qtabbar.cpp

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#include "private/qlayoutengine_p.h"
#include "qabstractitemdelegate.h"
#include "qapplication.h"
#include "qbitmap.h"
#include "qcursor.h"
#include "qevent.h"
#include "qpainter.h"
#include "qstyle.h"
#include "qstyleoption.h"
#include "qstylepainter.h"
#include "qtabwidget.h"
#include "qtooltip.h"
#include "qwhatsthis.h"
#include "private/qtextengine_p.h"
#ifndef QT_NO_ACCESSIBILITY
#include "qaccessible.h"
#endif

#include "qdebug.h"
#include "private/qtabbar_p.h"

#ifndef QT_NO_TABBAR

#ifdef Q_WS_MAC
#include <private/qt_mac_p.h>
#include <private/qt_cocoa_helpers_mac_p.h>
#endif

#ifndef QT_NO_STYLE_S60
#include "qs60style.h"
#endif

QT_BEGIN_NAMESPACE


inline static bool verticalTabs(QTabBar::Shape shape)
{
    return shape == QTabBar::RoundedWest
           || shape == QTabBar::RoundedEast
           || shape == QTabBar::TriangularWest
           || shape == QTabBar::TriangularEast;
}

void QTabBarPrivate::updateMacBorderMetrics()
{
#if (defined Q_WS_MAC) && (MAC_OS_X_VERSION_MAX_ALLOWED >= MAC_OS_X_VERSION_10_5)
    if (QSysInfo::MacintoshVersion >= QSysInfo::MV_10_5) {
        Q_Q(QTabBar);
        ::HIContentBorderMetrics metrics;

        // TODO: get metrics to preserve the bottom value
        // TODO: test tab bar position

        OSWindowRef window = qt_mac_window_for(q);

        // push base line separator down to the client are so we can paint over it (Carbon)
        metrics.top = (documentMode && q->isVisible()) ? 1 : 0;
        metrics.bottom = 0;
        metrics.left = 0;
        metrics.right = 0;
        qt_mac_updateContentBorderMetricts(window, metrics);
#if QT_MAC_USE_COCOA
        // In Cocoa we need to keep track of the drawRect method.
        // If documentMode is enabled we need to change it, unless
        // a toolbar is present.
        // Notice that all the information is kept in the window,
        // that's why we get the private widget for it instead of
        // the private widget for this widget.
        QWidgetPrivate *privateWidget = qt_widget_private(q->window());
        if(privateWidget)
            privateWidget->changeMethods = documentMode;
        // Since in Cocoa there is no simple way to remove the baseline, so we just ask the
        // top level to do the magic for us.
        privateWidget->syncUnifiedMode();
#endif // QT_MAC_USE_COCOA
    }
#endif
}

void QTabBar::initStyleOption(QStyleOptionTab *option, int tabIndex) const
{
    Q_D(const QTabBar);
    int totalTabs = d->tabList.size();

    if (!option || (tabIndex < 0 || tabIndex >= totalTabs))
        return;

    const QTabBarPrivate::Tab &tab = d->tabList.at(tabIndex);
    option->initFrom(this);
    option->state &= ~(QStyle::State_HasFocus | QStyle::State_MouseOver);
    option->rect = tabRect(tabIndex);
    bool isCurrent = tabIndex == d->currentIndex;
    option->row = 0;
    if (tabIndex == d->pressedIndex)
        option->state |= QStyle::State_Sunken;
    if (isCurrent)
        option->state |= QStyle::State_Selected;
    if (isCurrent && hasFocus())
        option->state |= QStyle::State_HasFocus;
    if (!tab.enabled)
        option->state &= ~QStyle::State_Enabled;
    if (isActiveWindow())
        option->state |= QStyle::State_Active;
    if (!d->dragInProgress && option->rect == d->hoverRect)
        option->state |= QStyle::State_MouseOver;
    option->shape = d->shape;
    option->text = tab.text;

    if (tab.textColor.isValid())
        option->palette.setColor(foregroundRole(), tab.textColor);

    option->icon = tab.icon;
    if (QStyleOptionTabV2 *optionV2 = qstyleoption_cast<QStyleOptionTabV2 *>(option))
        optionV2->iconSize = iconSize();  // Will get the default value then.

    if (QStyleOptionTabV3 *optionV3 = qstyleoption_cast<QStyleOptionTabV3 *>(option)) {
        optionV3->leftButtonSize = tab.leftWidget ? tab.leftWidget->size() : QSize();
        optionV3->rightButtonSize = tab.rightWidget ? tab.rightWidget->size() : QSize();
        optionV3->documentMode = d->documentMode;
    }

    if (tabIndex > 0 && tabIndex - 1 == d->currentIndex)
        option->selectedPosition = QStyleOptionTab::PreviousIsSelected;
    else if (tabIndex + 1 < totalTabs && tabIndex + 1 == d->currentIndex)
        option->selectedPosition = QStyleOptionTab::NextIsSelected;
    else
        option->selectedPosition = QStyleOptionTab::NotAdjacent;

    bool paintBeginning = (tabIndex == 0) || (d->dragInProgress && tabIndex == d->pressedIndex + 1);
    bool paintEnd = (tabIndex == totalTabs - 1) || (d->dragInProgress && tabIndex == d->pressedIndex - 1);
    if (paintBeginning) {
        if (paintEnd)
            option->position = QStyleOptionTab::OnlyOneTab;
        else
            option->position = QStyleOptionTab::Beginning;
    } else if (paintEnd) {
        option->position = QStyleOptionTab::End;
    } else {
        option->position = QStyleOptionTab::Middle;
    }

#ifndef QT_NO_TABWIDGET
    if (const QTabWidget *tw = qobject_cast<const QTabWidget *>(parentWidget())) {
        if (tw->cornerWidget(Qt::TopLeftCorner) || tw->cornerWidget(Qt::BottomLeftCorner))
            option->cornerWidgets |= QStyleOptionTab::LeftCornerWidget;
        if (tw->cornerWidget(Qt::TopRightCorner) || tw->cornerWidget(Qt::BottomRightCorner))
            option->cornerWidgets |= QStyleOptionTab::RightCornerWidget;
    }
#endif

    QRect textRect = style()->subElementRect(QStyle::SE_TabBarTabText, option, this);
    option->text = fontMetrics().elidedText(option->text, d->elideMode, textRect.width(),
                        Qt::TextShowMnemonic);
}

int QTabBarPrivate::extraWidth() const
{
    Q_Q(const QTabBar);
    return 2 * qMax(q->style()->pixelMetric(QStyle::PM_TabBarScrollButtonWidth, 0, q),
                    QApplication::globalStrut().width());
}

void QTabBarPrivate::init()
{
    Q_Q(QTabBar);
    leftB = new QToolButton(q);
    leftB->setAutoRepeat(true);
    QObject::connect(leftB, SIGNAL(clicked()), q, SLOT(_q_scrollTabs()));
    leftB->hide();
    rightB = new QToolButton(q);
    rightB->setAutoRepeat(true);
    QObject::connect(rightB, SIGNAL(clicked()), q, SLOT(_q_scrollTabs()));
    rightB->hide();
#ifdef QT_KEYPAD_NAVIGATION
    if (QApplication::keypadNavigationEnabled()) {
        leftB->setFocusPolicy(Qt::NoFocus);
        rightB->setFocusPolicy(Qt::NoFocus);
        q->setFocusPolicy(Qt::NoFocus);
    } else
#endif
    q->setFocusPolicy(Qt::TabFocus);
    q->setSizePolicy(QSizePolicy::Preferred, QSizePolicy::Fixed);
    elideMode = Qt::TextElideMode(q->style()->styleHint(QStyle::SH_TabBar_ElideMode, 0, q));
    useScrollButtons = !q->style()->styleHint(QStyle::SH_TabBar_PreferNoArrows, 0, q);
}

