Added PointerEvent firing on touch events.

Source/core/page/EventHandler.cpp

Index: Source/core/page/EventHandler.cpp
diff --git a/Source/core/page/EventHandler.cpp b/Source/core/page/EventHandler.cpp
index 6cfb5ac4da40857cf04b2ad674cc0e7b2891759a..8e842b41eee0e3edbeee93b75b5f52fe75e9edb0 100644
--- a/Source/core/page/EventHandler.cpp
+++ b/Source/core/page/EventHandler.cpp
@@ -45,6 +45,7 @@
 #include "core/events/EventPath.h"
 #include "core/events/KeyboardEvent.h"
 #include "core/events/MouseEvent.h"
+#include "core/events/PointerEvent.h"
 #include "core/events/TextEvent.h"
 #include "core/events/TouchEvent.h"
 #include "core/events/WheelEvent.h"
@@ -244,11 +245,13 @@ EventHandler::EventHandler(LocalFrame* frame)
     , m_lastShowPressTimestamp(0)
     , m_deltaConsumedForScrollSequence(false)
 {
+    m_primaryIdByPointerType.clear();
 }
 
 EventHandler::~EventHandler()
 {
     ASSERT(!m_fakeMouseMoveEventTimer.isActive());
+    m_primaryIdByPointerType.clear();
 }
 
 DEFINE_TRACE(EventHandler)
@@ -316,6 +319,7 @@ void EventHandler::clear()
     m_scrollbarHandlingScrollGesture = nullptr;
     m_maxMouseMovedDuration = 0;
     m_touchPressed = false;
+    m_primaryIdByPointerType.clear();
     m_mouseDownMayStartSelect = false;
     m_mouseDownMayStartDrag = false;
     m_lastShowPressTimestamp = 0;
@@ -3777,7 +3781,7 @@ void EventHandler::updateLastScrollbarUnderMouse(Scrollbar* scrollbar, bool setL
     }
 }
 
-static const AtomicString& eventNameForTouchPointState(PlatformTouchPoint::State state)
+static const AtomicString& touchEventNameForTouchPointState(PlatformTouchPoint::State state)
 {
     switch (state) {
     case PlatformTouchPoint::TouchReleased:
@@ -3796,6 +3800,25 @@ static const AtomicString& eventNameForTouchPointState(PlatformTouchPoint::State
     }
 }
 
+static const AtomicString& pointerEventNameForTouchPointState(PlatformTouchPoint::State state)
+{
+    switch (state) {
+    case PlatformTouchPoint::TouchReleased:
+        return EventTypeNames::pointerup;
+    case PlatformTouchPoint::TouchCancelled:
+        return EventTypeNames::pointercancel;
+    case PlatformTouchPoint::TouchPressed:
+        return EventTypeNames::pointerdown;
+    case PlatformTouchPoint::TouchMoved:
+        return EventTypeNames::pointermove;
+    case PlatformTouchPoint::TouchStationary:
+        // TouchStationary state is not converted to touch events, so fall through to assert.

[Rick Byers, 2015/06/11 04:14:56]

remove incorrect (and otherwise fairly useless) comment

[mustaq, 2015/06/12 16:05:23]

Done.

+    default:
+        ASSERT_NOT_REACHED();
+        return emptyAtom;
+    }
+}
+
 HitTestResult EventHandler::hitTestResultInFrame(LocalFrame* frame, const LayoutPoint& point, HitTestRequest::HitTestRequestType hitType)
 {
     HitTestResult result(HitTestRequest(hitType), point);
@@ -3815,13 +3838,14 @@ bool EventHandler::handleTouchEvent(const PlatformTouchEvent& event)
 {
     TRACE_EVENT0("blink", "EventHandler::handleTouchEvent");
 
+    const String& PointerTypeTouch("touch");
     const Vector<PlatformTouchPoint>& points = event.touchPoints();
 
