qsplitter.cpp

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// Copyright (C) 2016 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
 
#include "qsplitter.h"
 
#include "qapplication.h"
#include "qcursor.h"
#include "qdrawutil.h"
#include "qevent.h"
#include "qlayout.h"
#include "qlist.h"
#include "qpainter.h"
#if QT_CONFIG(rubberband)
#include "qrubberband.h"
#endif
#include "qstyle.h"
#include "qstyleoption.h"
#include "qtextstream.h"
#include "qvarlengtharray.h"
#include "private/qlayoutengine_p.h"
#include "private/qsplitter_p.h"
#include "qtimer.h"
#include "qdebug.h"
 
#include <ctype.h>
 
QT_BEGIN_NAMESPACE
 
using namespace Qt::StringLiterals;
 
//#define QSPLITTER_DEBUG
 
QSplitterPrivate::~QSplitterPrivate()
{
}
 
QSplitterHandle::QSplitterHandle(Qt::Orientation orientation, QSplitter *parent)
    : QWidget(*new QSplitterHandlePrivate, parent, { })
{
    Q_D(QSplitterHandle);
    d->s = parent;
    setOrientation(orientation);
}
 
QSplitterHandle::~QSplitterHandle()
{
}
 
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.initFrom(d->s);
    opt.state = QStyle::State_None;
    return parentWidget()->style()->sizeFromContents(QStyle::CT_Splitter, &opt, QSize(hw, hw), d->s);
}
 
void QSplitterHandle::resizeEvent(QResizeEvent *event)
{
    Q_D(const QSplitterHandle);
 
    // Ensure the actual grab area is at least 4 or 5 pixels
    const int handleMargin = (5 - d->s->handleWidth()) / 2;
 
    // Note that QSplitter uses contentsRect for layouting
    // and ensures that handles are drawn on top of widgets
    // We simply use the contents margins for draggin and only
    // paint the mask area
    const bool useTinyMode = handleMargin > 0;
    setAttribute(Qt::WA_MouseNoMask, useTinyMode);
    if (useTinyMode) {
        if (orientation() == Qt::Horizontal)
            setContentsMargins(handleMargin, 0, handleMargin, 0);
        else
            setContentsMargins(0, handleMargin, 0, handleMargin);
        setMask(QRegion(contentsRect()));
    } else {
        setContentsMargins(0, 0, 0, 0);
        clearMask();
    }
 
    QWidget::resizeEvent(event);
}
 
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 (!d->pressed)
        return;
 
    const int pos = d->pick(parentWidget()->mapFromGlobal(e->globalPosition().toPoint()))
                    - 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->position().toPoint());
        d->pressed = true;
        update();
    }
}
 
void QSplitterHandle::mouseReleaseEvent(QMouseEvent *e)
{
    Q_D(QSplitterHandle);
    if (!d->pressed)
        return;
 
    if (!opaqueResize()) {
        const int pos = d->pick(parentWidget()->mapFromGlobal(e->globalPosition().toPoint()))
                        - d->mouseOffset;
        d->s->setRubberBand(-1);
        moveSplitter(pos);
    }
 
    d->pressed = false;
    update();
}
 
void QSplitterHandle::paintEvent(QPaintEvent *)
{
    Q_D(QSplitterHandle);
    QPainter p(this);
    QStyleOption opt(0);
    opt.rect = contentsRect();
    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 (d->pressed)
        opt.state |= QStyle::State_Sunken;
    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.size();
    /*
      Splitter handles before the first visible widget or right
      before a hidden widget must be hidden.
    */
    bool first = true;
    bool allInvisible = n != 0;
    for (int i = 0; i < n ; ++i) {
        QSplitterLayoutStruct *s = list.at(i);
        bool widgetHidden = s->widget->isHidden();
        if (allInvisible && !widgetHidden && !s->collapsed)
            allInvisible = false;
        s->handle->setHidden(first || widgetHidden);
        if (!widgetHidden)
            first = false;
    }
 
    if (allInvisible)
        for (int i = 0; i < n ; ++i) {
            QSplitterLayoutStruct *s = list.at(i);
            if (!s->widget->isHidden()) {
                s->collapsed = false;
                break;
            }
        }
 
    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(qSmartMaxSize(s->widget));
            mint = qMax(mint, trans(minS));
            int tm = trans(qSmartMaxSize(s->widget));
            if (tm > 0)
                maxt = qMin(maxt, tm);
        }
    }
 
    if (empty) {
        if (qobject_cast<QSplitter *>(parent)) {
            // 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.size();
    QList<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(qSmartMaxSize(s->widget));
            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 = qMax(s->getWidgetSize(orient), a[j].minimumSize);
            }
        }
        ++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(qSmartMaxSize(s->widget));
    }
}
 
