q3scrollview.cpp

奇趣公司比较新的qt/emd版本

            needv=true;
            if (d->vMode == Auto)
                showv=true;
        }
        if (showv && !d->inresize && w-hsbExt-lmarg-rmarg < d->contentsWidth()) {
            needh=true;
            if (d->hMode == Auto)
                showh=true;
        }
    } else {
        // Scrollbars not needed, only show scroll bar that are always on.
        needh = needv = false;
        showh = d->hMode == AlwaysOn;
        showv = d->vMode == AlwaysOn;
    }

    bool sc = d->signal_choke;
    d->signal_choke=true;

    // Hide unneeded scroll bar, calculate viewport size
    if (showh) {
        porth=h-hsbExt-tmarg-bmarg;
    } else {
        if (!needh)
            d->hbar->setValue(0);
        d->hbar->hide();
        porth=h-tmarg-bmarg;
    }
    if (showv) {
        portw=w-vsbExt-lmarg-rmarg;
    } else {
        if (!needv)
            d->vbar->setValue(0);
        d->vbar->hide();
        portw=w-lmarg-rmarg;
    }

    // Configure scroll bars that we will show
    if (needv) {
        d->vbar->setRange(0, contentsHeight()-porth);
        d->vbar->setSteps(Q3ScrollView::d->vbar->lineStep(), porth);
    } else {
        d->vbar->setRange(0, 0);
    }
    if (needh) {
        d->hbar->setRange(0, QMAX(0, d->contentsWidth()-portw));
        d->hbar->setSteps(Q3ScrollView::d->hbar->lineStep(), portw);
    } else {
        d->hbar->setRange(0, 0);
    }

    // Position the scroll bars, viewport and corner widget.
    int bottom;
    bool reverse = QApplication::reverseLayout();
    int xoffset = (reverse && (showv || cornerWidget())) ? vsbExt : 0;
    int xpos = reverse ? 0 : w - vsbExt;
    bool frameContentsOnly =
        style()->styleHint(QStyle::SH_ScrollView_FrameOnlyAroundContents);

    if(! frameContentsOnly) {
        if (reverse)
            xpos += fw;
        else
            xpos -= fw;
    }
    if (showh) {
        int right = (showc || showv || cornerWidget()) ? w-vsbExt : w;
        if (! frameContentsOnly)
            setHBarGeometry(*d->hbar, fw + xoffset, h-hsbExt-fw,
                             right-fw-fw, hsbExt);
        else
            setHBarGeometry(*d->hbar, 0 + xoffset, h-hsbExt, right,
                             hsbExt);
        bottom=h-hsbExt;
    } else {
        bottom=h;
    }
    if (showv) {
        clipper()->setGeometry(lmarg + xoffset, tmarg,
                                w-vsbExt-lmarg-rmarg,
                                bottom-tmarg-bmarg);
        d->viewportResized(w-vsbExt-lmarg-rmarg, bottom-tmarg-bmarg);
        if (! frameContentsOnly)
            changeFrameRect(QRect(0, 0, w, h));
        else
            changeFrameRect(QRect(xoffset, 0, w-vsbExt, bottom));
        if (showc || cornerWidget()) {
            if (! frameContentsOnly)
                setVBarGeometry(*d->vbar, xpos,
                                 fw, vsbExt,
                                 h-hsbExt-fw-fw);
            else
                setVBarGeometry(*d->vbar, xpos, 0,
                                 vsbExt,
                                 h-hsbExt);
        }
        else {
            if (! frameContentsOnly)
                setVBarGeometry(*d->vbar, xpos,
                                 fw, vsbExt,
                                 bottom-fw-fw);
            else
                setVBarGeometry(*d->vbar, xpos, 0,
                                 vsbExt, bottom);
        }
    } else {
        if (! frameContentsOnly)
            changeFrameRect(QRect(0, 0, w, h));
        else
            changeFrameRect(QRect(0, 0, w, bottom));
        clipper()->setGeometry(lmarg, tmarg,
                                w-lmarg-rmarg, bottom-tmarg-bmarg);
        d->viewportResized(w-lmarg-rmarg, bottom-tmarg-bmarg);
    }