-    unsigned i;
     bool freshTouchEvents = true;
     bool allTouchReleased = true;
-    for (i = 0; i < points.size(); ++i) {
+    for (unsigned i = 0; i < points.size(); ++i) {
         const PlatformTouchPoint& point = points[i];
+
         if (point.state() != PlatformTouchPoint::TouchPressed)
             freshTouchEvents = false;
         if (point.state() != PlatformTouchPoint::TouchReleased && point.state() != PlatformTouchPoint::TouchCancelled)
@@ -3854,7 +3878,7 @@ bool EventHandler::handleTouchEvent(const PlatformTouchEvent& event)
     }
 
     // First do hit tests for any new touch points.
-    for (i = 0; i < points.size(); ++i) {
+    for (unsigned i = 0; i < points.size(); ++i) {
         const PlatformTouchPoint& point = points[i];
 
         // Touch events implicitly capture to the touched node, and don't change
@@ -3916,30 +3940,18 @@ bool EventHandler::handleTouchEvent(const PlatformTouchEvent& event)
         return false;
     }
 
-    // Build up the lists to use for the 'touches', 'targetTouches' and
-    // 'changedTouches' attributes in the JS event. See
-    // http://www.w3.org/TR/touch-events/#touchevent-interface for how these
-    // lists fit together.
-
-    // Holds the complete set of touches on the screen.
-    RefPtrWillBeRawPtr<TouchList> touches = TouchList::create();
-
-    // A different view on the 'touches' list above, filtered and grouped by
-    // event target. Used for the 'targetTouches' list in the JS event.
-    using TargetTouchesHeapMap = WillBeHeapHashMap<EventTarget*, RefPtrWillBeMember<TouchList>>;
-    TargetTouchesHeapMap touchesByTarget;
-
-    // Array of touches per state, used to assemble the 'changedTouches' list.
-    using EventTargetSet = WillBeHeapHashSet<RefPtrWillBeMember<EventTarget>>;
-    struct {
-        // The touches corresponding to the particular change state this struct
-        // instance represents.
-        RefPtrWillBeMember<TouchList> m_touches;
-        // Set of targets involved in m_touches.
-        EventTargetSet m_targets;
-    } changedTouches[PlatformTouchPoint::TouchStateEnd];
-
-    for (i = 0; i < points.size(); ++i) {
+    // Compute and store the common info used by both PointerEvent and TouchEvent.
+    using TouchInfo = struct {

[Rick Byers, 2015/06/11 04:14:56]

curious: how is this syntax different from the simpler 'struct TouchInfo {
...}'?

[mustaq, 2015/06/12 16:05:24]

I need to use 'typedef struct {...} TouchInfo' here because I am reusing the
definition later on. To me, typedef is slightly less intuitive here than it's
C++11 counterpart 'using'.

http://stackoverflow.com/questions/10747810/what-is-the-difference-between-ty...

[Rick Byers, 2015/06/16 17:25:38]

Ah, cool - thanks!

+        EventTarget* touchTarget;
+        LocalFrame* targetFrame;
+        FloatPoint adjustedPagePoint;
+        FloatSize adjustedRadius;
+        bool knownTarget;
+        bool consumed;
+    };
+    Vector<TouchInfo> touchInfos(points.size());
+
+    for (unsigned i = 0; i < points.size(); ++i) {
         const PlatformTouchPoint& point = points[i];
         PlatformTouchPoint::State pointState = point.state();
         RefPtrWillBeRawPtr<EventTarget> touchTarget = nullptr;
@@ -3988,21 +4000,127 @@ bool EventHandler::handleTouchEvent(const PlatformTouchEvent& event)
 
         // pagePoint should always be in the target element's document coordinates.
         FloatPoint pagePoint = targetFrame->view()->rootFrameToContents(point.pos());
-
         float scaleFactor = 1.0f / targetFrame->pageZoomFactor();
 
         FloatPoint adjustedPagePoint = pagePoint.scaledBy(scaleFactor);

[Rick Byers, 2015/06/11 04:14:56]

kind of silly to create these locals just to assign below.  Remove the
temporaries.

