Cleaning up PointerIdManager and add id re-mapping

third_party/WebKit/Source/core/events/PointerEventFactory.cpp

+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "config.h"
+#include "core/events/PointerEventFactory.h"
+
+namespace blink {
+
+namespace {
+
+inline int toInt(WebPointerProperties::PointerType t) { return static_cast<int>(t); }
+
+const char* pointerTypeNameForWebPointPointerType(WebPointerProperties::PointerType type)
+{
+    switch (type) {
+    case WebPointerProperties::PointerType::Unknown:
+        return "";
+    case WebPointerProperties::PointerType::Touch:
+        return "touch";
+    case WebPointerProperties::PointerType::Pen:
+        return "pen";
+    case WebPointerProperties::PointerType::Mouse:
+        return "mouse";
+    }
+    ASSERT_NOT_REACHED();
+    return "";
+}
+
+} // namespace
+
+const PointerEventFactory::MappedId PointerEventFactory::s_invalidId = 0;
+
+// Mouse id is 1 to behave the same as MS Edge for compatibility reasons.
+const PointerEventFactory::MappedId PointerEventFactory::s_mouseId = 1;
+
+PassRefPtrWillBeRawPtr<PointerEvent> PointerEventFactory::create(const AtomicString& type,
+    const PlatformMouseEvent& mouseEvent,
+    PassRefPtrWillBeRawPtr<Node> relatedTarget,
+    PassRefPtrWillBeRawPtr<AbstractView> view)
+{
+    PointerEventInit pointerEventInit;
+
+    const WebPointerProperties::PointerType pointerType = mouseEvent.pointerProperties().pointerType;
+    MappedId pointerId = add(PointerEventFactory::IncomingId(toInt(pointerType), mouseEvent.pointerProperties().id));
+
+    pointerEventInit.setPointerId(pointerId);

[mustaq, 2015/12/02 15:53:46]

In all create*() methods, the 4 lines dealing with MappedId is exactly the same,
looks like sort of an "atomic" id-related setter op. I suggest packing them in a
helper function, to help avoiding missed steps in future changes.

[Navid Zolghadr, 2015/12/02 16:49:07]

Done.

+    pointerEventInit.setPointerType(pointerTypeNameForWebPointPointerType(pointerType));
+    pointerEventInit.setIsPrimary(isPrimary(pointerId));
+
+    pointerEventInit.setScreenX(mouseEvent.globalPosition().x());
+    pointerEventInit.setScreenY(mouseEvent.globalPosition().y());
+    pointerEventInit.setClientX(mouseEvent.position().x());
+    pointerEventInit.setClientY(mouseEvent.position().y());
+
+    pointerEventInit.setButton(mouseEvent.button());
+    pointerEventInit.setButtons(MouseEvent::platformModifiersToButtons(mouseEvent.modifiers()));
+
+    UIEventWithKeyState::setFromPlatformModifiers(pointerEventInit, mouseEvent.modifiers());
+
+    pointerEventInit.setBubbles(type != EventTypeNames::pointerenter
+        && type != EventTypeNames::pointerleave);
+    pointerEventInit.setCancelable(type != EventTypeNames::pointerenter
+        && type != EventTypeNames::pointerleave && type != EventTypeNames::pointercancel);
+
+    pointerEventInit.setView(view);
+    if (relatedTarget)
+        pointerEventInit.setRelatedTarget(relatedTarget);
+
+    return PointerEvent::create(type, pointerEventInit);
+}
+
+PassRefPtrWillBeRawPtr<PointerEvent> PointerEventFactory::create(const AtomicString& type,
+    const PlatformTouchPoint& touchPoint, PlatformEvent::Modifiers modifiers,
+    const double width, const double height,
+    const double clientX, const double clientY)
+{
+    const PlatformTouchPoint::State pointState = touchPoint.state();
+
+    bool pointerReleasedOrCancelled = pointState == PlatformTouchPoint::TouchReleased
+        || pointState == PlatformTouchPoint::TouchCancelled;
+    const WebPointerProperties::PointerType pointerType = touchPoint.pointerProperties().pointerType;
+    MappedId pointerId = add(PointerEventFactory::IncomingId(toInt(pointerType), touchPoint.id()));
+
+    bool isEnterOrLeave = false;
+
+    PointerEventInit pointerEventInit;
+    pointerEventInit.setPointerId(pointerId);
+    pointerEventInit.setWidth(width);
+    pointerEventInit.setHeight(height);
+    pointerEventInit.setPressure(touchPoint.force());
+    pointerEventInit.setTiltX(touchPoint.pointerProperties().tiltX);
+    pointerEventInit.setTiltY(touchPoint.pointerProperties().tiltY);
+    pointerEventInit.setPointerType(pointerTypeNameForWebPointPointerType(pointerType));
+    pointerEventInit.setIsPrimary(isPrimary(pointerId));
+    pointerEventInit.setScreenX(touchPoint.screenPos().x());
+    pointerEventInit.setScreenY(touchPoint.screenPos().y());
+    pointerEventInit.setClientX(clientX);
+    pointerEventInit.setClientY(clientY);
+    pointerEventInit.setButton(0);
+    pointerEventInit.setButtons(pointerReleasedOrCancelled ? 0 : 1);
+
+    UIEventWithKeyState::setFromPlatformModifiers(pointerEventInit, modifiers);
+
+    pointerEventInit.setBubbles(!isEnterOrLeave);
+    pointerEventInit.setCancelable(!isEnterOrLeave && pointState != PlatformTouchPoint::TouchCancelled);
+
+    return PointerEvent::create(type, pointerEventInit);
+}
+
+
+PassRefPtrWillBeRawPtr<PointerEvent> PointerEventFactory::createPointerCancel(const PlatformTouchPoint& touchPoint)
+{
+    const WebPointerProperties::PointerType pointerType = touchPoint.pointerProperties().pointerType;
+    const String& pointerTypeStr = pointerTypeNameForWebPointPointerType(pointerType);
+
+    MappedId pointerId = add(PointerEventFactory::IncomingId(toInt(pointerType), touchPoint.id()));
+    PointerEventInit pointerEventInit;
+    pointerEventInit.setPointerId(pointerId);
+    pointerEventInit.setPointerType(pointerTypeStr);
+    pointerEventInit.setIsPrimary(isPrimary(pointerId));
+    pointerEventInit.setBubbles(true);
+    pointerEventInit.setCancelable(false);
+
+    return PointerEvent::create(EventTypeNames::pointercancel, pointerEventInit);
+}
+
+PointerEventFactory::PointerEventFactory()
+: m_currentId(PointerEventFactory::s_mouseId+1)