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.size());
 
    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.size();
    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::setSizes_helper(const QList<int> &sizes, bool clampNegativeSize)
{
    int j = 0;
 
    for (int i = 0; i < list.size(); ++i) {
        QSplitterLayoutStruct *s = list.at(i);
 
        s->collapsed = false;
        s->sizer = sizes.value(j++);
        if (clampNegativeSize && s->sizer < 0)
            s->sizer = 0;
        int smartMinSize = pick(qSmartMinSize(s->widget));
 
        // Make sure that we reset the collapsed state.
        if (s->sizer == 0) {
            if (collapsible(s) && smartMinSize > 0) {
                s->collapsed = true;
            } else {
                s->sizer = smartMinSize;
            }
        } else {
            if (s->sizer < smartMinSize)
                s->sizer = smartMinSize;
        }
    }
    doResize();
}
 
/*
    Used by various methods inserting a widget to find out if we need to show the widget
    explicitly, which we have to if the splitter is already visible, and if the widget hasn't
    been explicitly hidden before inserting it.
*/
bool QSplitterPrivate::shouldShowWidget(const QWidget *w) const
{
    Q_Q(const QSplitter);
    return q->isVisible() && !(w->isHidden() && w->testAttribute(Qt::WA_WState_ExplicitShowHide));
}
 
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();
        const QMargins m = h->contentsMargins();
        if (orient==Qt::Horizontal) {
            if (q->isRightToLeft())
                p = contents.width() - p + hs.width();
            h->setGeometry(p-hs.width() - m.left(), contents.y(), hs.width() + m.left() + m.right(), contents.height());
        } else {
            h->setGeometry(contents.x(), p-hs.height() - m.top(), contents.width(), hs.height() + m.top() + m.bottom());
        }
    }
}
 
void QSplitterPrivate::doMove(bool backwards, int hPos, int index, int delta, bool mayCollapse,
                              int *positions, int *widths)
{
    if (index < 0 || index >= list.size())
        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(qSmartMaxSize(w)));
            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 nullptr;
}
 
 
void QSplitterPrivate::insertWidget_helper(int index, QWidget *widget, bool show)
{
    Q_Q(QSplitter);
    QBoolBlocker b(blockChildAdd);
    const bool needShow = show && shouldShowWidget(widget);
    if (widget->parentWidget() != q)
        widget->setParent(q);
    if (needShow)
        widget->show();
    insertWidget(index, widget);
    recalc(q->isVisible());
}
 
/*
    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 = nullptr;
    int i;
    int last = list.size();
    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 {
        sls = new QSplitterLayoutStruct;
        QSplitterHandle *newHandle = q->createHandle();
        newHandle->setObjectName("qt_splithandle_"_L1 + w->objectName());
        sls->handle = newHandle;
        sls->widget = w;
        w->lower();
        list.insert(index,sls);
 
        if (newHandle && q->isVisible())
            newHandle->show(); // will trigger sending of post events
 
    }
    return sls;
}
 
QSplitter::QSplitter(QWidget *parent)
    : QSplitter(Qt::Horizontal, parent)
{
}
 
 
QSplitter::QSplitter(Qt::Orientation orientation, QWidget *parent)
    : QFrame(*new QSplitterPrivate, parent)
{
    Q_D(QSplitter);
    d->orient = orientation;
    d->init();
}
 
 
QSplitter::~QSplitter()
{
    Q_D(QSplitter);
#if QT_CONFIG(rubberband)
    delete d->rubberBand;
#endif
    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)) {
        setSizePolicy(sizePolicy().transposed());
        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 (Q_UNLIKELY(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 (Q_UNLIKELY(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.size(), widget);
}
 
void QSplitter::insertWidget(int index, QWidget *widget)
{
    Q_D(QSplitter);
    d->insertWidget_helper(index, widget, true);
}
 
QWidget *QSplitter::replaceWidget(int index, QWidget *widget)
{
    Q_D(QSplitter);
    if (!widget) {
        qWarning("QSplitter::replaceWidget: Widget can't be null");
        return nullptr;
    }
 
    if (index < 0 || index >= d->list.size()) {
        qWarning("QSplitter::replaceWidget: Index %d out of range", index);
        return nullptr;
    }
 