QTabBarPrivate::Tab *QTabBarPrivate::at(int index)
{
    return validIndex(index)?&tabList[index]:0;
}

const QTabBarPrivate::Tab *QTabBarPrivate::at(int index) const
{
    return validIndex(index)?&tabList[index]:0;
}

int QTabBarPrivate::indexAtPos(const QPoint &p) const
{
    Q_Q(const QTabBar);
    if (q->tabRect(currentIndex).contains(p))
        return currentIndex;
    for (int i = 0; i < tabList.count(); ++i)
        if (tabList.at(i).enabled && q->tabRect(i).contains(p))
            return i;
    return -1;
}

void QTabBarPrivate::layoutTabs()
{
    Q_Q(QTabBar);
    scrollOffset = 0;
    layoutDirty = false;
    QSize size = q->size();
    int last, available;
    int maxExtent;
    int i;
    bool vertTabs = verticalTabs(shape);
    int tabChainIndex = 0;

    Qt::Alignment tabAlignment = Qt::Alignment(q->style()->styleHint(QStyle::SH_TabBar_Alignment, 0, q));
    QVector<QLayoutStruct> tabChain(tabList.count() + 2);

    // We put an empty item at the front and back and set its expansive attribute
    // depending on tabAlignment.
    tabChain[tabChainIndex].init();
    tabChain[tabChainIndex].expansive = (tabAlignment != Qt::AlignLeft)
                                        && (tabAlignment != Qt::AlignJustify);
    tabChain[tabChainIndex].empty = true;
    ++tabChainIndex;

    // We now go through our list of tabs and set the minimum size and the size hint
    // This will allow us to elide text if necessary. Since we don't set
    // a maximum size, tabs will EXPAND to fill up the empty space.
    // Since tab widget is rather *ahem* strict about keeping the geometry of the
    // tab bar to its absolute minimum, this won't bleed through, but will show up
    // if you use tab bar on its own (a.k.a. not a bug, but a feature).
    // Update: if expanding is false, we DO set a maximum size to prevent the tabs
    // being wider than necessary.
    if (!vertTabs) {
        int minx = 0;
        int x = 0;
        int maxHeight = 0;
        for (i = 0; i < tabList.count(); ++i, ++tabChainIndex) {
            QSize sz = q->tabSizeHint(i);
            tabList[i].maxRect = QRect(x, 0, sz.width(), sz.height());
            x += sz.width();
            maxHeight = qMax(maxHeight, sz.height());
            sz = minimumTabSizeHint(i);
            tabList[i].minRect = QRect(minx, 0, sz.width(), sz.height());
            minx += sz.width();
            tabChain[tabChainIndex].init();
            tabChain[tabChainIndex].sizeHint = tabList.at(i).maxRect.width();
            tabChain[tabChainIndex].minimumSize = sz.width();
            tabChain[tabChainIndex].empty = false;
            tabChain[tabChainIndex].expansive = true;

            if (!expanding)
                tabChain[tabChainIndex].maximumSize = tabChain[tabChainIndex].sizeHint;
        }

        last = minx;
        available = size.width();
        maxExtent = maxHeight;
    } else {
        int miny = 0;
        int y = 0;
        int maxWidth = 0;
        for (i = 0; i < tabList.count(); ++i, ++tabChainIndex) {
            QSize sz = q->tabSizeHint(i);
            tabList[i].maxRect = QRect(0, y, sz.width(), sz.height());
            y += sz.height();
            maxWidth = qMax(maxWidth, sz.width());
            sz = minimumTabSizeHint(i);
            tabList[i].minRect = QRect(0, miny, sz.width(), sz.height());
            miny += sz.height();
            tabChain[tabChainIndex].init();
            tabChain[tabChainIndex].sizeHint = tabList.at(i).maxRect.height();
            tabChain[tabChainIndex].minimumSize = sz.height();
            tabChain[tabChainIndex].empty = false;
            tabChain[tabChainIndex].expansive = true;

            if (!expanding)
                tabChain[tabChainIndex].maximumSize = tabChain[tabChainIndex].sizeHint;
        }

        last = miny;
        available = size.height();
        maxExtent = maxWidth;
    }

    Q_ASSERT(tabChainIndex == tabChain.count() - 1); // add an assert just to make sure.
    // Mirror our front item.
    tabChain[tabChainIndex].init();
    tabChain[tabChainIndex].expansive = (tabAlignment != Qt::AlignRight)
                                        && (tabAlignment != Qt::AlignJustify);
    tabChain[tabChainIndex].empty = true;

    // Do the calculation
    qGeomCalc(tabChain, 0, tabChain.count(), 0, qMax(available, last), 0);

    // Use the results
    for (i = 0; i < tabList.count(); ++i) {
        const QLayoutStruct &lstruct = tabChain.at(i + 1);
        if (!vertTabs)
            tabList[i].rect.setRect(lstruct.pos, 0, lstruct.size, maxExtent);
        else
            tabList[i].rect.setRect(0, lstruct.pos, maxExtent, lstruct.size);
    }

    if (useScrollButtons && tabList.count() && last > available) {
        int extra = extraWidth();
#ifndef QT_NO_STYLE_S60
        QS60Style *s60Style = qobject_cast<QS60Style*>(QApplication::style());
#endif
        if (!vertTabs) {
            Qt::LayoutDirection ld = q->layoutDirection();
            QRect arrows = QStyle::visualRect(ld, q->rect(),
                                              QRect(available - extra, 0, extra, size.height()));
            int buttonOverlap = q->style()->pixelMetric(QStyle::PM_TabBar_ScrollButtonOverlap, 0, q);

            if (ld == Qt::LeftToRight) {
// In S60style, tab scroll buttons are layoutted separately, on the sides of the tabbar.
#ifndef QT_NO_STYLE_S60
                if (s60Style) {
                    rightB->setGeometry(arrows.left() + extra / 2, arrows.top(), extra / 2, arrows.height());
                    leftB->setGeometry(0, arrows.top(), extra / 2, arrows.height());
                } else {
#endif
                leftB->setGeometry(arrows.left(), arrows.top(), extra/2, arrows.height());
                rightB->setGeometry(arrows.right() - extra/2 + buttonOverlap, arrows.top(),
                                    extra/2, arrows.height());
#ifndef QT_NO_STYLE_S60
                }
#endif
                leftB->setArrowType(Qt::LeftArrow);
                rightB->setArrowType(Qt::RightArrow);
            } else {
#ifndef QT_NO_STYLE_S60
                if (s60Style) {
                    rightB->setGeometry(arrows.left() + extra / 2, arrows.top(), extra / 2, arrows.height());
                    leftB->setGeometry(0, arrows.top(), extra / 2, arrows.height());
                } else {
#endif
                rightB->setGeometry(arrows.left(), arrows.top(), extra/2, arrows.height());
                leftB->setGeometry(arrows.right() - extra/2 + buttonOverlap, arrows.top(),
                                    extra/2, arrows.height());
#ifndef QT_NO_STYLE_S60
                }
#endif
                rightB->setArrowType(Qt::LeftArrow);
                leftB->setArrowType(Qt::RightArrow);
            }
        } else {
#ifndef QT_NO_STYLE_S60
            if (s60Style) {
                QRect arrows = QRect(0, 0, size.width(), available );
                leftB->setGeometry(arrows.left(), arrows.top(), arrows.width(), extra / 2);
                leftB->setArrowType(Qt::UpArrow);
                rightB->setGeometry(arrows.left(), arrows.bottom() - extra / 2 + 1,
                                    arrows.width(), extra / 2);
                rightB->setArrowType(Qt::DownArrow);
            } else {
#endif
            QRect arrows = QRect(0, available - extra, size.width(), extra );
            leftB->setGeometry(arrows.left(), arrows.top(), arrows.width(), extra/2);
            leftB->setArrowType(Qt::UpArrow);
            rightB->setGeometry(arrows.left(), arrows.bottom() - extra/2 + 1,
                                arrows.width(), extra/2);
            rightB->setArrowType(Qt::DownArrow);
#ifndef QT_NO_STYLE_S60
            }
#endif
        }
        leftB->setEnabled(scrollOffset > 0);
        rightB->setEnabled(last - scrollOffset >= available - extra);
        leftB->show();
        rightB->show();
    } else {
        rightB->hide();
        leftB->hide();
    }

