need a separate one to send over to launcher.
+            SurfaceControl.Transaction otherStartT = new SurfaceControl.Transaction();
 
-        mPipHandler.startEnterAnimation(pipChange, otherStartT, finishTransaction, finishCB);
+            mPipHandler.startEnterAnimation(pipChange, otherStartT, finishTransaction, finishCB);
 
-        // Dispatch the rest of the transition normally.
-        if (mLeftoversHandler != null
-                && mLeftoversHandler.startAnimation(mTransition, info,
-                startTransaction, finishTransaction, finishCB)) {
+            // Dispatch the rest of the transition normally.
+            if (mLeftoversHandler != null
+                    && mLeftoversHandler.startAnimation(mTransition, info,
+                    startTransaction, finishTransaction, finishCB)) {
+                return true;
+            }
+            mLeftoversHandler = mPlayer.dispatchTransition(
+                    mTransition, info, startTransaction, finishTransaction, finishCB,
+                    mMixedHandler);
             return true;
+        } else if (pipChange == null && desktopChange != null) {
+            ProtoLog.v(ShellProtoLogGroup.WM_SHELL_TRANSITIONS, "Splitting desktop change into a"
+                            + "separate animation because remote-animation likely doesn't support"
+                            + "it #%d", info.getDebugId());
+            mInFlightSubAnimations = 2;
+            SurfaceControl.Transaction otherStartT = new SurfaceControl.Transaction();
+
+            mDesktopTasksController.animateDesktopChange(
+                            mTransition, desktopChange, otherStartT, finishTransaction, finishCB);
+
+            // Dispatch the rest of the transition normally.
+            if (mLeftoversHandler != null
+                    && mLeftoversHandler.startAnimation(mTransition, info,
+                    startTransaction, finishTransaction, finishCB)) {
+                return true;
+            }
+            mLeftoversHandler = mPlayer.dispatchTransition(
+                    mTransition, info, startTransaction, finishTransaction, finishCB,
+                    mMixedHandler);
+            return true;
+        } else {
+            throw new IllegalStateException(
+                    "All PIP and Immersive combinations should've been handled");
         }
-        mLeftoversHandler = mPlayer.dispatchTransition(
-                mTransition, info, startTransaction, finishTransaction, finishCB, mMixedHandler);
-        return true;
     }
 
     private boolean animateUnfold(
@@ -246,6 +301,51 @@
                 mTransition, info, startTransaction, finishTransaction, finishCB);
     }
 
+    private boolean animateOpenInDesktop(
+            @NonNull IBinder transition,
+            @NonNull TransitionInfo info,
+            @NonNull SurfaceControl.Transaction startTransaction,
+            @NonNull SurfaceControl.Transaction finishTransaction,
+            @NonNull Transitions.TransitionFinishCallback finishCallback) {
+        ProtoLog.v(ShellProtoLogGroup.WM_SHELL_TRANSITIONS, "animateOpenInDesktop");
+        TransitionInfo.Change desktopChange = null;
+        for (int i = info.getChanges().size() - 1; i >= 0; --i) {
+            TransitionInfo.Change change = info.getChanges().get(i);
+            if (mDesktopTasksController.isDesktopChange(mTransition, change)) {
+                if (desktopChange != null) {
+                    throw new IllegalStateException("More than 1 desktop changes in one"
+                            + " transition? " + info);
+                }
+                desktopChange = change;
+                info.getChanges().remove(i);
+            }
+        }
+        final Transitions.TransitionFinishCallback finishCB = (wct) -> {
+            --mInFlightSubAnimations;
+            joinFinishArgs(wct);
+            if (mInFlightSubAnimations > 0) return;
+            finishCallback.onTransitionFinished(mFinishWCT);
+        };
+        if (desktopChange == null) {
+            if (mLeftoversHandler != null) {
+                mInFlightSubAnimations = 1;
+                if (mLeftoversHandler.startAnimation(
+                        mTransition, info, startTransaction, finishTransaction, finishCB)) {
+                    return true;
+                }
+            }
+            return false;
+        }
+        ProtoLog.v(ShellProtoLogGroup.WM_SHELL_TRANSITIONS, "Splitting desktop change into a"
+                + "separate animation #%d", info.getDebugId());
+        mInFlightSubAnimations = 2;
+        mDesktopTasksController.animateDesktopChange(
+                transition, desktopChange, startTransaction, finishTransaction, finishCB);
+        mLeftoversHandler = mPlayer.dispatchTransition(
+                mTransition, info, startTransaction, finishTransaction, finishCB, mMixedHandler);
+        return true;
+    }
+
     @Override
     void mergeAnimation(
             @NonNull IBinder transition, @NonNull TransitionInfo info,
@@ -279,7 +379,7 @@
             case TYPE_KEYGUARD:
                 mKeyguardHandler.mergeAnimation(transition, info, t, mergeTarget, finishCallback);
                 return;
-            case TYPE_OPTIONS_REMOTE_AND_PIP_CHANGE:
+            case TYPE_OPTIONS_REMOTE_AND_PIP_OR_DESKTOP_CHANGE:
                 mPipHandler.end();
                 if (mLeftoversHandler != null) {
                     mLeftoversHandler.mergeAnimation(
@@ -289,6 +389,10 @@
             case TYPE_UNFOLD:
                 mUnfoldHandler.mergeAnimation(transition, info, t, mergeTarget, finishCallback);
                 return;
+            case TYPE_OPEN_IN_DESKTOP:
+                mDesktopTasksController.mergeAnimation(
+                        transition, info, t, mergeTarget, finishCallback);
+                return;
             default:
                 throw new IllegalStateException("Playing a default mixed transition with unknown or"
                         + " illegal type: " + mType);
@@ -310,12 +414,14 @@
             case TYPE_KEYGUARD:
                 mKeyguardHandler.onTransitionConsumed(transition, aborted, finishT);
                 break;
-            case TYPE_OPTIONS_REMOTE_AND_PIP_CHANGE:
+            case TYPE_OPTIONS_REMOTE_AND_PIP_OR_DESKTOP_CHANGE:
                 mLeftoversHandler.onTransitionConsumed(transition, aborted, finishT);
                 break;
             case TYPE_UNFOLD:
                 mUnfoldHandler.onTransitionConsumed(transition, aborted, finishT);
                 break;
+            case TYPE_OPEN_IN_DESKTOP:
+                mDesktopTasksController.onTransitionConsumed(transition, aborted, finishT);
             default:
                 break;
         }
diff --git a/libs/WindowManager/Shell/tests/unittest/src/com/android/wm/shell/desktopmode/DesktopFullImmersiveTransitionHandlerTest.kt b/libs/WindowManager/Shell/tests/unittest/src/com/android/wm/shell/desktopmode/DesktopImmersiveControllerTest.kt
similarity index 72%
rename from libs/WindowManager/Shell/tests/unittest/src/com/android/wm/shell/desktopmode/DesktopFullImmersiveTransitionHandlerTest.kt
rename to libs/WindowManager/Shell/tests/unittest/src/com/android/wm/shell/desktopmode/DesktopImmersiveControllerTest.kt
index 5842dfa..e83f5c7 100644
--- a/libs/WindowManager/Shell/tests/unittest/src/com/android/wm/shell/desktopmode/DesktopFullImmersiveTransitionHandlerTest.kt
+++ b/libs/WindowManager/Shell/tests/unittest/src/com/android/wm/shell/desktopmode/DesktopImmersiveControllerTest.kt
@@ -15,6 +15,7 @@
  */
 package com.android.wm.shell.desktopmode
 
