/* $Id: UIMouseHandler.cpp $ */
/** @file
 *
 * VBox frontends: Qt GUI ("VirtualBox"):
 * UIMouseHandler class implementation
 */

/*
 * Copyright (C) 2010-2012 Oracle Corporation
 *
 * This file is part of VirtualBox Open Source Edition (OSE), as
 * available from http://www.virtualbox.org. This file is free software;
 * you can redistribute it and/or modify it under the terms of the GNU
 * General Public License (GPL) as published by the Free Software
 * Foundation, in version 2 as it comes in the "COPYING" file of the
 * VirtualBox OSE distribution. VirtualBox OSE is distributed in the
 * hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
 */

/* Qt includes: */
#include <QDesktopWidget>
#include <QMouseEvent>

/* GUI includes: */
#include "VBoxGlobal.h"
#include "UIMessageCenter.h"
#include "UIKeyboardHandler.h"
#include "UIMouseHandler.h"
#include "UISession.h"
#include "UIMachineLogic.h"
#include "UIMachineWindow.h"
#include "UIMachineView.h"
#include "UIFrameBuffer.h"

#ifdef Q_WS_WIN
# include "VBoxUtils-win.h"
#endif /* Q_WS_WIN */

#ifdef Q_WS_X11
# include <X11/XKBlib.h>
# ifdef KeyPress
const int XFocusOut = FocusOut;
const int XFocusIn = FocusIn;
const int XKeyPress = KeyPress;
const int XKeyRelease = KeyRelease;
#  undef KeyRelease
#  undef KeyPress
#  undef FocusOut
#  undef FocusIn
# endif /* KeyPress */
#endif /* Q_WS_X11 */

#ifdef Q_WS_MAC
# include "VBoxUtils-darwin.h"
#endif /* Q_WS_MAC */

/* COM includes: */
#include "CConsole.h"
#include "CMouse.h"
#include "CFramebuffer.h"
#include "CDisplay.h"

/* Factory function to create mouse-handler: */
UIMouseHandler* UIMouseHandler::create(UIMachineLogic *pMachineLogic,
                                       UIVisualStateType visualStateType)
{
    /* Prepare mouse-handler: */
    UIMouseHandler *pMouseHandler = 0;
    /* Depending on visual-state type: */
    switch (visualStateType)
    {
        /* For now all the states using common mouse-handler: */
        case UIVisualStateType_Normal:
        case UIVisualStateType_Fullscreen:
        case UIVisualStateType_Seamless:
        case UIVisualStateType_Scale:
            pMouseHandler = new UIMouseHandler(pMachineLogic);
            break;
        default:
            break;
    }
    /* Return prepared mouse-handler: */
    return pMouseHandler;
}

/* Factory function to destroy mouse-handler: */
void UIMouseHandler::destroy(UIMouseHandler *pMouseHandler)
{
    /* Delete mouse-handler: */
    delete pMouseHandler;
}

/* Prepare listener for particular machine-window: */
void UIMouseHandler::prepareListener(ulong uIndex, UIMachineWindow *pMachineWindow)
{
    /* If that window is NOT registered yet: */
    if (!m_windows.contains(uIndex))
    {
        /* Register machine-window: */
        m_windows.insert(uIndex, pMachineWindow);
        /* Install event-filter for machine-window: */
        m_windows[uIndex]->installEventFilter(this);
    }

    /* If that view is NOT registered yet: */
    if (!m_views.contains(uIndex))
    {
        /* Register machine-view: */
        m_views.insert(uIndex, pMachineWindow->machineView());
        /* Install event-filter for machine-view: */
        m_views[uIndex]->installEventFilter(this);
        /* Make machine-view notify mouse-handler about resizeHintDone(): */
        connect(m_views[uIndex], SIGNAL(resizeHintDone()), this, SLOT(sltMousePointerShapeChanged()));
    }

    /* If that viewport is NOT registered yet: */
    if (!m_viewports.contains(uIndex))
    {
        /* Register machine-view-viewport: */
        m_viewports.insert(uIndex, pMachineWindow->machineView()->viewport());
        /* Install event-filter for machine-view-viewport: */
        m_viewports[uIndex]->installEventFilter(this);
    }
}

/* Cleanup listener for particular machine-window: */
void UIMouseHandler::cleanupListener(ulong uIndex)
{
    /* Check if we should release mouse first: */
    if ((int)uIndex == m_iMouseCaptureViewIndex)
        releaseMouse();

    /* If that window still registered: */
    if (m_windows.contains(uIndex))
    {
        /* Unregister machine-window: */
        m_windows.remove(uIndex);
    }

    /* If that view still registered: */
    if (m_views.contains(uIndex))
    {
        /* Unregister machine-view: */
        m_views.remove(uIndex);
    }

    /* If that viewport still registered: */
    if (m_viewports.contains(uIndex))
    {
        /* Unregister machine-view-viewport: */
        m_viewports.remove(uIndex);
    }
}

void UIMouseHandler::captureMouse(ulong uScreenId)
{
    /* Do not try to capture mouse if its captured already: */
    if (uisession()->isMouseCaptured())
        return;

