q3scrollview.cpp

qt-x11-opensource-src-4.1.4.tar.gz源码

  \sa QWidget::wheelEvent()
*/
#ifndef QT_NO_WHEELEVENT
void Q3ScrollView::viewportWheelEvent(QWheelEvent* e)
{
    /*
       Different than standard mouse events, because wheel events might
       be sent to the focus widget if the widget-under-mouse doesn't want
       the event itself.
    */
    QWheelEvent ce(viewportToContents(e->pos()),
        e->globalPos(), e->delta(), e->state());
    contentsWheelEvent(&ce);
    if (ce.isAccepted())
        e->accept();
    else
        e->ignore();
}
#endif

/*! \internal

  To provide simple processing of events on the contents, this function
  receives all context menu events sent to the viewport, translates the
  event and calls contentsContextMenuEvent().
*/
void Q3ScrollView::viewportContextMenuEvent(QContextMenuEvent *e)
{
    QContextMenuEvent ce(e->reason(), viewportToContents(e->pos()), e->globalPos(), e->state());
    contentsContextMenuEvent(&ce);
    if (ce.isAccepted())
        e->accept();
    else
        e->ignore();
}

/*!
    Returns the component horizontal scroll bar. It is made available
    to allow accelerators, autoscrolling, etc.

    It should not be used for other purposes.

    This function never returns 0.
*/
QScrollBar* Q3ScrollView::horizontalScrollBar() const
{
    return d->hbar;
}

/*!
    Returns the component vertical scroll bar. It is made available to
    allow accelerators, autoscrolling, etc.

    It should not be used for other purposes.

    This function never returns 0.
*/
QScrollBar* Q3ScrollView::verticalScrollBar() const {
    return d->vbar;
}


/*!
    Scrolls the content so that the point (\a x, \a y) is visible with at
    least 50-pixel margins (if possible, otherwise centered).
*/
void Q3ScrollView::ensureVisible(int x, int y)
{
    ensureVisible(x, y, 50, 50);
}

/*!
    \overload

    Scrolls the content so that the point (\a x, \a y) is visible with at
    least the \a xmargin and \a ymargin margins (if possible,
    otherwise centered).
*/
void Q3ScrollView::ensureVisible(int x, int y, int xmargin, int ymargin)
{
    int pw=visibleWidth();
    int ph=visibleHeight();

    int cx=-d->contentsX();
    int cy=-d->contentsY();
    int cw=d->contentsWidth();
    int ch=contentsHeight();

    if (pw < xmargin*2)
        xmargin=pw/2;
    if (ph < ymargin*2)
        ymargin=ph/2;

    if (cw <= pw) {
        xmargin=0;
        cx=0;
    }
    if (ch <= ph) {
        ymargin=0;
        cy=0;
    }

    if (x < -cx+xmargin)
        cx = -x+xmargin;
    else if (x >= -cx+pw-xmargin)
        cx = -x+pw-xmargin;

    if (y < -cy+ymargin)
        cy = -y+ymargin;
    else if (y >= -cy+ph-ymargin)
        cy = -y+ph-ymargin;

    if (cx > 0)
        cx=0;
    else if (cx < pw-cw && cw>pw)
        cx=pw-cw;

    if (cy > 0)
        cy=0;
    else if (cy < ph-ch && ch>ph)
        cy=ph-ch;

    setContentsPos(-cx, -cy);
}

/*!
    Scrolls the content so that the point (\a x, \a y) is in the top-left
    corner.
*/
void Q3ScrollView::setContentsPos(int x, int y)
{
#if 0
    // bounds checking...
    if (QApplication::reverseLayout())
        if (x > d->contentsWidth() - visibleWidth()) x = d->contentsWidth() - visibleWidth();
    else
#endif
        if (x < 0) x = 0;
    if (y < 0) y = 0;
    // Choke signal handling while we update BOTH sliders.
    d->signal_choke=true;
    moveContents(-x, -y);
    d->vbar->setValue(y);
    d->hbar->setValue(x);
    d->signal_choke=false;
}

