Create GestureManager class and move related logic

third_party/WebKit/Source/core/input/GestureManager.cpp

+// Copyright 2016 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 "core/input/GestureManager.h"
+
+#include "core/dom/Document.h"
+#include "core/editing/SelectionController.h"
+#include "core/events/GestureEvent.h"
+#include "core/frame/FrameHost.h"
+#include "core/frame/FrameView.h"
+#include "core/frame/Settings.h"
+#include "core/frame/VisualViewport.h"
+#include "core/input/EventHandler.h"
+#include "core/page/ChromeClient.h"
+#include "core/page/Page.h"
+
+namespace blink {
+
+GestureManager::GestureManager(LocalFrame* frame, ScrollManager* scrollManager,
+    PointerEventManager* pointerEventManager,
+    SelectionController* selectionController)
+: m_frame(frame)
+, m_scrollManager(scrollManager)
+, m_pointerEventManager(pointerEventManager)
+, m_selectionController(selectionController)
+{
+    clear();
+}
+
+GestureManager::~GestureManager()
+{
+}
+
+void GestureManager::clear()
+{
+    m_suppressMouseEventsFromGestures = false;
+    m_longTapShouldInvokeContextMenu = false;
+    m_lastShowPressTimestamp = 0;
+}
+
+DEFINE_TRACE(GestureManager)
+{
+    visitor->trace(m_frame);
+    visitor->trace(m_selectionController);
+}
+
+HitTestRequest::HitTestRequestType GestureManager::getHitTypeForGestureType(PlatformEvent::EventType type)
+{
+    HitTestRequest::HitTestRequestType hitType = HitTestRequest::TouchEvent;
+    switch (type) {
+    case PlatformEvent::GestureShowPress:
+    case PlatformEvent::GestureTapUnconfirmed:
+        return hitType | HitTestRequest::Active;
+    case PlatformEvent::GestureTapDownCancel:
+        // A TapDownCancel received when no element is active shouldn't really be changing hover state.
+        if (!m_frame->document()->activeHoverElement())
+            hitType |= HitTestRequest::ReadOnly;
+        return hitType | HitTestRequest::Release;
+    case PlatformEvent::GestureTap:
+        return hitType | HitTestRequest::Release;
+    case PlatformEvent::GestureTapDown:
+    case PlatformEvent::GestureLongPress:
+    case PlatformEvent::GestureLongTap:
+    case PlatformEvent::GestureTwoFingerTap:
+        // FIXME: Shouldn't LongTap and TwoFingerTap clear the Active state?
+        return hitType | HitTestRequest::Active | HitTestRequest::ReadOnly;
+    default:
+        NOTREACHED();
+        return hitType | HitTestRequest::Active | HitTestRequest::ReadOnly;
+    }
+}
+
+WebInputEventResult GestureManager::handleGestureEventInFrame(const GestureEventWithHitTestResults& targetedEvent)
+{
+    DCHECK(!targetedEvent.event().isScrollEvent());
+
+    Node* eventTarget = targetedEvent.hitTestResult().innerNode();
+    const PlatformGestureEvent& gestureEvent = targetedEvent.event();
+
+    if (m_scrollManager->canHandleGestureEvent(targetedEvent))
+        return WebInputEventResult::HandledSuppressed;
+
+    if (eventTarget) {
+        GestureEvent* gestureDomEvent = GestureEvent::create(eventTarget->document().domWindow(), gestureEvent);
+        if (gestureDomEvent) {
+            DispatchEventResult gestureDomEventResult = eventTarget->dispatchEvent(gestureDomEvent);
+            if (gestureDomEventResult != DispatchEventResult::NotCanceled) {
+                DCHECK(gestureDomEventResult != DispatchEventResult::CanceledByEventHandler);
+                return EventHandler::toWebInputEventResult(gestureDomEventResult);
+            }
+        }
+    }
+
+    switch (gestureEvent.type()) {
+    case PlatformEvent::GestureTapDown:
+        return handleGestureTapDown(targetedEvent);
+    case PlatformEvent::GestureTap:
