src/gui/widgets/qsplitter.cpp

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/****************************************************************************
**
** Copyright (C) 1992-2006 Trolltech ASA. All rights reserved.
**
** This file is part of the QtGui module of the Qt Toolkit.
**
** This file may be used under the terms of the GNU General Public
** License version 2.0 as published by the Free Software Foundation
** and appearing in the file LICENSE.GPL included in the packaging of
** this file.  Please review the following information to ensure GNU
** General Public Licensing requirements will be met:
** http://www.trolltech.com/products/qt/opensource.html
**
** If you are unsure which license is appropriate for your use, please
** review the following information:
** http://www.trolltech.com/products/qt/licensing.html or contact the
** sales department at sales@trolltech.com.
**
** This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
** WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
**
****************************************************************************/

#include "qsplitter.h"
#ifndef QT_NO_SPLITTER

#include "qapplication.h"
#include "qcursor.h"
#include "qdrawutil.h"
#include "qevent.h"
#include "qlayout.h"
#include "qlist.h"
#include "qpainter.h"
#include "qrubberband.h"
#include "qstyle.h"
#include "qstyleoption.h"
#include "qtextstream.h"
#include "qvarlengtharray.h"
#include "qvector.h"
#include "private/qlayoutengine_p.h"
#include "private/qsplitter_p.h"
#include "qdebug.h"

#include <ctype.h>

//#define QSPLITTER_DEBUG

QSplitterHandle::QSplitterHandle(Qt::Orientation orientation, QSplitter *parent)
    : QWidget(*new QSplitterHandlePrivate, parent, 0)
{
    Q_D(QSplitterHandle);
    d->s = parent;
    d->hover = false;
    setOrientation(orientation);
}

void QSplitterHandle::setOrientation(Qt::Orientation orientation)
{
    Q_D(QSplitterHandle);
    d->orient = orientation;
#ifndef QT_NO_CURSOR
    setCursor(orientation == Qt::Horizontal ? Qt::SplitHCursor : Qt::SplitVCursor);
#endif
}

Qt::Orientation QSplitterHandle::orientation() const
{
    Q_D(const QSplitterHandle);
    return d->orient;
}


bool QSplitterHandle::opaqueResize() const
{
    Q_D(const QSplitterHandle);
    return d->s->opaqueResize();
}


QSplitter *QSplitterHandle::splitter() const
{
    return d_func()->s;
}

void QSplitterHandle::moveSplitter(int pos)
{
    Q_D(QSplitterHandle);
    if (d->s->isRightToLeft() && d->orient == Qt::Horizontal)
        pos = d->s->contentsRect().width() - pos;
    d->s->moveSplitter(pos, d->s->indexOf(this));
}

int QSplitterHandle::closestLegalPosition(int pos)
{
    Q_D(QSplitterHandle);
    QSplitter *s = d->s;
    if (s->isRightToLeft() && d->orient == Qt::Horizontal) {
        int w = s->contentsRect().width();
        return w - s->closestLegalPosition(w - pos, s->indexOf(this));
    }
    return s->closestLegalPosition(pos, s->indexOf(this));
}

QSize QSplitterHandle::sizeHint() const
{
    Q_D(const QSplitterHandle);
    int hw = d->s->handleWidth();
    QStyleOption opt(0);
    opt.init(d->s);
    opt.state = QStyle::State_None;
    return parentWidget()->style()->sizeFromContents(QStyle::CT_Splitter, &opt, QSize(hw, hw), d->s)
        .expandedTo(QApplication::globalStrut());
}

bool QSplitterHandle::event(QEvent *event)
{
    Q_D(QSplitterHandle);
    switch(event->type()) {
    case QEvent::HoverEnter:
        d->hover = true;
        update();
        break;
    case QEvent::HoverLeave:
        d->hover = false;
        update();
        break;
    default:
        break;
    }
    return QWidget::event(event);
}

void QSplitterHandle::mouseMoveEvent(QMouseEvent *e)
{
    Q_D(QSplitterHandle);
    if (!(e->buttons() & Qt::LeftButton))
        return;
    int pos = d->pick(parentWidget()->mapFromGlobal(e->globalPos()))
                 - d->mouseOffset;
    if (opaqueResize()) {
        moveSplitter(pos);
    } else {
        d->s->setRubberBand(closestLegalPosition(pos));
    }
}

void QSplitterHandle::mousePressEvent(QMouseEvent *e)
{
    Q_D(QSplitterHandle);
    if (e->button() == Qt::LeftButton)
        d->mouseOffset = d->pick(e->pos());
}