    /* If such viewport exists: */
    if (m_viewports.contains(uScreenId))
    {
        /* Store mouse-capturing state value: */
        uisession()->setMouseCaptured(true);

        /* Memorize the index of machine-view-viewport captured mouse: */
        m_iMouseCaptureViewIndex = uScreenId;

        /* Memorize the host position where the cursor was captured: */
        m_capturedMousePos = QCursor::pos();

        /* Acquiring visible viewport rectangle in global coodrinates: */
        QRect visibleRectangle = m_viewports[m_iMouseCaptureViewIndex]->visibleRegion().boundingRect();
        QPoint visibleRectanglePos = m_views[m_iMouseCaptureViewIndex]->mapToGlobal(m_viewports[m_iMouseCaptureViewIndex]->pos());
        visibleRectangle.translate(visibleRectanglePos);
        visibleRectangle = visibleRectangle.intersected(QApplication::desktop()->availableGeometry());

#ifdef Q_WS_WIN
        /* Move the mouse to the center of the visible area: */
        m_lastMousePos = visibleRectangle.center();
        QCursor::setPos(m_lastMousePos);
        /* Update mouse clipping: */
        updateMouseCursorClipping();
#elif defined (Q_WS_MAC)
        /* Grab all mouse events: */
        ::darwinMouseGrab(m_viewports[m_iMouseCaptureViewIndex]);
#else /* Q_WS_MAC */
        /* Remember current mouse position: */
        m_lastMousePos = QCursor::pos();
        /* Grab all mouse events: */
        m_viewports[m_iMouseCaptureViewIndex]->grabMouse();
#endif /* !Q_WS_MAC */

        /* Switch guest mouse to the relative mode: */
        CMouse mouse = session().GetConsole().GetMouse();
        mouse.PutMouseEvent(0, 0, 0, 0, 0);

        /* Emit signal if required: */
        emit mouseStateChanged(mouseState());
    }
}

void UIMouseHandler::releaseMouse()
{
    /* Do not try to release mouse if its released already: */
    if (!uisession()->isMouseCaptured())
        return;

    /* If such viewport exists: */
    if (m_viewports.contains(m_iMouseCaptureViewIndex))
    {
        /* Store mouse-capturing state value: */
        uisession()->setMouseCaptured(false);

        /* Return the cursor to where it was when we captured it: */
        QCursor::setPos(m_capturedMousePos);
#ifdef Q_WS_WIN
        /* Update mouse clipping: */
        updateMouseCursorClipping();
#elif defined(Q_WS_MAC)
        /* Releasing grabbed mouse from that view: */
        ::darwinMouseRelease(m_viewports[m_iMouseCaptureViewIndex]);
#else /* Q_WS_MAC */
        /* Releasing grabbed mouse from that view: */
        m_viewports[m_iMouseCaptureViewIndex]->releaseMouse();
#endif /* !Q_WS_MAC */
        /* Reset mouse-capture index: */
        m_iMouseCaptureViewIndex = -1;

        /* Emit signal if required: */
        emit mouseStateChanged(mouseState());
    }
}

/* Setter for mouse-integration feature: */
void UIMouseHandler::setMouseIntegrationEnabled(bool fEnabled)
{
    /* Do not do anything if its already done: */
    if (uisession()->isMouseIntegrated() == fEnabled)
        return;

    /* Store mouse-integration state value: */
    uisession()->setMouseIntegrated(fEnabled);

    /* Reuse sltMouseCapabilityChanged() to update mouse state: */
    sltMouseCapabilityChanged();
}

/* Current mouse state: */
int UIMouseHandler::mouseState() const
{
    return (uisession()->isMouseCaptured() ? UIMouseStateType_MouseCaptured : 0) |
           (uisession()->isMouseSupportsAbsolute() ? UIMouseStateType_MouseAbsolute : 0) |
           (uisession()->isMouseIntegrated() ? 0 : UIMouseStateType_MouseAbsoluteDisabled);
}

#ifdef Q_WS_X11
bool UIMouseHandler::x11EventFilter(XEvent *pEvent, ulong /* uScreenId */)
{
    /* Check if some system event should be filtered-out.
     * Returning 'true' means filtering-out,
     * Returning 'false' means passing event to Qt. */
    bool fResult = false; /* Pass to Qt by default: */
    switch (pEvent->type)
    {
        /* We have to handle XFocusOut right here as this event is not passed to UIMachineView::event().
         * Handling this event is important for releasing the keyboard before the screen saver gets active.
         * See public ticket #3894: Apparently this makes problems with newer versions of Qt
         * and this hack is probably not necessary anymore. So disable it for Qt >= 4.5.0. */
        case XFocusOut:
        {
            if (uisession()->isRunning())
            {
                if (VBoxGlobal::qtRTVersion() < ((4 << 16) | (5 << 8) | 0))
                    releaseMouse();
            }
            fResult = false;
        }
        default:
            break;
    }
    /* Return result: */
    return fResult;
}
#endif /* Q_WS_X11 */