    layoutWidgets();
    q->tabLayoutChange();
}

void QTabBarPrivate::makeVisible(int index)
{
    Q_Q(QTabBar);
    if (!validIndex(index) || leftB->isHidden())
        return;

    const QRect tabRect = tabList.at(index).rect;
    const int oldScrollOffset = scrollOffset;
    const bool horiz = !verticalTabs(shape);
    const int available = (horiz ? q->width() : q->height()) - extraWidth();
    const int start = horiz ? tabRect.left() : tabRect.top();
    const int end = horiz ? tabRect.right() : tabRect.bottom();
    if (start < scrollOffset) // too far left
        scrollOffset = start - (index ? 8 : 0);
    else if (end > scrollOffset + available) // too far right
        scrollOffset = end - available + 1;

    leftB->setEnabled(scrollOffset > 0);
    const int last = horiz ? tabList.last().rect.right() : tabList.last().rect.bottom();
    rightB->setEnabled(last - scrollOffset >= available);
    if (oldScrollOffset != scrollOffset) {
        q->update();
        layoutWidgets();
    }
}

void QTabBarPrivate::layoutTab(int index)
{
    Q_Q(QTabBar);
    Q_ASSERT(index >= 0);

    Tab &tab = tabList[index];
    bool vertical = verticalTabs(shape);
    if (!(tab.leftWidget || tab.rightWidget))
        return;

    QStyleOptionTabV3 opt;
    q->initStyleOption(&opt, index);
    if (tab.leftWidget) {
        QRect rect = q->style()->subElementRect(QStyle::SE_TabBarTabLeftButton, &opt, q);
        QPoint p = rect.topLeft();
        if ((index == pressedIndex) || paintWithOffsets) {
            if (vertical)
                p.setY(p.y() + tabList[index].dragOffset);
            else
                p.setX(p.x() + tabList[index].dragOffset);
        }
        tab.leftWidget->move(p);
    }
    if (tab.rightWidget) {
        QRect rect = q->style()->subElementRect(QStyle::SE_TabBarTabRightButton, &opt, q);
        QPoint p = rect.topLeft();
        if ((index == pressedIndex) || paintWithOffsets) {
            if (vertical)
                p.setY(p.y() + tab.dragOffset);
            else
                p.setX(p.x() + tab.dragOffset);
        }
        tab.rightWidget->move(p);
    }
}

void QTabBarPrivate::layoutWidgets(int start)
{
    Q_Q(QTabBar);
    for (int i = start; i < q->count(); ++i) {
        layoutTab(i);
    }
}

void QTabBarPrivate::_q_closeTab()
{
    Q_Q(QTabBar);
    QObject *object = q->sender();
    int tabToClose = -1;
    QTabBar::ButtonPosition closeSide = (QTabBar::ButtonPosition)q->style()->styleHint(QStyle::SH_TabBar_CloseButtonPosition, 0, q);
    for (int i = 0; i < tabList.count(); ++i) {
        if (closeSide == QTabBar::LeftSide) {
            if (tabList.at(i).leftWidget == object) {
                tabToClose = i;
                break;
            }
        } else {
            if (tabList.at(i).rightWidget == object) {
                tabToClose = i;
                break;
            }
        }
    }
    if (tabToClose != -1)
        emit q->tabCloseRequested(tabToClose);
}

void QTabBarPrivate::_q_scrollTabs()
{
    Q_Q(QTabBar);
    const QObject *sender = q->sender();
    int i = -1;
    if (!verticalTabs(shape)) {
        if (sender == leftB) {
            for (i = tabList.count() - 1; i >= 0; --i) {
                if (tabList.at(i).rect.left() - scrollOffset < 0) {
                    makeVisible(i);
                    return;
                }
            }
        } else if (sender == rightB) {
            int availableWidth = q->width() - extraWidth();
            for (i = 0; i < tabList.count(); ++i) {
                if (tabList.at(i).rect.right() - scrollOffset > availableWidth) {
                    makeVisible(i);
                    return;
                }
            }
        }
    } else { // vertical
        if (sender == leftB) {
            for (i = tabList.count() - 1; i >= 0; --i) {
                if (tabList.at(i).rect.top() - scrollOffset < 0) {
                    makeVisible(i);
                    return;
                }
            }
        } else if (sender == rightB) {
            int available = q->height() - extraWidth();
            for (i = 0; i < tabList.count(); ++i) {
                if (tabList.at(i).rect.bottom() - scrollOffset > available) {
                    makeVisible(i);
                    return;
                }
            }
        }
    }
}

void QTabBarPrivate::refresh()
{
    Q_Q(QTabBar);

    // be safe in case a subclass is also handling move with the tabs
    if (pressedIndex != -1
        && movable
        && QApplication::mouseButtons() == Qt::NoButton) {
        moveTabFinished(pressedIndex);
        if (!validIndex(pressedIndex))
            pressedIndex = -1;
    }

    if (!q->isVisible()) {
        layoutDirty = true;
    } else {
        layoutTabs();
        makeVisible(currentIndex);
        q->update();
        q->updateGeometry();
    }
}

QTabBar::QTabBar(QWidget* parent)
    :QWidget(*new QTabBarPrivate, parent, 0)
{
    Q_D(QTabBar);
    d->init();
}


QTabBar::~QTabBar()
{
}

QTabBar::Shape QTabBar::shape() const
{
    Q_D(const QTabBar);
    return d->shape;
}

void QTabBar::setShape(Shape shape)
{
    Q_D(QTabBar);
    if (d->shape == shape)
        return;
    d->shape = shape;
    d->refresh();
}

void QTabBar::setDrawBase(bool drawBase)
{
    Q_D(QTabBar);
    if (d->drawBase == drawBase)
        return;
    d->drawBase = drawBase;
    update();
}

bool QTabBar::drawBase() const
{
    Q_D(const QTabBar);
    return d->drawBase;
}

int QTabBar::addTab(const QString &text)
{
    return insertTab(-1, text);
}

int QTabBar::addTab(const QIcon& icon, const QString &text)
{
    return insertTab(-1, icon, text);
}

int QTabBar::insertTab(int index, const QString &text)
{
    return insertTab(index, QIcon(), text);
}

int QTabBar::insertTab(int index, const QIcon& icon, const QString &text)
{
    Q_D(QTabBar);
    if (!d->validIndex(index)) {
        index = d->tabList.count();
        d->tabList.append(QTabBarPrivate::Tab(icon, text));
    } else {
        d->tabList.insert(index, QTabBarPrivate::Tab(icon, text));
    }
#ifndef QT_NO_SHORTCUT
    d->tabList[index].shortcutId = grabShortcut(QKeySequence::mnemonic(text));
#endif
    d->refresh();
    if (d->tabList.count() == 1)
        setCurrentIndex(index);
    else if (index <= d->currentIndex)
        ++d->currentIndex;

    if (d->closeButtonOnTabs) {
        QStyleOptionTabV3 opt;
        initStyleOption(&opt, index);
        ButtonPosition closeSide = (ButtonPosition)style()->styleHint(QStyle::SH_TabBar_CloseButtonPosition, 0, this);
        QAbstractButton *closeButton = new CloseButton(this);
        connect(closeButton, SIGNAL(clicked()), this, SLOT(_q_closeTab()));
        setTabButton(index, closeSide, closeButton);
    }

    for (int i = 0; i < d->tabList.count(); ++i) {
        if (d->tabList[i].lastTab >= index)
            ++d->tabList[i].lastTab;
    }