+        return handleGestureTap(targetedEvent);
+    case PlatformEvent::GestureShowPress:
+        return handleGestureShowPress();
+    case PlatformEvent::GestureLongPress:
+        return handleGestureLongPress(targetedEvent);
+    case PlatformEvent::GestureLongTap:
+        return handleGestureLongTap(targetedEvent);
+    case PlatformEvent::GestureTwoFingerTap:
+        return m_frame->eventHandler().sendContextMenuEventForGesture(targetedEvent);
+    case PlatformEvent::GesturePinchBegin:
+    case PlatformEvent::GesturePinchEnd:
+    case PlatformEvent::GesturePinchUpdate:
+    case PlatformEvent::GestureTapDownCancel:
+    case PlatformEvent::GestureTapUnconfirmed:
+        break;
+    default:
+        NOTREACHED();
+    }
+
+    return WebInputEventResult::NotHandled;
+}
+
+WebInputEventResult GestureManager::handleGestureTapDown(const GestureEventWithHitTestResults& targetedEvent)
+{
+    m_suppressMouseEventsFromGestures =
+        m_pointerEventManager->primaryPointerdownCanceled(targetedEvent.event().uniqueTouchEventId());
+    return WebInputEventResult::NotHandled;
+}
+
+WebInputEventResult GestureManager::handleGestureTap(const GestureEventWithHitTestResults& targetedEvent)
+{
+    FrameView* frameView(m_frame->view());
+    const PlatformGestureEvent& gestureEvent = targetedEvent.event();
+    HitTestRequest::HitTestRequestType hitType = getHitTypeForGestureType(gestureEvent.type());
+    uint64_t preDispatchDomTreeVersion = m_frame->document()->domTreeVersion();
+    uint64_t preDispatchStyleVersion = m_frame->document()->styleVersion();
+
+    UserGestureIndicator gestureIndicator(DefinitelyProcessingUserGesture);
+
+    HitTestResult currentHitTest = targetedEvent.hitTestResult();
+
+    // We use the adjusted position so the application isn't surprised to see a event with
+    // co-ordinates outside the target's bounds.
+    IntPoint adjustedPoint = frameView->rootFrameToContents(gestureEvent.position());
+
+    const unsigned modifiers = gestureEvent.getModifiers();
+
+    if (!m_suppressMouseEventsFromGestures) {
+        PlatformMouseEvent fakeMouseMove(gestureEvent.position(), gestureEvent.globalPosition(),
+            NoButton, PlatformEvent::MouseMoved, /* clickCount */ 0,
+            static_cast<PlatformEvent::Modifiers>(modifiers),
+            PlatformMouseEvent::FromTouch, gestureEvent.timestamp(), WebPointerProperties::PointerType::Mouse);
+        m_frame->eventHandler().dispatchMouseEvent(EventTypeNames::mousemove, currentHitTest.innerNode(), 0, fakeMouseMove);
+    }
+
+    // Do a new hit-test in case the mousemove event changed the DOM.
+    // Note that if the original hit test wasn't over an element (eg. was over a scrollbar) we
+    // don't want to re-hit-test because it may be in the wrong frame (and there's no way the page
+    // could have seen the event anyway).
+    // Also note that the position of the frame may have changed, so we need to recompute the content
+    // co-ordinates (updating layout/style as hitTestResultAtPoint normally would).
+    // FIXME: Use a hit-test cache to avoid unnecessary hit tests. http://crbug.com/398920
+    if (currentHitTest.innerNode()) {
+        LocalFrame* mainFrame = m_frame->localFrameRoot();
+        if (mainFrame && mainFrame->view())
+            mainFrame->view()->updateLifecycleToCompositingCleanPlusScrolling();
+        adjustedPoint = frameView->rootFrameToContents(gestureEvent.position());
+        currentHitTest = EventHandler::hitTestResultInFrame(m_frame, adjustedPoint, hitType);
+    }
+
+    // Capture data for showUnhandledTapUIIfNeeded.
