Require hold-to-drag for App Handle drags

Adds a holding period functionality to DragDetector, which requires a
hold within the slop region to be maintained for X amount of ms before
ACTION_MOVEs outside the slop are allowed (reported to the event
handler). This functionality is enabled for the App Handle's drag
detector behind a flag, and disable for every other drag detector
(header, resize listener).

Also modifies e2e test to check the type of input before entering
desktop with drag, and simulates a hold-to-drag when the input is from a
touchscreen.

Flag: com.android.window.flags.enable_hold_to_drag_app_handle
Bug: 356409496
Test: atest WMShellUnitTests; atest PlatformScenarioTests
Change-Id: Ib57be0ce8b63aaa17ecc57b70d1629ab88c69787

9 files changed, 340 insertions, 52 deletions

diff --git a/libs/WindowManager/Shell/src/com/android/wm/shell/windowdecor/CaptionWindowDecorViewModel.java b/libs/WindowManager/Shell/src/com/android/wm/shell/windowdecor/CaptionWindowDecorViewModel.java
index 015139519f1f..431461a27e6f 100644
--- a/libs/WindowManager/Shell/src/com/android/wm/shell/windowdecor/CaptionWindowDecorViewModel.java
+++ b/libs/WindowManager/Shell/src/com/android/wm/shell/windowdecor/CaptionWindowDecorViewModel.java
@@ -44,6 +44,7 @@ import android.view.IWindowManager;
 import android.view.MotionEvent;
 import android.view.SurfaceControl;
 import android.view.View;
+import android.view.ViewConfiguration;
 import android.window.DisplayAreaInfo;
 import android.window.WindowContainerToken;
 import android.window.WindowContainerTransaction;
@@ -310,7 +311,6 @@ public class CaptionWindowDecorViewModel implements WindowDecorViewModel {
                 new CaptionTouchEventListener(taskInfo, taskPositioner);
         windowDecoration.setCaptionListeners(touchEventListener, touchEventListener);
         windowDecoration.setDragPositioningCallback(taskPositioner);
-        windowDecoration.setDragDetector(touchEventListener.mDragDetector);
         windowDecoration.setTaskDragResizer(taskPositioner);
         windowDecoration.relayout(taskInfo, startT, finishT,
                 false /* applyStartTransactionOnDraw */, false /* setTaskCropAndPosition */);
@@ -334,7 +334,8 @@ public class CaptionWindowDecorViewModel implements WindowDecorViewModel {
             mTaskId = taskInfo.taskId;
             mTaskToken = taskInfo.token;
             mDragPositioningCallback = dragPositioningCallback;
-            mDragDetector = new DragDetector(this);
+            mDragDetector = new DragDetector(this, 0 /* holdToDragMinDurationMs */,
+                    ViewConfiguration.get(mContext).getScaledTouchSlop());
             mDisplayId = taskInfo.displayId;
         }
 
diff --git a/libs/WindowManager/Shell/src/com/android/wm/shell/windowdecor/CaptionWindowDecoration.java b/libs/WindowManager/Shell/src/com/android/wm/shell/windowdecor/CaptionWindowDecoration.java
index 0caa8e93d4eb..1539b5fb34e5 100644
--- a/libs/WindowManager/Shell/src/com/android/wm/shell/windowdecor/CaptionWindowDecoration.java
+++ b/libs/WindowManager/Shell/src/com/android/wm/shell/windowdecor/CaptionWindowDecoration.java
@@ -74,7 +74,6 @@ public class CaptionWindowDecoration extends WindowDecoration<WindowDecorLinearL
     private View.OnTouchListener mOnCaptionTouchListener;
     private DragPositioningCallback mDragPositioningCallback;
     private DragResizeInputListener mDragResizeListener;
-    private DragDetector mDragDetector;
 
     private RelayoutParams mRelayoutParams = new RelayoutParams();
     private final RelayoutResult<WindowDecorLinearLayout> mResult =
@@ -176,12 +175,6 @@ public class CaptionWindowDecoration extends WindowDecoration<WindowDecorLinearL
         return stableBounds.bottom - requiredEmptySpace;
     }
 
-
-    void setDragDetector(DragDetector dragDetector) {
-        mDragDetector = dragDetector;
-        mDragDetector.setTouchSlop(ViewConfiguration.get(mContext).getScaledTouchSlop());
-    }
-
     @Override
     void relayout(RunningTaskInfo taskInfo) {
         final SurfaceControl.Transaction t = new SurfaceControl.Transaction();
@@ -288,7 +281,6 @@ public class CaptionWindowDecoration extends WindowDecoration<WindowDecorLinearL
 
         final int touchSlop = ViewConfiguration.get(mResult.mRootView.getContext())
                 .getScaledTouchSlop();
-        mDragDetector.setTouchSlop(touchSlop);
 