    tabInserted(index);
    return index;
}


void QTabBar::removeTab(int index)
{
    Q_D(QTabBar);
    if (d->validIndex(index)) {
#ifndef QT_NO_SHORTCUT
        releaseShortcut(d->tabList.at(index).shortcutId);
#endif
        if (d->tabList[index].leftWidget) {
            d->tabList[index].leftWidget->hide();
            d->tabList[index].leftWidget->deleteLater();
            d->tabList[index].leftWidget = 0;
        }
        if (d->tabList[index].rightWidget) {
            d->tabList[index].rightWidget->hide();
            d->tabList[index].rightWidget->deleteLater();
            d->tabList[index].rightWidget = 0;
        }

        int newIndex = d->tabList[index].lastTab;
        d->tabList.removeAt(index);
        for (int i = 0; i < d->tabList.count(); ++i) {
            if (d->tabList[i].lastTab == index)
                d->tabList[i].lastTab = -1;
            if (d->tabList[i].lastTab > index)
                --d->tabList[i].lastTab;
        }
        if (index == d->currentIndex) {
            // The current tab is going away, in order to make sure
            // we emit that "current has changed", we need to reset this
            // around.
            d->currentIndex = -1;
            if (d->tabList.size() > 0) {
                switch(d->selectionBehaviorOnRemove) {
                case SelectPreviousTab:
                    if (newIndex > index)
                        newIndex--;
                    if (d->validIndex(newIndex))
                        break;
                    // else fallthrough
                case SelectRightTab:
                    newIndex = index;
                    if (newIndex >= d->tabList.size())
                        newIndex = d->tabList.size() - 1;
                    break;
                case SelectLeftTab:
                    newIndex = index - 1;
                    if (newIndex < 0)
                        newIndex = 0;
                    break;
                default:
                    break;
                }

                if (d->validIndex(newIndex)) {
                    // don't loose newIndex's old through setCurrentIndex
                    int bump = d->tabList[newIndex].lastTab;
                    setCurrentIndex(newIndex);
                    d->tabList[newIndex].lastTab = bump;
                }
            } else {
                emit currentChanged(-1);
            }
        } else if (index < d->currentIndex) {
            setCurrentIndex(d->currentIndex - 1);
        }
        d->refresh();
        tabRemoved(index);
    }
}


bool QTabBar::isTabEnabled(int index) const
{
    Q_D(const QTabBar);
    if (const QTabBarPrivate::Tab *tab = d->at(index))
        return tab->enabled;
    return false;
}

void QTabBar::setTabEnabled(int index, bool enabled)
{
    Q_D(QTabBar);
    if (QTabBarPrivate::Tab *tab = d->at(index)) {
        tab->enabled = enabled;
#ifndef QT_NO_SHORTCUT
        setShortcutEnabled(tab->shortcutId, enabled);
#endif
        update();
        if (!enabled && index == d->currentIndex)
            setCurrentIndex(d->validIndex(index+1)?index+1:0);
        else if (enabled && !d->validIndex(d->currentIndex))
            setCurrentIndex(index);
    }
}


QString QTabBar::tabText(int index) const
{
    Q_D(const QTabBar);
    if (const QTabBarPrivate::Tab *tab = d->at(index))
        return tab->text;
    return QString();
}

void QTabBar::setTabText(int index, const QString &text)
{
    Q_D(QTabBar);
    if (QTabBarPrivate::Tab *tab = d->at(index)) {
        tab->text = text;
#ifndef QT_NO_SHORTCUT
        releaseShortcut(tab->shortcutId);
        tab->shortcutId = grabShortcut(QKeySequence::mnemonic(text));
        setShortcutEnabled(tab->shortcutId, tab->enabled);
#endif
        d->refresh();
    }
}

QColor QTabBar::tabTextColor(int index) const
{
    Q_D(const QTabBar);
    if (const QTabBarPrivate::Tab *tab = d->at(index))
        return tab->textColor;
    return QColor();
}

void QTabBar::setTabTextColor(int index, const QColor &color)
{
    Q_D(QTabBar);
    if (QTabBarPrivate::Tab *tab = d->at(index)) {
        tab->textColor = color;
        update(tabRect(index));
    }
}

QIcon QTabBar::tabIcon(int index) const
{
    Q_D(const QTabBar);
    if (const QTabBarPrivate::Tab *tab = d->at(index))
        return tab->icon;
    return QIcon();
}

void QTabBar::setTabIcon(int index, const QIcon & icon)
{
    Q_D(QTabBar);
    if (QTabBarPrivate::Tab *tab = d->at(index)) {
        bool simpleIconChange = (!icon.isNull() && !tab->icon.isNull());
        tab->icon = icon;
        if (simpleIconChange)
            update(tabRect(index));
        else
            d->refresh();
    }
}

#ifndef QT_NO_TOOLTIP

void QTabBar::setTabToolTip(int index, const QString & tip)
{
    Q_D(QTabBar);
    if (QTabBarPrivate::Tab *tab = d->at(index))
        tab->toolTip = tip;
}

QString QTabBar::tabToolTip(int index) const
{
    Q_D(const QTabBar);
    if (const QTabBarPrivate::Tab *tab = d->at(index))
        return tab->toolTip;
    return QString();
}
#endif // QT_NO_TOOLTIP

#ifndef QT_NO_WHATSTHIS

void QTabBar::setTabWhatsThis(int index, const QString &text)
{
    Q_D(QTabBar);
    if (QTabBarPrivate::Tab *tab = d->at(index))
        tab->whatsThis = text;
}

QString QTabBar::tabWhatsThis(int index) const
{
    Q_D(const QTabBar);
    if (const QTabBarPrivate::Tab *tab = d->at(index))
        return tab->whatsThis;
    return QString();
}

#endif // QT_NO_WHATSTHIS

void QTabBar::setTabData(int index, const QVariant & data)
{
    Q_D(QTabBar);
    if (QTabBarPrivate::Tab *tab = d->at(index))
        tab->data = data;
}

QVariant QTabBar::tabData(int index) const
{
    Q_D(const QTabBar);
    if (const QTabBarPrivate::Tab *tab = d->at(index))
        return tab->data;
    return QVariant();
}

QRect QTabBar::tabRect(int index) const
{
    Q_D(const QTabBar);
    if (const QTabBarPrivate::Tab *tab = d->at(index)) {
        if (d->layoutDirty)
            const_cast<QTabBarPrivate*>(d)->layoutTabs();
        QRect r = tab->rect;
        if (verticalTabs(d->shape))
            r.translate(0, -d->scrollOffset);
        else
            r.translate(-d->scrollOffset, 0);
        if (!verticalTabs(d->shape))
            r = QStyle::visualRect(layoutDirection(), rect(), r);
        return r;
    }
    return QRect();
}

int QTabBar::tabAt(const QPoint &position) const
{
    Q_D(const QTabBar);
    if (d->validIndex(d->currentIndex)
        && tabRect(d->currentIndex).contains(position)) {
        return d->currentIndex;
    }
    const int max = d->tabList.size();
    for (int i = 0; i < max; ++i) {
        if (tabRect(i).contains(position)) {
            return i;
        }
    }
    return -1;
}

int QTabBar::currentIndex() const
{
    Q_D(const QTabBar);
    if (d->validIndex(d->currentIndex))
        return d->currentIndex;
    return -1;
}


void QTabBar::setCurrentIndex(int index)
{
    Q_D(QTabBar);
    if (d->dragInProgress && d->pressedIndex != -1)
        return;

    int oldIndex = d->currentIndex;
    if (d->validIndex(index) && d->currentIndex != index) {
        d->currentIndex = index;
        update();
        d->makeVisible(index);
        d->tabList[index].lastTab = oldIndex;
        if (oldIndex >= 0 && oldIndex < count())
            d->layoutTab(oldIndex);
        d->layoutTab(index);
#ifndef QT_NO_ACCESSIBILITY
        if (QAccessible::isActive()) {
            QAccessible::updateAccessibility(this, oldIndex + 1, QAccessible::Selection);

            QAccessible::updateAccessibility(this, index + 1, QAccessible::Focus);
            QAccessible::updateAccessibility(this, index + 1, QAccessible::Selection);
        }
#endif
#ifdef QT3_SUPPORT
        emit selected(index);
#endif
        emit currentChanged(index);
    }
}