+    Node* tappedNode = currentHitTest.innerNode();
+    IntPoint tappedPosition = gestureEvent.position();
+    Node* tappedNonTextNode = tappedNode;
+
+    if (tappedNonTextNode && tappedNonTextNode->isTextNode())
+        tappedNonTextNode = FlatTreeTraversal::parent(*tappedNonTextNode);
+
+    m_frame->eventHandler().setClickNode(tappedNonTextNode);
+
+    PlatformMouseEvent fakeMouseDown(gestureEvent.position(), gestureEvent.globalPosition(),
+        LeftButton, PlatformEvent::MousePressed, gestureEvent.tapCount(),
+        static_cast<PlatformEvent::Modifiers>(modifiers | PlatformEvent::LeftButtonDown),
+        PlatformMouseEvent::FromTouch, gestureEvent.timestamp(), WebPointerProperties::PointerType::Mouse);
+
+    // TODO(mustaq): We suppress MEs plus all it's side effects. What would that
+    // mean for for TEs?  What's the right balance here? crbug.com/617255
+    WebInputEventResult mouseDownEventResult = WebInputEventResult::HandledSuppressed;
+    if (!m_suppressMouseEventsFromGestures) {
+        mouseDownEventResult = m_frame->eventHandler().dispatchMouseEvent(EventTypeNames::mousedown, currentHitTest.innerNode(), gestureEvent.tapCount(), fakeMouseDown);
+        m_selectionController->initializeSelectionState();
+        if (mouseDownEventResult == WebInputEventResult::NotHandled)
+            mouseDownEventResult = m_frame->eventHandler().handleMouseFocus(MouseEventWithHitTestResults(fakeMouseDown, currentHitTest), InputDeviceCapabilities::firesTouchEventsSourceCapabilities());
+        if (mouseDownEventResult == WebInputEventResult::NotHandled)
+            mouseDownEventResult = m_frame->eventHandler().handleMousePressEvent(MouseEventWithHitTestResults(fakeMouseDown, currentHitTest));
+    }
+
+    if (currentHitTest.innerNode()) {
+        DCHECK(gestureEvent.type() == PlatformEvent::GestureTap);
+        HitTestResult result = currentHitTest;
+        result.setToShadowHostIfInUserAgentShadowRoot();
+        m_frame->chromeClient().onMouseDown(result.innerNode());
+    }
+
+    // FIXME: Use a hit-test cache to avoid unnecessary hit tests. http://crbug.com/398920
+    if (currentHitTest.innerNode()) {
+        LocalFrame* mainFrame = m_frame->localFrameRoot();
+        if (mainFrame && mainFrame->view())
+            mainFrame->view()->updateAllLifecyclePhases();
+        adjustedPoint = frameView->rootFrameToContents(gestureEvent.position());
+        currentHitTest = EventHandler::hitTestResultInFrame(m_frame, adjustedPoint, hitType);
+    }
+
+    PlatformMouseEvent fakeMouseUp(gestureEvent.position(), gestureEvent.globalPosition(),
+        LeftButton, PlatformEvent::MouseReleased, gestureEvent.tapCount(),
+        static_cast<PlatformEvent::Modifiers>(modifiers),
+        PlatformMouseEvent::FromTouch, gestureEvent.timestamp(), WebPointerProperties::PointerType::Mouse);
+    WebInputEventResult mouseUpEventResult = m_suppressMouseEventsFromGestures
+        ? WebInputEventResult::HandledSuppressed
+        : m_frame->eventHandler().dispatchMouseEvent(EventTypeNames::mouseup, currentHitTest.innerNode(), gestureEvent.tapCount(), fakeMouseUp);
+
+    WebInputEventResult clickEventResult = WebInputEventResult::NotHandled;
+    if (tappedNonTextNode) {
+        if (currentHitTest.innerNode()) {
+            // Updates distribution because a mouseup (or mousedown) event listener can make the
+            // tree dirty at dispatchMouseEvent() invocation above.
+            // Unless distribution is updated, commonAncestor would hit DCHECK.
+            // Both tappedNonTextNode and currentHitTest.innerNode()) don't need to be updated
+            // because commonAncestor() will exit early if their documents are different.