void QSplitterHandle::mouseReleaseEvent(QMouseEvent *e)
{
    Q_D(QSplitterHandle);
    if (!opaqueResize() && e->button() == Qt::LeftButton) {
        int pos = d->pick(parentWidget()->mapFromGlobal(e->globalPos()))
                     - d->mouseOffset;
        d->s->setRubberBand(-1);
        moveSplitter(pos);
    }
}

void QSplitterHandle::paintEvent(QPaintEvent *)
{
    Q_D(QSplitterHandle);
    QPainter p(this);
    QStyleOption opt(0);
    opt.rect = rect();
    opt.palette = palette();
    if (orientation() == Qt::Horizontal)
        opt.state = QStyle::State_Horizontal;
    else
        opt.state = QStyle::State_None;
    if (d->hover)
        opt.state |= QStyle::State_MouseOver;
    if (isEnabled())
        opt.state |= QStyle::State_Enabled;
    parentWidget()->style()->drawControl(QStyle::CE_Splitter, &opt, &p, d->s);
}


int QSplitterLayoutStruct::getWidgetSize(Qt::Orientation orient)
{
    if (sizer == -1) {
        QSize s = widget->sizeHint();
        const int presizer = pick(s, orient);
        const int realsize = pick(widget->size(), orient);
        if (!s.isValid() || (widget->testAttribute(Qt::WA_Resized) && (realsize > presizer))) {
            sizer = pick(widget->size(), orient);
        } else {
            sizer = presizer;
        }
        QSizePolicy p = widget->sizePolicy();
        int sf = (orient == Qt::Horizontal) ? p.horizontalStretch() : p.verticalStretch();
        if (sf > 1)
            sizer *= sf;
    }
    return sizer;
}

int QSplitterLayoutStruct::getHandleSize(Qt::Orientation orient)
{
    return pick(handle->sizeHint(), orient);
}

void QSplitterPrivate::init()
{
    Q_Q(QSplitter);
    QSizePolicy sp(QSizePolicy::Expanding, QSizePolicy::Preferred);
    if (orient == Qt::Vertical)
        sp.transpose();
    q->setSizePolicy(sp);
    q->setAttribute(Qt::WA_WState_OwnSizePolicy, false);
}

void QSplitterPrivate::recalc(bool update)
{
    Q_Q(QSplitter);
    int n = list.count();
    /*
      Splitter handles before the first visible widget or right
      before a hidden widget must be hidden.
    */
    bool first = true;
    for (int i = 0; i < n ; ++i) {
        QSplitterLayoutStruct *s = list.at(i);
        s->handle->setHidden(first || s->widget->isHidden());
        if (!s->widget->isHidden())
            first = false;
    }

    int fi = 2 * q->frameWidth();
    int maxl = fi;
    int minl = fi;
    int maxt = QWIDGETSIZE_MAX;
    int mint = fi;
    /*
      calculate min/max sizes for the whole splitter
    */
    bool empty = true;
    for (int j = 0; j < n; j++) {
        QSplitterLayoutStruct *s = list.at(j);

        if (!s->widget->isHidden()) {
            empty = false;
            if (!s->handle->isHidden()) {
                minl += s->getHandleSize(orient);
                maxl += s->getHandleSize(orient);
            }

            QSize minS = qSmartMinSize(s->widget);
            minl += pick(minS);
            maxl += pick(s->widget->maximumSize());
            mint = qMax(mint, trans(minS));
            int tm = trans(s->widget->maximumSize());
            if (tm > 0)
                maxt = qMin(maxt, tm);
        }
    }

    if (empty) {
        if (qobject_cast<QSplitter *>(q->parentWidget())) {
            // nested splitters; be nice
            maxl = maxt = 0;
        } else {
            // QSplitter with no children yet
            maxl = QWIDGETSIZE_MAX;
        }
    } else {
        maxl = qMin<int>(maxl, QWIDGETSIZE_MAX);
    }
    if (maxt < mint)
        maxt = mint;

    if (update) {
        if (orient == Qt::Horizontal) {
            q->setMaximumSize(maxl, maxt);
            if (q->isWindow())
                q->setMinimumSize(minl,mint);
        } else {
            q->setMaximumSize(maxt, maxl);
            if (q->isWindow())
                q->setMinimumSize(mint,minl);
        }
        doResize();
        q->updateGeometry();
    } else {
        firstShow = true;
    }
}

void QSplitterPrivate::doResize()
{
    Q_Q(QSplitter);
    QRect r = q->contentsRect();
    int n = list.count();
    QVector<QLayoutStruct> a(n*2);
    int i;