/*!
    Scrolls the content by \a dx to the left and \a dy upwards.
*/
void Q3ScrollView::scrollBy(int dx, int dy)
{
    setContentsPos(QMAX(d->contentsX()+dx, 0), QMAX(d->contentsY()+dy, 0));
}

/*!
    Scrolls the content so that the point (\a x, \a y) is in the center
    of visible area.
*/
void Q3ScrollView::center(int x, int y)
{
    ensureVisible(x, y, 32000, 32000);
}

/*!
    \overload

    Scrolls the content so that the point (\a x, \a y) is visible with
    the \a xmargin and \a ymargin margins (as fractions of visible
    the area).

    For example:
    \list
    \i Margin 0.0 allows (x, y) to be on the edge of the visible area.
    \i Margin 0.5 ensures that (x, y) is in middle 50% of the visible area.
    \i Margin 1.0 ensures that (x, y) is in the center of the the visible area.
    \endlist
*/
void Q3ScrollView::center(int x, int y, float xmargin, float ymargin)
{
    int pw=visibleWidth();
    int ph=visibleHeight();
    ensureVisible(x, y, int(xmargin/2.0*pw+0.5), int(ymargin/2.0*ph+0.5));
}


/*!
    \fn void Q3ScrollView::contentsMoving(int x, int y)

    This signal is emitted just before the contents are moved to
    position (\a x, \a y).

    \sa contentsX(), contentsY()
*/

/*!
    Moves the contents by (\a x, \a y).
*/
void Q3ScrollView::moveContents(int x, int y)
{
    if (-x+visibleWidth() > d->contentsWidth())
#if 0
        if(QApplication::reverseLayout())
            x=QMAX(0,-d->contentsWidth()+visibleWidth());
        else
#endif
            x=QMIN(0,-d->contentsWidth()+visibleWidth());
    if (-y+visibleHeight() > contentsHeight())
        y=QMIN(0,-contentsHeight()+visibleHeight());

    int dx = x - d->vx;
    int dy = y - d->vy;

    if (!dx && !dy)
        return; // Nothing to do

    emit contentsMoving(-x, -y);

    d->vx = x;
    d->vy = y;

    if (d->clipped_viewport || d->static_bg) {
        // Cheap move (usually)
        d->moveAllBy(dx,dy);
    } else if (/*dx && dy ||*/
         (QABS(dy) * 5 > visibleHeight() * 4) ||
         (QABS(dx) * 5 > visibleWidth() * 4)
       )
    {
        // Big move
        if (viewport()->updatesEnabled())
            viewport()->update();
        d->moveAllBy(dx,dy);
    } else if (!d->fake_scroll || d->contentsWidth() > visibleWidth()) {
        // Small move
        clipper()->scroll(dx,dy);
    }
    d->hideOrShowAll(this, true);
}

/*!
    \property Q3ScrollView::contentsX
    \brief the X coordinate of the contents that are at the left edge of
    the viewport.
*/
int Q3ScrollView::contentsX() const
{
    return d->contentsX();
}

/*!
    \property Q3ScrollView::contentsY
    \brief the Y coordinate of the contents that are at the top edge of
    the viewport.
*/
int Q3ScrollView::contentsY() const
{
    return d->contentsY();
}

/*!
    \property Q3ScrollView::contentsWidth
    \brief the width of the contents area
*/
int Q3ScrollView::contentsWidth() const
{
    return d->contentsWidth();
}

/*!
    \property Q3ScrollView::contentsHeight
    \brief the height of the contents area
*/
int Q3ScrollView::contentsHeight() const
{
    return d->vheight;
}

