qwt_picker.cpp

QWT5.01用于Qt开发的二维图形库程序

{
    if ( d_data->enabled != enabled )
    {
        d_data->enabled = enabled;

        QWidget *w = parentWidget();
        if ( w )
        {
            if ( enabled )
                w->installEventFilter(this);
            else
                w->removeEventFilter(this);
        }

        updateDisplay();
    }
}

/*!
  \return true when enabled, false otherwise
  \sa setEnabled, eventFilter()
*/

bool QwtPicker::isEnabled() const
{
    return d_data->enabled;
}

/*!
  Set the font for the tracker

  \param font Tracker font
  \sa trackerFont(), setTrackerMode(), setTrackerPen()
*/
void QwtPicker::setTrackerFont(const QFont &font)
{
    if ( font != d_data->trackerFont )
    {
        d_data->trackerFont = font;
        updateDisplay();
    }
}

/*!
  \return Tracker font
  \sa setTrackerFont(), trackerMode(), trackerPen()
*/

QFont QwtPicker::trackerFont() const
{
    return d_data->trackerFont;
}

/*!
  Set the pen for the tracker

  \param pen Tracker pen
  \sa trackerPen(), setTrackerMode(), setTrackerFont()
*/
void QwtPicker::setTrackerPen(const QPen &pen)
{
    if ( pen != d_data->trackerPen )
    {
        d_data->trackerPen = pen;
        updateDisplay();
    }
}

/*!
  \return Tracker pen
  \sa setTrackerPen(), trackerMode(), trackerFont()
*/
QPen QwtPicker::trackerPen() const
{
    return d_data->trackerPen;
}

/*!
  Set the pen for the rubberband

  \param pen Rubberband pen
  \sa rubberBandPen(), setRubberBand()
*/
void QwtPicker::setRubberBandPen(const QPen &pen)
{
    if ( pen != d_data->rubberBandPen )
    {
        d_data->rubberBandPen = pen;
        updateDisplay();
    }
}

/*!
  \return Rubberband pen
  \sa setRubberBandPen(), rubberBand()
*/
QPen QwtPicker::rubberBandPen() const
{
    return d_data->rubberBandPen;
}

/*!
   \brief Return the label for a position

   In case of HLineRubberBand the label is the value of the
   y position, in case of VLineRubberBand the value of the x position.
   Otherwise the label contains x and y position separated by a ',' .

   The format for the string conversion is "%d".

   \param pos Position
   \return Converted position as string
*/

QwtText QwtPicker::trackerText(const QPoint &pos) const
{
    QString label;

    switch(rubberBand())
    {
        case HLineRubberBand:
            label.sprintf("%d", pos.y());
            break;
        case VLineRubberBand:
            label.sprintf("%d", pos.x());
            break;
        default:
            label.sprintf("%d, %d", pos.x(), pos.y());
    }
    return label;
}

/*!
   Draw a rubberband , depending on rubberBand() and selectionFlags()

   \param painter Painter, initialized with clip rect 

   \sa rubberBand(), RubberBand, selectionFlags()
*/

void QwtPicker::drawRubberBand(QPainter *painter) const
{
    if ( !isActive() || rubberBand() == NoRubberBand || 
        rubberBandPen().style() == Qt::NoPen )
    {
        return;
    }

    const QRect &pRect = pickRect();
    const QwtPolygon &pa = d_data->selection;

    if ( selectionFlags() & PointSelection )
    {
        if ( pa.count() < 1 )
            return;

        const QPoint pos = pa[0];

        switch(rubberBand())
        {
            case VLineRubberBand:
                QwtPainter::drawLine(painter, pos.x(),
                    pRect.top(), pos.x(), pRect.bottom());
                break;

            case HLineRubberBand:
                QwtPainter::drawLine(painter, pRect.left(), 
                    pos.y(), pRect.right(), pos.y());
                break;

            case CrossRubberBand:
                QwtPainter::drawLine(painter, pos.x(),
                    pRect.top(), pos.x(), pRect.bottom());
                QwtPainter::drawLine(painter, pRect.left(), 
                    pos.y(), pRect.right(), pos.y());
                break;
            default:
                break;
        }
    }

    else if ( selectionFlags() & RectSelection )
    {
        if ( pa.count() < 2 )
            return;