    bool noStretchFactorsSet = true;
    for (i = 0; i < n; ++i) {
        QSizePolicy p = list.at(i)->widget->sizePolicy();
        int sf = orient == Qt::Horizontal ? p.horizontalStretch() : p.verticalStretch();
        if (sf != 0) {
            noStretchFactorsSet = false;
            break;
        }
    }

    int j=0;
    for (i = 0; i < n; ++i) {
        QSplitterLayoutStruct *s = list.at(i);
#ifdef QSPLITTER_DEBUG
        qDebug("widget %d hidden: %d collapsed: %d handle hidden: %d", i, s->widget->isHidden(),
               s->collapsed, s->handle->isHidden());
#endif

        a[j].init();
        if (s->handle->isHidden()) {
            a[j].maximumSize = 0;
        } else {
            a[j].sizeHint = a[j].minimumSize = a[j].maximumSize = s->getHandleSize(orient);
            a[j].empty = false;
        }
        ++j;

        a[j].init();
        if (s->widget->isHidden() || s->collapsed) {
            a[j].maximumSize = 0;
        } else {
            a[j].minimumSize = pick(qSmartMinSize(s->widget));
            a[j].maximumSize = pick(s->widget->maximumSize());
            a[j].empty = false;

            bool stretch = noStretchFactorsSet;
            if (!stretch) {
                QSizePolicy p = s->widget->sizePolicy();
                int sf = orient == Qt::Horizontal ? p.horizontalStretch() : p.verticalStretch();
                stretch = (sf != 0);
            }
            if (stretch) {
                a[j].stretch = s->getWidgetSize(orient);
                a[j].sizeHint = a[j].minimumSize;
                a[j].expansive = true;
            } else {
                a[j].sizeHint = s->getWidgetSize(orient);
            }
        }
        ++j;
    }

    qGeomCalc(a, 0, n*2, pick(r.topLeft()), pick(r.size()), 0);

#ifdef QSPLITTER_DEBUG
    for (i = 0; i < n*2; ++i) {
        qDebug("%*s%d: stretch %d, sh %d, minS %d, maxS %d, exp %d, emp %d -> %d, %d",
               i, "", i,
               a[i].stretch,
               a[i].sizeHint,
               a[i].minimumSize,
               a[i].maximumSize,
               a[i].expansive,
               a[i].empty,
               a[i].pos,
               a[i].size);
    }
#endif

    for (i = 0; i < n; ++i) {
        QSplitterLayoutStruct *s = list.at(i);
        setGeo(s, a[i*2+1].pos, a[i*2+1].size, false);
    }
}

void QSplitterPrivate::storeSizes()
{
    for (int i = 0; i < list.size(); ++i) {
        QSplitterLayoutStruct *sls = list.at(i);
        sls->sizer = pick(sls->rect.size());
    }
}

void QSplitterPrivate::addContribution(int index, int *min, int *max, bool mayCollapse) const
{
    QSplitterLayoutStruct *s = list.at(index);
    if (!s->widget->isHidden()) {
        if (!s->handle->isHidden()) {
            *min += s->getHandleSize(orient);
            *max += s->getHandleSize(orient);
        }
        if (mayCollapse || !s->collapsed)
            *min += pick(qSmartMinSize(s->widget));

        *max += pick(s->widget->maximumSize());
    }
}

int QSplitterPrivate::findWidgetJustBeforeOrJustAfter(int index, int delta, int &collapsibleSize) const
{
    if (delta < 0)
        index += delta;
    do {
        QWidget *w = list.at(index)->widget;
        if (!w->isHidden()) {
            if (collapsible(list.at(index)))
                collapsibleSize = pick(qSmartMinSize(w));
            return index;
        }
        index += delta;
    } while (index >= 0 && index < list.count());

    return -1;
}

/*
  For the splitter handle with index \a index, \a min and \a max give the range without collapsing any widgets,
  and \a farMin and farMax give the range with collapsing included.
*/
void QSplitterPrivate::getRange(int index, int *farMin, int *min, int *max, int *farMax) const
{
    Q_Q(const QSplitter);
    int n = list.count();
    if (index <= 0 || index >= n)
        return;

    int collapsibleSizeBefore = 0;
    int idJustBefore = findWidgetJustBeforeOrJustAfter(index, -1, collapsibleSizeBefore);

    int collapsibleSizeAfter = 0;
    int idJustAfter = findWidgetJustBeforeOrJustAfter(index, +1, collapsibleSizeAfter);

    int minBefore = 0;
    int minAfter = 0;
    int maxBefore = 0;
    int maxAfter = 0;
    int i;

    for (i = 0; i < index; ++i)
        addContribution(i, &minBefore, &maxBefore, i == idJustBefore);
    for (i = index; i < n; ++i)
        addContribution(i, &minAfter, &maxAfter, i == idJustAfter);