QSize QTabBar::iconSize() const
{
    Q_D(const QTabBar);
    if (d->iconSize.isValid())
        return d->iconSize;
    int iconExtent = style()->pixelMetric(QStyle::PM_TabBarIconSize, 0, this);
    return QSize(iconExtent, iconExtent);

}

void QTabBar::setIconSize(const QSize &size)
{
    Q_D(QTabBar);
    d->iconSize = size;
    d->layoutDirty = true;
    update();
    updateGeometry();
}

int QTabBar::count() const
{
    Q_D(const QTabBar);
    return d->tabList.count();
}


QSize QTabBar::sizeHint() const
{
    Q_D(const QTabBar);
    if (d->layoutDirty)
        const_cast<QTabBarPrivate*>(d)->layoutTabs();
    QRect r;
    for (int i = 0; i < d->tabList.count(); ++i)
        r = r.united(d->tabList.at(i).maxRect);
    QSize sz = QApplication::globalStrut();
    return r.size().expandedTo(sz);
}

QSize QTabBar::minimumSizeHint() const
{
    Q_D(const QTabBar);
    if (d->layoutDirty)
        const_cast<QTabBarPrivate*>(d)->layoutTabs();
    if (!d->useScrollButtons) {
        QRect r;
        for (int i = 0; i < d->tabList.count(); ++i)
            r = r.united(d->tabList.at(i).minRect);
        return r.size().expandedTo(QApplication::globalStrut());
    }
    if (verticalTabs(d->shape))
        return QSize(sizeHint().width(), d->rightB->sizeHint().height() * 2 + 75);
    else
        return QSize(d->rightB->sizeHint().width() * 2 + 75, sizeHint().height());
}

// Compute the most-elided possible text, for minimumSizeHint
static QString computeElidedText(Qt::TextElideMode mode, const QString &text)
{
    if (text.length() <= 3)
        return text;

    static const QLatin1String Ellipses("...");
    QString ret;
    switch (mode) {
    case Qt::ElideRight:
        ret = text.left(2) + Ellipses;
        break;
    case Qt::ElideMiddle:
        ret = text.left(1) + Ellipses + text.right(1);
        break;
    case Qt::ElideLeft:
        ret = Ellipses + text.right(2);
        break;
    case Qt::ElideNone:
        ret = text;
        break;
    }
    return ret;
}

QSize QTabBarPrivate::minimumTabSizeHint(int index)
{
    Q_Q(QTabBar);
    // ### Qt 5: make this a protected virtual function in QTabBar
    Tab &tab = tabList[index];
    QString oldText = tab.text;
    tab.text = computeElidedText(elideMode, oldText);
    QSize size = q->tabSizeHint(index);
    tab.text = oldText;
    return size;
}

QSize QTabBar::tabSizeHint(int index) const
{
    //Note: this must match with the computations in QCommonStylePrivate::tabLayout
    Q_D(const QTabBar);
    if (const QTabBarPrivate::Tab *tab = d->at(index)) {
        QStyleOptionTabV3 opt;
        initStyleOption(&opt, index);
        opt.text = d->tabList.at(index).text;
        QSize iconSize = tab->icon.isNull() ? QSize(0, 0) : opt.iconSize;
        int hframe = style()->pixelMetric(QStyle::PM_TabBarTabHSpace, &opt, this);
        int vframe = style()->pixelMetric(QStyle::PM_TabBarTabVSpace, &opt, this);
        const QFontMetrics fm = fontMetrics();

        int maxWidgetHeight = qMax(opt.leftButtonSize.height(), opt.rightButtonSize.height());
        int maxWidgetWidth = qMax(opt.leftButtonSize.width(), opt.rightButtonSize.width());

        int widgetWidth = 0;
        int widgetHeight = 0;
        int padding = 0;
        if (!opt.leftButtonSize.isEmpty()) {
            padding += 4;
            widgetWidth += opt.leftButtonSize.width();
            widgetHeight += opt.leftButtonSize.height();
        }
        if (!opt.rightButtonSize.isEmpty()) {
            padding += 4;
            widgetWidth += opt.rightButtonSize.width();
            widgetHeight += opt.rightButtonSize.height();
        }
        if (!opt.icon.isNull())
            padding += 4;

        QSize csz;
        if (verticalTabs(d->shape)) {
            csz = QSize( qMax(maxWidgetWidth, qMax(fm.height(), iconSize.height())) + vframe,
                    fm.size(Qt::TextShowMnemonic, tab->text).width() + iconSize.width() + hframe + widgetHeight + padding);
        } else {
            csz = QSize(fm.size(Qt::TextShowMnemonic, tab->text).width() + iconSize.width() + hframe
                  + widgetWidth + padding,
                  qMax(maxWidgetHeight, qMax(fm.height(), iconSize.height())) + vframe);
        }

        QSize retSize = style()->sizeFromContents(QStyle::CT_TabBarTab, &opt, csz, this);
        return retSize;
    }
    return QSize();
}

void QTabBar::tabInserted(int index)
{
    Q_UNUSED(index)
}

void QTabBar::tabRemoved(int index)
{
    Q_UNUSED(index)
}

void QTabBar::tabLayoutChange()
{
}


void QTabBar::showEvent(QShowEvent *)
{
    Q_D(QTabBar);
    if (d->layoutDirty)
        d->refresh();
    if (!d->validIndex(d->currentIndex))
        setCurrentIndex(0);
    d->updateMacBorderMetrics();
}

void QTabBar::hideEvent(QHideEvent *)
{
    Q_D(QTabBar);
    d->updateMacBorderMetrics();
}

bool QTabBar::event(QEvent *event)
{
    Q_D(QTabBar);
    if (event->type() == QEvent::HoverMove
        || event->type() == QEvent::HoverEnter) {
        QHoverEvent *he = static_cast<QHoverEvent *>(event);
        if (!d->hoverRect.contains(he->pos())) {
            QRect oldHoverRect = d->hoverRect;
            for (int i = 0; i < d->tabList.count(); ++i) {
                QRect area = tabRect(i);
                if (area.contains(he->pos())) {
                    d->hoverRect = area;
                    break;
                }
            }
            if (he->oldPos() != QPoint(-1, -1))
                update(oldHoverRect);
            update(d->hoverRect);
        }
        return true;
    } else if (event->type() == QEvent::HoverLeave ) {
        QRect oldHoverRect = d->hoverRect;
        d->hoverRect = QRect();
        update(oldHoverRect);
        return true;
#ifndef QT_NO_TOOLTIP
    } else if (event->type() == QEvent::ToolTip) {
        if (const QTabBarPrivate::Tab *tab = d->at(tabAt(static_cast<QHelpEvent*>(event)->pos()))) {
            if (!tab->toolTip.isEmpty()) {
                QToolTip::showText(static_cast<QHelpEvent*>(event)->globalPos(), tab->toolTip, this);
                return true;
            }
        }
#endif // QT_NO_TOOLTIP
#ifndef QT_NO_WHATSTHIS
    } else if (event->type() == QEvent::QueryWhatsThis) {
        const QTabBarPrivate::Tab *tab = d->at(d->indexAtPos(static_cast<QHelpEvent*>(event)->pos()));
        if (!tab || tab->whatsThis.isEmpty())
            event->ignore();
        return true;
    } else if (event->type() == QEvent::WhatsThis) {
        if (const QTabBarPrivate::Tab *tab = d->at(d->indexAtPos(static_cast<QHelpEvent*>(event)->pos()))) {
            if (!tab->whatsThis.isEmpty()) {
                QWhatsThis::showText(static_cast<QHelpEvent*>(event)->globalPos(),
                                     tab->whatsThis, this);
                return true;
            }
        }
#endif // QT_NO_WHATSTHIS
#ifndef QT_NO_SHORTCUT
    } else if (event->type() == QEvent::Shortcut) {
        QShortcutEvent *se = static_cast<QShortcutEvent *>(event);
        for (int i = 0; i < d->tabList.count(); ++i) {
            const QTabBarPrivate::Tab *tab = &d->tabList.at(i);
            if (tab->shortcutId == se->shortcutId()) {
                setCurrentIndex(i);
                return true;
            }
        }
#endif
    }
    return QWidget::event(event);
}

void QTabBar::resizeEvent(QResizeEvent *)
{
    Q_D(QTabBar);
    if (d->layoutDirty)
        updateGeometry();
    d->layoutTabs();

    d->makeVisible(d->currentIndex);
}

void QTabBar::paintEvent(QPaintEvent *)
{
    Q_D(QTabBar);

