Fix properties of got/lostpointercapture

third_party/WebKit/LayoutTests/fast/events/pointerevents/mouse-pointer-capture.html

Index: third_party/WebKit/LayoutTests/fast/events/pointerevents/mouse-pointer-capture.html
diff --git a/third_party/WebKit/LayoutTests/fast/events/pointerevents/mouse-pointer-capture.html b/third_party/WebKit/LayoutTests/fast/events/pointerevents/mouse-pointer-capture.html
index 09fddcc5c56c2769e4e1a7f77e077a3332768d1a..869b77031ef2d630bc6e469144f31b7aa4c34c9e 100644
--- a/third_party/WebKit/LayoutTests/fast/events/pointerevents/mouse-pointer-capture.html
+++ b/third_party/WebKit/LayoutTests/fast/events/pointerevents/mouse-pointer-capture.html
@@ -41,6 +41,56 @@ var rect = document.getElementById("blue").getBoundingClientRect();
 var x3 = rect.left + 5;
 var y3 = rect.top + 5;
 
+var lastPointerEvent = null;
+var pointereventProperties = [
+    "clientX",
+    "clientY",
+    "layerX",
+    "layerY",
+    "movementX",
+    "movementY",
+    "offsetX",
+    "offsetY",
+    "pageX",
+    "pageY",
+    "screenX",
+    "screenY",
+    "x",
+    "y",
+    "button",
+    "buttons",
+    "pressure",
+    "tiltX",
+    "tiltY",
+    "width",
+    "height"
+];
+
+function checkPointerCaptureProperties(lastPointerEvent, currentPointerEvent) {
+  if (lastPointerEvent == null)
+    return false;
+
+  var isImmediateRelease = (lastPointerEvent.type == 'pointerup') &&
+                           (currentPointerEvent.type == 'lostpointercapture');
+  var isDelayedCapture = lastPointerEvent.type.includes('pointercapture');
+  var isImplicitReleaseOutside =  implicitReleaseOutside &&
+                                  (currentPointerEvent.type == 'lostpointercapture');
+
+  if (!isImmediateRelease && !isDelayedCapture && !isImplicitReleaseOutside)
+    return false;

[mustaq, 2016/08/04 21:43:05]

Can't it be simpler? Why not return false for all events except
got/lostpointercapture?

[Navid Zolghadr, 2016/08/05 14:26:08]

I cannot imagine a way to make it simpler. Note that we have two events in this
function. One is the previous event and one is the current event. Sometime we
need to do the check when the current event is got/lostpointercapture and
sometime we need to do that when the previous event is got/lostpointercapture. I
tried to capture the three scenarios in three different booleans to make it more
clear.  Do you know a better way of making it simpler?

[mustaq, 2016/08/05 15:51:22]

Does the following miss any cases?

For any current PE, check the attributes if the last PE is got/lost, otherwise
do nothing. (In Line 127 below, set "lastPointerEvent = event" unconditionally
for any PE.)

[Navid Zolghadr, 2016/08/05 17:08:03]

I removed one of the cases as we discussed offline.

+
+  for (var i = 0; i< pointereventProperties. length; i++) {
+    var property = pointereventProperties[i];
+    if (lastPointerEvent[property] !== currentPointerEvent[property]) {
+      debug("Capture pointer event attributes are incorrect!");
+      return true;
+    }
+  }
+
+  debug("Capture pointer event attributes are correct!");
+  return true
+}
+
 function init() {
   var eventList = ["mouseenter", "mouseleave", "mouseover", "mouseout", "mousemove", "mousedown", "mouseup",
                    "pointerenter", "pointerleave", "pointerover", "pointerout", "pointermove", "pointerdown", "pointerup",
@@ -49,6 +99,7 @@ function init() {
   document.addEventListener("lostpointercapture", function(event) {
     if (event.eventPhase == Event.AT_TARGET) {
       debug("document received " + event.type);
+      lastPointerEvent = event;
     }
   });
   ["grey", "green", "blue"].forEach(function(id) {
@@ -73,6 +124,12 @@ function init() {
               removeElement = false;
             }
           }
+          if (checkPointerCaptureProperties(lastPointerEvent, event)) {
+              lastPointerEvent = null;
+          } else {
+            if (event.type.includes('pointer'))
+              lastPointerEvent = event;
+          }
         }
       });
     });