    QRect r = q->contentsRect();
    int farMinVal;
    int minVal;
    int maxVal;
    int farMaxVal;

    int smartMinBefore = qMax(minBefore, pick(r.size()) - maxAfter);
    int smartMaxBefore = qMin(maxBefore, pick(r.size()) - minAfter);

    minVal = pick(r.topLeft()) + smartMinBefore;
    maxVal = pick(r.topLeft()) + smartMaxBefore;

    farMinVal = minVal;
    if (minBefore - collapsibleSizeBefore >= pick(r.size()) - maxAfter)
        farMinVal -= collapsibleSizeBefore;
    farMaxVal = maxVal;
    if (pick(r.size()) - (minAfter - collapsibleSizeAfter) <= maxBefore)
        farMaxVal += collapsibleSizeAfter;

    if (farMin)
        *farMin = farMinVal;
    if (min)
        *min = minVal;
    if (max)
        *max = maxVal;
    if (farMax)
        *farMax = farMaxVal;
}

int QSplitterPrivate::adjustPos(int pos, int index, int *farMin, int *min, int *max, int *farMax) const
{
    const int Threshold = 40;

    getRange(index, farMin, min, max, farMax);

    if (pos >= *min) {
        if (pos <= *max) {
            return pos;
        } else {
            int delta = pos - *max;
            int width = *farMax - *max;

            if (delta > width / 2 && delta >= qMin(Threshold, width)) {
                return *farMax;
            } else {
                return *max;
            }
        }
    } else {
        int delta = *min - pos;
        int width = *min - *farMin;

        if (delta > width / 2 && delta >= qMin(Threshold, width)) {
            return *farMin;
        } else {
            return *min;
        }
    }
}

bool QSplitterPrivate::collapsible(QSplitterLayoutStruct *s) const
{
    if (s->collapsible != Default) {
        return (bool)s->collapsible;
    } else {
        return childrenCollapsible;
    }
}

void QSplitterPrivate::updateHandles()
{
    Q_Q(QSplitter);
    recalc(q->isVisible());
}

void QSplitterPrivate::setGeo(QSplitterLayoutStruct *sls, int p, int s, bool allowCollapse)
{
    Q_Q(QSplitter);
    QWidget *w = sls->widget;
    QRect r;
    QRect contents = q->contentsRect();
    if (orient == Qt::Horizontal) {
        r.setRect(p, contents.y(), s, contents.height());
    } else {
        r.setRect(contents.x(), p, contents.width(), s);
    }
    sls->rect = r;

    int minSize = pick(qSmartMinSize(w));

    if (orient == Qt::Horizontal && q->isRightToLeft())
        r.moveRight(contents.width() - r.left());

    if (allowCollapse)
        sls->collapsed = s <= 0 && minSize > 0 && !w->isHidden();

    //   Hide the child widget, but without calling hide() so that
    //   the splitter handle is still shown.
    if (sls->collapsed)
        r.moveTopLeft(QPoint(-r.width()-1, -r.height()-1));

    w->setGeometry(r);

    if (!sls->handle->isHidden()) {
        QSplitterHandle *h = sls->handle;
        QSize hs = h->sizeHint();
        if (orient==Qt::Horizontal) {
            if (q->isRightToLeft())
                p = contents.width() - p + hs.width();
            h->setGeometry(p-hs.width(), contents.y(), hs.width(), contents.height());
        } else {
            h->setGeometry(contents.x(), p-hs.height(), contents.width(), hs.height());
        }
    }
}

void QSplitterPrivate::doMove(bool backwards, int hPos, int index, int delta, bool mayCollapse,
                              int *positions, int *widths)
{
    if (index < 0 || index >= list.count())
        return;

#ifdef QSPLITTER_DEBUG
    qDebug() << "QSplitterPrivate::doMove" << backwards << hPos << index << delta << mayCollapse;
#endif

    QSplitterLayoutStruct *s = list.at(index);
    QWidget *w = s->widget;

    int nextId = backwards ? index - delta : index + delta;

    if (w->isHidden()) {
        doMove(backwards, hPos, nextId, delta, collapsible(nextId), positions, widths);
    } else {
        int hs =s->handle->isHidden() ? 0 : s->getHandleSize(orient);

        int  ws = backwards ? hPos - pick(s->rect.topLeft())
                 : pick(s->rect.bottomRight()) - hPos -hs + 1;
        if (ws > 0 || (!s->collapsed && !mayCollapse)) {
            ws = qMin(ws, pick(w->maximumSize()));
            ws = qMax(ws, pick(qSmartMinSize(w)));
        } else {
            ws = 0;
        }
        positions[index] = backwards ? hPos - ws : hPos + hs;
        widths[index] = ws;
        doMove(backwards, backwards ? hPos - ws - hs : hPos + hs + ws, nextId, delta,
               collapsible(nextId), positions, widths);
    }