         final Resources res = mResult.mRootView.getResources();
         mDragResizeListener.setGeometry(new DragResizeWindowGeometry(0 /* taskCornerRadius */,
diff --git a/libs/WindowManager/Shell/src/com/android/wm/shell/windowdecor/DesktopModeWindowDecorViewModel.java b/libs/WindowManager/Shell/src/com/android/wm/shell/windowdecor/DesktopModeWindowDecorViewModel.java
index b311359ae624..3d41870ca159 100644
--- a/libs/WindowManager/Shell/src/com/android/wm/shell/windowdecor/DesktopModeWindowDecorViewModel.java
+++ b/libs/WindowManager/Shell/src/com/android/wm/shell/windowdecor/DesktopModeWindowDecorViewModel.java
@@ -79,6 +79,7 @@ import android.view.MotionEvent;
 import android.view.SurfaceControl;
 import android.view.SurfaceControl.Transaction;
 import android.view.View;
+import android.view.ViewConfiguration;
 import android.widget.Toast;
 import android.window.TaskSnapshot;
 import android.window.WindowContainerToken;
@@ -651,11 +652,14 @@ public class DesktopModeWindowDecorViewModel implements WindowDecorViewModel {
     private class DesktopModeTouchEventListener extends GestureDetector.SimpleOnGestureListener
             implements View.OnClickListener, View.OnTouchListener, View.OnLongClickListener,
             View.OnGenericMotionListener, DragDetector.MotionEventHandler {
+        private static final long APP_HANDLE_HOLD_TO_DRAG_DURATION_MS = 100;
+        private static final long APP_HEADER_HOLD_TO_DRAG_DURATION_MS = 0;
 
         private final int mTaskId;
         private final WindowContainerToken mTaskToken;
         private final DragPositioningCallback mDragPositioningCallback;
-        private final DragDetector mDragDetector;
+        private final DragDetector mHandleDragDetector;
+        private final DragDetector mHeaderDragDetector;
         private final GestureDetector mGestureDetector;
         private final int mDisplayId;
         private final Rect mOnDragStartInitialBounds = new Rect();
@@ -677,7 +681,13 @@ public class DesktopModeWindowDecorViewModel implements WindowDecorViewModel {
             mTaskId = taskInfo.taskId;
             mTaskToken = taskInfo.token;
             mDragPositioningCallback = dragPositioningCallback;
-            mDragDetector = new DragDetector(this);
+            final int touchSlop = ViewConfiguration.get(mContext).getScaledTouchSlop();
+            final long appHandleHoldToDragDuration = Flags.enableHoldToDragAppHandle()
+                    ? APP_HANDLE_HOLD_TO_DRAG_DURATION_MS : 0;
+            mHandleDragDetector = new DragDetector(this, appHandleHoldToDragDuration,
+                    touchSlop);
+            mHeaderDragDetector = new DragDetector(this, APP_HEADER_HOLD_TO_DRAG_DURATION_MS,
+                    touchSlop);
             mGestureDetector = new GestureDetector(mContext, this);
             mDisplayId = taskInfo.displayId;
         }
@@ -736,7 +746,7 @@ public class DesktopModeWindowDecorViewModel implements WindowDecorViewModel {
                     && id != R.id.maximize_window && id != R.id.minimize_window) {
                 return false;
             }
-
+            final boolean isAppHandle = !getTaskInfo().isFreeform();
             final int actionMasked = e.getActionMasked();
             final boolean isDown = actionMasked == MotionEvent.ACTION_DOWN;
             final boolean isUpOrCancel = actionMasked == MotionEvent.ACTION_CANCEL
@@ -785,7 +795,11 @@ public class DesktopModeWindowDecorViewModel implements WindowDecorViewModel {
                 // Gesture is finished, reset state.
                 mShouldPilferCaptionEvents = false;
             }
-            return mDragDetector.onMotionEvent(v, e);
+            if (isAppHandle) {
+                return mHandleDragDetector.onMotionEvent(v, e);
+            } else {
+                return mHeaderDragDetector.onMotionEvent(v, e);
+            }
         }
 
         @Override
@@ -853,6 +867,12 @@ public class DesktopModeWindowDecorViewModel implements WindowDecorViewModel {
             }
         }
 
