[DO NOT MERGE] Start dragging where the fingers initially went down.

This does not apply when transitioning from touch exploration to dragging.
Bug: 162521649
Test: manual

Change-Id: I92022ca0359040a6563e6a48c110face574dc9df

1 files changed, 54 insertions, 3 deletions

diff --git a/services/accessibility/java/com/android/server/accessibility/gestures/TouchExplorer.java b/services/accessibility/java/com/android/server/accessibility/gestures/TouchExplorer.java
index b5417cc1504d..90806969816e 100644
--- a/services/accessibility/java/com/android/server/accessibility/gestures/TouchExplorer.java
+++ b/services/accessibility/java/com/android/server/accessibility/gestures/TouchExplorer.java
@@ -608,12 +608,20 @@ public class TouchExplorer extends BaseEventStreamTransformation
                 if (isDraggingGesture(event)) {
                     // Two pointers moving in the same direction within
                     // a given distance perform a drag.
-                    mState.startDragging();
                     computeDraggingPointerIdIfNeeded(event);
                     pointerIdBits = 1 << mDraggingPointerId;
                     event.setEdgeFlags(mReceivedPointerTracker.getLastReceivedDownEdgeFlags());
-                    mDispatcher.sendMotionEvent(
-                            event, MotionEvent.ACTION_DOWN, rawEvent, pointerIdBits, policyFlags);
+                    MotionEvent downEvent = computeDownEventForDrag(event);
+                    if (downEvent != null) {
+                        mDispatcher.sendMotionEvent(downEvent, MotionEvent.ACTION_DOWN, rawEvent,
+                                pointerIdBits, policyFlags);
+                        mDispatcher.sendMotionEvent(event, MotionEvent.ACTION_MOVE, rawEvent,
+                                pointerIdBits, policyFlags);
+                    } else {
+                        mDispatcher.sendMotionEvent(event, MotionEvent.ACTION_DOWN, rawEvent,
+                                pointerIdBits, policyFlags);
+                    }
+                    mState.startDragging();
                 } else {
                     // Two pointers moving arbitrary are delegated to the view hierarchy.
                     mState.startDelegating();
@@ -987,6 +995,49 @@ public class TouchExplorer extends BaseEventStreamTransformation
         return distance;
     }
 
+    /**
+     * Creates a down event using the down coordinates of the dragging pointer and other information
+     * from the supplied event. The supplied event's down time is adjusted to reflect the time when
+     * the dragging pointer initially went down.
+     */
+    private MotionEvent computeDownEventForDrag(MotionEvent event) {
+        // Creating a down event only  makes sense if we haven't started touch exploring yet.
+        if (mState.isTouchExploring()
+                || mDraggingPointerId == INVALID_POINTER_ID
+                || event == null) {
+            return null;
+        }
+        final float x = mReceivedPointerTracker.getReceivedPointerDownX(mDraggingPointerId);
+        final float y = mReceivedPointerTracker.getReceivedPointerDownY(mDraggingPointerId);
+        final long time = mReceivedPointerTracker.getReceivedPointerDownTime(mDraggingPointerId);
+        MotionEvent.PointerCoords[] coords = new MotionEvent.PointerCoords[1];
+        coords[0] = new MotionEvent.PointerCoords();
+        coords[0].x = x;
+        coords[0].y = y;
+        MotionEvent.PointerProperties[] properties = new MotionEvent.PointerProperties[1];
+        properties[0] = new MotionEvent.PointerProperties();
+        properties[0].id = mDraggingPointerId;
+        properties[0].toolType = MotionEvent.TOOL_TYPE_FINGER;
+        MotionEvent downEvent =
+                MotionEvent.obtain(
+                        time,
+                        time,
+                        MotionEvent.ACTION_DOWN,
+                        1,
+                        properties,
+                        coords,
+                        event.getMetaState(),
+                        event.getButtonState(),
+                        event.getXPrecision(),
+                        event.getYPrecision(),
+                        event.getDeviceId(),
+                        event.getEdgeFlags(),
+                        event.getSource(),
+                        event.getFlags());
+        event.setDownTime(time);
+        return downEvent;
+    }
+
     public TouchState getState() {
         return mState;
     }