/* Machine state-change handler: */
void UIMouseHandler::sltMachineStateChanged()
{
    /* Get machine state: */
    KMachineState state = uisession()->machineState();
    /* Handle particular machine states: */
    switch (state)
    {
        case KMachineState_Paused:
        case KMachineState_TeleportingPausedVM:
        case KMachineState_Stuck:
        {
            /* Release the mouse: */
            releaseMouse();
            break;
        }
        default:
            break;
    }

    /* Notify all listeners: */
    emit mouseStateChanged(mouseState());
}

/* Mouse capability-change handler: */
void UIMouseHandler::sltMouseCapabilityChanged()
{
    /* If mouse supports absolute pointing and mouse-integration activated: */
    if (uisession()->isMouseSupportsAbsolute() && uisession()->isMouseIntegrated())
    {
        /* Release the mouse: */
        releaseMouse();
        /* Also we should switch guest mouse to the absolute mode: */
        CMouse mouse = session().GetConsole().GetMouse();
        mouse.PutMouseEventAbsolute(-1, -1, 0, 0, 0);
    }
#if 0 /* current team's decision is NOT to capture mouse on mouse-absolute mode loosing! */
    /* If mouse-integration deactivated or mouse doesn't supports absolute pointing: */
    else
    {
        /* Search for the machine-view focused now: */
        int iFocusedView = -1;
        QList<ulong> screenIds = m_views.keys();
        for (int i = 0; i < screenIds.size(); ++i)
        {
            if (m_views[screenIds[i]]->hasFocus())
            {
                iFocusedView = screenIds[i];
                break;
            }
        }
        /* If there is no focused view but views are present we will use the first one: */
        if (iFocusedView == -1 && !screenIds.isEmpty())
            iFocusedView = screenIds[0];
        /* Capture mouse using that view: */
        if (iFocusedView != -1)
            captureMouse(iFocusedView);
    }
#else /* but just to switch the guest mouse into relative mode! */
    /* If mouse-integration deactivated or mouse doesn't supports absolute pointing: */
    else
    {
        /* Switch guest mouse to the relative mode: */
        CMouse mouse = session().GetConsole().GetMouse();
        mouse.PutMouseEvent(0, 0, 0, 0, 0);
    }
#endif

    /* Notify user about mouse supports or not absolute pointing if that method was called by signal: */
    if (sender())
    {
        /* don't annoy the user while restoring a VM */
        KMachineState state = uisession()->machineState();
        if (state != KMachineState_Restoring)
            msgCenter().remindAboutMouseIntegration(uisession()->isMouseSupportsAbsolute());
    }

    /* Notify all listeners: */
    emit mouseStateChanged(mouseState());
}

/* Mouse pointer-shape-change handler: */
void UIMouseHandler::sltMousePointerShapeChanged()
{
    /* First of all, we should check if the host pointer should be visible.
     * We should hide host pointer in case of:
     * 1. mouse is 'captured' or
     * 2. machine is NOT 'paused' and mouse is NOT 'captured' and 'integrated' and 'absolute' but host pointer is 'hidden' by the guest. */
    if (uisession()->isMouseCaptured() ||
        (!uisession()->isPaused() &&
         uisession()->isMouseIntegrated() &&
         uisession()->isMouseSupportsAbsolute() &&
         uisession()->isHidingHostPointer()))
    {
        QList<ulong> screenIds = m_viewports.keys();
        for (int i = 0; i < screenIds.size(); ++i)
            m_viewports[screenIds[i]]->setCursor(Qt::BlankCursor);
    }

    else

    /* Otherwise we should show host pointer with guest shape assigned to it if:
     * machine is NOT 'paused', mouse is 'integrated' and 'absolute' and valid pointer shape is present. */
    if (!uisession()->isPaused() &&
        uisession()->isMouseIntegrated() &&
        uisession()->isMouseSupportsAbsolute() &&
        uisession()->isValidPointerShapePresent())
    {
        QList<ulong> screenIds = m_viewports.keys();
        for (int i = 0; i < screenIds.size(); ++i)
            m_viewports[screenIds[i]]->setCursor(uisession()->cursor());
    }

    else

    /* There could be other states covering such situations as:
     * 1. machine is 'paused' or
     * 2. mouse is NOT 'captured' and 'integrated' but NOT 'absolute' or
     * 3. mouse is NOT 'captured' and 'absolute' but NOT 'integrated'.
     * We have nothing to do with that except just unset the cursor. */
    {
        QList<ulong> screenIds = m_viewports.keys();
        for (int i = 0; i < screenIds.size(); ++i)
            m_viewports[screenIds[i]]->unsetCursor();
    }
}