+import android.app.ActivityManager.RunningTaskInfo
 import android.app.WindowConfiguration.WINDOW_CONFIG_BOUNDS
 import android.graphics.Rect
 import android.os.Binder
@@ -58,13 +59,13 @@
 import org.mockito.kotlin.whenever
 
 /**
- * Tests for [DesktopFullImmersiveTransitionHandler].
+ * Tests for [DesktopImmersiveController].
  *
- * Usage: atest WMShellUnitTests:DesktopFullImmersiveTransitionHandlerTest
+ * Usage: atest WMShellUnitTests:DesktopImmersiveControllerTest
  */
 @SmallTest
 @RunWith(AndroidTestingRunner::class)
-class DesktopFullImmersiveTransitionHandlerTest : ShellTestCase() {
+class DesktopImmersiveControllerTest : ShellTestCase() {
 
     @JvmField @Rule val setFlagsRule = SetFlagsRule()
 
@@ -75,7 +76,7 @@
     @Mock private lateinit var mockDisplayLayout: DisplayLayout
     private val transactionSupplier = { SurfaceControl.Transaction() }
 
-    private lateinit var immersiveHandler: DesktopFullImmersiveTransitionHandler
+    private lateinit var controller: DesktopImmersiveController
 
     @Before
     fun setUp() {
@@ -87,7 +88,7 @@
         whenever(mockDisplayLayout.getStableBounds(any())).thenAnswer { invocation ->
             (invocation.getArgument(0) as Rect).set(STABLE_BOUNDS)
         }
-        immersiveHandler = DesktopFullImmersiveTransitionHandler(
+        controller = DesktopImmersiveController(
             transitions = mockTransitions,
             desktopRepository = desktopRepository,
             displayController = mockDisplayController,
@@ -100,7 +101,7 @@
     fun enterImmersive_transitionReady_updatesRepository() {
         val task = createFreeformTask()
         val mockBinder = mock(IBinder::class.java)
-        whenever(mockTransitions.startTransition(eq(TRANSIT_CHANGE), any(), eq(immersiveHandler)))
+        whenever(mockTransitions.startTransition(eq(TRANSIT_CHANGE), any(), eq(controller)))
             .thenReturn(mockBinder)
         desktopRepository.setTaskInFullImmersiveState(
             displayId = task.displayId,
@@ -108,16 +109,14 @@
             immersive = false
         )
 
-        immersiveHandler.moveTaskToImmersive(task)
-        immersiveHandler.onTransitionReady(
+        controller.moveTaskToImmersive(task)
+        controller.onTransitionReady(
             transition = mockBinder,
             info = createTransitionInfo(
-                changes = listOf(
-                    TransitionInfo.Change(task.token, SurfaceControl()).apply {
-                        taskInfo = task
-                    }
-                )
-            )
+                changes = listOf(createChange(task))
+            ),
+            startTransaction = SurfaceControl.Transaction(),
+            finishTransaction = SurfaceControl.Transaction(),
         )
 
         assertThat(desktopRepository.isTaskInFullImmersiveState(task.taskId)).isTrue()
@@ -128,7 +127,7 @@
     fun enterImmersive_savesPreImmersiveBounds() {
         val task = createFreeformTask()
         val mockBinder = mock(IBinder::class.java)
-        whenever(mockTransitions.startTransition(eq(TRANSIT_CHANGE), any(), eq(immersiveHandler)))
+        whenever(mockTransitions.startTransition(eq(TRANSIT_CHANGE), any(), eq(controller)))
             .thenReturn(mockBinder)
         desktopRepository.setTaskInFullImmersiveState(
             displayId = task.displayId,
@@ -137,16 +136,14 @@
         )
         assertThat(desktopRepository.removeBoundsBeforeFullImmersive(task.taskId)).isNull()
 
-        immersiveHandler.moveTaskToImmersive(task)
-        immersiveHandler.onTransitionReady(
+        controller.moveTaskToImmersive(task)
+        controller.onTransitionReady(
             transition = mockBinder,
             info = createTransitionInfo(
-                changes = listOf(
-                    TransitionInfo.Change(task.token, SurfaceControl()).apply {
-                        taskInfo = task
-                    }
-                )
-            )
+                changes = listOf(createChange(task))
+            ),
+            startTransaction = SurfaceControl.Transaction(),
+            finishTransaction = SurfaceControl.Transaction(),
         )
 
         assertThat(desktopRepository.removeBoundsBeforeFullImmersive(task.taskId)).isNotNull()
@@ -156,7 +153,7 @@
     fun exitImmersive_transitionReady_updatesRepository() {
         val task = createFreeformTask()
         val mockBinder = mock(IBinder::class.java)
-        whenever(mockTransitions.startTransition(eq(TRANSIT_CHANGE), any(), eq(immersiveHandler)))
+        whenever(mockTransitions.startTransition(eq(TRANSIT_CHANGE), any(), eq(controller)))
             .thenReturn(mockBinder)
         desktopRepository.setTaskInFullImmersiveState(
             displayId = task.displayId,
@@ -164,16 +161,14 @@
             immersive = true
         )
 