/*!
    Sets the size of the contents area to \a w pixels wide and \a h
    pixels high and updates the viewport accordingly.
*/
void Q3ScrollView::resizeContents(int w, int h)
{
    int ow = d->vwidth;
    int oh = d->vheight;
    d->vwidth = w;
    d->vheight = h;

    d->scrollbar_timer.start(0, true);

    if (d->children.isEmpty() && d->policy == Default)
        setResizePolicy(Manual);

    if (ow > w) {
        // Swap
        int t=w;
        w=ow;
        ow=t;
    }
    // Refresh area ow..w
    if (ow < visibleWidth() && w >= 0) {
        if (ow < 0)
            ow = 0;
        if (w > visibleWidth())
            w = visibleWidth();
        clipper()->update(d->contentsX()+ow, 0, w-ow, visibleHeight());
    }

    if (oh > h) {
        // Swap
        int t=h;
        h=oh;
        oh=t;
    }
    // Refresh area oh..h
    if (oh < visibleHeight() && h >= 0) {
        if (oh < 0)
            oh = 0;
        if (h > visibleHeight())
            h = visibleHeight();
        clipper()->update(0, d->contentsY()+oh, visibleWidth(), h-oh);
    }
}

/*!
    Calls update() on a rectangle defined by \a x, \a y, \a w, \a h,
    translated appropriately. If the rectangle is not visible, nothing
    is repainted.

    \sa repaintContents()
*/
void Q3ScrollView::updateContents(int x, int y, int w, int h)
{
    if (!isVisible() || !updatesEnabled())
        return;

    QWidget* vp = viewport();

    // Translate
    x -= d->contentsX();
    y -= d->contentsY();

    if (x < 0) {
        w += x;
        x = 0;
    }
    if (y < 0) {
        h += y;
        y = 0;
    }

    if (w < 0 || h < 0)
        return;
    if (x > visibleWidth() || y > visibleHeight())
        return;

    if (w > visibleWidth())
        w = visibleWidth();
    if (h > visibleHeight())
        h = visibleHeight();

    if (d->clipped_viewport) {
        // Translate clipper() to viewport()
        x -= d->clipped_viewport->x();
        y -= d->clipped_viewport->y();
    }

    vp->update(x, y, w, h);
}

/*!
    \overload

    Updates the contents in rectangle \a r
*/
void Q3ScrollView::updateContents(const QRect& r)
{
    updateContents(r.x(), r.y(), r.width(), r.height());
}

/*!
    \overload
*/
void Q3ScrollView::updateContents()
{
    updateContents(d->contentsX(), d->contentsY(), visibleWidth(), visibleHeight());
}

/*!
    \overload

    Repaints the contents of rectangle \a r. If \a erase is true the
    background is cleared using the background color.
*/
void Q3ScrollView::repaintContents(const QRect& r, bool erase)
{
    repaintContents(r.x(), r.y(), r.width(), r.height(), erase);
}


/*!
    \overload

    Repaints the contents. If \a erase is true the background is
    cleared using the background color.
*/
void Q3ScrollView::repaintContents(bool erase)
{
    repaintContents(d->contentsX(), d->contentsY(), visibleWidth(), visibleHeight(), erase);
}


/*!
    Calls repaint() on a rectangle defined by \a x, \a y, \a w, \a h,
    translated appropriately. If the rectangle is not visible, nothing
    is repainted. If \a erase is true the background is cleared using
    the background color.

    \sa updateContents()
*/
void Q3ScrollView::repaintContents(int x, int y, int w, int h, bool erase)
{
    if (!isVisible() || !updatesEnabled())
        return;

    QWidget* vp = viewport();

    // Translate logical to clipper()
    x -= d->contentsX();
    y -= d->contentsY();

    if (x < 0) {
        w += x;
        x = 0;
    }
    if (y < 0) {
        h += y;
        y = 0;
    }

    if (w < 0 || h < 0)
        return;
    if (w > visibleWidth())
        w = visibleWidth();
    if (h > visibleHeight())
        h = visibleHeight();

    if (d->clipped_viewport) {
        // Translate clipper() to viewport()
        x -= d->clipped_viewport->x();
        y -= d->clipped_viewport->y();
    }

    vp->repaint(x, y, w, h, erase);
}


/*!
    For backward-compatibility only. It is easier to use
    drawContents(Q