/* Mouse-handler constructor: */
UIMouseHandler::UIMouseHandler(UIMachineLogic *pMachineLogic)
    : QObject(pMachineLogic)
    , m_pMachineLogic(pMachineLogic)
    , m_iLastMouseWheelDelta(0)
    , m_iMouseCaptureViewIndex(-1)
{
    /* Machine state-change updater: */
    connect(uisession(), SIGNAL(sigMachineStateChange()), this, SLOT(sltMachineStateChanged()));

    /* Mouse capability state-change updater: */
    connect(uisession(), SIGNAL(sigMouseCapabilityChange()), this, SLOT(sltMouseCapabilityChanged()));

    /* Mouse pointer shape state-change updaters: */
    connect(uisession(), SIGNAL(sigMousePointerShapeChange()), this, SLOT(sltMousePointerShapeChanged()));
    connect(this, SIGNAL(mouseStateChanged(int)), this, SLOT(sltMousePointerShapeChanged()));

    /* Initialize: */
    sltMachineStateChanged();
    sltMousePointerShapeChanged();
    sltMouseCapabilityChanged();
}

/* Mouse-handler destructor: */
UIMouseHandler::~UIMouseHandler()
{
}

/* Machine-logic getter: */
UIMachineLogic* UIMouseHandler::machineLogic() const
{
    return m_pMachineLogic;
}

/* UI Session getter: */
UISession* UIMouseHandler::uisession() const
{
    return machineLogic()->uisession();
}

/* Main Session getter: */
CSession& UIMouseHandler::session() const
{
    return uisession()->session();
}

/* Event handler for registered machine-view(s): */
bool UIMouseHandler::eventFilter(QObject *pWatched, QEvent *pEvent)
{
    /* If that object is of QWidget type: */
    if (QWidget *pWatchedWidget = qobject_cast<QWidget*>(pWatched))
    {
        /* Check if that widget is in windows list: */
        if (m_windows.values().contains(pWatchedWidget))
        {
#ifdef Q_WS_WIN
            /* Handle window events: */
            switch (pEvent->type())
            {
                case QEvent::Move:
                {
                    /* Update mouse clipping if window was moved
                     * by Operating System desktop manager: */
                    updateMouseCursorClipping();
                    break;
                }
                default:
                    break;
            }
#endif /* Q_WS_WIN */
        }

        else

        /* Check if that widget is of UIMachineView type: */
        if (UIMachineView *pWatchedMachineView = qobject_cast<UIMachineView*>(pWatchedWidget))
        {
            /* Check if that widget is in views list: */
            if (m_views.values().contains(pWatchedMachineView))
            {
                /* Handle view events: */
                switch (pEvent->type())
                {
                    case QEvent::FocusOut:
                    {
                        /* Release the mouse: */
                        releaseMouse();
                        break;
                    }
                    default:
                        break;
                }
            }
        }

        else

        /* Check if that widget is in viewports list: */
        if (m_viewports.values().contains(pWatchedWidget))
        {
            /* Get current watched widget screen id: */
            ulong uScreenId = m_viewports.key(pWatchedWidget);
            /* Handle viewport events: */
            switch (pEvent->type())
            {
#ifdef Q_WS_MAC
                case UIGrabMouseEvent::GrabMouseEvent:
                {
                    UIGrabMouseEvent *pDeltaEvent = static_cast<UIGrabMouseEvent*>(pEvent);
                    QPoint p = QPoint(pDeltaEvent->xDelta() + m_lastMousePos.x(),
                                      pDeltaEvent->yDelta() + m_lastMousePos.y());
                    if (mouseEvent(pDeltaEvent->mouseEventType(), uScreenId,
                                   m_viewports[uScreenId]->mapFromGlobal(p), p,
                                   pDeltaEvent->buttons(),
                                   pDeltaEvent->wheelDelta(), pDeltaEvent->orientation()))
                        return true;
                    break;
                }
#endif /* Q_WS_MAC */
                case QEvent::MouseMove:
                case QEvent::MouseButtonRelease:
                {
                    /* Check if we should propagate this event to another window: */
                    QPoint pos = QCursor::pos();
                    Log(("pos[%d,%d]\n", pos.x(), pos.y()));

                    QWidget *pHoveredWidget = QApplication::widgetAt(pos);
                    Log(("pWatchedWidget %#p, viewport(%d)\n", pWatchedWidget, (pWatchedWidget ? !!m_viewports.values().contains(pWatchedWidget) : 0)));
                    Log(("pHoveredWidget %#p, viewport(%d)\n", pHoveredWidget, (pHoveredWidget ? !!m_viewports.values().contains(pHoveredWidget) : 0)));
                    bool fRepost = pHoveredWidget && pHoveredWidget != pWatchedWidget && m_viewports.values().contains(pHoveredWidget);
#ifdef Q_WS_MAC
                    /* Fullscreen for dualscreen host and VM:
                     * for some reason when cursor reaches 0 on the secondary display, the event is posted to the widget
                     * located on the primary screen and hover widget is zero,
                     * detect this case and try to find the proper widget.
                     * Also OSX/Qt for some reasons allows cursor values to be [x0,x0+desktop_width] inclusive and [y0,y0+desktop_height],
                     * (note the "inclusive" for the width/height), which leads to fullscreen misbehave,
                     * which we also have to deal with */
                    if (!fRepost && !pWatchedWidget->rect().contains(pWatchedWidget->mapFromGlobal(pos)))
                    {
                        Log(("trying to find  proper widget\n"));
                        /* this is the slow way, as we need to iterate through the views and to search the proper one */
                        QList<QWidget *> values = m_viewports.values();
                        pHoveredWidget = NULL;
                        for (QList<QWidget *>::const_iterator iter = values.begin(); iter != values.end(); ++iter)
                        {
                            Log(("checking %#p\n", (*iter)));
                            QPoint iterPos = (*iter)->mapFromGlobal(pos);