+        @NonNull
+        private RunningTaskInfo getTaskInfo() {
+            final DesktopModeWindowDecoration decoration = mWindowDecorByTaskId.get(mTaskId);
+            return decoration.mTaskInfo;
+        }
+
         private boolean handleNonFreeformMotionEvent(DesktopModeWindowDecoration decoration,
                 View v, MotionEvent e) {
             final int id = v.getId();
@@ -1421,7 +1441,6 @@ public class DesktopModeWindowDecorViewModel implements WindowDecorViewModel {
                 touchEventListener, touchEventListener, touchEventListener, touchEventListener);
         windowDecoration.setExclusionRegionListener(mExclusionRegionListener);
         windowDecoration.setDragPositioningCallback(taskPositioner);
-        windowDecoration.setDragDetector(touchEventListener.mDragDetector);
         windowDecoration.relayout(taskInfo, startT, finishT,
                 false /* applyStartTransactionOnDraw */, false /* shouldSetTaskPositionAndCrop */);
         if (!Flags.enableAdditionalWindowsAboveStatusBar()) {
diff --git a/libs/WindowManager/Shell/src/com/android/wm/shell/windowdecor/DesktopModeWindowDecoration.java b/libs/WindowManager/Shell/src/com/android/wm/shell/windowdecor/DesktopModeWindowDecoration.java
index 5521c2ee6578..fe2b6717429e 100644
--- a/libs/WindowManager/Shell/src/com/android/wm/shell/windowdecor/DesktopModeWindowDecoration.java
+++ b/libs/WindowManager/Shell/src/com/android/wm/shell/windowdecor/DesktopModeWindowDecoration.java
@@ -139,7 +139,6 @@ public class DesktopModeWindowDecoration extends WindowDecoration<WindowDecorLin
     private Function0<Unit> mOnManageWindowsClickListener;
     private DragPositioningCallback mDragPositioningCallback;
     private DragResizeInputListener mDragResizeListener;
-    private DragDetector mDragDetector;
     private RelayoutParams mRelayoutParams = new RelayoutParams();
     private final WindowDecoration.RelayoutResult<WindowDecorLinearLayout> mResult =
             new WindowDecoration.RelayoutResult<>();
@@ -320,11 +319,6 @@ public class DesktopModeWindowDecoration extends WindowDecoration<WindowDecorLin
         mDragPositioningCallback = dragPositioningCallback;
     }
 
-    void setDragDetector(DragDetector dragDetector) {
-        mDragDetector = dragDetector;
-        mDragDetector.setTouchSlop(ViewConfiguration.get(mContext).getScaledTouchSlop());
-    }
-
     void setOpenInBrowserClickListener(Consumer<Uri> listener) {
         mOpenInBrowserClickListener = listener;
     }
@@ -482,7 +476,6 @@ public class DesktopModeWindowDecoration extends WindowDecoration<WindowDecorLin
 
         final int touchSlop = ViewConfiguration.get(mResult.mRootView.getContext())
                 .getScaledTouchSlop();
-        mDragDetector.setTouchSlop(touchSlop);
 
         // If either task geometry or position have changed, update this task's
         // exclusion region listener
diff --git a/libs/WindowManager/Shell/src/com/android/wm/shell/windowdecor/DragDetector.java b/libs/WindowManager/Shell/src/com/android/wm/shell/windowdecor/DragDetector.java
index 3fd3656ccbc5..01bb7f74ba06 100644
--- a/libs/WindowManager/Shell/src/com/android/wm/shell/windowdecor/DragDetector.java
+++ b/libs/WindowManager/Shell/src/com/android/wm/shell/windowdecor/DragDetector.java
@@ -26,6 +26,7 @@ import static android.view.MotionEvent.ACTION_MOVE;
 import static android.view.MotionEvent.ACTION_POINTER_UP;
 import static android.view.MotionEvent.ACTION_UP;
 
+import android.annotation.NonNull;
 import android.graphics.PointF;
 import android.view.MotionEvent;
 import android.view.View;
@@ -48,12 +49,18 @@ class DragDetector {
     private int mTouchSlop;
     private boolean mIsDragEvent;
     private int mDragPointerId = -1;
+    private final long mHoldToDragMinDurationMs;
+    private boolean mDidStrayBeforeFullHold;
+    private boolean mDidHoldForMinDuration;
 
     private boolean mResultOfDownAction;
 
-    DragDetector(MotionEventHandler eventHandler) {
+    DragDetector(@NonNull MotionEventHandler eventHandler, long holdToDragMinDurationMs,
+            int touchSlop) {
         resetState();
         mEventHandler = eventHandler;
+        mHoldToDragMinDurationMs = holdToDragMinDurationMs;
+        mTouchSlop = touchSlop;
     }
 
     /**
@@ -101,9 +108,26 @@ class DragDetector {
                 if (!mIsDragEvent) {
                     float dx = ev.getRawX(dragPointerIndex) - mInputDownPoint.x;
                     float dy = ev.getRawY(dragPointerIndex) - mInputDownPoint.y;
+                    final float dt = ev.getEventTime() - ev.getDownTime();
+                    final boolean pastTouchSlop = Math.hypot(dx, dy) > mTouchSlop;
+                    final boolean withinHoldRegion = !pastTouchSlop;
+
+                    if (mHoldToDragMinDurationMs <= 0) {
+                        mDidHoldForMinDuration = true;
+                    } else {
+                        if (!withinHoldRegion && dt < mHoldToDragMinDurationMs) {
+                            // Mark as having strayed so that in case the (x,y) ends up in the
+                            // original position we know it's not actually valid.
+                            mDidStrayBeforeFullHold = true;
+                        }
+                        if (!mDidStrayBeforeFullHold && dt >= mHoldToDragMinDurationMs) {
+                            mDidHoldForMinDuration = true;
+                        }
+                    }
+
                     // Touches generate noisy moves, so only once the move is past the touch
                     // slop threshold should it be considered a drag.
-                    mIsDragEvent = Math.hypot(dx, dy) > mTouchSlop;
+                    mIsDragEvent = mDidHoldForMinDuration && pastTouchSlop;
                 }
                 // The event handler should only be notified about 'move' events if a drag has been
                 // detected.
@@ -162,6 +186,8 @@ class DragDetector {
         mInputDownPoint.set(0, 0);
         mDragPointerId = -1;
         mResultOfDownAction = false;
+        mDidStrayBeforeFullHold = false;
+        mDidHoldForMinDuration = false;
     }
 
