Add EventHandlerRegistry

Source/core/dom/EventHandlerRegistry.cpp

+// Copyright 2014 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/dom/EventHandlerRegistry.h"
+
+#include "core/dom/Document.h"
+#include "core/events/ThreadLocalEventNames.h"
+#include "core/events/WheelEvent.h"
+#include "core/frame/FrameHost.h"
+#include "core/frame/LocalFrame.h"
+#include "core/page/Chrome.h"
+#include "core/page/ChromeClient.h"
+#include "core/page/Page.h"
+#include "core/page/scrolling/ScrollingCoordinator.h"
+
+namespace WebCore {
+
+EventHandlerRegistry::EventHandlerRegistry(Document& document)
+    : DOMWindowLifecycleObserver(document.domWindow())
+    , m_scrollEventHandlerCount(0)
+    , m_wheelEventHandlerCount(0)
+{
+}
+
+EventHandlerRegistry::~EventHandlerRegistry()
+{
+}
+
+const char* EventHandlerRegistry::supplementName()
+{
+    return "EventHandlerRegistry";
+}
+
+EventHandlerRegistry* EventHandlerRegistry::from(Document& document)
+{
+    EventHandlerRegistry* controller = static_cast<EventHandlerRegistry*>(DocumentSupplement::from(document, supplementName()));
+    if (!controller) {
+        controller = new EventHandlerRegistry(document);
+        DocumentSupplement::provideTo(document, supplementName(), adoptPtr(controller));
+    }
+    return controller;
+}
+
+void EventHandlerRegistry::didChangeWheelEventHandlerCount(Document& document, int delta)
+{
+    if (delta < 0)
+        ASSERT(m_wheelEventHandlerCount > 0);
+    m_wheelEventHandlerCount += delta;
+
+    Page* page = document.page();
+    if (!page)
+        return;
+
+    LocalFrame* mainFrame = page->mainFrame();
+    if (mainFrame)
+        mainFrame->notifyChromeClientWheelEventHandlerCountChanged();
+
+    ScrollingCoordinator* scrollingCoordinator = page->scrollingCoordinator();
+    if (!scrollingCoordinator)
+        return;
+
+    FrameView* frameView = document.view();
+    if (!frameView)
+        return;
+
+    scrollingCoordinator->frameViewWheelEventHandlerCountChanged(frameView);
+}
+
+void EventHandlerRegistry::didChangeScrollEventHandlerCount(Document& document, int delta)
+{
+    if (delta < 0)
+        ASSERT(m_scrollEventHandlerCount > 0);
+    m_scrollEventHandlerCount += delta;
+
+    Page* page = document.page();
+    if (!page)
+        return;
+
+    ScrollingCoordinator* scrollingCoordinator = page->scrollingCoordinator();
+    if (!scrollingCoordinator)
+        return;
+
+    FrameView* frameView = document.view();
+    if (!frameView)
+        return;
+
+    scrollingCoordinator->frameViewScrollEventHandlerCountChanged(frameView);
+}
+
+static void notifyTouchRectsChanged(Document& document)
+{
+    Page* page = document.page();
+    if (!page)
+        return;
+
+    ScrollingCoordinator* scrollingCoordinator = page->scrollingCoordinator();
+    if (!scrollingCoordinator)
+        return;
+
+    scrollingCoordinator->touchEventTargetRectsDidChange();
+}
+
+void EventHandlerRegistry::didAddTouchEventHandler(Document& document, Node& handler)
+{
+    // The node should either be in the document, or be the Document node of a child
+    // of the document.
+    ASSERT(&handler.document() == &document
+        || (handler.isDocumentNode() && toDocument(&handler)->parentDocument() == &document));
+
+    if (!m_touchEventTargets.get())
+        m_touchEventTargets = adoptPtr(new TouchEventTargetSet);
+    bool isFirstHandler = m_touchEventTargets->isEmpty();
+
+    if (!m_touchEventTargets->add(&handler).isNewEntry) {
+        // Just incremented refcount, no real change.
+        // If this is a child document node, then the count should never go above 1.
+        ASSERT(!handler.isDocumentNode() || &handler->document() == &document);
+        return;
+    }
+
+    if (isFirstHandler) {
+        if (Document* parent = document.parentDocument()) {
+            didAddTouchEventHandler(*parent, document);
+        } else {
+            // This is the first touch handler on the whole page.
+            if (FrameHost* frameHost = document.frameHost())
+                frameHost->chrome().client().needTouchEvents(true);
+        }
+    }
+
+    // When we're all done with all frames, ensure touch hit rects are marked as dirty.