                            Log(("iter widget[%#p] [(%d,%d),(%d,%d)], [(%d,%d)]\n", (*iter),
                                    (*iter)->rect().x(), (*iter)->rect().y(), (*iter)->rect().width(), (*iter)->rect().height(),
                                    iterPos.x(), iterPos.y()));
                            if (pWatchedWidget != (*iter))
                            {
                                if ((*iter)->rect().contains(iterPos))
                                {
                                    Log(("exact match!\n"));
                                    pHoveredWidget = (*iter);
                                    break;
                                }
                                else
                                {
                                    iterPos.setX(iterPos.x() - 1);
                                    iterPos.setY(iterPos.y() - 1);
                                    if ((*iter)->rect().contains(iterPos))
                                    {
                                        Log(("no-exact match\n"));
                                        pHoveredWidget = (*iter);
                                    }
                                    else
                                        Log(("NOT matched!\n"));
                                }
                            }
                            else
                                Log(("watched widget matching iter"));
                        }

                        fRepost = !!pHoveredWidget;
                    }
#endif
                    if (fRepost)
                    {
                        /* Get current mouse-move event: */
                        QMouseEvent *pOldMouseEvent = static_cast<QMouseEvent*>(pEvent);

                        /* Prepare redirected mouse-move event: */
                        QMouseEvent *pNewMouseEvent = new QMouseEvent(pOldMouseEvent->type(),
                                                                      pHoveredWidget->mapFromGlobal(pOldMouseEvent->globalPos()),
                                                                      pOldMouseEvent->globalPos(),
                                                                      pOldMouseEvent->button(),
                                                                      pOldMouseEvent->buttons(),
                                                                      pOldMouseEvent->modifiers());

                        /* Send that event to real destination: */
                        QApplication::postEvent(pHoveredWidget, pNewMouseEvent);

                        /* Filter out that event: */
                        return true;
                    }

#ifdef Q_WS_X11
                    /* Make sure that we are focused after a click.  Rather
                     * ugly, but works around a problem with GNOME
                     * screensaver, which sometimes removes our input focus
                     * and gives us no way to get it back. */
                    if (pEvent->type() == QEvent::MouseButtonRelease)
                        pWatchedWidget->window()->activateWindow();
#endif /* Q_WS_X11 */
                    /* Check if we should activate window under cursor: */
                    if (!uisession()->isMouseCaptured() &&
                        QApplication::activeWindow() &&
                        m_windows.values().contains(QApplication::activeWindow()) &&
                        m_windows.values().contains(pWatchedWidget->window()) &&
                        QApplication::activeWindow() != pWatchedWidget->window())
                    {
                        /* Activating hovered machine window: */
                        pWatchedWidget->window()->activateWindow();
#ifdef Q_WS_X11
                        /* On X11 its not enough to just activate window if you
                         * want to raise it also, so we will make it separately: */
                        pWatchedWidget->window()->raise();
#endif /* Q_WS_X11 */
                    }

