eventhandler.cpp

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/*
 * Copyright (C) 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.
 * Copyright (C) 2006 Alexey Proskuryakov ([e-mail])
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
 */

#include "config.h"
#include "EventHandler.h"

#include "AXObjectCache.h"
#include "CachedImage.h"
#include "ChromeClient.h"
#include "Cursor.h"
#include "Document.h"
#include "DragController.h"
#include "Editor.h"
#include "EventNames.h"
#include "FloatPoint.h"
#include "FloatRect.h"
#include "FocusController.h"
#include "Frame.h"
#include "FrameLoader.h"
#include "FrameTree.h"
#include "FrameView.h"
#include "HitTestRequest.h"
#include "HitTestResult.h"
#include "HTMLFrameSetElement.h"
#include "HTMLFrameElementBase.h"
#include "HTMLInputElement.h"
#include "HTMLNames.h"
#include "Image.h"
#include "InspectorController.h"
#include "KeyboardEvent.h"
#include "MouseEvent.h"
#include "MouseEventWithHitTestResults.h"
#include "Page.h"
#include "PlatformKeyboardEvent.h"
#include "PlatformWheelEvent.h"
#include "RenderFrameSet.h"
#include "RenderTextControlSingleLine.h"
#include "RenderWidget.h"
#include "RenderView.h"
#include "Scrollbar.h"
#include "SelectionController.h"
#include "Settings.h"
#include "TextEvent.h"
#include <wtf/StdLibExtras.h>

#if ENABLE(SVG)
#include "SVGDocument.h"
#include "SVGElementInstance.h"
#include "SVGNames.h"
#include "SVGUseElement.h"
#endif

namespace WebCore {

using namespace HTMLNames;

// The link drag hysteresis is much larger than the others because there
// needs to be enough space to cancel the link press without starting a link drag,
// and because dragging links is rare.
const int LinkDragHysteresis = 40;
const int ImageDragHysteresis = 5;
const int TextDragHysteresis = 3;
const int GeneralDragHysteresis = 3;

// Match key code of composition keydown event on windows.
// IE sends VK_PROCESSKEY which has value 229;
const int CompositionEventKeyCode = 229;

#if ENABLE(SVG)
using namespace SVGNames;
#endif

// When the autoscroll or the panScroll is triggered when do the scroll every 0.05s to make it smooth
const double autoscrollInterval = 0.05;

static Frame* subframeForTargetNode(Node*);
static Frame* subframeForHitTestResult(const MouseEventWithHitTestResults&);

static inline void scrollAndAcceptEvent(float delta, ScrollDirection positiveDirection, ScrollDirection negativeDirection, PlatformWheelEvent& e, Node* node)
{
    if (!delta)
        return;
        
    // Find the nearest enclosing box.
    RenderBox* enclosingBox = node->renderer()->enclosingBox();

    if (e.granularity() == ScrollByPageWheelEvent) {
        if (enclosingBox->scroll(delta < 0 ? negativeDirection : positiveDirection, ScrollByPage, 1))
            e.accept();
        return;
    } 
    float pixelsToScroll = delta > 0 ? delta : -delta;
    if (enclosingBox->scroll(delta < 0 ? negativeDirection : positiveDirection, ScrollByPixel, pixelsToScroll))
        e.accept();
}

EventHandler::EventHandler(Frame* frame)
    : m_frame(frame)
    , m_mousePressed(false)
    , m_capturesDragging(false)
    , m_mouseDownMayStartSelect(false)
    , m_mouseDownMayStartDrag(false)
    , m_mouseDownWasSingleClickInSelection(false)
    , m_beganSelectingText(false)
    , m_panScrollInProgress(false)
    , m_hoverTimer(this, &EventHandler::hoverTimerFired)
    , m_autoscrollTimer(this, &EventHandler::autoscrollTimerFired)
    , m_autoscrollRenderer(0)
    , m_autoscrollInProgress(false)
    , m_mouseDownMayStartAutoscroll(false)
    , m_mouseDownWasInSubframe(false)
#if ENABLE(SVG)
    , m_svgPan(false)
#endif
    , m_resizeLayer(0)
    , m_capturingMouseEventsNode(0)
    , m_clickCount(0)
    , m_mouseDownTimestamp(0)
    , m_pendingFrameUnloadEventCount(0)
    , m_pendingFrameBeforeUnloadEventCount(0)
#if PLATFORM(MAC)
    , m_mouseDownView(nil)
    , m_sendingEventToSubview(false)
    , m_activationEventNumber(0)
#endif
{
}