[mustaq, 2015/06/12 16:05:24]

Done.

         FloatSize adjustedRadius = point.radius().scaledBy(scaleFactor);
 
+        TouchInfo& touchInfo = touchInfos[i];
+        touchInfo.touchTarget = touchTarget.get();
+        touchInfo.targetFrame = targetFrame;
+        touchInfo.adjustedPagePoint = adjustedPagePoint;
+        touchInfo.adjustedRadius = adjustedRadius;
+        touchInfo.knownTarget = knownTarget;
+        touchInfo.consumed = false;
+    }
+
+    if (RuntimeEnabledFeatures::pointerEventEnabled()) {

[Rick Byers, 2015/06/11 04:14:56]

could some of this be factored out to another function without too much pain? 
EventHandler::handleTouchEvent is already a bit of a monster!

[mustaq, 2015/06/12 16:05:23]

Done.

+        bool hasPrimaryIdForTouch = m_primaryIdByPointerType.contains(PointerTypeTouch);
+        unsigned primaryIdForTouch = hasPrimaryIdForTouch? m_primaryIdByPointerType.get(PointerTypeTouch) : 0;

[Rick Byers, 2015/06/11 04:14:56]

nit: space before ?

[mustaq, 2015/06/12 16:05:24]

Done.

+
+        // Iterate through the touch points, sending PointerEvents to the targets as required.
+        for (unsigned i = 0; i < points.size(); ++i) {
+            const PlatformTouchPoint& point = points[i];
+            TouchInfo& touchInfo = touchInfos[i];
+
+            const PlatformTouchPoint::State pointState = point.state();
+            const AtomicString& eventName(pointerEventNameForTouchPointState(pointState));

[USE eero AT chromium.org, 2015/06/11 11:12:42]

This does not handle correctly touch points whose state is
PlatformTouchPoint::TouchStationary. Those cases seem to even cause some kind of
corruption resulting in an assert failure from line 4161.

Those touch points should probably be ignored by adding a conditional continue
statement.

[mustaq, 2015/06/12 16:05:23]

Done.

+
+            if (pointState == PlatformTouchPoint::TouchPressed && !hasPrimaryIdForTouch) {
+                primaryIdForTouch = point.id();
+                m_primaryIdByPointerType.set(PointerTypeTouch, primaryIdForTouch);
+                hasPrimaryIdForTouch = true;
+            }
+
+            bool isEnterOrLeave = false;
+            bool isCancelable = !(isEnterOrLeave || pointState == PlatformTouchPoint::TouchCancelled);
+            bool isBubbling = !isEnterOrLeave;
+
+            PointerEventInit pointerEventInit;
+            pointerEventInit.setPointerId(point.id());
+            pointerEventInit.setWidth(touchInfo.adjustedRadius.width());
+            pointerEventInit.setHeight(touchInfo.adjustedRadius.height());
+            pointerEventInit.setPressure(point.force());
+            pointerEventInit.setTiltX(0.0);
+            pointerEventInit.setTiltY(0.0);
+            pointerEventInit.setPointerType(PointerTypeTouch);
+            pointerEventInit.setIsPrimary(hasPrimaryIdForTouch && primaryIdForTouch == point.id());
+            pointerEventInit.setScreenX(point.screenPos().x());
+            pointerEventInit.setScreenY(point.screenPos().y());
+            pointerEventInit.setClientX(0);
+            pointerEventInit.setClientY(0);

[Rick Byers, 2015/06/11 04:14:56]

These are wrong - it should have client co-ordinates (same as in the touch
events).  Please add to test.

[mustaq, 2015/06/12 16:05:23]

Done.