                    /* This event should be also processed using next 'case': */
                }
                case QEvent::MouseButtonPress:
                case QEvent::MouseButtonDblClick:
                {
                    QMouseEvent *pMouseEvent = static_cast<QMouseEvent*>(pEvent);
                    m_iLastMouseWheelDelta = 0;
                    if (mouseEvent(pMouseEvent->type(), uScreenId,
                                   pMouseEvent->pos(), pMouseEvent->globalPos(),
                                   pMouseEvent->buttons(), 0, Qt::Horizontal))
                        return true;
                    break;
                }
                case QEvent::Wheel:
                {
                    QWheelEvent *pWheelEvent = static_cast<QWheelEvent*>(pEvent);
                    /* There are pointing devices which send smaller values for the delta than 120.
                     * Here we sum them up until we are greater than 120. This allows to have finer control
                     * over the speed acceleration & enables such devices to send a valid wheel event to our
                     * guest mouse device at all: */
                    int iDelta = 0;
                    m_iLastMouseWheelDelta += pWheelEvent->delta();
                    if (qAbs(m_iLastMouseWheelDelta) >= 120)
                    {
                        iDelta = m_iLastMouseWheelDelta;
                        m_iLastMouseWheelDelta = m_iLastMouseWheelDelta % 120;
                    }
                    if (mouseEvent(pWheelEvent->type(), uScreenId,
                                   pWheelEvent->pos(), pWheelEvent->globalPos(),
#ifdef QT_MAC_USE_COCOA
                                   /* Qt Cocoa is buggy. It always reports a left button pressed when the
                                    * mouse wheel event occurs. A workaround is to ask the application which
                                    * buttons are pressed currently: */
                                   QApplication::mouseButtons(),
#else /* QT_MAC_USE_COCOA */
                                   pWheelEvent->buttons(),
#endif /* !QT_MAC_USE_COCOA */
                                   iDelta, pWheelEvent->orientation()))
                        return true;
                    break;
                }
#ifdef Q_WS_MAC
                case QEvent::Leave:
                {
                    /* Enable mouse event compression if we leave the VM view.
                     * This is necessary for having smooth resizing of the VM/other windows: */
                    ::darwinSetMouseCoalescingEnabled(true);
                    break;
                }
                case QEvent::Enter:
                {
                    /* Disable mouse event compression if we enter the VM view.
                     * So all mouse events are registered in the VM.
                     * Only do this if the keyboard/mouse is grabbed
                     * (this is when we have a valid event handler): */
                    if (machineLogic()->keyboardHandler()->isKeyboardGrabbed())
                        darwinSetMouseCoalescingEnabled(false);
                    break;
                }
#endif /* Q_WS_MAC */
#ifdef Q_WS_WIN
                case QEvent::Resize:
                {
                    /* Update mouse clipping: */
                    updateMouseCursorClipping();
                    break;
                }
#endif /* Q_WS_WIN */
                default:
                    break;
            }
        }
    }
    return QObject::eventFilter(pWatched, pEvent);
}

/* Separate function to handle most of existing mouse-events: */
bool UIMouseHandler::mouseEvent(int iEventType, ulong uScreenId,
                                const QPoint &relativePos, const QPoint &globalPos,
                                Qt::MouseButtons mouseButtons,
                                int wheelDelta, Qt::Orientation wheelDirection)
{
    /* Check if machine is still running: */
    if (!uisession()->isRunning())
        return true;

    /* Check if such view & viewport are registered: */
    if (!m_views.contains(uScreenId) || !m_viewports.contains(uScreenId))
        return true;

    int iMouseButtonsState = 0;
    if (mouseButtons & Qt::LeftButton)
        iMouseButtonsState |= KMouseButtonState_LeftButton;
    if (mouseButtons & Qt::RightButton)
        iMouseButtonsState |= KMouseButtonState_RightButton;
    if (mouseButtons & Qt::MidButton)
        iMouseButtonsState |= KMouseButtonState_MiddleButton;
    if (mouseButtons & Qt::XButton1)
        iMouseButtonsState |= KMouseButtonState_XButton1;
    if (mouseButtons & Qt::XButton2)
        iMouseButtonsState |= KMouseButtonState_XButton2;

#ifdef Q_WS_MAC
    /* Simulate the right click on host-key + left-mouse-button: */
    if (machineLogic()->keyboardHandler()->isHostKeyPressed() &&
        machineLogic()->keyboardHandler()->isHostKeyAlone() &&
        iMouseButtonsState == KMouseButtonState_LeftButton)
        iMouseButtonsState = KMouseButtonState_RightButton;
#endif /* Q_WS_MAC */

    int iWheelVertical = 0;
    int iWheelHorizontal = 0;
    if (wheelDirection == Qt::Vertical)
    {
        /* The absolute value of wheel delta is 120 units per every wheel move;
         * positive deltas correspond to counterclockwise rotations (usually up),
         * negative deltas correspond to clockwise (usually down). */
        iWheelVertical = - (wheelDelta / 120);
    }
    else if (wheelDirection == Qt::Horizontal)
        iWheelHorizontal = wheelDelta / 120;

    if (uisession()->isMouseCaptured())
    {
#ifdef Q_WS_WIN
        /* Send pending WM_PAINT events: */
        ::UpdateWindow(m_viewports[uScreenId]->winId());
#endif
        CMouse mouse = session().GetConsole().GetMouse();
        mouse.PutMouseEvent(globalPos.x() - m_lastMousePos.x(),
                            globalPos.y() - m_lastMousePos.y(),
                            iWheelVertical, iWheelHorizontal, iMouseButtonsState);

#ifdef Q_WS_WIN
        /* Bringing mouse to the opposite side to simulate the endless moving: */

        /* Get visible-viewport-rectangle in global coordinates: */
        QRect viewportRectangle = m_mouseCursorClippingRect;
        /* Get top-left point of full-viewport-rectangle in global coordinates: */
        QPoint viewportRectangleGlobalPos = m_views[uScreenId]->mapToGlobal(m_viewports[uScreenId]->pos());
        /* Shift visible-viewport-rectangle to local position because relative position is in local coordinates: */
        viewportRectangle.translate(-viewportRectangleGlobalPos);