}

QSplitterLayoutStruct *QSplitterPrivate::findWidget(QWidget *w) const
{
    for (int i = 0; i < list.size(); ++i) {
        if (list.at(i)->widget == w)
            return list.at(i);
    }
    return 0;
}

#ifdef QT3_SUPPORT
static void setStretch(QWidget *w, int sf)
{
    QSizePolicy sp = w->sizePolicy();
    sp.setHorizontalStretch(sf);
    sp.setVerticalStretch(sf);
    w->setSizePolicy(sp);
}

static int getStretch(const QWidget *w)
{
    QSizePolicy sp = w->sizePolicy();
    return qMax(sp.horizontalStretch(), sp.verticalStretch());
}

void QSplitter::setResizeMode(QWidget *w, ResizeMode mode)
{
    /*
        Internal comment:

        This function tries to simulate the Qt 3.x ResizeMode
        behavior using QSizePolicy stretch factors. This isn't easy,
        because the default \l ResizeMode was \l Stretch, not \l
        KeepSize, whereas the default stetch factor is 0.

        So what we do is this: When the user calls setResizeMode()
        the first time, we iterate through all the child widgets and
        set their stretch factors to 1. Later on, if children are
        added (using addWidget()), their stretch factors are also set
        to 1.

        There is just one problem left: Often, setResizeMode() is
        called \e{before} addWidget(), because addWidget() is called
        from the event loop. In that case, we use a special value,
        243, instead of 0 to prevent 0 from being overwritten with 1
        in addWidget(). This is a wicked hack, but fortunately it
        only occurs as a result of calling a \c QT3_SUPPORT function.
    */

    Q_D(QSplitter);
    bool metWidget = false;
    if (!d->compatMode) {
        d->compatMode = true;
        for (int i = 0; i < d->list.size(); ++i) {
            QSplitterLayoutStruct *s = d->list.at(i);
            if (s->widget == w)
                metWidget = true;
            if (getStretch(s->widget) == 0)
                setStretch(s->widget, 1);
        }
    }
    int sf;
    if (mode == KeepSize)
        sf = metWidget ? 0 : 243;
    else
        sf = 1;
    setStretch(w, sf);
}

QSplitter::QSplitter(QWidget *parent, const char *name)
    : QFrame(*new QSplitterPrivate, parent)
{
    Q_D(QSplitter);
    setObjectName(QString::fromAscii(name));
    d->orient = Qt::Horizontal;
    d->init();
}


QSplitter::QSplitter(Qt::Orientation orientation, QWidget *parent, const char *name)
    : QFrame(*new QSplitterPrivate, parent)
{
    Q_D(QSplitter);
    setObjectName(QString::fromAscii(name));
    d->orient = orientation;
    d->init();
}
#endif

/*
    Inserts the widget \a w at position \a index in the splitter's list of widgets.

    If \a w is already in the splitter, it will be moved to the new position.
*/

QSplitterLayoutStruct *QSplitterPrivate::insertWidget(int index, QWidget *w)
{
    Q_Q(QSplitter);
    QSplitterLayoutStruct *sls = 0;
    int i;
    int last = list.count();
    for (i = 0; i < list.size(); ++i) {
        QSplitterLayoutStruct *s = list.at(i);
        if (s->widget == w) {
            sls = s;
            --last;
            break;
        }
    }
    if (index < 0 || index > last)
        index = last;

    if (sls) {
        list.move(i,index);
    } else {
        QSplitterHandle *newHandle = 0;
        sls = new QSplitterLayoutStruct;
        QString tmp = QLatin1String("qt_splithandle_");
        tmp += w->objectName();
        newHandle = q->createHandle();
        newHandle->setObjectName(tmp);
        sls->handle = newHandle;
        sls->widget = w;
        list.insert(index,sls);

        if (newHandle && q->isVisible())
            newHandle->show(); // will trigger sending of post events

#ifdef QT3_SUPPORT
        if (compatMode) {
            int sf = getStretch(sls->widget);
            if (sf == 243)
                setStretch(sls->widget, 0);
            else if (sf == 0)
                setStretch(sls->widget, 1);
        }
#endif
    }
    return sls;
}