    QStyleOptionTabBarBaseV2 optTabBase;
    QTabBarPrivate::initStyleBaseOption(&optTabBase, this, size());

    QStylePainter p(this);
    int selected = -1;
    int cut = -1;
    bool rtl = optTabBase.direction == Qt::RightToLeft;
    bool vertical = verticalTabs(d->shape);
    QStyleOptionTab cutTab;
    selected = d->currentIndex;
    if (d->dragInProgress)
        selected = d->pressedIndex;

    for (int i = 0; i < d->tabList.count(); ++i)
         optTabBase.tabBarRect |= tabRect(i);

    optTabBase.selectedTabRect = tabRect(selected);

    if (d->drawBase)
        p.drawPrimitive(QStyle::PE_FrameTabBarBase, optTabBase);

    for (int i = 0; i < d->tabList.count(); ++i) {
        QStyleOptionTabV3 tab;
        initStyleOption(&tab, i);
        if (d->paintWithOffsets && d->tabList[i].dragOffset != 0) {
            if (vertical) {
                tab.rect.moveTop(tab.rect.y() + d->tabList[i].dragOffset);
            } else {
                tab.rect.moveLeft(tab.rect.x() + d->tabList[i].dragOffset);
            }
        }
        if (!(tab.state & QStyle::State_Enabled)) {
            tab.palette.setCurrentColorGroup(QPalette::Disabled);
        }
        // If this tab is partially obscured, make a note of it so that we can pass the information
        // along when we draw the tear.
        if (((!vertical && (!rtl && tab.rect.left() < 0)) || (rtl && tab.rect.right() > width()))
            || (vertical && tab.rect.top() < 0)) {
            cut = i;
            cutTab = tab;
        }
        // Don't bother drawing a tab if the entire tab is outside of the visible tab bar.
        if ((!vertical && (tab.rect.right() < 0 || tab.rect.left() > width()))
            || (vertical && (tab.rect.bottom() < 0 || tab.rect.top() > height())))
            continue;

        optTabBase.tabBarRect |= tab.rect;
        if (i == selected)
            continue;

        p.drawControl(QStyle::CE_TabBarTab, tab);
    }

    // Draw the selected tab last to get it "on top"
    if (selected >= 0) {
        QStyleOptionTabV3 tab;
        initStyleOption(&tab, selected);
        if (d->paintWithOffsets && d->tabList[selected].dragOffset != 0) {
            if (vertical)
                tab.rect.moveTop(tab.rect.y() + d->tabList[selected].dragOffset);
            else
                tab.rect.moveLeft(tab.rect.x() + d->tabList[selected].dragOffset);
        }
        if (!d->dragInProgress)
            p.drawControl(QStyle::CE_TabBarTab, tab);
        else {
            int taboverlap = style()->pixelMetric(QStyle::PM_TabBarTabOverlap, 0, this);
            d->movingTab->setGeometry(tab.rect.adjusted(-taboverlap, 0, taboverlap, 0));
        }
    }

    // Only draw the tear indicator if necessary. Most of the time we don't need too.
    if (d->leftB->isVisible() && cut >= 0) {
        cutTab.rect = rect();
        cutTab.rect = style()->subElementRect(QStyle::SE_TabBarTearIndicator, &cutTab, this);
        p.drawPrimitive(QStyle::PE_IndicatorTabTear, cutTab);
    }
}

/*
    Given that index at position from moved to position to where return where index goes.
 */
int QTabBarPrivate::calculateNewPosition(int from, int to, int index) const
{
    if (index == from)
        return to;

    int start = qMin(from, to);
    int end = qMax(from, to);
    if (index >= start && index <= end)
        index += (from < to) ? -1 : 1;
    return index;
}

void QTabBar::moveTab(int from, int to)
{
    Q_D(QTabBar);
    if (from == to
        || !d->validIndex(from)
        || !d->validIndex(to))
        return;

    bool vertical = verticalTabs(d->shape);
    int oldPressedPosition = 0;
    if (d->pressedIndex != -1) {
        // Record the position of the pressed tab before reordering the tabs.
        oldPressedPosition = vertical ? d->tabList[d->pressedIndex].rect.y()
                             : d->tabList[d->pressedIndex].rect.x();
    }

    // Update the locations of the tabs first
    int start = qMin(from, to);
    int end = qMax(from, to);
    int width = vertical ? d->tabList[from].rect.height() : d->tabList[from].rect.width();
    if (from < to)
        width *= -1;
    bool rtl = isRightToLeft();
    for (int i = start; i <= end; ++i) {
        if (i == from)
            continue;
        if (vertical)
            d->tabList[i].rect.moveTop(d->tabList[i].rect.y() + width);
        else
            d->tabList[i].rect.moveLeft(d->tabList[i].rect.x() + width);
        int direction = -1;
        if (rtl && !vertical)
            direction *= -1;
        if (d->tabList[i].dragOffset != 0)
            d->tabList[i].dragOffset += (direction * width);
    }

    if (vertical) {
        if (from < to)
            d->tabList[from].rect.moveTop(d->tabList[to].rect.bottom() + 1);
        else
            d->tabList[from].rect.moveTop(d->tabList[to].rect.top() - width);
    } else {
        if (from < to)
            d->tabList[from].rect.moveLeft(d->tabList[to].rect.right() + 1);
        else
            d->tabList[from].rect.moveLeft(d->tabList[to].rect.left() - width);
    }

    // Move the actual data structures
    d->tabList.move(from, to);

    // update lastTab locations
    for (int i = 0; i < d->tabList.count(); ++i)
        d->tabList[i].lastTab = d->calculateNewPosition(from, to, d->tabList[i].lastTab);

    // update external variables
    d->currentIndex = d->calculateNewPosition(from, to, d->currentIndex);

    // If we are in the middle of a drag update the dragStartPosition
    if (d->pressedIndex != -1) {
        d->pressedIndex = d->calculateNewPosition(from, to, d->pressedIndex);
        int newPressedPosition = vertical ? d->tabList[d->pressedIndex].rect.top() : d->tabList[d->pressedIndex].rect.left();
        int diff = oldPressedPosition - newPressedPosition;
        if (isRightToLeft() && !vertical)
            diff *= -1;
        if (vertical)
            d->dragStartPosition.setY(d->dragStartPosition.y() - diff);
        else
            d->dragStartPosition.setX(d->dragStartPosition.x() - diff);
    }

    d->layoutWidgets(start);
    update();
    emit tabMoved(from, to);
    emit tabLayoutChange();
}

void QTabBarPrivate::slide(int from, int to)
{
    Q_Q(QTabBar);
    if (from == to
            || !validIndex(from)
            || !validIndex(to))
        return;
    bool vertical = verticalTabs(shape);
    int preLocation = vertical ? q->tabRect(from).y() : q->tabRect(from).x();
    q->setUpdatesEnabled(false);
    q->moveTab(from, to);
    q->setUpdatesEnabled(true);
    int postLocation = vertical ? q->tabRect(to).y() : q->tabRect(to).x();
    int length = postLocation - preLocation;
    tabList[to].dragOffset -= length;
    tabList[to].startAnimation(this, ANIMATION_DURATION);
}

void QTabBarPrivate::moveTab(int index, int offset)
{
    if (!validIndex(index))
        return;
    tabList[index].dragOffset = offset;
    layoutTab(index); // Make buttons follow tab
    q_func()->update();
}