EventHandler::~EventHandler()
{
}
    
EventHandler::EventHandlerDragState& EventHandler::dragState()
{
    DEFINE_STATIC_LOCAL(EventHandlerDragState, state, ());
    return state;
}
    
void EventHandler::clear()
{
    m_hoverTimer.stop();
    m_resizeLayer = 0;
    m_nodeUnderMouse = 0;
    m_lastNodeUnderMouse = 0;
#if ENABLE(SVG)
    m_instanceUnderMouse = 0;
    m_lastInstanceUnderMouse = 0;
#endif
    m_lastMouseMoveEventSubframe = 0;
    m_lastScrollbarUnderMouse = 0;
    m_clickCount = 0;
    m_clickNode = 0;
    m_frameSetBeingResized = 0;
    m_dragTarget = 0;
    m_currentMousePosition = IntPoint();
    m_mousePressNode = 0;
    m_mousePressed = false;
    m_capturesDragging = false;
    m_capturingMouseEventsNode = 0;
}

void EventHandler::selectClosestWordFromMouseEvent(const MouseEventWithHitTestResults& result)
{
    Node* innerNode = result.targetNode();
    VisibleSelection newSelection;

    if (innerNode && innerNode->renderer() && m_mouseDownMayStartSelect) {
        VisiblePosition pos(innerNode->renderer()->positionForPoint(result.localPoint()));
        if (pos.isNotNull()) {
            newSelection = VisibleSelection(pos);
            newSelection.expandUsingGranularity(WordGranularity);
        }
    
        if (newSelection.isRange()) {
            m_frame->setSelectionGranularity(WordGranularity);
            m_beganSelectingText = true;
            if (result.event().clickCount() == 2 && m_frame->editor()->isSelectTrailingWhitespaceEnabled()) 
                newSelection.appendTrailingWhitespace();            
        }
        
        if (m_frame->shouldChangeSelection(newSelection))
            m_frame->selection()->setSelection(newSelection);
    }
}

void EventHandler::selectClosestWordOrLinkFromMouseEvent(const MouseEventWithHitTestResults& result)
{
    if (!result.hitTestResult().isLiveLink())
        return selectClosestWordFromMouseEvent(result);

    Node* innerNode = result.targetNode();

    if (innerNode && innerNode->renderer() && m_mouseDownMayStartSelect) {
        VisibleSelection newSelection;
        Element* URLElement = result.hitTestResult().URLElement();
        VisiblePosition pos(innerNode->renderer()->positionForPoint(result.localPoint()));
        if (pos.isNotNull() && pos.deepEquivalent().node()->isDescendantOf(URLElement))
            newSelection = VisibleSelection::selectionFromContentsOfNode(URLElement);
    
        if (newSelection.isRange()) {
            m_frame->setSelectionGranularity(WordGranularity);
            m_beganSelectingText = true;
        }

        if (m_frame->shouldChangeSelection(newSelection))
            m_frame->selection()->setSelection(newSelection);
    }
}

bool EventHandler::handleMousePressEventDoubleClick(const MouseEventWithHitTestResults& event)
{
    if (event.event().button() != LeftButton)
        return false;

    if (m_frame->selection()->isRange())
        // A double-click when range is already selected
        // should not change the selection.  So, do not call
        // selectClosestWordFromMouseEvent, but do set
        // m_beganSelectingText to prevent handleMouseReleaseEvent
        // from setting caret selection.
        m_beganSelectingText = true;
    else
        selectClosestWordFromMouseEvent(event);

    return true;
}

bool EventHandler::handleMousePressEventTripleClick(const MouseEventWithHitTestResults& event)
{
    if (event.event().button() != LeftButton)
        return false;
    