    QWidget *corner = d->corner;
    if (d->corner) {
        if (! frameContentsOnly)
            corner->setGeometry(xpos,
                                h-hsbExt-fw,
                                vsbExt,
                                hsbExt);
        else
            corner->setGeometry(xpos,
                                h-hsbExt,
                                vsbExt,
                                hsbExt);
    }

    d->signal_choke=sc;

    if (d->contentsX()+visibleWidth() > d->contentsWidth()) {
        int x;
#if 0
        if (reverse)
            x =QMIN(0,d->contentsWidth()-visibleWidth());
        else
#endif
            x =QMAX(0,d->contentsWidth()-visibleWidth());
        d->hbar->setValue(x);
        // Do it even if it is recursive
        moveContents(-x, -d->contentsY());
    }
    if (d->contentsY()+visibleHeight() > contentsHeight()) {
        int y=QMAX(0,contentsHeight()-visibleHeight());
        d->vbar->setValue(y);
        // Do it even if it is recursive
        moveContents(-d->contentsX(), -y);
    }

    // Finally, show the scroll bars
    if (showh && (d->hbar->isHidden() || !d->hbar->isVisible()))
        d->hbar->show();
    if (showv && (d->vbar->isHidden() || !d->vbar->isVisible()))
        d->vbar->show();

    d->signal_choke=true;
    d->vbar->setValue(d->contentsY());
    d->hbar->setValue(d->contentsX());
    d->signal_choke=false;

    QSize newVisibleSize(visibleWidth(), visibleHeight());
    if (d->clipped_viewport && oldVisibleSize != newVisibleSize) {
        QResizeEvent e(newVisibleSize, oldVisibleSize);
        viewportResizeEvent(&e);
    }
}


/*!
    \reimp
*/
void Q3ScrollView::setVisible(bool visible)
{
    if (visible && !isVisible()) {
        QWidget::setVisible(visible);
        updateScrollBars();
        d->hideOrShowAll(this);
    } else {
        QWidget::setVisible(visible);
    }
}

/*!
    \internal
 */
void Q3ScrollView::resize(int w, int h)
{
    QWidget::resize(w, h);
}

/*!
    \internal
*/
void Q3ScrollView::resize(const QSize& s)
{
    resize(s.width(), s.height());
}

/*!
    \reimp
*/
void Q3ScrollView::resizeEvent(QResizeEvent* event)
{
    Q3Frame::resizeEvent(event);

#if 0
    if (QApplication::reverseLayout()) {
        d->fake_scroll = true;
        scrollBy(-event->size().width() + event->oldSize().width(), 0);
        d->fake_scroll = false;
    }
#endif

    bool inresize = d->inresize;
    d->inresize = true;
    updateScrollBars();
    d->inresize = inresize;
    d->scrollbar_timer.start(0, true);

    d->hideOrShowAll(this);
}



/*!
    \reimp
*/
void  Q3ScrollView::mousePressEvent(QMouseEvent * e)
{
    e->ignore();
}

/*!
    \reimp
*/
void  Q3ScrollView::mouseReleaseEvent(QMouseEvent *e)
{
    e->ignore();
}


/*!
    \reimp
*/
void  Q3ScrollView::mouseDoubleClickEvent(QMouseEvent *e)
{
    e->ignore();
}

/*!
    \reimp
*/
void  Q3ScrollView::mouseMoveEvent(QMouseEvent *e)
{
    e->ignore();
}

/*!
    \reimp
*/
#ifndef QT_NO_WHEELEVENT
void Q3ScrollView::wheelEvent(QWheelEvent *e)
{
    QWheelEvent ce(viewport()->mapFromGlobal(e->globalPos()),
                    e->globalPos(), e->delta(), e->state());
    viewportWheelEvent(&ce);
    if (!ce.isAccepted()) {
        if (e->orientation() == Horizontal && horizontalScrollBar())
            horizontalScrollBar()->event(e);
        else  if (e->orientation() == Vertical && verticalScrollBar())
            verticalScrollBar()->event(e);
    } else {
        e->accept();
    }
}
#endif

/*!
    \reimp
*/
void Q3ScrollView::contextMenuEvent(QContextMenuEvent *e)
{
    if (e->reason() != QContextMenuEvent::Keyboard) {
        e->ignore();
        return;
    }