[mustaq, 2015/12/02 15:53:46]

Perhaps we should set m_currentId in clear().

[Navid Zolghadr, 2015/12/02 16:49:08]

Done.

+{
+    clear();
+}
+
+PointerEventFactory::~PointerEventFactory()
+{
+    clear();
+}
+
+void PointerEventFactory::clear()
+{
+    for (int type = 0; type <= toInt(WebPointerProperties::PointerType::LastEntry); type++) {
+        m_primaryId[type] = PointerEventFactory::s_invalidId;
+        m_idCount[type] = 0;
+    }
+    m_idMapping.clear();
+    m_idReverseMapping.clear();
+
+    // Always add mouse pointer in initialization and never remove it.
+    // No need to add it to m_idMapping as it is not going to be used with the existing APIs
+    m_primaryId[toInt(WebPointerProperties::PointerType::Mouse)] = s_mouseId;
+    m_idReverseMapping.add(s_mouseId, IncomingId(toInt(WebPointerProperties::PointerType::Mouse), 0));
+}
+
+PointerEventFactory::MappedId PointerEventFactory::add(const IncomingId p)
+{
+    // Do not add extra mouse pointer as it was added in initialization
+    if (p.first == toInt(WebPointerProperties::PointerType::Mouse))
+        return s_mouseId;
+
+    int type = p.first;
+    if (m_idMapping.contains(p))
+        return m_idMapping.get(p);
+    // We do not handle the overflow of m_currentId as it should be very rare
+    MappedId mappedId = m_currentId++;
+    if (!m_idCount[type])
+        m_primaryId[type] = mappedId;
+    m_idCount[type]++;
+    m_idMapping.add(p, mappedId);
+    m_idReverseMapping.add(mappedId, p);
+    return static_cast<PointerEventFactory::MappedId>(mappedId);
+}
+
+void PointerEventFactory::remove(const PassRefPtrWillBeRawPtr<PointerEvent> pointerEvent)
+{
+    MappedId mappedId = pointerEvent->pointerId();
+    // Do not remove mouse pointer id as it should always be there
+    if (mappedId == s_mouseId || !m_idReverseMapping.contains(mappedId))
+        return;
+
+    IncomingId p = m_idReverseMapping.get(mappedId);
+    int type = p.first;
+    m_idReverseMapping.remove(mappedId);
+    m_idMapping.remove(p);
+    if (m_primaryId[type] == mappedId)
+        m_primaryId[type] = PointerEventFactory::s_invalidId;
+    m_idCount[type]--;
+}
+
+bool PointerEventFactory::isPrimary(PointerEventFactory::MappedId mappedId) const
+{
+    if (!m_idReverseMapping.contains(mappedId))
+        return false;
+
+    IncomingId p = m_idReverseMapping.get(mappedId);
+    int type = p.first;
+    return m_primaryId[type] == mappedId;
+}
+
+
+} // namespace blink