    QSplitterLayoutStruct *s = d->list.at(index);
    QWidget *current = s->widget;
    if (current == widget) {
        qWarning("QSplitter::replaceWidget: Trying to replace a widget with itself");
        return nullptr;
    }
 
    if (widget->parentWidget() == this) {
        qWarning("QSplitter::replaceWidget: Trying to replace a widget with one of its siblings");
        return nullptr;
    }
 
    QBoolBlocker b(d->blockChildAdd);
 
    const QRect geom = current->geometry();
    const bool wasHidden = current->isHidden();
 
    s->widget = widget;
    current->setParent(nullptr);
    widget->setParent(this);
 
    // The splitter layout struct's geometry is already set and
    // should not change. Only set the geometry on the new widget
    widget->setGeometry(geom);
    widget->lower();
    if (wasHidden)
        widget->hide();
    else if (d->shouldShowWidget(widget))
        widget->show();
 
    return current;
}
 
int QSplitter::indexOf(QWidget *widget) const
{
    Q_D(const QSplitter);
    for (int i = 0; i < d->list.size(); ++i) {
        QSplitterLayoutStruct *s = d->list.at(i);
        if (s->widget == widget || s->handle == widget)
            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 nullptr;
    return d->list.at(index)->handle;
}
 
QWidget *QSplitter::widget(int index) const
{
    Q_D(const QSplitter);
    if (index < 0 || index >= d->list.size())
        return nullptr;
    return d->list.at(index)->widget;
}
 
int QSplitter::count() const
{
    Q_D(const QSplitter);
    return d->list.size();
}
 
void QSplitter::childEvent(QChildEvent *c)
{
    Q_D(QSplitter);
    if (c->added()) {
        if (!c->child()->isWidgetType()) {
            if (Q_UNLIKELY(qobject_cast<QLayout *>(c->child())))
                qWarning("Adding a QLayout to a QSplitter is not supported.");
            return;
        }
        QWidget *w = static_cast<QWidget*>(c->child());
        if (!d->blockChildAdd && !w->isWindow() && !d->findWidget(w))
            d->insertWidget_helper(d->list.size(), w, false);
    } else if (c->polished()) {
        if (!c->child()->isWidgetType())
            return;
        QWidget *w = static_cast<QWidget*>(c->child());
        if (!d->blockChildAdd && !w->isWindow() && d->shouldShowWidget(w))
            w->show();
    } else if (c->removed()) {
        QObject *child = c->child();
        for (int i = 0; i < d->list.size(); ++i) {
            QSplitterLayoutStruct *s = d->list.at(i);
            if (s->widget == child) {
                d->list.removeAt(i);
                delete s;
                d->recalc(isVisible());
                return;
            }
        }
    }
}
 
 
void QSplitter::setRubberBand(int pos)
{
#if QT_CONFIG(rubberband)
    Q_D(QSplitter);
    if (pos < 0) {
        if (d->rubberBand)
            d->rubberBand->deleteLater();
        return;
    }
    QRect r = contentsRect();
    const int rBord = 3; // customizable?
    int hw = handleWidth();
    if (!d->rubberBand) {
        QBoolBlocker b(d->blockChildAdd);
        d->rubberBand = new QRubberBand(QRubberBand::Line, this);
        // For accessibility to identify this special widget.
        d->rubberBand->setObjectName("qt_rubberband"_L1);
    }
 
    const QRect newGeom = d->orient == Qt::Horizontal ? QRect(QPoint(pos + hw / 2 - rBord, r.y()), QSize(2 * rBord, r.height()))
                                                      : QRect(QPoint(r.x(), pos + hw / 2 - rBord), QSize(r.width(), 2 * rBord));
    d->rubberBand->setGeometry(newGeom);
    d->rubberBand->show();
#else
    Q_UNUSED(pos);
#endif
}
 
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;
        Q_FALLTHROUGH();
    case QEvent::HideToParent:
    case QEvent::ShowToParent:
    case QEvent::LayoutRequest:
        d->recalc(isVisible());
        break;
    default:
        ;
    }
    return QFrame::event(e);
}
 
void QSplitter::moveSplitter(int pos, int index)
{
    Q_D(QSplitter);
    QSplitterLayoutStruct *s = d->list.at(index);
    int farMin = 0;
    int min = 0;
    int max = 0;
    int farMax = 0;
 