-        immersiveHandler.moveTaskToNonImmersive(task)
-        immersiveHandler.onTransitionReady(
+        controller.moveTaskToNonImmersive(task)
+        controller.onTransitionReady(
             transition = mockBinder,
             info = createTransitionInfo(
-                changes = listOf(
-                    TransitionInfo.Change(task.token, SurfaceControl()).apply {
-                        taskInfo = task
-                    }
-                )
-            )
+                changes = listOf(createChange(task))
+            ),
+            startTransaction = SurfaceControl.Transaction(),
+            finishTransaction = SurfaceControl.Transaction(),
         )
 
         assertThat(desktopRepository.isTaskInFullImmersiveState(task.taskId)).isFalse()
@@ -184,7 +179,7 @@
     fun exitImmersive_onTransitionReady_removesBoundsBeforeImmersive() {
         val task = createFreeformTask()
         val mockBinder = mock(IBinder::class.java)
-        whenever(mockTransitions.startTransition(eq(TRANSIT_CHANGE), any(), eq(immersiveHandler)))
+        whenever(mockTransitions.startTransition(eq(TRANSIT_CHANGE), any(), eq(controller)))
             .thenReturn(mockBinder)
         desktopRepository.setTaskInFullImmersiveState(
             displayId = task.displayId,
@@ -193,16 +188,14 @@
         )
         desktopRepository.saveBoundsBeforeFullImmersive(task.taskId, Rect(100, 100, 600, 600))
 
-        immersiveHandler.moveTaskToNonImmersive(task)
-        immersiveHandler.onTransitionReady(
+        controller.moveTaskToNonImmersive(task)
+        controller.onTransitionReady(
             transition = mockBinder,
             info = createTransitionInfo(
-                changes = listOf(
-                    TransitionInfo.Change(task.token, SurfaceControl()).apply {
-                        taskInfo = task
-                    }
-                )
-            )
+                changes = listOf(createChange(task))
+            ),
+            startTransaction = SurfaceControl.Transaction(),
+            finishTransaction = SurfaceControl.Transaction(),
         )
 
         assertThat(desktopRepository.removeBoundsBeforeMaximize(task.taskId)).isNull()
@@ -217,16 +210,15 @@
             immersive = true
         )
 
-        immersiveHandler.onTransitionReady(
+        controller.onTransitionReady(
             transition = mock(IBinder::class.java),
             info = createTransitionInfo(
-                changes = listOf(
-                    TransitionInfo.Change(task.token, SurfaceControl()).apply {
-                        taskInfo = task
-                        setRotation(/* start= */ Surface.ROTATION_0, /* end= */ Surface.ROTATION_90)
-                    }
-                )
-            )
+                changes = listOf(createChange(task).apply {
+                    setRotation(/* start= */ Surface.ROTATION_0, /* end= */ Surface.ROTATION_90)
+                })
+            ),
+            startTransaction = SurfaceControl.Transaction(),
+            finishTransaction = SurfaceControl.Transaction(),
         )
 
         assertThat(desktopRepository.isTaskInFullImmersiveState(task.taskId)).isFalse()
@@ -236,28 +228,28 @@
     fun enterImmersive_inProgress_ignores() {
         val task = createFreeformTask()
         val mockBinder = mock(IBinder::class.java)
-        whenever(mockTransitions.startTransition(eq(TRANSIT_CHANGE), any(), eq(immersiveHandler)))
+        whenever(mockTransitions.startTransition(eq(TRANSIT_CHANGE), any(), eq(controller)))
             .thenReturn(mockBinder)
 
-        immersiveHandler.moveTaskToImmersive(task)
-        immersiveHandler.moveTaskToImmersive(task)
+        controller.moveTaskToImmersive(task)
+        controller.moveTaskToImmersive(task)
 
         verify(mockTransitions, times(1))
-            .startTransition(eq(TRANSIT_CHANGE), any(), eq(immersiveHandler))
+            .startTransition(eq(TRANSIT_CHANGE), any(), eq(controller))
     }
 
     @Test
     fun exitImmersive_inProgress_ignores() {
         val task = createFreeformTask()
         val mockBinder = mock(IBinder::class.java)
-        whenever(mockTransitions.startTransition(eq(TRANSIT_CHANGE), any(), eq(immersiveHandler)))
+        whenever(mockTransitions.startTransition(eq(TRANSIT_CHANGE), any(), eq(controller)))
             .thenReturn(mockBinder)
 
-        immersiveHandler.moveTaskToNonImmersive(task)
-        immersiveHandler.moveTaskToNonImmersive(task)
+        controller.moveTaskToNonImmersive(task)
+        controller.moveTaskToNonImmersive(task)
 
         verify(mockTransitions, times(1))
-            .startTransition(eq(TRANSIT_CHANGE), any(), eq(immersiveHandler))
+            .startTransition(eq(TRANSIT_CHANGE), any(), eq(controller))
     }
 
     @Test
@@ -273,9 +265,9 @@
             immersive = true
         )
 
-        immersiveHandler.exitImmersiveIfApplicable(transition, wct, DEFAULT_DISPLAY)
+        controller.exitImmersiveIfApplicable(transition, wct, DEFAULT_DISPLAY)
 
-        assertThat(immersiveHandler.pendingExternalExitTransitions.any { exit ->
+        assertThat(controller.pendingExternalExitTransitions.any { exit ->
             exit.transition == transition && exit.displayId == DEFAULT_DISPLAY
                     && exit.taskId == task.taskId
         }).isTrue()
@@ -294,9 +286,9 @@
             immersive = false
         )
 
-        immersiveHandler.exitImmersiveIfApplicable(transition, wct, DEFAULT_DISPLAY)
+        controller.exitImmersiveIfApplicable(transition, wct, DEFAULT_DISPLAY)
 