    Node* innerNode = event.targetNode();
    if (!(innerNode && innerNode->renderer() && m_mouseDownMayStartSelect))
        return false;

    VisibleSelection newSelection;
    VisiblePosition pos(innerNode->renderer()->positionForPoint(event.localPoint()));
    if (pos.isNotNull()) {
        newSelection = VisibleSelection(pos);
        newSelection.expandUsingGranularity(ParagraphGranularity);
    }
    if (newSelection.isRange()) {
        m_frame->setSelectionGranularity(ParagraphGranularity);
        m_beganSelectingText = true;
    }
    
    if (m_frame->shouldChangeSelection(newSelection))
        m_frame->selection()->setSelection(newSelection);

    return true;
}

bool EventHandler::handleMousePressEventSingleClick(const MouseEventWithHitTestResults& event)
{
    if (event.event().button() != LeftButton)
        return false;
    
    Node* innerNode = event.targetNode();
    if (!(innerNode && innerNode->renderer() && m_mouseDownMayStartSelect))
        return false;

    // Extend the selection if the Shift key is down, unless the click is in a link.
    bool extendSelection = event.event().shiftKey() && !event.isOverLink();

    // Don't restart the selection when the mouse is pressed on an
    // existing selection so we can allow for text dragging.
    IntPoint vPoint = m_frame->view()->windowToContents(event.event().pos());
    if (!extendSelection && m_frame->selection()->contains(vPoint)) {
        m_mouseDownWasSingleClickInSelection = true;
        return false;
    }

    VisiblePosition visiblePos(innerNode->renderer()->positionForPoint(event.localPoint()));
    if (visiblePos.isNull())
        visiblePos = VisiblePosition(innerNode, 0, DOWNSTREAM);
    Position pos = visiblePos.deepEquivalent();
    
    VisibleSelection newSelection = m_frame->selection()->selection();
    if (extendSelection && newSelection.isCaretOrRange()) {
        m_frame->selection()->setLastChangeWasHorizontalExtension(false);
        
        // See <rdar://problem/3668157> REGRESSION (Mail): shift-click deselects when selection 
        // was created right-to-left
        Position start = newSelection.start();
        Position end = newSelection.end();
        short before = Range::compareBoundaryPoints(pos.node(), pos.offset(), start.node(), start.offset());
        if (before <= 0)
            newSelection = VisibleSelection(pos, end);
        else
            newSelection = VisibleSelection(start, pos);

        if (m_frame->selectionGranularity() != CharacterGranularity)
            newSelection.expandUsingGranularity(m_frame->selectionGranularity());
        m_beganSelectingText = true;
    } else {
        newSelection = VisibleSelection(visiblePos);
        m_frame->setSelectionGranularity(CharacterGranularity);
    }
    
    if (m_frame->shouldChangeSelection(newSelection))
        m_frame->selection()->setSelection(newSelection);

    return true;
}

bool EventHandler::handleMousePressEvent(const MouseEventWithHitTestResults& event)
{
    // Reset drag state.
    dragState().m_dragSrc = 0;

    bool singleClick = event.event().clickCount() <= 1;

    // If we got the event back, that must mean it wasn't prevented,
    // so it's allowed to start a drag or selection.
    m_mouseDownMayStartSelect = canMouseDownStartSelect(event.targetNode());
    
    // Careful that the drag starting logic stays in sync with eventMayStartDrag()
    m_mouseDownMayStartDrag = singleClick;

    m_mouseDownWasSingleClickInSelection = false;

    if (event.isOverWidget() && passWidgetMouseDownEventToWidget(event))
        return true;