C++ QwtPlotCanvas::removeEventFilter方法代码示例

void CanvasPicker::setEnabled( bool enabled )
{
	if( m_isEnabled != enabled )
	{
		QwtPlotCanvas* canvas = qobject_cast<QwtPlotCanvas*>( plot()->canvas() );
		m_isEnabled = enabled;
		if( enabled )
			canvas->installEventFilter( this );
		else
			canvas->removeEventFilter( this );
	}
}

/*!
  \brief Draw a set of points of a seriesItem.

  When observing an measurement while it is running, new points have to be
  added to an existing seriesItem. drawSeries can be used to display them avoiding
  a complete redraw of the canvas.

  Setting plot()->canvas()->setAttribute(Qt::WA_PaintOutsidePaintEvent, true);
  will result in faster painting, if the paint engine of the canvas widget
  supports this feature.

  \param seriesItem Item to be painted
  \param from Index of the first point to be painted
  \param to Index of the last point to be painted. If to < 0 the
         series will be painted to its last point.
*/
void QwtPlotDirectPainter::drawSeries(
    QwtPlotAbstractSeriesItem *seriesItem, int from, int to )
{
    if ( seriesItem == NULL || seriesItem->plot() == NULL )
        return;

    QwtPlotCanvas *canvas = seriesItem->plot()->canvas();
    const QRect canvasRect = canvas->contentsRect();

    const bool hasBackingStore = 
        canvas->testPaintAttribute( QwtPlotCanvas::BackingStore ) 
        && canvas->backingStore() && !canvas->backingStore()->isNull();

    if ( hasBackingStore )
    {
        QPainter painter( const_cast<QPixmap *>( canvas->backingStore() ) );

        if ( d_data->hasClipping )
            painter.setClipRegion( d_data->clipRegion );

        renderItem( &painter, canvasRect, seriesItem, from, to );

        if ( testAttribute( QwtPlotDirectPainter::FullRepaint ) )
        {
            canvas->repaint();
            return;
        }
    }

    bool immediatePaint = true;
    if ( !canvas->testAttribute( Qt::WA_WState_InPaintEvent ) )
    {
        immediatePaint = false;
    }

    if ( immediatePaint )
    {
        if ( !d_data->painter.isActive() )
        {
            reset();

            d_data->painter.begin( canvas );
            canvas->installEventFilter( this );
        }

        if ( d_data->hasClipping )
        {
            d_data->painter.setClipRegion( 
                QRegion( canvasRect ) & d_data->clipRegion );
        }
        else
        {
            if ( !d_data->painter.hasClipping() )
                d_data->painter.setClipRect( canvasRect );
        }

        renderItem( &d_data->painter, canvasRect, seriesItem, from, to );

        if ( d_data->attributes & QwtPlotDirectPainter::AtomicPainter )
        {
            reset();
        }
        else
        {
            if ( d_data->hasClipping )
                d_data->painter.setClipping( false );
        }
    }
    else
    {
        reset();

        d_data->seriesItem = seriesItem;
        d_data->from = from;
        d_data->to = to;

        QRegion clipRegion = canvasRect;
        if ( d_data->hasClipping )
            clipRegion &= d_data->clipRegion;

        canvas->installEventFilter( this );
        canvas->repaint(clipRegion);
        canvas->removeEventFilter( this );

//.........这里部分代码省略.........

/*!
  \brief Draw a set of points of a seriesItem.

  When observing an measurement while it is running, new points have to be
  added to an existing seriesItem. drawSeries can be used to display them avoiding
  a complete redraw of the canvas.

  Setting plot()->canvas()->setAttribute(Qt::WA_PaintOutsidePaintEvent, true);
  will result in faster painting, if the paint engine of the canvas widget
  supports this feature.

  \param seriesItem Item to be painted
  \param from Index of the first point to be painted
  \param to Index of the last point to be painted. If to < 0 the
         series will be painted to its last point.
*/
void QwtPlotDirectPainter::drawSeries(
    QwtPlotAbstractSeriesItem *seriesItem, int from, int to )
{
    if ( seriesItem == NULL || seriesItem->plot() == NULL )
        return;

    QwtPlotCanvas *canvas = seriesItem->plot()->canvas();

    if ( canvas->testPaintAttribute( QwtPlotCanvas::PaintCached ) &&
        canvas->paintCache() && !canvas->paintCache()->isNull() )
    {
        QPainter painter( ( QPixmap * )canvas->paintCache() );
        painter.translate( -canvas->contentsRect().x(),
            -canvas->contentsRect().y() );

        renderItem( &painter, seriesItem, from, to );

        if ( d_data->attributes & FullRepaint )
        {
            canvas->repaint();
            return;
        }
    }

    bool immediatePaint = true;
    if ( !canvas->testAttribute( Qt::WA_WState_InPaintEvent ) &&
        !canvas->testAttribute( Qt::WA_PaintOutsidePaintEvent ) )
    {
        immediatePaint = false;
    }

    if ( immediatePaint )
    {
        QwtPlotCanvas *canvas = seriesItem->plot()->canvas();
        if ( !( d_data->painter.isActive() &&
            d_data->painter.device() == canvas ) )
        {
            reset();

            d_data->painter.begin( canvas );
            d_data->painter.setClipping( true );
            d_data->painter.setClipRect( canvas->contentsRect() );

            canvas->installEventFilter( this );
        }

        renderItem( &d_data->painter, seriesItem, from, to );

        if ( d_data->attributes & AtomicPainter )
            reset();
    }
    else
    {
        reset();

        d_data->seriesItem = seriesItem;
        d_data->from = from;
        d_data->to = to;

        canvas->installEventFilter( this );
        canvas->repaint();
        canvas->removeEventFilter( this );

        d_data->seriesItem = NULL;
    }
}