     interface MotionEventHandler {
diff --git a/libs/WindowManager/Shell/src/com/android/wm/shell/windowdecor/DragResizeInputListener.java b/libs/WindowManager/Shell/src/com/android/wm/shell/windowdecor/DragResizeInputListener.java
index a27c506e3e60..b5ed32bbd4e9 100644
--- a/libs/WindowManager/Shell/src/com/android/wm/shell/windowdecor/DragResizeInputListener.java
+++ b/libs/WindowManager/Shell/src/com/android/wm/shell/windowdecor/DragResizeInputListener.java
@@ -318,7 +318,8 @@ class DragResizeInputListener implements AutoCloseable {
                 }
             };
 
-            mDragDetector = new DragDetector(this);
+            mDragDetector = new DragDetector(this, 0 /* holdToDragMinDurationMs */,
+                    ViewConfiguration.get(mContext).getScaledTouchSlop());
             mDisplayLayoutSizeSupplier = displayLayoutSizeSupplier;
             mTouchRegionConsumer = touchRegionConsumer;
         }
diff --git a/libs/WindowManager/Shell/tests/unittest/src/com/android/wm/shell/windowdecor/DragDetectorTest.kt b/libs/WindowManager/Shell/tests/unittest/src/com/android/wm/shell/windowdecor/DragDetectorTest.kt
index 56224b4b4025..7f7211d65fde 100644
--- a/libs/WindowManager/Shell/tests/unittest/src/com/android/wm/shell/windowdecor/DragDetectorTest.kt
+++ b/libs/WindowManager/Shell/tests/unittest/src/com/android/wm/shell/windowdecor/DragDetectorTest.kt
@@ -21,6 +21,7 @@ import android.testing.AndroidTestingRunner
 import android.view.MotionEvent
 import android.view.InputDevice
 import androidx.test.filters.SmallTest
+import com.android.wm.shell.ShellTestCase
 import org.junit.After
 import org.junit.Assert.assertFalse
 import org.junit.Assert.assertTrue
@@ -34,6 +35,7 @@ import org.mockito.Mockito.any
 import org.mockito.Mockito.argThat
 import org.mockito.Mockito.never
 import org.mockito.Mockito.verify
+import org.mockito.kotlin.times
 
 /**
  * Tests for [DragDetector].
@@ -43,22 +45,17 @@ import org.mockito.Mockito.verify
  */
 @SmallTest
 @RunWith(AndroidTestingRunner::class)
-class DragDetectorTest {
+class DragDetectorTest : ShellTestCase() {
     private val motionEvents = mutableListOf<MotionEvent>()
 
     @Mock
     private lateinit var eventHandler: DragDetector.MotionEventHandler
 
-    private lateinit var dragDetector: DragDetector
-
     @Before
     fun setUp() {
         MockitoAnnotations.initMocks(this)
 
         `when`(eventHandler.handleMotionEvent(any(), any())).thenReturn(true)
-
-        dragDetector = DragDetector(eventHandler)
-        dragDetector.setTouchSlop(SLOP)
     }
 
     @After
@@ -71,6 +68,7 @@ class DragDetectorTest {
 
     @Test
     fun testNoMove_passesDownAndUp() {
+        val dragDetector = createDragDetector()
         assertTrue(dragDetector.onMotionEvent(createMotionEvent(MotionEvent.ACTION_DOWN)))
         verify(eventHandler).handleMotionEvent(any(), argThat {
             return@argThat it.action == MotionEvent.ACTION_DOWN && it.x == X && it.y == Y &&
@@ -86,6 +84,7 @@ class DragDetectorTest {
 
     @Test
     fun testNoMove_mouse_passesDownAndUp() {
+        val dragDetector = createDragDetector()
         assertTrue(dragDetector.onMotionEvent(
             createMotionEvent(MotionEvent.ACTION_DOWN, isTouch = false)))
         verify(eventHandler).handleMotionEvent(any(), argThat {
@@ -103,6 +102,7 @@ class DragDetectorTest {
 
     @Test
     fun testMoveInSlop_touch_passesDownAndUp() {
+        val dragDetector = createDragDetector()
         `when`(eventHandler.handleMotionEvent(any(), argThat {
             return@argThat it.action == MotionEvent.ACTION_DOWN
         })).thenReturn(false)
@@ -129,6 +129,7 @@ class DragDetectorTest {
 
     @Test
     fun testMoveInSlop_mouse_passesDownMoveAndUp() {
+        val dragDetector = createDragDetector()
         `when`(eventHandler.handleMotionEvent(any(), argThat {
             it.action == MotionEvent.ACTION_DOWN
         })).thenReturn(false)
@@ -158,6 +159,7 @@ class DragDetectorTest {
 