        QPoint p1 = pa[0];
        QPoint p2 = pa[int(pa.count() - 1)];

        if ( selectionFlags() & CenterToCorner )
        {
            p1.setX(p1.x() - (p2.x() - p1.x()));
            p1.setY(p1.y() - (p2.y() - p1.y()));
        }
        else if ( selectionFlags() & CenterToRadius )
        {
            const int radius = qwtMax(qwtAbs(p2.x() - p1.x()), 
                qwtAbs(p2.y() - p1.y()));
            p2.setX(p1.x() + radius);
            p2.setY(p1.y() + radius);
            p1.setX(p1.x() - radius);
            p1.setY(p1.y() - radius);
        }

#if QT_VERSION < 0x040000
        const QRect rect = QRect(p1, p2).normalize();
#else
        const QRect rect = QRect(p1, p2).normalized();
#endif
        switch(rubberBand())
        {
            case EllipseRubberBand:
                QwtPainter::drawEllipse(painter, rect);
                break;
            case RectRubberBand:
                QwtPainter::drawRect(painter, rect);
                break;
            default:
                break;
        }
    }
    else if ( selectionFlags() & PolygonSelection )
    {
        if ( rubberBand() == PolygonRubberBand )
            painter->drawPolyline(pa);
    }
}

/*!
   Draw the tracker

   \param painter Painter
   \sa trackerRect(), trackerText()
*/

void QwtPicker::drawTracker(QPainter *painter) const
{
    const QRect textRect = trackerRect(painter);
    if ( !textRect.isEmpty() )
    {
        QwtText label = trackerText(d_data->labelPosition);
        if ( !label.isEmpty() )
        {

#if defined(Q_WS_MAC)
#if QT_VERSION >= 0x040000
            // Antialiased fonts are broken on the Mac.
            painter->save();
            painter->setRenderHint(QPainter::TextAntialiasing, false);
#else
            QFont fnt = label.usedFont(painter->font());
            fnt.setStyleStrategy(QFont::NoAntialias);
            label.setFont(fnt);
#endif
#endif
            label.draw(painter, textRect);

#if defined(Q_WS_MAC)
#if QT_VERSION >= 0x040000
            painter->restore();
#endif
#endif
        }
    }
}

QRect QwtPicker::trackerRect(QPainter *painter) const
{
    if ( trackerMode() == AlwaysOff || 
        (trackerMode() == ActiveOnly && !isActive() ) )
    {
        return QRect();
    }

    if ( d_data->labelPosition.x() < 0 || d_data->labelPosition.y() < 0 )
        return QRect();

    QwtText text = trackerText(d_data->labelPosition);
    if ( text.isEmpty() )
        return QRect();

    QRect textRect(QPoint(0, 0), text.textSize(painter->font()));

    const QPoint &pos = d_data->labelPosition;

    int alignment = 0;
    if ( isActive() && d_data->selection.count() > 1 
        && rubberBand() != NoRubberBand )
    {
        const QPoint last = 
            d_data->selection[int(d_data->selection.count()) - 2];

        alignment |= (pos.x() >= last.x()) ? Qt::AlignRight : Qt::AlignLeft;
        alignment |= (pos.y() > last.y()) ? Qt::AlignBottom : Qt::AlignTop;
    }
    else
        alignment = Qt::AlignTop | Qt::AlignRight;

    const int margin = 5;

    int x = pos.x();
    if ( alignment & Qt::AlignLeft )
        x -= textRect.width() + margin;
    else if ( alignment & Qt::AlignRight )
        x += margin;

    int y = pos.y();
    if ( alignment & Qt::AlignBottom )
        y += margin;
    else if ( alignment & Qt::AlignTop )
        y -= textRect.height() + margin;
    
    textRect.moveTopLeft(QPoint(x, y));

    int right = qwtMin(textRect.right(), pickRect().right() - margin);
    int bottom = qwtMin(textRect.bottom(), pickRect().bottom() - margin);
    textRect.moveBottomRight(QPoint(right, bottom));

    int left = qwtMax(textRect.left(), pickRect().left() + margin);
    int top = qwtMax(textRect.top(), pickRect().top() + margin);
    textRect.moveTopLeft(QPoint(left, top));

    return textRect;
}

/*!
  \brief Event filter

  When isEnabled() == true all events of the observed widget are filtered.
  Mouse and keyboard events are translated into widgetMouse- and widgetKey-
  and widgetWheel-events. Paint and Resize events are handled to keep 
  rubberband and tracker up to date.