-        assertThat(immersiveHandler.pendingExternalExitTransitions.any { exit ->
+        assertThat(controller.pendingExternalExitTransitions.any { exit ->
             exit.transition == transition && exit.displayId == DEFAULT_DISPLAY
                     && exit.taskId == task.taskId
         }).isFalse()
@@ -315,7 +307,7 @@
             immersive = true
         )
 
-        immersiveHandler.exitImmersiveIfApplicable(transition, wct, DEFAULT_DISPLAY)
+        controller.exitImmersiveIfApplicable(transition, wct, DEFAULT_DISPLAY)
 
         assertThat(wct.hasBoundsChange(task.token)).isTrue()
     }
@@ -333,7 +325,7 @@
             immersive = false
         )
 
-        immersiveHandler.exitImmersiveIfApplicable(transition, wct, DEFAULT_DISPLAY)
+        controller.exitImmersiveIfApplicable(transition, wct, DEFAULT_DISPLAY)
 
         assertThat(wct.hasBoundsChange(task.token)).isFalse()
     }
@@ -351,13 +343,13 @@
             immersive = true
         )
 
-        immersiveHandler.exitImmersiveIfApplicable(
+        controller.exitImmersiveIfApplicable(
             wct = wct,
             displayId = DEFAULT_DISPLAY,
             excludeTaskId = task.taskId
         )?.invoke(transition)
 
-        assertThat(immersiveHandler.pendingExternalExitTransitions.any { exit ->
+        assertThat(controller.pendingExternalExitTransitions.any { exit ->
             exit.transition == transition && exit.displayId == DEFAULT_DISPLAY
                     && exit.taskId == task.taskId
         }).isFalse()
@@ -375,7 +367,7 @@
             immersive = true
         )
 
-        immersiveHandler.exitImmersiveIfApplicable(wct = wct, taskInfo = task)
+        controller.exitImmersiveIfApplicable(wct = wct, taskInfo = task)
 
         assertThat(wct.hasBoundsChange(task.token)).isTrue()
     }
@@ -392,7 +384,7 @@
             immersive = false
         )
 
-        immersiveHandler.exitImmersiveIfApplicable(wct, task)
+        controller.exitImmersiveIfApplicable(wct, task)
 
         assertThat(wct.hasBoundsChange(task.token)).isFalse()
     }
@@ -410,9 +402,9 @@
             immersive = true
         )
 
-        immersiveHandler.exitImmersiveIfApplicable(wct, task)?.invoke(transition)
+        controller.exitImmersiveIfApplicable(wct, task)?.invoke(transition)
 
-        assertThat(immersiveHandler.pendingExternalExitTransitions.any { exit ->
+        assertThat(controller.pendingExternalExitTransitions.any { exit ->
             exit.transition == transition && exit.displayId == DEFAULT_DISPLAY
                     && exit.taskId == task.taskId
         }).isTrue()
@@ -431,9 +423,9 @@
             immersive = false
         )
 
-        immersiveHandler.exitImmersiveIfApplicable(wct, task)?.invoke(transition)
+        controller.exitImmersiveIfApplicable(wct, task)?.invoke(transition)
 
-        assertThat(immersiveHandler.pendingExternalExitTransitions.any { exit ->
+        assertThat(controller.pendingExternalExitTransitions.any { exit ->
             exit.transition == transition && exit.displayId == DEFAULT_DISPLAY
                     && exit.taskId == task.taskId
         }).isFalse()
@@ -441,7 +433,7 @@
 
     @Test
     @EnableFlags(Flags.FLAG_ENABLE_FULLY_IMMERSIVE_IN_DESKTOP)
-    fun onTransitionReady_pendingExit_removesPendingExit() {
+    fun onTransitionReady_pendingExit_removesPendingExitOnFinish() {
         val task = createFreeformTask()
         whenever(mockShellTaskOrganizer.getRunningTaskInfo(task.taskId)).thenReturn(task)
         val wct = WindowContainerTransaction()
@@ -451,18 +443,19 @@
             taskId = task.taskId,
             immersive = true
         )
-        immersiveHandler.exitImmersiveIfApplicable(transition, wct, DEFAULT_DISPLAY)
+        controller.exitImmersiveIfApplicable(transition, wct, DEFAULT_DISPLAY)
 
-        immersiveHandler.onTransitionReady(
+        controller.onTransitionReady(
             transition = transition,
             info = createTransitionInfo(
-                changes = listOf(
-                    TransitionInfo.Change(task.token, SurfaceControl()).apply { taskInfo = task }
-                )
-            )
+                changes = listOf(createChange(task))
+            ),
+            startTransaction = SurfaceControl.Transaction(),
+            finishTransaction = SurfaceControl.Transaction(),
         )
+        controller.onTransitionFinished(transition, aborted = false)
 
-        assertThat(immersiveHandler.pendingExternalExitTransitions.any { exit ->
+        assertThat(controller.pendingExternalExitTransitions.any { exit ->
             exit.transition == transition && exit.displayId == DEFAULT_DISPLAY
                     && exit.taskId == task.taskId
         }).isFalse()
@@ -470,6 +463,42 @@
 
     @Test
     @EnableFlags(Flags.FLAG_ENABLE_FULLY_IMMERSIVE_IN_DESKTOP)
+    fun onTransitionReady_pendingExit_withMerge_removesPendingExitOnFinish() {
+        val task = createFreeformTask()
+        whenever(mockShellTaskOrganizer.getRunningTaskInfo(task.taskId)).thenReturn(task)
+        val wct = WindowContainerTransaction()
+        val transition = Binder()
+        val mergedToTransition = Binder()
+        desktopRepository.setTaskInFullImmersiveState(
+            displayId = DEFAULT_DISPLAY,
+            taskId = task.taskId,
+            immersive = true
+        )
+        controller.exitImmersiveIfApplicable(transition, wct, DEFAULT_DISPLAY)
+
+        controller.onTransitionReady(
+            transition = transition,
+            info = createTransitionInfo(
+                changes = listOf(createChange(task))
+            ),
+            startTransaction = SurfaceControl.Transaction(),
+            finishTransaction = SurfaceControl.Transaction(),
+        )
+        controller.onTransitionMerged(transition, mergedToTransition)
+        controller.onTransitionFinished(mergedToTransition, aborted = false)
+
+        assertThat(controller.pendingExternalExitTransitions.any { exit ->
+            exit.transition == transition && exit.displayId == DEFAULT_DISPLAY
+                    && exit.taskId == task.taskId
+        }).isFalse()
+        assertThat(controller.pendingExternalExitTransitions.any { exit ->
+            exit.transition == mergedToTransition && exit.displayId == DEFAULT_DISPLAY
+                    && exit.taskId == task.taskId
+        }).isFalse()
+    }
+
+    @Test
+    @EnableFlags(Flags.FLAG_ENABLE_FULLY_IMMERSIVE_IN_DESKTOP)
     fun onTransitionReady_pendingExit_updatesRepository() {
         val task = createFreeformTask()
         whenever(mockShellTaskOrganizer.getRunningTaskInfo(task.taskId)).thenReturn(task)
@@ -480,15 +509,15 @@
             taskId = task.taskId,
             immersive = true
         )
-        immersiveHandler.exitImmersiveIfApplicable(transition, wct, DEFAULT_DISPLAY)
+        controller.exitImmersiveIfApplicable(transition, wct, DEFAULT_DISPLAY)
 