+            tappedNonTextNode->updateDistribution();
+            Node* clickTargetNode = currentHitTest.innerNode()->commonAncestor(*tappedNonTextNode, EventHandler::parentForClickEvent);
+            clickEventResult = m_frame->eventHandler().dispatchMouseEvent(EventTypeNames::click, clickTargetNode, gestureEvent.tapCount(), fakeMouseUp);
+        }
+        m_frame->eventHandler().setClickNode(nullptr);
+    }
+
+    if (mouseUpEventResult == WebInputEventResult::NotHandled)
+        mouseUpEventResult = m_frame->eventHandler().handleMouseReleaseEvent(MouseEventWithHitTestResults(fakeMouseUp, currentHitTest));
+    m_frame->eventHandler().clearDragHeuristicState();
+
+    WebInputEventResult eventResult = EventHandler::mergeEventResult(EventHandler::mergeEventResult(mouseDownEventResult, mouseUpEventResult), clickEventResult);
+    if (eventResult == WebInputEventResult::NotHandled && tappedNode && m_frame->page()) {
+        bool domTreeChanged = preDispatchDomTreeVersion != m_frame->document()->domTreeVersion();
+        bool styleChanged = preDispatchStyleVersion != m_frame->document()->styleVersion();
+
+        IntPoint tappedPositionInViewport = frameHost()->visualViewport().rootFrameToViewport(tappedPosition);
+        m_frame->chromeClient().showUnhandledTapUIIfNeeded(tappedPositionInViewport, tappedNode, domTreeChanged || styleChanged);
+    }
+    return eventResult;
+}
+
+WebInputEventResult GestureManager::handleGestureLongPress(const GestureEventWithHitTestResults& targetedEvent)
+{
+    const PlatformGestureEvent& gestureEvent = targetedEvent.event();
+
+    // FIXME: Ideally we should try to remove the extra mouse-specific hit-tests here (re-using the
+    // supplied HitTestResult), but that will require some overhaul of the touch drag-and-drop code
+    // and LongPress is such a special scenario that it's unlikely to matter much in practice.
+
+    m_longTapShouldInvokeContextMenu = false;
+    if (m_frame->eventHandler().handleDragDropIfPossible(targetedEvent)) {
+        m_longTapShouldInvokeContextMenu = true;
+        return WebInputEventResult::HandledSystem;
+    }
+    IntPoint hitTestPoint = m_frame->view()->rootFrameToContents(gestureEvent.position());
+    HitTestResult result = m_frame->eventHandler().hitTestResultAtPoint(hitTestPoint);
+    if (m_selectionController->handleGestureLongPress(gestureEvent, result)) {
+        m_frame->eventHandler().focusDocumentView();
+        return WebInputEventResult::HandledSystem;
+    }
+
+    return m_frame->eventHandler().sendContextMenuEventForGesture(targetedEvent);
+}
+
+WebInputEventResult GestureManager::handleGestureLongTap(const GestureEventWithHitTestResults& targetedEvent)
+{
+#if !OS(ANDROID)
+    if (m_longTapShouldInvokeContextMenu) {
+        m_longTapShouldInvokeContextMenu = false;
+        return m_frame->eventHandler().sendContextMenuEventForGesture(targetedEvent);
+    }
+#endif
+    return WebInputEventResult::NotHandled;
+}
+
+WebInputEventResult GestureManager::handleGestureShowPress()
+{
+    m_lastShowPressTimestamp = WTF::monotonicallyIncreasingTime();
+
+    FrameView* view = m_frame->view();
+    if (!view)
+        return WebInputEventResult::NotHandled;
+    if (ScrollAnimatorBase* scrollAnimator = view->existingScrollAnimator())
+        scrollAnimator->cancelAnimation();
+    const FrameView::ScrollableAreaSet* areas = view->scrollableAreas();
+    if (!areas)
+        return WebInputEventResult::NotHandled;
+    for (const ScrollableArea* scrollableArea : *areas) {
+        ScrollAnimatorBase* animator = scrollableArea->existingScrollAnimator();
+        if (animator)
+            animator->cancelAnimation();
+    }
+    return WebInputEventResult::NotHandled;
+}
+
+
+FrameHost* GestureManager::frameHost() const
+{
+    if (!m_frame->page())
+        return nullptr;
+
+    return &m_frame->page()->frameHost();
+}
+
+double GestureManager::getLastShowPressTimestamp()
+{
+    return m_lastShowPressTimestamp;
+}
+
+} // namespace blink