        /* Get boundaries: */
        int ix1 = viewportRectangle.left() + 1;
        int iy1 = viewportRectangle.top() + 1;
        int ix2 = viewportRectangle.right() - 1;
        int iy2 = viewportRectangle.bottom() - 1;

        /* Simulate infinite movement: */
        QPoint p = relativePos;
        if (relativePos.x() == ix1)
            p.setX(ix2 - 1);
        else if (relativePos.x() == ix2)
            p.setX(ix1 + 1);
        if (relativePos.y() == iy1)
            p.setY(iy2 - 1);
        else if (relativePos.y() == iy2)
            p.setY(iy1 + 1);
        if (p != relativePos)
        {
            m_lastMousePos = m_viewports[uScreenId]->mapToGlobal(p);
            QCursor::setPos(m_lastMousePos);
        }
        else
            m_lastMousePos = globalPos;
#else /* Q_WS_WIN */
        int iWe = QApplication::desktop()->width() - 1;
        int iHe = QApplication::desktop()->height() - 1;
        QPoint p = globalPos;
        if (globalPos.x() == 0)
            p.setX(iWe - 1);
        else if (globalPos.x() == iWe)
            p.setX( 1 );
        if (globalPos.y() == 0)
            p.setY(iHe - 1);
        else if (globalPos.y() == iHe)
            p.setY(1);

        if (p != globalPos)
        {
            m_lastMousePos =  p;
            /* No need for cursor updating on the Mac, there is no one. */
# ifndef Q_WS_MAC
            QCursor::setPos(m_lastMousePos);
# endif /* Q_WS_MAC */
        }
        else
            m_lastMousePos = globalPos;
#endif /* !Q_WS_WIN */
        return true; /* stop further event handling */
    }
    else /* !uisession()->isMouseCaptured() */
    {
#if 0 // TODO: Move that to fullscreen event-handler:
        if (vboxGlobal().vmRenderMode() != SDLMode)
        {
            /* try to automatically scroll the guest canvas if the
             * mouse is on the screen border */
            /// @todo (r=dmik) better use a timer for autoscroll
            QRect scrGeo = QApplication::desktop()->screenGeometry (this);
            int iDx = 0, iDy = 0;
            if (scrGeo.width() < contentsWidth())
            {
                if (scrGeo.left() == globalPos.x()) iDx = -1;
                if (scrGeo.right() == globalPos.x()) iDx = +1;
            }
            if (scrGeo.height() < contentsHeight())
            {
                if (scrGeo.top() == globalPos.y()) iDy = -1;
                if (scrGeo.bottom() == globalPos.y()) iDy = +1;
            }
            if (iDx || iDy)
                scrollBy(iDx, iDy);
        }
#endif

        if (uisession()->isMouseSupportsAbsolute() && uisession()->isMouseIntegrated())
        {
            int iCw = m_views[uScreenId]->contentsWidth(), iCh = m_views[uScreenId]->contentsHeight();
            int iVw = m_views[uScreenId]->visibleWidth(), iVh = m_views[uScreenId]->visibleHeight();

            if (vboxGlobal().vmRenderMode() != SDLMode)
            {
                /* Try to automatically scroll the guest canvas if the
                 * mouse goes outside its visible part: */
                int iDx = 0;
                if (relativePos.x() > iVw) iDx = relativePos.x() - iVw;
                else if (relativePos.x() < 0) iDx = relativePos.x();
                int iDy = 0;
                if (relativePos.y() > iVh) iDy = relativePos.y() - iVh;
                else if (relativePos.y() < 0) iDy = relativePos.y();
                if (iDx != 0 || iDy != 0) m_views[uScreenId]->scrollBy(iDx, iDy);
            }

            /* Get mouse-pointer location: */
            QPoint cpnt = m_views[uScreenId]->viewportToContents(relativePos);

            /* Determine scaling: */
            UIFrameBuffer *pFrameBuffer = m_views[uScreenId]->frameBuffer();
            QSize scaledSize = pFrameBuffer->scaledSize();
            double xRatio = scaledSize.isValid() ? (double)pFrameBuffer->width() / (double)scaledSize.width() : 1;
            double yRatio = scaledSize.isValid() ? (double)pFrameBuffer->height() / (double)scaledSize.height() : 1;
            /* Set scaling if scale-factor is present: */
            cpnt.setX((int)(cpnt.x() * xRatio));
            cpnt.setY((int)(cpnt.y() * yRatio));

#ifdef VBOX_WITH_DRAG_AND_DROP
# ifdef VBOX_WITH_DRAG_AND_DROP_GH
            if (   cpnt.x() < 0
                || cpnt.x() > iCw - 1
                || cpnt.y() < 0
                || cpnt.y() > iCh - 1)
            {
                if ((mouseButtons.testFlag(Qt::LeftButton)))
                {
                    m_views[uScreenId]->handleGHDnd();

                    return false;
                }
            }
# endif
#endif /* VBOX_WITH_DRAG_AND_DROP */

