qsplitter.cpp

qt-x11-opensource-src-4.1.4.tar.gz源码

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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.
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#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

static int mouseOffset;

/*!
    \class QSplitterHandle
    \brief The QSplitterHandle class provides handle functionality of the splitter.

    \ingroup organizers

    QSplitterHandle is typically what people think about when they think about
    a splitter. It is the handle that is used to resize the widgets.

    A typical developer using QSplitter will never have to worry about QSplitterHandle.
    It is provided for developers who want splitter handles that do more. The typical
    way one would create splitter handles is to subclass QSplitter and then
    reimplement QSplitter::createHandle() to instatiate the custom splitter
    handle.

    Most of the functions inside QSplitterHandle are forwards to QSplitter or
    like orientation() and opaqueResize(), controlled by the QSplitter.

    \sa QSplitter
*/

/*!
    Creates a QSplitter handle with the given \a orientation and
    QSplitter \a parent.
*/
QSplitterHandle::QSplitterHandle(Qt::Orientation orientation, QSplitter *parent)
    : QWidget(*new QSplitterHandlePrivate, parent, 0)
{
    Q_D(QSplitterHandle);
    d->s = parent;
    d->hover = false;
    setOrientation(orientation);
}

/*!
    Sets the orientation of the splitter handle to \a orientation.
    This is usually propogated from the QSplitter.

    \sa QSplitter::setOrientation()
*/
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
}

/*!
   Returns the handle's orientation. This is usually propagated from the QSplitter.

   \sa QSplitter::orientation()
*/
Qt::Orientation QSplitterHandle::orientation() const
{
    Q_D(const QSplitterHandle);
    return d->orient;
}


/*!
    Returns true if widgets are resized dynamically (opaquely), otherwise
    returns false. This value is controlled by the QSplitter.

    \sa QSplitter::opaqueResize()

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


/*!
    Returns the splitter associated with this splitter handle.

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

/*!
    Tells the splitter to move this handle to position \a pos, which is
    the distance from the left or top edge of the widget.

    Note that \a pos is also measured from the left (or top) for
    right-to-left languages. This function will map \a pos to the
    appropriate position before calling QSplitter::moveSplitter().

    \sa QSplitter::moveSplitter() closestLegalPosition()
*/
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));
}

/*!
   Returns the closest legal position to \a pos of the splitter
   handle. The positions are measured from the left or top edge of
   the splitter, even for right-to-left languages.

   \sa QSplitter::closestLegalPosition(), moveSplitter()
*/

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));
}

/*!
    \reimp
*/
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());
}

/*!
    \reimp
*/
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);
}

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

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

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

/*!
   \reimp
*/
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);