QSplitter::QSplitter(QWidget *parent)
    : QFrame(*new QSplitterPrivate, parent)
{
    Q_D(QSplitter);
    d->orient = Qt::Horizontal;
    d->init();
}


QSplitter::QSplitter(Qt::Orientation orientation, QWidget *parent)
    : QFrame(*new QSplitterPrivate, parent)
{
    Q_D(QSplitter);
    d->orient = orientation;
    d->init();
}


QSplitter::~QSplitter()
{
    Q_D(QSplitter);
    while (!d->list.isEmpty())
        delete d->list.takeFirst();
}

void QSplitter::refresh()
{
    Q_D(QSplitter);
    d->recalc(true);
}

void QSplitter::setOrientation(Qt::Orientation orientation)
{
    Q_D(QSplitter);
    if (d->orient == orientation)
        return;

    if (!testAttribute(Qt::WA_WState_OwnSizePolicy)) {
        QSizePolicy sp = sizePolicy();
        sp.transpose();
        setSizePolicy(sp);
        setAttribute(Qt::WA_WState_OwnSizePolicy, false);
    }

    d->orient = orientation;

    for (int i = 0; i < d->list.size(); ++i) {
        QSplitterLayoutStruct *s = d->list.at(i);
        s->handle->setOrientation(orientation);
    }
    d->recalc(isVisible());
}

Qt::Orientation QSplitter::orientation() const
{
    Q_D(const QSplitter);
    return d->orient;
}

void QSplitter::setChildrenCollapsible(bool collapse)
{
    Q_D(QSplitter);
    d->childrenCollapsible = collapse;
}

bool QSplitter::childrenCollapsible() const
{
    Q_D(const QSplitter);
    return d->childrenCollapsible;
}

void QSplitter::setCollapsible(int index, bool collapse)
{
    Q_D(QSplitter);

    if (index < 0 || index >= d->list.size()) {
        qWarning("QSplitter::setCollapsible: Index %d out of range", index);
        return;
    }
    d->list.at(index)->collapsible = collapse ? 1 : 0;
}

bool QSplitter::isCollapsible(int index) const
{
    Q_D(const QSplitter);
    if (index < 0 || index >= d->list.size()) {
        qWarning("QSplitter::isCollapsible: Index %d out of range", index);
        return false;
    }
    return d->list.at(index)->collapsible;
}

void QSplitter::resizeEvent(QResizeEvent *)
{
    Q_D(QSplitter);
    d->doResize();
}

void QSplitter::addWidget(QWidget *widget)
{
    Q_D(QSplitter);
    insertWidget(d->list.count(), widget);
}

void QSplitter::insertWidget(int index, QWidget *widget)
{
    Q_D(QSplitter);
    QBoolBlocker b(d->blockChildAdd);
    bool needShow = isVisible() &&
                    !(widget->isHidden() && widget->testAttribute(Qt::WA_WState_ExplicitShowHide));
    if (widget->parentWidget() != this)
        widget->setParent(this);
    if (needShow)
        widget->show();
    d->insertWidget(index, widget);
    d->recalc(isVisible());
}

int QSplitter::indexOf(QWidget *w) const
{
    Q_D(const QSplitter);
    for (int i = 0; i < d->list.size(); ++i) {
        QSplitterLayoutStruct *s = d->list.at(i);
        if (s->widget == w || s->handle == w)
            return i;
    }
    return -1;
}

QSplitterHandle *QSplitter::createHandle()
{
    Q_D(QSplitter);
    return new QSplitterHandle(d->orient, this);
}

QSplitterHandle *QSplitter::handle(int index) const
{
    Q_D(const QSplitter);
    if (index < 0 || index >= d->list.size())
        return 0;
    return d->list.at(index)->handle;
}

QWidget *QSplitter::widget(int index) const
{
    Q_D(const QSplitter);
    if (index < 0 || index >= d->list.size())
        return 0;
    return d->list.at(index)->widget;
}

int QSplitter::count() const
{
    Q_D(const QSplitter);
    return d->list.count();
}

void QSplitter::childEvent(QChildEvent *c)
{
    Q_D(QSplitter);
    if (!c->child()->isWidgetType())
        return;
    QWidget *w = static_cast<QWidget*>(c->child());

    if (c->added() && !d->blockChildAdd && !w->isWindow() && !d->findWidget(w)) {
        addWidget(w);
    } else  if (c->type() == QEvent::ChildRemoved) {
        for (int i = 0; i < d->list.size(); ++i) {
            QSplitterLayoutStruct *s = d->list.at(i);
            if (s->widget == w) {
                d->list.removeAt(i);
                delete s;
                d->recalc(isVisible());
                return;
            }
        }
    }
}