-        immersiveHandler.onTransitionReady(
+        controller.onTransitionReady(
             transition = transition,
             info = createTransitionInfo(
-                changes = listOf(
-                    TransitionInfo.Change(task.token, SurfaceControl()).apply { taskInfo = task }
-                )
-            )
+                changes = listOf(createChange(task))
+            ),
+            startTransaction = SurfaceControl.Transaction(),
+            finishTransaction = SurfaceControl.Transaction(),
         )
 
         assertThat(desktopRepository.isTaskInFullImmersiveState(task.taskId)).isFalse()
@@ -510,15 +539,15 @@
             immersive = true
         )
         desktopRepository.saveBoundsBeforeFullImmersive(task.taskId, Rect(100, 100, 600, 600))
-        immersiveHandler.exitImmersiveIfApplicable(transition, wct, DEFAULT_DISPLAY)
+        controller.exitImmersiveIfApplicable(transition, wct, DEFAULT_DISPLAY)
 
-        immersiveHandler.onTransitionReady(
+        controller.onTransitionReady(
             transition = transition,
             info = createTransitionInfo(
-                changes = listOf(
-                    TransitionInfo.Change(task.token, SurfaceControl()).apply { taskInfo = task }
-                )
-            )
+                changes = listOf(createChange(task))
+            ),
+            startTransaction = SurfaceControl.Transaction(),
+            finishTransaction = SurfaceControl.Transaction(),
         )
 
         assertThat(desktopRepository.removeBoundsBeforeMaximize(task.taskId)).isNull()
@@ -537,7 +566,7 @@
             immersive = true
         )
 
-        immersiveHandler.exitImmersiveIfApplicable(wct = wct, taskInfo = task)
+        controller.exitImmersiveIfApplicable(wct = wct, taskInfo = task)
 
         assertThat(
             wct.hasBoundsChange(task.token, calculateMaximizeBounds(mockDisplayLayout, task))
@@ -561,7 +590,7 @@
         val preImmersiveBounds = Rect(100, 100, 500, 500)
         desktopRepository.saveBoundsBeforeFullImmersive(task.taskId, preImmersiveBounds)
 
-        immersiveHandler.exitImmersiveIfApplicable(wct = wct, taskInfo = task)
+        controller.exitImmersiveIfApplicable(wct = wct, taskInfo = task)
 
         assertThat(
             wct.hasBoundsChange(task.token, preImmersiveBounds)
@@ -584,7 +613,7 @@
             immersive = true
         )
 
-        immersiveHandler.exitImmersiveIfApplicable(wct = wct, taskInfo = task)
+        controller.exitImmersiveIfApplicable(wct = wct, taskInfo = task)
 
         assertThat(
             wct.hasBoundsChange(task.token, calculateInitialBounds(mockDisplayLayout, task))
@@ -602,13 +631,32 @@
             taskId = task.taskId,
             immersive = true
         )
-        immersiveHandler.exitImmersiveIfApplicable(wct, task)?.invoke(Binder())
+        controller.exitImmersiveIfApplicable(wct, task)?.invoke(Binder())
 
-        immersiveHandler.moveTaskToNonImmersive(task)
+        controller.moveTaskToNonImmersive(task)
 
         verify(mockTransitions, never()).startTransition(any(), any(), any())
     }
 
+    @Test
+    @EnableFlags(Flags.FLAG_ENABLE_FULLY_IMMERSIVE_IN_DESKTOP)
+    fun exitImmersiveIfApplicable_inImmersive_isImmersiveChange() {
+        val task = createFreeformTask()
+        whenever(mockShellTaskOrganizer.getRunningTaskInfo(task.taskId)).thenReturn(task)
+        val wct = WindowContainerTransaction()
+        val transition = Binder()
+        val change = createChange(task)
+        desktopRepository.setTaskInFullImmersiveState(
+            displayId = DEFAULT_DISPLAY,
+            taskId = task.taskId,
+            immersive = true
+        )
+
+        controller.exitImmersiveIfApplicable(transition, wct, DEFAULT_DISPLAY)
+
+        assertThat(controller.isImmersiveChange(transition, change)).isTrue()
+    }
+
     private fun createTransitionInfo(
         @TransitionType type: Int = TRANSIT_CHANGE,
         @TransitionFlags flags: Int = 0,
@@ -617,6 +665,11 @@
         changes.forEach { change -> addChange(change) }
     }
 