     @Test
     fun testMoveBeyondSlop_passesDownMoveAndUp() {
+        val dragDetector = createDragDetector()
         `when`(eventHandler.handleMotionEvent(any(), argThat {
             it.action == MotionEvent.ACTION_DOWN
         })).thenReturn(false)
@@ -184,6 +186,7 @@ class DragDetectorTest {
 
     @Test
     fun testDownMoveDown_shouldIgnoreTheSecondDownMotion() {
+        val dragDetector = createDragDetector()
         assertTrue(dragDetector.onMotionEvent(createMotionEvent(MotionEvent.ACTION_DOWN)))
         verify(eventHandler).handleMotionEvent(any(), argThat {
             return@argThat it.action == MotionEvent.ACTION_DOWN && it.x == X && it.y == Y &&
@@ -206,6 +209,7 @@ class DragDetectorTest {
 
     @Test
     fun testDownMouseMoveDownTouch_shouldIgnoreTheTouchDownMotion() {
+        val dragDetector = createDragDetector()
         assertTrue(dragDetector.onMotionEvent(
             createMotionEvent(MotionEvent.ACTION_DOWN, isTouch = false)))
         verify(eventHandler).handleMotionEvent(any(), argThat {
@@ -230,6 +234,7 @@ class DragDetectorTest {
 
     @Test
     fun testPassesHoverEnter() {
+        val dragDetector = createDragDetector()
         `when`(eventHandler.handleMotionEvent(any(), argThat {
             it.action == MotionEvent.ACTION_HOVER_ENTER
         })).thenReturn(false)
@@ -242,6 +247,7 @@ class DragDetectorTest {
 
     @Test
     fun testPassesHoverMove() {
+        val dragDetector = createDragDetector()
         assertTrue(dragDetector.onMotionEvent(createMotionEvent(MotionEvent.ACTION_HOVER_MOVE)))
         verify(eventHandler).handleMotionEvent(any(), argThat {
             return@argThat it.action == MotionEvent.ACTION_HOVER_MOVE && it.x == X && it.y == Y
@@ -250,21 +256,240 @@ class DragDetectorTest {
 
     @Test
     fun testPassesHoverExit() {
+        val dragDetector = createDragDetector()
         assertTrue(dragDetector.onMotionEvent(createMotionEvent(MotionEvent.ACTION_HOVER_EXIT)))
         verify(eventHandler).handleMotionEvent(any(), argThat {
             return@argThat it.action == MotionEvent.ACTION_HOVER_EXIT && it.x == X && it.y == Y
         })
     }
 