void QSplitter::setRubberBand(int pos)
{
    Q_D(QSplitter);
    if (pos < 0) {
        if (d->rubberBand)
            d->rubberBand->hide();
        return;
    }
    QRect r = contentsRect();
    const int rBord = 3; // customizable?
    int hw = handleWidth();
    if (!d->rubberBand) {
        QBoolBlocker block(d->blockChildAdd);
        d->rubberBand = new QRubberBand(QRubberBand::Line, this);
    }
    if (d->orient == Qt::Horizontal)
        d->rubberBand->setGeometry(QRect(QPoint(pos + hw / 2 - rBord, r.y()),
                                         QSize(2 * rBord, r.height())));
    else
        d->rubberBand->setGeometry(QRect(QPoint(r.x(), pos + hw / 2 - rBord),
                                   QSize(r.width(), 2 * rBord)));
    if (!d->rubberBand->isVisible())
        d->rubberBand->show();
}

bool QSplitter::event(QEvent *e)
{
    Q_D(QSplitter);
    switch (e->type()) {
    case QEvent::Hide:
        // Reset firstShow to false here since things can be done to the splitter in between
        if (!d->firstShow)
            d->firstShow = true;
        break;
    case QEvent::Show:
        if (!d->firstShow)
            break;
        d->firstShow = false;
        // fall through
    case QEvent::HideToParent:
    case QEvent::ShowToParent:
    case QEvent::LayoutRequest:
#ifdef QT3_SUPPORT
    case QEvent::LayoutHint:
#endif
        d->recalc(isVisible());
        break;
    default:
        ;
    }
    return QWidget::event(e);
}

void QSplitter::moveSplitter(int pos, int index)
{
    Q_D(QSplitter);
    QSplitterLayoutStruct *s = d->list.at(index);
    int farMin;
    int min;
    int max;
    int farMax;

#ifdef QSPLITTER_DEBUG
    int debugp = pos;
#endif

    pos = d->adjustPos(pos, index, &farMin, &min, &max, &farMax);
    int oldP = d->pick(s->rect.topLeft());
#ifdef QSPLITTER_DEBUG
    qDebug() << "QSplitter::moveSplitter" << debugp << index << "adjusted" << pos << "oldP" << oldP;
#endif

    QVarLengthArray<int, 32> poss(d->list.count());
    QVarLengthArray<int, 32> ws(d->list.count());
    bool upLeft;

    d->doMove(false, pos, index, +1, (d->collapsible(s) && (pos > max)), poss.data(), ws.data());
    d->doMove(true, pos, index - 1, +1, (d->collapsible(index - 1) && (pos < min)), poss.data(), ws.data());
    upLeft = (pos < oldP);

    int wid, delta, count = d->list.count();
    if (upLeft) {
        wid = 0;
        delta = 1;
    } else {
        wid = count - 1;
        delta = -1;
    }
    for (; wid >= 0 && wid < count; wid += delta) {
        QSplitterLayoutStruct *sls = d->list.at( wid );
        if (!sls->widget->isHidden())
            d->setGeo(sls, poss[wid], ws[wid], true);
    }
    d->storeSizes();

    emit splitterMoved(pos, index);
}


void QSplitter::getRange(int index, int *min, int *max) const
{
    Q_D(const QSplitter);
    d->getRange(index, min, 0, 0, max);
}


int QSplitter::closestLegalPosition(int pos, int index)
{
    Q_D(QSplitter);
    int x, i, n, u;
    return d->adjustPos(pos, index, &u, &n, &i, &x);
}

bool QSplitter::opaqueResize() const
{
    Q_D(const QSplitter);
    return d->opaque;
}


void QSplitter::setOpaqueResize(bool on)
{
    Q_D(QSplitter);
    d->opaque = on;
}

#ifdef QT3_SUPPORT

#endif

QSize QSplitter::sizeHint() const
{
    Q_D(const QSplitter);
    ensurePolished();
    int l = 0;
    int t = 0;
    QObjectList childList = children();
    for (int i = 0; i < childList.size(); ++i) {
        if (QWidget *w = qobject_cast<QWidget *>(childList.at(i))) {
            if (w->isHidden())
                continue;
            QSize s = w->sizeHint();
            if (s.isValid()) {
                l += d->pick(s);
                t = qMax(t, d->trans(s));
            }
        }
    }
    return orientation() == Qt::Horizontal ? QSize(l, t) : QSize(t, l);
}