void QTabBar::mousePressEvent(QMouseEvent *event)
{
    Q_D(QTabBar);
    if (event->button() != Qt::LeftButton) {
        event->ignore();
        return;
    }
    // Be safe!
    if (d->pressedIndex != -1 && d->movable)
        d->moveTabFinished(d->pressedIndex);

    d->pressedIndex = d->indexAtPos(event->pos());
#ifdef Q_WS_MAC
    d->previousPressedIndex = d->pressedIndex;
#endif
    if (d->validIndex(d->pressedIndex)) {
        QStyleOptionTabBarBaseV2 optTabBase;
        optTabBase.init(this);
        optTabBase.documentMode = d->documentMode;
        if (event->type() == style()->styleHint(QStyle::SH_TabBar_SelectMouseType, &optTabBase, this))
            setCurrentIndex(d->pressedIndex);
        else
            repaint(tabRect(d->pressedIndex));
        if (d->movable) {
            d->dragStartPosition = event->pos();
        }
    }
}

void QTabBar::mouseMoveEvent(QMouseEvent *event)
{
    Q_D(QTabBar);
    if (d->movable) {
        // Be safe!
        if (d->pressedIndex != -1
            && event->buttons() == Qt::NoButton)
            d->moveTabFinished(d->pressedIndex);
        
        // Start drag
        if (!d->dragInProgress && d->pressedIndex != -1) {
            if ((event->pos() - d->dragStartPosition).manhattanLength() > QApplication::startDragDistance()) {
                d->dragInProgress = true;
                d->setupMovableTab();
            }
        }

        int offset = (event->pos() - d->dragStartPosition).manhattanLength();
        if (event->buttons() == Qt::LeftButton
            && offset > QApplication::startDragDistance()
            && d->validIndex(d->pressedIndex)) {
            bool vertical = verticalTabs(d->shape);
            int dragDistance;
            if (vertical) {
                dragDistance = (event->pos().y() - d->dragStartPosition.y());
            } else {
                dragDistance = (event->pos().x() - d->dragStartPosition.x());
            }
            d->tabList[d->pressedIndex].dragOffset = dragDistance;

            QRect startingRect = tabRect(d->pressedIndex);
            if (vertical)
                startingRect.moveTop(startingRect.y() + dragDistance);
            else
                startingRect.moveLeft(startingRect.x() + dragDistance);

            int overIndex;
            if (dragDistance < 0)
                overIndex = tabAt(startingRect.topLeft());
            else
                overIndex = tabAt(startingRect.topRight());

            if (overIndex != d->pressedIndex && overIndex != -1) {
                int offset = 1;
                if (isRightToLeft() && !vertical)
                    offset *= -1;
                if (dragDistance < 0) {
                    dragDistance *= -1;
                    offset *= -1;
                }
                for (int i = d->pressedIndex;
                     offset > 0 ? i < overIndex : i > overIndex;
                     i += offset) {
                    QRect overIndexRect = tabRect(overIndex);
                    int needsToBeOver = (vertical ? overIndexRect.height() : overIndexRect.width()) / 2;
                    if (dragDistance > needsToBeOver)
                        d->slide(i + offset, d->pressedIndex);
                }
            }
            // Buttons needs to follow the dragged tab
            d->layoutTab(d->pressedIndex);

            update();
        }
#ifdef Q_WS_MAC
    } else if (!d->documentMode && event->buttons() == Qt::LeftButton && d->previousPressedIndex != -1) {
        int newPressedIndex = d->indexAtPos(event->pos());
        if (d->pressedIndex == -1 && d->previousPressedIndex == newPressedIndex) {
            d->pressedIndex = d->previousPressedIndex;
            update(tabRect(d->pressedIndex));
        } else if(d->pressedIndex != newPressedIndex) {
            d->pressedIndex = -1;
            update(tabRect(d->previousPressedIndex));
        }
#endif
    }

    if (event->buttons() != Qt::LeftButton) {
        event->ignore();
        return;
    }
    QStyleOptionTabBarBaseV2 optTabBase;
    optTabBase.init(this);
    optTabBase.documentMode = d->documentMode;
}

void QTabBarPrivate::setupMovableTab()
{
    Q_Q(QTabBar);
    if (!movingTab)
        movingTab = new QWidget(q);

    int taboverlap = q->style()->pixelMetric(QStyle::PM_TabBarTabOverlap, 0 ,q);
    QRect grabRect = q->tabRect(pressedIndex);
    grabRect.adjust(-taboverlap, 0, taboverlap, 0);

    QPixmap grabImage(grabRect.size());
    grabImage.fill(Qt::transparent);
    QStylePainter p(&grabImage, q);
    p.initFrom(q);

    QStyleOptionTabV3 tab;
    q->initStyleOption(&tab, pressedIndex);
    tab.rect.moveTopLeft(QPoint(taboverlap, 0));
    p.drawControl(QStyle::CE_TabBarTab, tab);
    p.end();

    QPalette pal;
    pal.setBrush(QPalette::All, QPalette::Window, grabImage);
    movingTab->setPalette(pal);
    movingTab->setGeometry(grabRect);
    movingTab->setAutoFillBackground(true);
    movingTab->raise();

    // Re-arrange widget order to avoid overlaps
    if (tabList[pressedIndex].leftWidget)
        tabList[pressedIndex].leftWidget->raise();
    if (tabList[pressedIndex].rightWidget)
        tabList[pressedIndex].rightWidget->raise();
    if (leftB)
        leftB->raise();
    if (rightB)
        rightB->raise();
    movingTab->setVisible(true);
}

void QTabBarPrivate::moveTabFinished(int index)
{
    Q_Q(QTabBar);
    bool cleanup = (pressedIndex == index) || (pressedIndex == -1) || !validIndex(index);
    bool allAnimationsFinished = true;
#ifndef QT_NO_ANIMATION
    for(int i = 0; allAnimationsFinished && i < tabList.count(); ++i) {
        const Tab &t = tabList.at(i);
        if (t.animation && t.animation->state() == QAbstractAnimation::Running)
            allAnimationsFinished = false;
    }
#endif //QT_NO_ANIMATION
    if (allAnimationsFinished && cleanup) {
        if(movingTab)
            movingTab->setVisible(false); // We might not get a mouse release
        for (int i = 0; i < tabList.count(); ++i) {
            tabList[i].dragOffset = 0;
        }
        if (pressedIndex != -1 && movable) {
            pressedIndex = -1;
            dragInProgress = false;
            dragStartPosition = QPoint();
        }
        layoutWidgets();
    } else {
        if (!validIndex(index))
            return;
        tabList[index].dragOffset = 0;
    }
    q->update();
}

void QTabBar::mouseReleaseEvent(QMouseEvent *event)
{
    Q_D(QTabBar);
    if (event->button() != Qt::LeftButton) {
        event->ignore();
        return;
    }
#ifdef Q_WS_MAC
    d->previousPressedIndex = -1;
#endif
    if (d->movable && d->dragInProgress && d->validIndex(d->pressedIndex)) {
        int length = d->tabList[d->pressedIndex].dragOffset;
        int width = verticalTabs(d->shape)
            ? tabRect(d->pressedIndex).height()
            : tabRect(d->pressedIndex).width();
        int duration = qMin(ANIMATION_DURATION,
                (qAbs(length) * ANIMATION_DURATION) / width);
        d->tabList[d->pressedIndex].startAnimation(d, duration);
        d->dragInProgress = false;
        d->movingTab->setVisible(false);
        d->dragStartPosition = QPoint();
    }

    int i = d->indexAtPos(event->pos()) == d->pressedIndex ? d->pressedIndex : -1;
    d->pressedIndex = -1;
    QStyleOptionTabBarBaseV2 optTabBase;
    optTabBase.initFrom(this);
    optTabBase.documentMode = d->documentMode;
    if (style()->styleHint(QStyle::SH_TabBar_SelectMouseType, &optTabBase, this) == QEvent::MouseButtonRelease)
        setCurrentIndex(i);
}

void QTabBar::keyPressEvent(QKeyEvent *event)
{
    Q_D(QTabBar);
    if (event->key() != Qt::Key_Left && event->key() != Qt::Key_Right) {
        event->ignore();
        return;
    }
    int offset = event->key() == (isRightToLeft() ? Qt::Key_Right : Qt::Key_Left) ? -1 : 1;
    d->setCurrentNextEnabledIndex(offset);
}