-    private fun createMotionEvent(action: Int, x: Float = X, y: Float = Y, isTouch: Boolean = true):
-            MotionEvent {
-        val time = SystemClock.uptimeMillis()
-        val ev = MotionEvent.obtain(time, time, action, x, y, 0)
+    @Test
+    fun testHoldToDrag_holdsWithMovementWithinSlop_passesDragMoveEvents() {
+        val dragDetector = createDragDetector(holdToDragMinDurationMs = 100, slop = 20)
+        val downTime = SystemClock.uptimeMillis()
+        dragDetector.onMotionEvent(createMotionEvent(
+            action = MotionEvent.ACTION_DOWN,
+            x = 500f,
+            y = 10f,
+            isTouch = true,
+            downTime = downTime,
+            eventTime = downTime
+        ))
+
+        // Couple of movements within the slop, still counting as "holding"
+        dragDetector.onMotionEvent(createMotionEvent(
+            action = MotionEvent.ACTION_MOVE,
+            x = 500f + 10f, // within slop
+            y = 10f + 10f, // within slop
+            isTouch = true,
+            downTime = downTime,
+            eventTime = downTime + 30
+        ))
+        dragDetector.onMotionEvent(createMotionEvent(
+            action = MotionEvent.ACTION_MOVE,
+            x = 500f - 10f, // within slop
+            y = 10f - 5f, // within slop
+            isTouch = true,
+            downTime = downTime,
+            eventTime = downTime + 70
+        ))
+        // Now go beyond slop, but after the required holding period.
+        dragDetector.onMotionEvent(createMotionEvent(
+            action = MotionEvent.ACTION_MOVE,
+            x = 500f + 50f, // beyond slop
+            y = 10f + 50f, // beyond slop
+            isTouch = true,
+            downTime = downTime,
+            eventTime = downTime + 101 // after hold period
+        ))
+
+        // Had a valid hold, so there should be 1 "move".
+        verify(eventHandler, times(1))
+            .handleMotionEvent(any(), argThat { ev -> ev.action == MotionEvent.ACTION_MOVE })
+    }
+
+    @Test
+    fun testHoldToDrag_holdsWithoutAnyMovement_passesMoveEvents() {
+        val dragDetector = createDragDetector(holdToDragMinDurationMs = 100, slop = 20)
+        val downTime = SystemClock.uptimeMillis()
+        dragDetector.onMotionEvent(createMotionEvent(
+            action = MotionEvent.ACTION_DOWN,
+            x = 500f,
+            y = 10f,
+            isTouch = true,
+            downTime = downTime,
+            eventTime = downTime
+        ))
+
+        // First |move| is already beyond slop and after holding period.
+        dragDetector.onMotionEvent(createMotionEvent(
+            action = MotionEvent.ACTION_MOVE,
+            x = 500f + 50f, // beyond slop
+            y = 10f + 50f, // beyond slop
+            isTouch = true,
+            downTime = downTime,
+            eventTime = downTime + 101 // after hold period
+        ))
+
+        // Considered a valid hold, so there should be 1 "move".
+        verify(eventHandler, times(1))
+            .handleMotionEvent(any(), argThat { ev -> ev.action == MotionEvent.ACTION_MOVE })
+    }
+
+    @Test
+    fun testHoldToDrag_returnsWithinSlopAfterHoldPeriod_passesDragMoveEvents() {
+        val dragDetector = createDragDetector(holdToDragMinDurationMs = 100, slop = 20)
+        val downTime = SystemClock.uptimeMillis()
+        dragDetector.onMotionEvent(createMotionEvent(
+            action = MotionEvent.ACTION_DOWN,
+            x = 500f,
+            y = 10f,
+            isTouch = true,
+            downTime = downTime,
+            eventTime = downTime
+        ))
+        // Go beyond slop after the required holding period.
+        dragDetector.onMotionEvent(createMotionEvent(
+            action = MotionEvent.ACTION_MOVE,
+            x = 500f + 50f, // beyond slop
+            y = 10f + 50f, // beyond slop
+            isTouch = true,
+            downTime = downTime,
+            eventTime = downTime + 101 // after hold period
+        ))
+
+        // Return to original coordinates after holding period.
+        dragDetector.onMotionEvent(createMotionEvent(
+            action = MotionEvent.ACTION_MOVE,
+            x = 500f, // within slop
+            y = 10f, // within slop
+            isTouch = true,
+            downTime = downTime,
+            eventTime = downTime + 102 // after hold period
+        ))
+
+        // Both |moves| should be passed, even the one in the slop region since it was after the
+        // holding period. (e.g. after you drag the handle you may return to its original position).
+        verify(eventHandler, times(2))
+            .handleMotionEvent(any(), argThat { ev -> ev.action == MotionEvent.ACTION_MOVE })
+    }
+
+    @Test
+    fun testHoldToDrag_straysDuringHoldPeriod_skipsMoveEvents() {
+        val dragDetector = createDragDetector(holdToDragMinDurationMs = 100, slop = 20)
+        val downTime = SystemClock.uptimeMillis()
+        dragDetector.onMotionEvent(createMotionEvent(
+            action = MotionEvent.ACTION_DOWN,
+            x = 500f,
+            y = 10f,
+            isTouch = true,
+            downTime = downTime,
+            eventTime = downTime
+        ))
+
+        // Go beyond slop before the required holding period.
+        dragDetector.onMotionEvent(createMotionEvent(
+            action = MotionEvent.ACTION_MOVE,
+            x = 500f + 50f, // beyond slop
+            y = 10f + 50f, // beyond slop
+            isTouch = true,
+            downTime = downTime,
+            eventTime = downTime + 30 // during hold period
+        ))
+
+        // The |move| was too quick and did not held, do not pass it to the handler.
+        verify(eventHandler, never())
+            .handleMotionEvent(any(), argThat { ev -> ev.action == MotionEvent.ACTION_MOVE })
+    }
+
+    @Test
+    fun testHoldToDrag_straysDuringHoldPeriodAndReturnsWithinSlop_skipsMoveEvents() {
+        val dragDetector = createDragDetector(holdToDragMinDurationMs = 100, slop = 20)
+        val downTime = SystemClock.uptimeMillis()
+        dragDetector.onMotionEvent(createMotionEvent(
+            action = MotionEvent.ACTION_DOWN,
+            x = 500f,
+            y = 10f,
+            isTouch = true,
+            downTime = downTime,
+            eventTime = downTime
+        ))
+        // Go beyond slop before the required holding period.
+        dragDetector.onMotionEvent(createMotionEvent(
+            action = MotionEvent.ACTION_MOVE,
+            x = 500f + 50f, // beyond slop
+            y = 10f + 50f, // beyond slop
+            isTouch = true,
+            downTime = downTime,
+            eventTime = downTime + 30 // during hold period
+        ))
+
+        // Return to slop area during holding period.
+        dragDetector.onMotionEvent(createMotionEvent(
+            action = MotionEvent.ACTION_MOVE,
+            x = 500f + 10f, // within slop
+            y = 10f + 10f, // within slop
+            isTouch = true,
+            downTime = downTime,
+            eventTime = downTime + 50 // during hold period
+        ))
+
+        // The first |move| invalidates the drag even if you return within the hold period, so the
+        // |move| should not be passed to the handler.
+        verify(eventHandler, never())
+            .handleMotionEvent(any(), argThat { ev -> ev.action == MotionEvent.ACTION_MOVE })
+    }
+
+    @Test
+    fun testHoldToDrag_noHoldRequired_passesMoveEvents() {
+        val dragDetector = createDragDetector(holdToDragMinDurationMs = 0, slop = 20)
+        val downTime = SystemClock.uptimeMillis()
+        dragDetector.onMotionEvent(createMotionEvent(
+            action = MotionEvent.ACTION_DOWN,
+            x = 500f,
+            y = 10f,
+            isTouch = true,
+            downTime = downTime,
+            eventTime = downTime
+        ))
+
+        dragDetector.onMotionEvent(createMotionEvent(
+            action = MotionEvent.ACTION_MOVE,
+            x = 500f + 50f, // beyond slop
+            y = 10f + 50f, // beyond slop
+            isTouch = true,
+            downTime = downTime,
+            eventTime = downTime + 1
+        ))
+
+        // The |move| should be passed to the handler as no hold period was needed.
+        verify(eventHandler, times(1))
+            .handleMotionEvent(any(), argThat { ev -> ev.action == MotionEvent.ACTION_MOVE })
+    }
+
+    private fun createMotionEvent(
+        action: Int,
+        x: Float = X,
+        y: Float = Y,
+        isTouch: Boolean = true,
+        downTime: Long = SystemClock.uptimeMillis(),
+        eventTime: Long = SystemClock.uptimeMillis()
+    ): MotionEvent {
+        val ev = MotionEvent.obtain(downTime, eventTime, action, x, y, 0)
         ev.source = if (isTouch) InputDevice.SOURCE_TOUCHSCREEN else InputDevice.SOURCE_MOUSE
         motionEvents.add(ev)
         return ev
     }
 