QSize QSplitter::minimumSizeHint() const
{
    Q_D(const QSplitter);
    ensurePolished();
    int l = 0;
    int t = 0;
    QObjectList childList = children();
    for (int i = 0; i < childList.size(); ++i) {
        if (QWidget *w = qobject_cast<QWidget *>(childList.at(i))) {
            if (w->isHidden())
                continue;
            QSize s = qSmartMinSize(w);
            if (s.isValid()) {
                l += d->pick(s);
                t = qMax(t, d->trans(s));
            }
        }
    }
    return orientation() == Qt::Horizontal ? QSize(l, t) : QSize(t, l);
}


QList<int> QSplitter::sizes() const
{
    Q_D(const QSplitter);
    ensurePolished();

    QList<int> list;
    for (int i = 0; i < d->list.size(); ++i) {
        QSplitterLayoutStruct *s = d->list.at(i);
        list.append(d->pick(s->rect.size()));
    }
    return list;
}

void QSplitter::setSizes(const QList<int> &list)
{
    Q_D(QSplitter);
    int j = 0;

    for (int i = 0; i < d->list.size(); ++i) {
        QSplitterLayoutStruct *s = d->list.at(i);

        s->collapsed = false;
        s->sizer = qMax(list.value(j++), 0);
        int smartMinSize = d->pick(qSmartMinSize(s->widget));

        // Make sure that we reset the collapsed state.
        if (s->sizer == 0) {
            if (d->collapsible(s) && smartMinSize > 0) {
                s->collapsed = true;
            } else {
                s->sizer = smartMinSize;
            }
        } else {
            if (s->sizer < smartMinSize)
                s->sizer = smartMinSize;
        }
    }
    d->doResize();
}

int QSplitter::handleWidth() const
{
    Q_D(const QSplitter);
    if (d->handleWidth > 0) {
        return d->handleWidth;
    } else {
        return style()->pixelMetric(QStyle::PM_SplitterWidth, 0, this);
    }
}

void QSplitter::setHandleWidth(int width)
{
    Q_D(QSplitter);
    d->handleWidth = width;
    d->updateHandles();
}

void QSplitter::changeEvent(QEvent *ev)
{
    Q_D(QSplitter);
    if(ev->type() == QEvent::StyleChange)
        d->updateHandles();
    QFrame::changeEvent(ev);
}

static const qint32 SplitterMagic = 0xff;

QByteArray QSplitter::saveState() const
{
    int version = 0;
    QByteArray data;
    QDataStream stream(&data, QIODevice::WriteOnly);

    stream << qint32(SplitterMagic);
    stream << qint32(version);
    stream << sizes();
    stream << childrenCollapsible();
    stream << qint32(handleWidth());
    stream << opaqueResize();
    stream << qint32(orientation());
    return data;
}

bool QSplitter::restoreState(const QByteArray &state)
{
    Q_D(QSplitter);
    int version = 0;
    QByteArray sd = state;
    QDataStream stream(&sd, QIODevice::ReadOnly);
    QList<int> list;
    bool b;
    qint32 i;
    qint32 marker;
    qint32 v;

    stream >> marker;
    stream >> v;
    if (marker != SplitterMagic || v != version)
        return false;

    stream >> list;
    setSizes(list);

    stream >> b;
    setChildrenCollapsible(b);

    stream >> i;
    setHandleWidth(i);

    stream >> b;
    setOpaqueResize(b);

    stream >> i;
    setOrientation(Qt::Orientation(i));
    d->doResize();

    return true;
}

void QSplitter::setStretchFactor(int index, int stretch)
{
    Q_D(QSplitter);
    if (index <= -1 || index >= d->list.count())
        return;

    QWidget *widget = d->list.at(index)->widget;
    QSizePolicy sp = widget->sizePolicy();
    sp.setHorizontalStretch(stretch);
    sp.setVerticalStretch(stretch);
    widget->setSizePolicy(sp);
}


//#ifdef QT3_SUPPORT
#ifndef QT_NO_TEXTSTREAM

QTextStream& operator<<(QTextStream& ts, const QSplitter& splitter)
{
    ts << splitter.saveState() << endl;
    return ts;
}

QTextStream& operator>>(QTextStream& ts, QSplitter& splitter)
{
    QString line = ts.readLine();
    line = line.simplified();
    line.replace(QLatin1Char(' '), QString());
    line = line.toUpper();

    splitter.restoreState(line.toAscii());
    return ts;
}
#endif // QT_NO_TEXTSTREAM
//#endif // QT3_SUPPORT

#endif // QT_NO_SPLITTER

---