+    if (!handler.isDocumentNode() || &handler == &document)
+        notifyTouchRectsChanged(document);
+}
+
+void EventHandlerRegistry::didRemoveTouchEventHandler(Document& document, Node& handler, bool clearAll)
+{
+    // Note that we can't assert that |handler| is in this document because it might be in
+    // the process of moving out of it.
+    ASSERT(clearAll || m_touchEventTargets->contains(&handler));
+    if (!m_touchEventTargets.get())
+        return;
+
+    if (clearAll) {
+        if (!m_touchEventTargets->contains(&handler))
+            return;
+        m_touchEventTargets->removeAll(&handler);
+    } else {
+        if (!m_touchEventTargets->remove(&handler)) {
+            // Just decremented refcount, no real update.
+            return;
+        }
+    }
+
+    if (m_touchEventTargets->isEmpty()) {
+        if (Document* parent = document.parentDocument()) {
+            // This was the last handler in the document, update the parent document too.
+            didRemoveTouchEventHandler(*parent, document, clearAll);
+        } else {
+            // We just removed the last touch handler on the whole page.
+            if (FrameHost* frameHost = document.frameHost())
+                frameHost->chrome().client().needTouchEvents(false);
+        }
+    }
+
+    // When we're all done with all frames, ensure touch hit rects are marked as dirty.
+    if (!handler.isDocumentNode() || &handler == &document)
+        notifyTouchRectsChanged(document);
+}
+
+void EventHandlerRegistry::didAddEventHandler(Document& document, const AtomicString& eventType, Node* targetNode)
+{
+    if (eventType == EventTypeNames::wheel || eventType == EventTypeNames::mousewheel)
+        didChangeWheelEventHandlerCount(document, 1);
+    else if (eventType == EventTypeNames::scroll)
+        didChangeScrollEventHandlerCount(document, 1);
+    else if (isTouchEventType(eventType))
+        didAddTouchEventHandler(document, *targetNode);
+}
+
+void EventHandlerRegistry::didRemoveEventHandler(Document& document, const AtomicString& eventType, Node* targetNode)
+{
+    if (eventType == EventTypeNames::wheel || eventType == EventTypeNames::mousewheel)
+        didChangeWheelEventHandlerCount(document, -1);
+    else if (eventType == EventTypeNames::scroll)
+        didChangeScrollEventHandlerCount(document, -1);
+    else if (isTouchEventType(eventType))
+        didRemoveTouchEventHandler(document, *targetNode, false);
+}
+
+void EventHandlerRegistry::didAddEventListener(DOMWindow* window, const AtomicString& eventType)
+{
+    didAddEventHandler(*window->document(), eventType, window->document());
+}
+
+void EventHandlerRegistry::didRemoveEventListener(DOMWindow* window, const AtomicString& eventType)
+{
+    didRemoveEventHandler(*window->document(), eventType, window->document());
+}
+
+void EventHandlerRegistry::didMoveNodeToNewDocument(Node& targetNode, Document& oldDocument)
+{
+    didChangeAllEventHandlers(targetNode, oldDocument, Removed);
+    didChangeAllEventHandlers(targetNode, targetNode.document(), Added);
+}
+
+void EventHandlerRegistry::didRemoveAllEventHandlers(Node& targetNode)
+{
+    didChangeAllEventHandlers(targetNode, targetNode.document(), RemovedAll);
+}
+
+void EventHandlerRegistry::didChangeAllEventHandlers(Node& targetNode, Document& document, ChangeOperation op)
+{
+    if (!targetNode.hasEventListeners())
+        return;
+    EventHandlerRegistry* registry = EventHandlerRegistry::from(document);
+    int wheelHandlerCount = targetNode.getEventListeners(EventTypeNames::wheel).size() +
+        targetNode.getEventListeners(EventTypeNames::mousewheel).size();
+    registry->didChangeWheelEventHandlerCount(
+        document, (op == Added) ? wheelHandlerCount : -wheelHandlerCount);
+
+    int scrollHandlerCount = targetNode.getEventListeners(EventTypeNames::scroll).size();
+    registry->didChangeScrollEventHandlerCount(
+        document, (op == Added) ? scrollHandlerCount : -scrollHandlerCount);
+
+    const Vector<AtomicString> eventTypes = targetNode.eventTypes();
+    for (size_t i = 0; i < eventTypes.size(); ++i) {
+        if (!isTouchEventType(eventTypes[i]))
+            continue;
+        const EventListenerVector& eventListeners =
+            targetNode.getEventListeners(eventTypes[i]);
+        for (size_t j = 0; j < eventListeners.size(); ++j) {
+            if (op == Added)
+                registry->didAddTouchEventHandler(document, targetNode);
+            else
+                registry->didRemoveTouchEventHandler(document, targetNode, op == RemovedAll);
+        }
+    }
+}
+
+} // namespace WebCore