+    private fun createChange(task: RunningTaskInfo): TransitionInfo.Change =
+        TransitionInfo.Change(task.token, SurfaceControl()).apply {
+            taskInfo = task
+        }
+
     private fun WindowContainerTransaction.hasBoundsChange(token: WindowContainerToken): Boolean =
         this.changes.any { change ->
             change.key == token.asBinder()
diff --git a/libs/WindowManager/Shell/tests/unittest/src/com/android/wm/shell/desktopmode/DesktopTasksControllerTest.kt b/libs/WindowManager/Shell/tests/unittest/src/com/android/wm/shell/desktopmode/DesktopTasksControllerTest.kt
index 7a3d44b..bc2b36c 100644
--- a/libs/WindowManager/Shell/tests/unittest/src/com/android/wm/shell/desktopmode/DesktopTasksControllerTest.kt
+++ b/libs/WindowManager/Shell/tests/unittest/src/com/android/wm/shell/desktopmode/DesktopTasksControllerTest.kt
@@ -201,7 +201,7 @@
   lateinit var toggleResizeDesktopTaskTransitionHandler: ToggleResizeDesktopTaskTransitionHandler
   @Mock lateinit var dragToDesktopTransitionHandler: DragToDesktopTransitionHandler
   @Mock
-  lateinit var mockDesktopFullImmersiveTransitionHandler: DesktopFullImmersiveTransitionHandler
+  lateinit var mMockDesktopImmersiveController: DesktopImmersiveController
   @Mock lateinit var launchAdjacentController: LaunchAdjacentController
   @Mock lateinit var splitScreenController: SplitScreenController
   @Mock lateinit var recentsTransitionHandler: RecentsTransitionHandler
@@ -322,7 +322,7 @@
         dragAndDropTransitionHandler,
         toggleResizeDesktopTaskTransitionHandler,
         dragToDesktopTransitionHandler,
-        mockDesktopFullImmersiveTransitionHandler,
+        mMockDesktopImmersiveController,
         taskRepository,
         desktopModeLoggerTransitionObserver,
         launchAdjacentController,
@@ -1773,7 +1773,7 @@
 
     controller.minimizeTask(task)
 
-    verify(mockDesktopFullImmersiveTransitionHandler).exitImmersiveIfApplicable(any(), eq(task))
+    verify(mMockDesktopImmersiveController).exitImmersiveIfApplicable(any(), eq(task))
   }
 
   @Test
@@ -1783,7 +1783,7 @@
     val runOnTransit = RunOnStartTransitionCallback()
     whenever(freeformTaskTransitionStarter.startMinimizedModeTransition(any()))
       .thenReturn(transition)
-    whenever(mockDesktopFullImmersiveTransitionHandler.exitImmersiveIfApplicable(any(), eq(task)))
+    whenever(mMockDesktopImmersiveController.exitImmersiveIfApplicable(any(), eq(task)))
       .thenReturn(runOnTransit)
 
     controller.minimizeTask(task)
@@ -3092,13 +3092,13 @@
     val transition = Binder()
     whenever(transitions.startTransition(eq(TRANSIT_OPEN), any(), anyOrNull()))
       .thenReturn(transition)
-    whenever(mockDesktopFullImmersiveTransitionHandler
+    whenever(mMockDesktopImmersiveController
       .exitImmersiveIfApplicable(any(), eq(immersiveTask.displayId), eq(freeformTask.taskId)))
       .thenReturn(runOnStartTransit)
 
     runOpenInstance(immersiveTask, freeformTask.taskId)
 
-    verify(mockDesktopFullImmersiveTransitionHandler)
+    verify(mMockDesktopImmersiveController)
       .exitImmersiveIfApplicable(any(), eq(immersiveTask.displayId), eq(freeformTask.taskId))
     runOnStartTransit.assertOnlyInvocation(transition)
   }
@@ -3446,7 +3446,7 @@
 
     controller.toggleDesktopTaskFullImmersiveState(task)
 
-    verify(mockDesktopFullImmersiveTransitionHandler).moveTaskToImmersive(task)
+    verify(mMockDesktopImmersiveController).moveTaskToImmersive(task)
   }
 
   @Test
@@ -3456,7 +3456,7 @@
 
     controller.toggleDesktopTaskFullImmersiveState(task)
 
-    verify(mockDesktopFullImmersiveTransitionHandler).moveTaskToNonImmersive(task)
+    verify(mMockDesktopImmersiveController).moveTaskToNonImmersive(task)
   }
 
   @Test
@@ -3468,7 +3468,7 @@
     task.requestedVisibleTypes = WindowInsets.Type.statusBars()
     controller.onTaskInfoChanged(task)
 
-    verify(mockDesktopFullImmersiveTransitionHandler).moveTaskToNonImmersive(task)
+    verify(mMockDesktopImmersiveController).moveTaskToNonImmersive(task)
   }
 
   @Test
@@ -3480,7 +3480,7 @@
     task.requestedVisibleTypes = WindowInsets.Type.statusBars()
     controller.onTaskInfoChanged(task)
 
-    verify(mockDesktopFullImmersiveTransitionHandler, never()).moveTaskToNonImmersive(task)
+    verify(mMockDesktopImmersiveController, never()).moveTaskToNonImmersive(task)
   }
 
   @Test
@@ -3489,13 +3489,13 @@
     val wct = WindowContainerTransaction()
     val runOnStartTransit = RunOnStartTransitionCallback()
     val transition = Binder()
-    whenever(mockDesktopFullImmersiveTransitionHandler
+    whenever(mMockDesktopImmersiveController
       .exitImmersiveIfApplicable(wct, task.displayId, task.taskId)).thenReturn(runOnStartTransit)
     whenever(enterDesktopTransitionHandler.moveToDesktop(wct, UNKNOWN)).thenReturn(transition)
 
     controller.moveTaskToDesktop(taskId = task.taskId, wct = wct, transitionSource = UNKNOWN)
 
-    verify(mockDesktopFullImmersiveTransitionHandler)
+    verify(mMockDesktopImmersiveController)
       .exitImmersiveIfApplicable(wct, task.displayId, task.taskId)
     runOnStartTransit.assertOnlyInvocation(transition)
   }
@@ -3506,13 +3506,13 @@
     val wct = WindowContainerTransaction()
     val runOnStartTransit = RunOnStartTransitionCallback()
     val transition = Binder()
-    whenever(mockDesktopFullImmersiveTransitionHandler
+    whenever(mMockDesktopImmersiveController
       .exitImmersiveIfApplicable(wct, task.displayId, task.taskId)).thenReturn(runOnStartTransit)
     whenever(enterDesktopTransitionHandler.moveToDesktop(wct, UNKNOWN)).thenReturn(transition)
 
     controller.moveTaskToDesktop(taskId = task.taskId, wct = wct, transitionSource = UNKNOWN)
 