#ifndef QT_NO_WHEELEVENT
void QTabBar::wheelEvent(QWheelEvent *event)
{
    Q_D(QTabBar);
    int offset = event->delta() > 0 ? -1 : 1;
    d->setCurrentNextEnabledIndex(offset);
    QWidget::wheelEvent(event);
}
#endif //QT_NO_WHEELEVENT

void QTabBarPrivate::setCurrentNextEnabledIndex(int offset)
{
    Q_Q(QTabBar);
    for (int index = currentIndex + offset; validIndex(index); index += offset) {
        if (tabList.at(index).enabled) {
            q->setCurrentIndex(index);
            break;
        }
    }
}

void QTabBar::changeEvent(QEvent *event)
{
    Q_D(QTabBar);
    if (event->type() == QEvent::StyleChange) {
        if (!d->elideModeSetByUser)
            d->elideMode = Qt::TextElideMode(style()->styleHint(QStyle::SH_TabBar_ElideMode, 0, this));
        if (!d->useScrollButtonsSetByUser)
            d->useScrollButtons = !style()->styleHint(QStyle::SH_TabBar_PreferNoArrows, 0, this);
        d->refresh();
    } else if (event->type() == QEvent::FontChange) {
        d->refresh();
    }
    QWidget::changeEvent(event);
}

Qt::TextElideMode QTabBar::elideMode() const
{
    Q_D(const QTabBar);
    return d->elideMode;
}

void QTabBar::setElideMode(Qt::TextElideMode mode)
{
    Q_D(QTabBar);
    d->elideMode = mode;
    d->elideModeSetByUser = true;
    d->refresh();
}

bool QTabBar::usesScrollButtons() const
{
    return d_func()->useScrollButtons;
}

void QTabBar::setUsesScrollButtons(bool useButtons)
{
    Q_D(QTabBar);
    d->useScrollButtonsSetByUser = true;
    if (d->useScrollButtons == useButtons)
        return;
    d->useScrollButtons = useButtons;
    d->refresh();
}

bool QTabBar::tabsClosable() const
{
    Q_D(const QTabBar);
    return d->closeButtonOnTabs;
}

void QTabBar::setTabsClosable(bool closable)
{
    Q_D(QTabBar);
    if (d->closeButtonOnTabs == closable)
        return;
    d->closeButtonOnTabs = closable;
    ButtonPosition closeSide = (ButtonPosition)style()->styleHint(QStyle::SH_TabBar_CloseButtonPosition, 0, this);
    if (!closable) {
        for (int i = 0; i < d->tabList.count(); ++i) {
            if (closeSide == LeftSide && d->tabList[i].leftWidget) {
                d->tabList[i].leftWidget->deleteLater();
                d->tabList[i].leftWidget = 0;
            }
            if (closeSide == RightSide && d->tabList[i].rightWidget) {
                d->tabList[i].rightWidget->deleteLater();
                d->tabList[i].rightWidget = 0;
            }
        }
    } else {
        bool newButtons = false;
        for (int i = 0; i < d->tabList.count(); ++i) {
            if (tabButton(i, closeSide))
                continue;
            newButtons = true;
            QAbstractButton *closeButton = new CloseButton(this);
            connect(closeButton, SIGNAL(clicked()), this, SLOT(_q_closeTab()));
            setTabButton(i, closeSide, closeButton);
        }
        if (newButtons)
            d->layoutTabs();
    }
    update();
}

QTabBar::SelectionBehavior QTabBar::selectionBehaviorOnRemove() const
{
    Q_D(const QTabBar);
    return d->selectionBehaviorOnRemove;
}

void QTabBar::setSelectionBehaviorOnRemove(QTabBar::SelectionBehavior behavior)
{
    Q_D(QTabBar);
    d->selectionBehaviorOnRemove = behavior;
}

bool QTabBar::expanding() const
{
    Q_D(const QTabBar);
    return d->expanding;
}

void QTabBar::setExpanding(bool enabled)
{
    Q_D(QTabBar);
    if (d->expanding == enabled)
        return;
    d->expanding = enabled;
    d->layoutTabs();
}

bool QTabBar::isMovable() const
{
    Q_D(const QTabBar);
    return d->movable;
}

void QTabBar::setMovable(bool movable)
{
    Q_D(QTabBar);
    d->movable = movable;
}


bool QTabBar::documentMode() const
{
    return d_func()->documentMode;
}

void QTabBar::setDocumentMode(bool enabled)
{
    Q_D(QTabBar);

    d->documentMode = enabled;
    d->updateMacBorderMetrics();
}

void QTabBar::setTabButton(int index, ButtonPosition position, QWidget *widget)
{
    Q_D(QTabBar);
    if (index < 0 || index >= d->tabList.count())
        return;
    if (widget) {
        widget->setParent(this);
        // make sure our left and right widgets stay on top
        widget->lower();
        widget->show();
    }
    if (position == LeftSide) {
        if (d->tabList[index].leftWidget)
            d->tabList[index].leftWidget->hide();
        d->tabList[index].leftWidget = widget;
    } else {
        if (d->tabList[index].rightWidget)
            d->tabList[index].rightWidget->hide();
        d->tabList[index].rightWidget = widget;
    }
    d->layoutTabs();
    d->refresh();
    update();
}

QWidget *QTabBar::tabButton(int index, ButtonPosition position) const
{
    Q_D(const QTabBar);
    if (index < 0 || index >= d->tabList.count())
        return 0;
    if (position == LeftSide)
        return d->tabList.at(index).leftWidget;
    else
        return d->tabList.at(index).rightWidget;
}

CloseButton::CloseButton(QWidget *parent)
    : QAbstractButton(parent)
{
    setFocusPolicy(Qt::NoFocus);
#ifndef QT_NO_CURSOR
    setCursor(Qt::ArrowCursor);
#endif
#ifndef QT_NO_TOOLTIP
    setToolTip(tr("Close Tab"));
#endif
    resize(sizeHint());
}

QSize CloseButton::sizeHint() const
{
    ensurePolished();
    int width = style()->pixelMetric(QStyle::PM_TabCloseIndicatorWidth, 0, this);
    int height = style()->pixelMetric(QStyle::PM_TabCloseIndicatorHeight, 0, this);
    return QSize(width, height);
}

void CloseButton::enterEvent(QEvent *event)
{
    if (isEnabled())
        update();
    QAbstractButton::enterEvent(event);
}

void CloseButton::leaveEvent(QEvent *event)
{
    if (isEnabled())
        update();
    QAbstractButton::leaveEvent(event);
}

void CloseButton::paintEvent(QPaintEvent *)
{
    QPainter p(this);
    QStyleOption opt;
    opt.init(this);
    opt.state |= QStyle::State_AutoRaise;
    if (isEnabled() && underMouse() && !isChecked() && !isDown())
        opt.state |= QStyle::State_Raised;
    if (isChecked())
        opt.state |= QStyle::State_On;
    if (isDown())
        opt.state |= QStyle::State_Sunken;

    if (const QTabBar *tb = qobject_cast<const QTabBar *>(parent())) {
        int index = tb->currentIndex();
        QTabBar::ButtonPosition position = (QTabBar::ButtonPosition)style()->styleHint(QStyle::SH_TabBar_CloseButtonPosition, 0, tb);
        if (tb->tabButton(index, position) == this)
            opt.state |= QStyle::State_Selected;
    }

    style()->drawPrimitive(QStyle::PE_IndicatorTabClose, &opt, &p, this);
}

QT_END_NAMESPACE

#include "moc_qtabbar.cpp"

#endif // QT_NO_TABBAR