+    private fun createDragDetector(
+        holdToDragMinDurationMs: Long = 0,
+        slop: Int = SLOP
+    ) = DragDetector(
+        eventHandler,
+        holdToDragMinDurationMs,
+        slop
+    )
+
     companion object {
         private const val SLOP = 10
         private const val X = 123f
diff --git a/tests/FlickerTests/test-apps/app-helpers/src/com/android/server/wm/flicker/helpers/DesktopModeAppHelper.kt b/tests/FlickerTests/test-apps/app-helpers/src/com/android/server/wm/flicker/helpers/DesktopModeAppHelper.kt
index 3f6a0bf49eb4..c77413b6a55a 100644
--- a/tests/FlickerTests/test-apps/app-helpers/src/com/android/server/wm/flicker/helpers/DesktopModeAppHelper.kt
+++ b/tests/FlickerTests/test-apps/app-helpers/src/com/android/server/wm/flicker/helpers/DesktopModeAppHelper.kt
@@ -20,6 +20,7 @@ import android.content.Context
 import android.graphics.Insets
 import android.graphics.Rect
 import android.graphics.Region
+import android.os.SystemClock
 import android.platform.uiautomator_helpers.DeviceHelpers
 import android.tools.device.apphelpers.IStandardAppHelper
 import android.tools.helpers.SYSTEMUI_PACKAGE
@@ -27,11 +28,14 @@ import android.tools.traces.parsers.WindowManagerStateHelper
 import android.tools.traces.wm.WindowingMode
 import android.view.WindowInsets
 import android.view.WindowManager
+import androidx.test.platform.app.InstrumentationRegistry.getInstrumentation
 import androidx.test.uiautomator.By
 import androidx.test.uiautomator.BySelector
 import androidx.test.uiautomator.UiDevice
 import androidx.test.uiautomator.UiObject2
 import androidx.test.uiautomator.Until
+import com.android.server.wm.flicker.helpers.MotionEventHelper.InputMethod.TOUCH
+import com.android.window.flags.Flags
 import java.time.Duration
 
 /**
@@ -69,13 +73,22 @@ open class DesktopModeAppHelper(private val innerHelper: IStandardAppHelper) :
     fun enterDesktopWithDrag(
         wmHelper: WindowManagerStateHelper,
         device: UiDevice,
+        motionEventHelper: MotionEventHelper = MotionEventHelper(getInstrumentation(), TOUCH)
     ) {
         innerHelper.launchViaIntent(wmHelper)
-        dragToDesktop(wmHelper, device)
+        dragToDesktop(
+            wmHelper = wmHelper,
+            device = device,
+            motionEventHelper = motionEventHelper
+        )
         waitForAppToMoveToDesktop(wmHelper)
     }
 
-    private fun dragToDesktop(wmHelper: WindowManagerStateHelper, device: UiDevice) {
+    private fun dragToDesktop(
+        wmHelper: WindowManagerStateHelper,
+        device: UiDevice,
+        motionEventHelper: MotionEventHelper
+    ) {
         val windowRect = wmHelper.getWindowRegion(innerHelper).bounds
         val startX = windowRect.centerX()
 
@@ -88,7 +101,17 @@ open class DesktopModeAppHelper(private val innerHelper: IStandardAppHelper) :
         val endY = displayRect.centerY() / 2
 