-    verify(mockDesktopFullImmersiveTransitionHandler)
+    verify(mMockDesktopImmersiveController)
       .exitImmersiveIfApplicable(wct, task.displayId, task.taskId)
     runOnStartTransit.assertOnlyInvocation(transition)
   }
@@ -3522,14 +3522,14 @@
     val task = setUpFreeformTask(background = true)
     val runOnStartTransit = RunOnStartTransitionCallback()
     val transition = Binder()
-    whenever(mockDesktopFullImmersiveTransitionHandler
+    whenever(mMockDesktopImmersiveController
       .exitImmersiveIfApplicable(any(), eq(task.displayId), eq(task.taskId)))
       .thenReturn(runOnStartTransit)
     whenever(transitions.startTransition(any(), any(), anyOrNull())).thenReturn(transition)
 
     controller.moveTaskToFront(task.taskId, remoteTransition = null)
 
-    verify(mockDesktopFullImmersiveTransitionHandler)
+    verify(mMockDesktopImmersiveController)
       .exitImmersiveIfApplicable(any(), eq(task.displayId), eq(task.taskId))
     runOnStartTransit.assertOnlyInvocation(transition)
   }
@@ -3539,14 +3539,14 @@
     val task = setUpFreeformTask(background = false)
     val runOnStartTransit = RunOnStartTransitionCallback()
     val transition = Binder()
-    whenever(mockDesktopFullImmersiveTransitionHandler
+    whenever(mMockDesktopImmersiveController
       .exitImmersiveIfApplicable(any(), eq(task.displayId), eq(task.taskId)))
       .thenReturn(runOnStartTransit)
     whenever(transitions.startTransition(any(), any(), anyOrNull())).thenReturn(transition)
 
     controller.moveTaskToFront(task.taskId, remoteTransition = null)
 
-    verify(mockDesktopFullImmersiveTransitionHandler)
+    verify(mMockDesktopImmersiveController)
       .exitImmersiveIfApplicable(any(), eq(task.displayId), eq(task.taskId))
     runOnStartTransit.assertOnlyInvocation(transition)
   }
@@ -3560,7 +3560,7 @@
 
     controller.handleRequest(binder, createTransition(task))
 
-    verify(mockDesktopFullImmersiveTransitionHandler)
+    verify(mMockDesktopImmersiveController)
       .exitImmersiveIfApplicable(eq(binder), any(), eq(task.displayId))
   }
 
@@ -3572,10 +3572,117 @@
 
     controller.handleRequest(binder, createTransition(task))
 
-    verify(mockDesktopFullImmersiveTransitionHandler)
+    verify(mMockDesktopImmersiveController)
       .exitImmersiveIfApplicable(eq(binder), any(), eq(task.displayId))
   }
 
+  @Test
+  @EnableFlags(Flags.FLAG_ENABLE_FULLY_IMMERSIVE_IN_DESKTOP)
+  fun shouldPlayDesktopAnimation_notShowingDesktop_doesNotPlay() {
+    val triggerTask = setUpFullscreenTask(displayId = 5)
+    taskRepository.setTaskInFullImmersiveState(
+      displayId = triggerTask.displayId,
+      taskId = triggerTask.taskId,
+      immersive = true
+    )
+
+    assertThat(controller.shouldPlayDesktopAnimation(
+      TransitionRequestInfo(TRANSIT_OPEN, triggerTask, /* remoteTransition= */ null)
+    )).isFalse()
+  }
+
+  @Test
+  @EnableFlags(Flags.FLAG_ENABLE_FULLY_IMMERSIVE_IN_DESKTOP)
+  fun shouldPlayDesktopAnimation_notOpening_doesNotPlay() {
+    val triggerTask = setUpFreeformTask(displayId = 5)
+    taskRepository.setTaskInFullImmersiveState(
+      displayId = triggerTask.displayId,
+      taskId = triggerTask.taskId,
+      immersive = true
+    )
+
+    assertThat(controller.shouldPlayDesktopAnimation(
+      TransitionRequestInfo(TRANSIT_CHANGE, triggerTask, /* remoteTransition= */ null)
+    )).isFalse()
+  }
+
+  @Test
+  @EnableFlags(Flags.FLAG_ENABLE_FULLY_IMMERSIVE_IN_DESKTOP)
+  fun shouldPlayDesktopAnimation_notImmersive_doesNotPlay() {
+    val triggerTask = setUpFreeformTask(displayId = 5)
+    taskRepository.setTaskInFullImmersiveState(
+      displayId = triggerTask.displayId,
+      taskId = triggerTask.taskId,
+      immersive = false
+    )
+
+    assertThat(controller.shouldPlayDesktopAnimation(
+      TransitionRequestInfo(TRANSIT_OPEN, triggerTask, /* remoteTransition= */ null)
+    )).isFalse()
+  }
+
+  @Test
+  @EnableFlags(Flags.FLAG_ENABLE_FULLY_IMMERSIVE_IN_DESKTOP)
+  fun shouldPlayDesktopAnimation_fullscreenEntersDesktop_plays() {
+    // At least one freeform task to be in a desktop.
+    val existingTask = setUpFreeformTask(displayId = 5)
+    val triggerTask = setUpFullscreenTask(displayId = 5)
+    assertThat(controller.isDesktopModeShowing(triggerTask.displayId)).isTrue()
+    taskRepository.setTaskInFullImmersiveState(
+      displayId = existingTask.displayId,
+      taskId = existingTask.taskId,
+      immersive = true
+    )
+
+    assertThat(
+      controller.shouldPlayDesktopAnimation(
+        TransitionRequestInfo(TRANSIT_OPEN, triggerTask, /* remoteTransition= */ null)
+      )
+    ).isTrue()
+  }
+
+  @Test
+  @EnableFlags(Flags.FLAG_ENABLE_FULLY_IMMERSIVE_IN_DESKTOP)
+  fun shouldPlayDesktopAnimation_fullscreenStaysFullscreen_doesNotPlay() {
+    val triggerTask = setUpFullscreenTask(displayId = 5)
+    assertThat(controller.isDesktopModeShowing(triggerTask.displayId)).isFalse()
+
+    assertThat(controller.shouldPlayDesktopAnimation(
+      TransitionRequestInfo(TRANSIT_OPEN, triggerTask, /* remoteTransition= */ null)
+    )).isFalse()
+  }
+
+  @Test
+  @EnableFlags(Flags.FLAG_ENABLE_FULLY_IMMERSIVE_IN_DESKTOP)
+  fun shouldPlayDesktopAnimation_freeformStaysInDesktop_plays() {
+    // At least one freeform task to be in a desktop.
+    val existingTask = setUpFreeformTask(displayId = 5)
+    val triggerTask = setUpFreeformTask(displayId = 5, active = false)
+    assertThat(controller.isDesktopModeShowing(triggerTask.displayId)).isTrue()
+    taskRepository.setTaskInFullImmersiveState(
+      displayId = existingTask.displayId,
+      taskId = existingTask.taskId,
+      immersive = true
+    )
+
+    assertThat(
+      controller.shouldPlayDesktopAnimation(
+        TransitionRequestInfo(TRANSIT_OPEN, triggerTask, /* remoteTransition= */ null)
+      )
+    ).isTrue()
+  }
+
+  @Test
+  @EnableFlags(Flags.FLAG_ENABLE_FULLY_IMMERSIVE_IN_DESKTOP)
+  fun shouldPlayDesktopAnimation_freeformExitsDesktop_doesNotPlay() {
+    val triggerTask = setUpFreeformTask(displayId = 5, active = false)
+    assertThat(controller.isDesktopModeShowing(triggerTask.displayId)).isFalse()
+
+    assertThat(controller.shouldPlayDesktopAnimation(
+      TransitionRequestInfo(TRANSIT_OPEN, triggerTask, /* remoteTransition= */ null)
+    )).isFalse()
+  }
+
   private class RunOnStartTransitionCallback : ((IBinder) -> Unit) {
     var invocations = 0
       private set
diff --git a/libs/WindowManager/Shell/tests/unittest/src/com/android/wm/shell/freeform/FreeformTaskTransitionObserverTest.java b/libs/WindowManager/Shell/tests/unittest/src/com/android/wm/shell/freeform/FreeformTaskTransitionObserverTest.java
index 7ae0bcd..90ab2b8 100644
--- a/libs/WindowManager/Shell/tests/unittest/src/com/android/wm/shell/freeform/FreeformTaskTransitionObserverTest.java
+++ b/libs/WindowManager/Shell/tests/unittest/src/com/android/wm/shell/freeform/FreeformTaskTransitionObserverTest.java
@@ -43,7 +43,7 @@
 import androidx.test.filters.SmallTest;
 