#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.size());
    QVarLengthArray<int, 32> ws(d->list.size());
    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.size();
    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, nullptr, nullptr, max);
}
 
 
int QSplitter::closestLegalPosition(int pos, int index)
{
    Q_D(QSplitter);
    int x = 0;
    int i = 0;
    int n = 0;
    int u = 0;
    return d->adjustPos(pos, index, &u, &n, &i, &x);
}
 
bool QSplitter::opaqueResize() const
{
    Q_D(const QSplitter);
    return d->opaqueResizeSet ? d->opaque : style()->styleHint(QStyle::SH_Splitter_OpaqueResize, nullptr, this);
}
 
 
void QSplitter::setOpaqueResize(bool on)
{
    Q_D(QSplitter);
    d->opaqueResizeSet = true;
    d->opaque = on;
}
 
 
QSize QSplitter::sizeHint() const
{
    Q_D(const QSplitter);
    ensurePolished();
    int l = 0;
    int t = 0;
    for (int i = 0; i < d->list.size(); ++i) {
        QWidget *w = d->list.at(i)->widget;
        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;
 
    for (int i = 0; i < d->list.size(); ++i) {
        QSplitterLayoutStruct *s = d->list.at(i);
        if (!s || !s->widget)
            continue;
        if (s->widget->isHidden())
            continue;
        QSize widgetSize = qSmartMinSize(s->widget);
        if (widgetSize.isValid()) {
            l += d->pick(widgetSize);
            t = qMax(t, d->trans(widgetSize));
        }
        if (!s->handle || s->handle->isHidden())
            continue;
        QSize splitterSize = s->handle->sizeHint();
        if (splitterSize.isValid()) {
            l += d->pick(splitterSize);
            t = qMax(t, d->trans(splitterSize));
        }
    }
    return orientation() == Qt::Horizontal ? QSize(l, t) : QSize(t, l);
}
 
 
QList<int> QSplitter::sizes() const
{
    Q_D(const QSplitter);
    ensurePolished();
 
    const int numSizes = d->list.size();
    QList<int> list;
    list.reserve(numSizes);
 
    for (int i = 0; i < numSizes; ++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);
    d->setSizes_helper(list, true);
}
 
int QSplitter::handleWidth() const
{
    Q_D(const QSplitter);
    if (d->handleWidth >= 0) {
        return d->handleWidth;
    } else {
        return style()->pixelMetric(QStyle::PM_SplitterWidth, nullptr, 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
{
    Q_D(const QSplitter);
    int version = 1;
    QByteArray data;
    QDataStream stream(&data, QIODevice::WriteOnly);
    stream.setVersion(QDataStream::Qt_5_0);
 
    stream << qint32(SplitterMagic);
    stream << qint32(version);
    const int numSizes = d->list.size();
    QList<int> list;
    list.reserve(numSizes);
    for (int i = 0; i < numSizes; ++i) {
        QSplitterLayoutStruct *s = d->list.at(i);
        list.append(s->sizer);
    }
    stream << list;
    stream << childrenCollapsible();
    stream << qint32(d->handleWidth);
    stream << opaqueResize();
    stream << qint32(orientation());
    stream << d->opaqueResizeSet;
    return data;
}
 
bool QSplitter::restoreState(const QByteArray &state)
{
    Q_D(QSplitter);
    int version = 1;
    QByteArray sd = state;
    QDataStream stream(&sd, QIODevice::ReadOnly);
    stream.setVersion(QDataStream::Qt_5_0);
    QList<int> list;
    bool b;
    qint32 i;
    qint32 marker;
    qint32 v;
 
    stream >> marker;
    stream >> v;
    if (marker != SplitterMagic || v > version)
        return false;
 
    stream >> list;
    d->setSizes_helper(list, false);
 
    stream >> b;
    setChildrenCollapsible(b);
 
    stream >> i;
    setHandleWidth(i);
 
    stream >> b;
    setOpaqueResize(b);
 
    stream >> i;
    setOrientation(Qt::Orientation(i));
    d->doResize();
 
    if (v >= 1)
        stream >> d->opaqueResizeSet;
 
    return true;
}
 
void QSplitter::setStretchFactor(int index, int stretch)
{
    Q_D(QSplitter);
    if (index <= -1 || index >= d->list.size())
        return;
 
    QWidget *widget = d->list.at(index)->widget;
    QSizePolicy sp = widget->sizePolicy();
    sp.setHorizontalStretch(stretch);
    sp.setVerticalStretch(stretch);
    widget->setSizePolicy(sp);
}
 
QT_END_NAMESPACE
 
#include "moc_qsplitter.cpp"