+            pointerEventInit.setMovementX(0);
+            pointerEventInit.setMovementY(0);
+            pointerEventInit.setButton(0);
+            pointerEventInit.setButtons(0);

[Rick Byers, 2015/06/11 04:14:56]

This is wrong, should be 1
http://w3c.github.io/pointerevents/#button-states
Please test this too.

[mustaq, 2015/06/12 16:05:23]

Done.

+            pointerEventInit.setRelatedTarget(nullptr);
+
+            pointerEventInit.setCtrlKey(event.ctrlKey());
+            pointerEventInit.setShiftKey(event.shiftKey());
+            pointerEventInit.setAltKey(event.altKey());
+            pointerEventInit.setMetaKey(event.metaKey());
+
+            pointerEventInit.setBubbles(isBubbling);
+            pointerEventInit.setCancelable(isCancelable);
+
+            RefPtrWillBeRawPtr<PointerEvent> pointerEvent = PointerEvent::create(eventName, pointerEventInit);
+            touchInfo.touchTarget->toNode()->dispatchPointerEvent(pointerEvent.get());
+            touchInfo.consumed = pointerEvent->defaultPrevented() || pointerEvent->defaultHandled();
+        }
+
+        if (allTouchReleased)
+            m_primaryIdByPointerType.remove(PointerTypeTouch);

[Rick Byers, 2015/06/11 04:14:56]

This logic deserves a test (at first I thought it was wrong, but I see it's
right) - eg.  Eg. pointerdown ID=1, pointerdown ID=2, pointerup ID=1.  Now
verify that a new pointerdown isn't considered primary (and 2 didn't suddenly
become primary).

[mustaq, 2015/06/12 16:05:23]

Done.

[mustaq, 2015/06/12 20:37:18]

Just discovered that Chrome reuses 'retired' pointerIds, and this is supported
by the spec! The current logic fails in the following reuse case:
- Finger1 touches the screen, id=0, primary.
- Finger2 touches the screen, id=1, not primary.
- Finger1 goes off the screen.
- Another finger (Finger3/Finger1) touches the screen, Chrome reuses id=0, which
is wrongly considered primary.

Solution:
- Track the set of current IDs.
- The first id that enters an empty set is primary.
- Store the id only as long the id is not touch-released.

I will work on a fix now.

+    }
+
+    bool swallowedEvent = false;
+
+    // Build up the lists to use for the 'touches', 'targetTouches' and
+    // 'changedTouches' attributes in the JS event. See
+    // http://www.w3.org/TR/touch-events/#touchevent-interface for how these
+    // lists fit together.
+
+    // Holds the complete set of touches on the screen.
+    RefPtrWillBeRawPtr<TouchList> touches = TouchList::create();
+
+    // A different view on the 'touches' list above, filtered and grouped by
+    // event target. Used for the 'targetTouches' list in the JS event.
+    using TargetTouchesHeapMap = WillBeHeapHashMap<EventTarget*, RefPtrWillBeMember<TouchList>>;
+    TargetTouchesHeapMap touchesByTarget;
+
+    // Array of touches per state, used to assemble the 'changedTouches' list.
+    using EventTargetSet = WillBeHeapHashSet<RefPtrWillBeMember<EventTarget>>;
+    struct {
+        // The touches corresponding to the particular change state this struct
+        // instance represents.
+        RefPtrWillBeMember<TouchList> m_touches;
+        // Set of targets involved in m_touches.
+        EventTargetSet m_targets;
+    } changedTouches[PlatformTouchPoint::TouchStateEnd];
+
+    for (unsigned i = 0; i < points.size(); ++i) {
+        const PlatformTouchPoint& point = points[i];
+        const TouchInfo& touchInfo = touchInfos[i];
+        PlatformTouchPoint::State pointState = point.state();
+
+        if (touchInfo.consumed)
+            continue;
+
         RefPtrWillBeRawPtr<Touch> touch = Touch::create(
-            targetFrame, touchTarget.get(), point.id(), point.screenPos(), adjustedPagePoint, adjustedRadius, point.rotationAngle(), point.force());
+            touchInfo.targetFrame,
+            touchInfo.touchTarget,
+            point.id(),
+            point.screenPos(),
+            touchInfo.adjustedPagePoint,
+            touchInfo.adjustedRadius,
+            point.rotationAngle(),
+            point.force());
 