    QContextMenuEvent ce(e->reason(), viewport()->mapFromGlobal(e->globalPos()),
                          e->globalPos(), e->state());
    viewportContextMenuEvent(&ce);
    if (ce.isAccepted())
        e->accept();
    else
        e->ignore();
}

Q3ScrollView::ScrollBarMode Q3ScrollView::vScrollBarMode() const
{
    return d->vMode;
}


/*!
    \enum Q3ScrollView::ScrollBarMode

    This enum type describes the various modes of Q3ScrollView's scroll
    bars.

    \value Auto  Q3ScrollView shows a scroll bar when the content is
    too large to fit and not otherwise. This is the default.

    \value AlwaysOff  Q3ScrollView never shows a scroll bar.

    \value AlwaysOn  Q3ScrollView always shows a scroll bar.

    (The modes for the horizontal and vertical scroll bars are
    independent.)
*/


/*!
    \property Q3ScrollView::vScrollBarMode
    \brief the mode for the vertical scroll bar

    The default mode is Q3ScrollView::Auto.

    \sa hScrollBarMode
*/
void  Q3ScrollView::setVScrollBarMode(ScrollBarMode mode)
{
    if (d->vMode != mode) {
        d->vMode = mode;
        updateScrollBars();
    }
}


/*!
    \property Q3ScrollView::hScrollBarMode
    \brief the mode for the horizontal scroll bar

    The default mode is Q3ScrollView::Auto.

    \sa vScrollBarMode
*/
Q3ScrollView::ScrollBarMode Q3ScrollView::hScrollBarMode() const
{
    return d->hMode;
}

void Q3ScrollView::setHScrollBarMode(ScrollBarMode mode)
{
    if (d->hMode != mode) {
        d->hMode = mode;
        updateScrollBars();
    }
}


/*!
    Returns the widget in the corner between the two scroll bars.

    By default, no corner widget is present.
*/
QWidget* Q3ScrollView::cornerWidget() const
{
    return d->corner;
}

/*!
    Sets the widget in the \a corner between the two scroll bars.

    You will probably also want to set at least one of the scroll bar
    modes to \c AlwaysOn.

    Passing 0 shows no widget in the corner.

    Any previous \a corner widget is hidden.

    You may call setCornerWidget() with the same widget at different
    times.

    All widgets set here will be deleted by the Q3ScrollView when it is
    destroyed unless you separately reparent the widget after setting
    some other corner widget (or 0).

    Any \e newly set widget should have no current parent.

    By default, no corner widget is present.

    \sa setVScrollBarMode(), setHScrollBarMode()
*/
void Q3ScrollView::setCornerWidget(QWidget* corner)
{
    QWidget* oldcorner = d->corner;
    if (oldcorner != corner) {
        if (oldcorner) oldcorner->hide();
        d->corner = corner;
        corner->setParent(this);
        updateScrollBars();
        if (corner) corner->show();
    }
}


void Q3ScrollView::setResizePolicy(ResizePolicy r)
{
    d->policy = r;
}

/*!
    \property Q3ScrollView::resizePolicy
    \brief the resize policy

    The default is \c Default.

    \sa ResizePolicy
*/
Q3ScrollView::ResizePolicy Q3ScrollView::resizePolicy() const
{
    return d->policy;
}

/*!
    \internal
*/
void Q3ScrollView::setEnabled(bool enable)
{
    Q3Frame::setEnabled(enable);
}

/*!
    Removes the \a child widget from the scrolled area. Note that this
    happens automatically if the \a child is deleted.
*/
void Q3ScrollView::removeChild(QWidget* child)
{
    if (!d || !child) // First check in case we are destructing
        return;

    QSVChildRec *r = d->rec(child);
    if (r) d->deleteChildRec(r);
}

/*!
    \internal
*/
void Q3ScrollView::removeChild(QObject* child)
{
    Q3Frame::removeChild(child);
}

/*!
    Inserts the widget, \a child, into the scrolled area positioned at
    (\a x, \a y). The position defaults to (0, 0). If the child is
    already in the view, it is just moved.