            /* Bound coordinates: */
            if (cpnt.x() < 0) cpnt.setX(0);
            else if (cpnt.x() > iCw - 1) cpnt.setX(iCw - 1);
            if (cpnt.y() < 0) cpnt.setY(0);
            else if (cpnt.y() > iCh - 1) cpnt.setY(iCh - 1);

            /* Determine shifting: */
            CFramebuffer framebuffer;
            LONG xShift = 0, yShift = 0;
            session().GetConsole().GetDisplay().GetFramebuffer(uScreenId, framebuffer, xShift, yShift);
            /* Set shifting: */
            cpnt.setX(cpnt.x() + xShift);
            cpnt.setY(cpnt.y() + yShift);

            /* Post absolute mouse-event into guest: */
            CMouse mouse = session().GetConsole().GetMouse();
            mouse.PutMouseEventAbsolute(cpnt.x() + 1, cpnt.y() + 1, iWheelVertical, iWheelHorizontal, iMouseButtonsState);
            return true;
        }
        else
        {
            if (m_views[uScreenId]->hasFocus() && (iEventType == QEvent::MouseButtonRelease && mouseButtons == Qt::NoButton))
            {
                if (uisession()->isPaused())
                {
                    msgCenter().remindAboutPausedVMInput();
                }
                else if (uisession()->isRunning())
                {
                    /* Temporarily disable auto capture that will take place after this dialog is dismissed because
                     * the capture state is to be defined by the dialog result itself: */
                    uisession()->setAutoCaptureDisabled(true);
                    bool autoConfirmed = false;
                    bool ok = msgCenter().confirmInputCapture(&autoConfirmed);
                    if (autoConfirmed)
                        uisession()->setAutoCaptureDisabled(false);
                    /* Otherwise, the disable flag will be reset in the next console view's focus in event (since
                     * may happen asynchronously on some platforms, after we return from this code): */
                    if (ok)
                    {
#ifdef Q_WS_X11
                        /* Make sure that pending FocusOut events from the previous message box are handled,
                         * otherwise the mouse is immediately ungrabbed again: */
                        qApp->processEvents();
#endif
                        machineLogic()->keyboardHandler()->captureKeyboard(uScreenId);
                        captureMouse(uScreenId);
                    }
                }
            }
        }
    }

    return false;
}

#ifdef Q_WS_WIN
/* This method is actually required only because under win-host
 * we do not really grab the mouse in case of capturing it: */
void UIMouseHandler::updateMouseCursorClipping()
{
    /* Check if such view && viewport are registered: */
    if (!m_views.contains(m_iMouseCaptureViewIndex) || !m_viewports.contains(m_iMouseCaptureViewIndex))
        return;

    if (uisession()->isMouseCaptured())
    {
        /* Get full-viewport-rectangle in local coordinates: */
        QRect viewportRectangle = m_viewports[m_iMouseCaptureViewIndex]->visibleRegion().boundingRect();
        /* Get top-left point of full-viewport-rectangle in global coordinates: */
        QPoint viewportRectangleGlobalPos = m_views[m_iMouseCaptureViewIndex]->mapToGlobal(m_viewports[m_iMouseCaptureViewIndex]->pos());
        /* Get full-viewport-rectangle in global coordinates: */
        viewportRectangle.translate(viewportRectangleGlobalPos);
        /* Trim full-viewport-rectangle by available geometry: */
        viewportRectangle = viewportRectangle.intersected(QApplication::desktop()->availableGeometry());
        /* Trim partial-viewport-rectangle by top-most windows: */
        QRegion viewportRegion(viewportRectangle);
        QRegion topMostRegion(NativeWindowSubsystem::areaCoveredByTopMostWindows());
        viewportRegion -= topMostRegion;
        /* Check if partial-viewport-region consists of 1 rectangle: */
        if (viewportRegion.rectCount() > 1)
        {
            /* Choose the largest rectangle: */
            QVector<QRect> rects = viewportRegion.rects();
            QRect largestRect;
            for (int i = 0; i < rects.size(); ++i)
                largestRect = largestRect.width() * largestRect.height() < rects[i].width() * rects[i].height() ? rects[i] : largestRect;
            /* Assign the partial-viewport-region to the largest rect: */
            viewportRegion = largestRect;
        }
        /* Assign the partial-viewport-rectangle to the partial-viewport-region: */
        viewportRectangle = viewportRegion.boundingRect();
        /* Assign the visible-viewport-rectangle to the partial-viewport-rectangle: */
        m_mouseCursorClippingRect = viewportRectangle;
        /* Prepare clipping area: */
        RECT rect = { m_mouseCursorClippingRect.left() + 1, m_mouseCursorClippingRect.top() + 1, m_mouseCursorClippingRect.right(), m_mouseCursorClippingRect.bottom() };
        ::ClipCursor(&rect);
    }
    else
    {
        ::ClipCursor(NULL);
    }
}
#endif /* Q_WS_WIN */

