qsplitter.cpp

奇趣公司比较新的qt/emd版本

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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

/*!
    \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 provide extra features, such as popup menus.

    The typical way one would create splitter handles is to subclass QSplitter then
    reimplement QSplitter::createHandle() to instantiate the custom splitter
    handle. For example, a minimum QSplitter subclass might look like this:

    \quotefromfile snippets/splitterhandle/splitter.h
    \skipto class Splitter : public QSplitter
    \printuntil /^\};/

    The \l{QSplitter::}{createHandle()} implementation simply constructs a
    custom splitter handle, called \c Splitter in this example:

    \quotefromfile snippets/splitterhandle/splitter.cpp
    \skipto createHandle()
    \printuntil /^\}/

    Information about a given handle can be obtained using functions like
    orientation() and opaqueResize(), and is retrieved from its parent splitter.
    Details like these can be used to give custom handles different appearances
    depending on the splitter's orientation.

    The complexity of a custom handle subclass depends on the tasks that it
    needs to perform. A simple subclass might only provide a paintEvent()
    implementation:

    \quotefromfile snippets/splitterhandle/splitter.cpp
    \skipto paintEvent
    \printuntil /^\}/

    In this example, a predefined gradient is set up differently depending on
    the orientation of the handle. QSplitterHandle provides a reasonable
    size hint for the handle, so the subclass does not need to provide a
    reimplementation of sizeHint() unless the handle has special size
    requirements.

    \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()))
                 - d->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)
        d->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()))
                     - d->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;
        }