 import com.android.window.flags.Flags;
-import com.android.wm.shell.desktopmode.DesktopFullImmersiveTransitionHandler;
+import com.android.wm.shell.desktopmode.DesktopImmersiveController;
 import com.android.wm.shell.sysui.ShellInit;
 import com.android.wm.shell.transition.FocusTransitionObserver;
 import com.android.wm.shell.transition.TransitionInfoBuilder;
@@ -70,7 +70,7 @@
     @Mock
     private Transitions mTransitions;
     @Mock
-    private DesktopFullImmersiveTransitionHandler mDesktopFullImmersiveTransitionHandler;
+    private DesktopImmersiveController mDesktopImmersiveController;
     @Mock
     private WindowDecorViewModel mWindowDecorViewModel;
     @Mock
@@ -92,7 +92,7 @@
 
         mTransitionObserver = new FreeformTaskTransitionObserver(
                 context, mShellInit, mTransitions,
-                Optional.of(mDesktopFullImmersiveTransitionHandler),
+                Optional.of(mDesktopImmersiveController),
                 mWindowDecorViewModel, Optional.of(mTaskChangeListener), mFocusTransitionObserver);
 
         final ArgumentCaptor<Runnable> initRunnableCaptor = ArgumentCaptor.forClass(
@@ -321,7 +321,7 @@
 
     @Test
     @EnableFlags(Flags.FLAG_ENABLE_FULLY_IMMERSIVE_IN_DESKTOP)
-    public void onTransitionReady_forwardsToDesktopImmersiveHandler() {
+    public void onTransitionReady_forwardsToDesktopImmersiveController() {
         final IBinder transition = mock(IBinder.class);
         final TransitionInfo info = new TransitionInfoBuilder(TRANSIT_CHANGE, 0).build();
         final SurfaceControl.Transaction startT = mock(SurfaceControl.Transaction.class);
@@ -329,7 +329,38 @@
 
         mTransitionObserver.onTransitionReady(transition, info, startT, finishT);
 
-        verify(mDesktopFullImmersiveTransitionHandler).onTransitionReady(transition, info);
+        verify(mDesktopImmersiveController).onTransitionReady(transition, info, startT, finishT);
+    }
+
+    @Test
+    @EnableFlags(Flags.FLAG_ENABLE_FULLY_IMMERSIVE_IN_DESKTOP)
+    public void onTransitionMerged_forwardsToDesktopImmersiveController() {
+        final IBinder merged = mock(IBinder.class);
+        final IBinder playing = mock(IBinder.class);
+
+        mTransitionObserver.onTransitionMerged(merged, playing);
+
+        verify(mDesktopImmersiveController).onTransitionMerged(merged, playing);
+    }
+
+    @Test
+    @EnableFlags(Flags.FLAG_ENABLE_FULLY_IMMERSIVE_IN_DESKTOP)
+    public void onTransitionStarting_forwardsToDesktopImmersiveController() {
+        final IBinder transition = mock(IBinder.class);
+
+        mTransitionObserver.onTransitionStarting(transition);
+
+        verify(mDesktopImmersiveController).onTransitionStarting(transition);
+    }
+
+    @Test
+    @EnableFlags(Flags.FLAG_ENABLE_FULLY_IMMERSIVE_IN_DESKTOP)
+    public void onTransitionFinished_forwardsToDesktopImmersiveController() {
+        final IBinder transition = mock(IBinder.class);
+
+        mTransitionObserver.onTransitionFinished(transition, /* aborted= */ false);
+
+        verify(mDesktopImmersiveController).onTransitionFinished(transition, /* aborted= */ false);
     }
 
     private static TransitionInfo.Change createChange(int mode, int taskId, int windowingMode) {