  \sa event(), widgetMousePressEvent(), widgetMouseReleaseEvent(),
      widgetMouseDoubleClickEvent(), widgetMouseMoveEvent(),
      widgetWheelEvent(), widgetKeyPressEvent(), widgetKeyReleaseEvent()
*/
bool QwtPicker::eventFilter(QObject *o, QEvent *e)
{
    if ( o && o == parentWidget() )
    {
        switch(e->type())
        {
            case QEvent::Resize:
            {
                const QResizeEvent *re = (QResizeEvent *)e;
                if ( d_data->resizeMode == Stretch )
                    stretchSelection(re->oldSize(), re->size());

                if ( d_data->rubberBandWidget )
                    d_data->rubberBandWidget->resize(re->size());
             
                if ( d_data->trackerWidget )
                    d_data->trackerWidget->resize(re->size());
                break;
            }
            case QEvent::Leave:
                widgetLeaveEvent(e);
                break;
            case QEvent::MouseButtonPress:
                widgetMousePressEvent((QMouseEvent *)e);
                break;
            case QEvent::MouseButtonRelease:
                widgetMouseReleaseEvent((QMouseEvent *)e);
                break;
            case QEvent::MouseButtonDblClick:
                widgetMouseDoubleClickEvent((QMouseEvent *)e);
                break;
            case QEvent::MouseMove:
                widgetMouseMoveEvent((QMouseEvent *)e);
                break;
            case QEvent::KeyPress:
                widgetKeyPressEvent((QKeyEvent *)e);
                break;
            case QEvent::KeyRelease:
                widgetKeyReleaseEvent((QKeyEvent *)e);
                break;
            case QEvent::Wheel:
                widgetWheelEvent((QWheelEvent *)e);
                break;
            default:
                break;
        }
    }
    return false;
}

/*!
  Handle a mouse press event for the observed widget.

  Begin and/or end a selection depending on the selection flags.

  \sa QwtPicker, selectionFlags()
  \sa eventFilter(), widgetMouseReleaseEvent(),
      widgetMouseDoubleClickEvent(), widgetMouseMoveEvent(),
      widgetWheelEvent(), widgetKeyPressEvent(), widgetKeyReleaseEvent()
*/
void QwtPicker::widgetMousePressEvent(QMouseEvent *e)
{
    transition(e);
}

/*!
  Handle a mouse move event for the observed widget.

  Move the last point of the selection in case of isActive() == true

  \sa eventFilter(), widgetMousePressEvent(), widgetMouseReleaseEvent(),
      widgetMouseDoubleClickEvent(),
      widgetWheelEvent(), widgetKeyPressEvent(), widgetKeyReleaseEvent()
*/
void QwtPicker::widgetMouseMoveEvent(QMouseEvent *e)
{
    if ( pickRect().contains(e->pos()) )
        d_data->labelPosition = e->pos();
    else
        d_data->labelPosition = QPoint(-1, -1);

    if ( !isActive() )
        updateDisplay();

    transition(e);
}

/*!
  Handle a leave event for the observed widget.

  \sa eventFilter(), widgetMousePressEvent(), widgetMouseReleaseEvent(),
      widgetMouseDoubleClickEvent(),
      widgetWheelEvent(), widgetKeyPressEvent(), widgetKeyReleaseEvent()
*/
void QwtPicker::widgetLeaveEvent(QEvent *)   
{
    d_data->labelPosition = QPoint(-1, -1);
    if ( !isActive() )
        updateDisplay();
}

/*!
  Handle a mouse relase event for the observed widget.

  End a selection depending on the selection flags.

  \sa QwtPicker, selectionFlags()
  \sa eventFilter(), widgetMousePressEvent(), 
      widgetMouseDoubleClickEvent(), widgetMouseMoveEvent(),
      widgetWheelEvent(), widgetKeyPressEvent(), widgetKeyReleaseEvent()
*/
void QwtPicker::widgetMouseReleaseEvent(QMouseEvent *e)
{