         // drag the window to move to desktop
-        device.drag(startX, startY, startX, endY, 100)
+        if (motionEventHelper.inputMethod == TOUCH
+            && Flags.enableHoldToDragAppHandle()) {
+            // Touch requires hold-to-drag.
+            val downTime = SystemClock.uptimeMillis()
+            motionEventHelper.actionDown(startX, startY, time = downTime)
+            SystemClock.sleep(100L) // hold for 100ns before starting the move.
+            motionEventHelper.actionMove(startX, startY, startX, endY, 100, downTime = downTime)
+            motionEventHelper.actionUp(startX, endY, downTime = downTime)
+        } else {
+            device.drag(startX, startY, startX, endY, 100)
+        }
     }
 
     private fun getMaximizeButtonForTheApp(caption: UiObject2?): UiObject2 {
@@ -220,9 +243,10 @@ open class DesktopModeAppHelper(private val innerHelper: IStandardAppHelper) :
         val endY = startY + verticalChange
         val endX = startX + horizontalChange
 
-        motionEvent.actionDown(startX, startY)
-        motionEvent.actionMove(startX, startY, endX, endY, /* steps= */100)
-        motionEvent.actionUp(endX, endY)
+        val downTime = SystemClock.uptimeMillis()
+        motionEvent.actionDown(startX, startY, time = downTime)
+        motionEvent.actionMove(startX, startY, endX, endY, /* steps= */100, downTime = downTime)
+        motionEvent.actionUp(endX, endY, downTime = downTime)
         wmHelper
             .StateSyncBuilder()
             .withAppTransitionIdle()
diff --git a/tests/FlickerTests/test-apps/app-helpers/src/com/android/server/wm/flicker/helpers/MotionEventHelper.kt b/tests/FlickerTests/test-apps/app-helpers/src/com/android/server/wm/flicker/helpers/MotionEventHelper.kt
index 083539890906..86a0b0f8c66e 100644
--- a/tests/FlickerTests/test-apps/app-helpers/src/com/android/server/wm/flicker/helpers/MotionEventHelper.kt
+++ b/tests/FlickerTests/test-apps/app-helpers/src/com/android/server/wm/flicker/helpers/MotionEventHelper.kt
@@ -21,6 +21,7 @@ import android.os.SystemClock
 import android.view.ContentInfo.Source
 import android.view.InputDevice.SOURCE_MOUSE
 import android.view.InputDevice.SOURCE_STYLUS
+import android.view.InputDevice.SOURCE_TOUCHSCREEN
 import android.view.MotionEvent
 import android.view.MotionEvent.ACTION_DOWN
 import android.view.MotionEvent.ACTION_MOVE
@@ -36,23 +37,24 @@ import android.view.MotionEvent.ToolType
  */
 class MotionEventHelper(
     private val instr: Instrumentation,
-    private val inputMethod: InputMethod
+    val inputMethod: InputMethod
 ) {
     enum class InputMethod(@ToolType val toolType: Int, @Source val source: Int) {
         STYLUS(TOOL_TYPE_STYLUS, SOURCE_STYLUS),
         MOUSE(TOOL_TYPE_MOUSE, SOURCE_MOUSE),
-        TOUCHPAD(TOOL_TYPE_FINGER, SOURCE_MOUSE)
+        TOUCHPAD(TOOL_TYPE_FINGER, SOURCE_MOUSE),
+        TOUCH(TOOL_TYPE_FINGER, SOURCE_TOUCHSCREEN)
     }
 
-    fun actionDown(x: Int, y: Int) {
-        injectMotionEvent(ACTION_DOWN, x, y)
+    fun actionDown(x: Int, y: Int, time: Long = SystemClock.uptimeMillis()) {
+        injectMotionEvent(ACTION_DOWN, x, y, downTime = time, eventTime = time)
     }
 
-    fun actionUp(x: Int, y: Int) {
-        injectMotionEvent(ACTION_UP, x, y)
+    fun actionUp(x: Int, y: Int, downTime: Long) {
+        injectMotionEvent(ACTION_UP, x, y, downTime = downTime)
     }
 
-    fun actionMove(startX: Int, startY: Int, endX: Int, endY: Int, steps: Int) {
+    fun actionMove(startX: Int, startY: Int, endX: Int, endY: Int, steps: Int, downTime: Long) {
         val incrementX = (endX - startX).toFloat() / (steps - 1)
         val incrementY = (endY - startY).toFloat() / (steps - 1)
 
@@ -61,14 +63,19 @@ class MotionEventHelper(
             val x = startX + incrementX * i
             val y = startY + incrementY * i
 
-            val moveEvent = getMotionEvent(time, time, ACTION_MOVE, x, y)
+            val moveEvent = getMotionEvent(downTime, time, ACTION_MOVE, x, y)
             injectMotionEvent(moveEvent)
         }
     }
 
-    private fun injectMotionEvent(action: Int, x: Int, y: Int): MotionEvent {
-        val eventTime = SystemClock.uptimeMillis()
-        val event = getMotionEvent(eventTime, eventTime, action, x.toFloat(), y.toFloat())
+    private fun injectMotionEvent(
+        action: Int,
+        x: Int,
+        y: Int,
+        downTime: Long = SystemClock.uptimeMillis(),
+        eventTime: Long = SystemClock.uptimeMillis()
+    ): MotionEvent {
+        val event = getMotionEvent(downTime, eventTime, action, x.toFloat(), y.toFloat())
         injectMotionEvent(event)
         return event
     }