         // Ensure this target's touch list exists, even if it ends up empty, so
         // it can always be passed to TouchEvent::Create below.
-        TargetTouchesHeapMap::iterator targetTouchesIterator = touchesByTarget.find(touchTarget.get());
+        TargetTouchesHeapMap::iterator targetTouchesIterator = touchesByTarget.find(touchInfo.touchTarget);
         if (targetTouchesIterator == touchesByTarget.end()) {
-            touchesByTarget.set(touchTarget.get(), TouchList::create());
-            targetTouchesIterator = touchesByTarget.find(touchTarget.get());
+            touchesByTarget.set(touchInfo.touchTarget, TouchList::create());
+            targetTouchesIterator = touchesByTarget.find(touchInfo.touchTarget);
         }
 
         // touches and targetTouches should only contain information about
@@ -4019,12 +4137,12 @@ bool EventHandler::handleTouchEvent(const PlatformTouchEvent& event)
         // never be in the changedTouches list so we do not handle them
         // explicitly here. See https://bugs.webkit.org/show_bug.cgi?id=37609
         // for further discussion about the TouchStationary state.
-        if (pointState != PlatformTouchPoint::TouchStationary && knownTarget) {
+        if (pointState != PlatformTouchPoint::TouchStationary && touchInfo.knownTarget) {
             ASSERT(pointState < PlatformTouchPoint::TouchStateEnd);
             if (!changedTouches[pointState].m_touches)
                 changedTouches[pointState].m_touches = TouchList::create();
             changedTouches[pointState].m_touches->append(touch);
-            changedTouches[pointState].m_targets.add(touchTarget);
+            changedTouches[pointState].m_targets.add(touchInfo.touchTarget);
         }
     }
     if (allTouchReleased) {
@@ -4032,20 +4150,19 @@ bool EventHandler::handleTouchEvent(const PlatformTouchEvent& event)
         m_touchSequenceUserGestureToken.clear();
     }
 
-    // Now iterate the changedTouches list and m_targets within it, sending
-    // events to the targets as required.
-    bool swallowedEvent = false;
+    // Now iterate through the changedTouches list and m_targets within it, sending
+    // TouchEvents to the targets as required.
     for (unsigned state = 0; state != PlatformTouchPoint::TouchStateEnd; ++state) {
         if (!changedTouches[state].m_touches)
             continue;
 
-        const AtomicString& stateName(eventNameForTouchPointState(static_cast<PlatformTouchPoint::State>(state)));
+        const AtomicString& eventName(touchEventNameForTouchPointState(static_cast<PlatformTouchPoint::State>(state)));
         const EventTargetSet& targetsForState = changedTouches[state].m_targets;
         for (const RefPtrWillBeMember<EventTarget>& eventTarget : targetsForState) {
             EventTarget* touchEventTarget = eventTarget.get();
             RefPtrWillBeRawPtr<TouchEvent> touchEvent = TouchEvent::create(
                 touches.get(), touchesByTarget.get(touchEventTarget), changedTouches[state].m_touches.get(),
-                stateName, touchEventTarget->toNode()->document().domWindow(),
+                eventName, touchEventTarget->toNode()->document().domWindow(),
                 event.ctrlKey(), event.altKey(), event.shiftKey(), event.metaKey(), event.cancelable(), event.causesScrollingIfUncanceled(), event.timestamp());
             touchEventTarget->toNode()->dispatchTouchEvent(touchEvent.get());
             swallowedEvent = swallowedEvent || touchEvent->defaultPrevented() || touchEvent->defaultHandled();