void QwtWidgetOverlay::updateMask()
{
d_data->resetRgbaBuffer();
QRegion mask;
if ( d_data->maskMode == QwtWidgetOverlay::MaskHint )
{
mask = maskHint();
}
else if ( d_data->maskMode == QwtWidgetOverlay::AlphaMask )
{
// TODO: the image doesn't need to be larger than
// the bounding rectangle of the hint !!
QRegion hint = maskHint();
if ( hint.isEmpty() )
hint += QRect( 0, 0, width(), height() );
// A fresh buffer from calloc() is usually faster
// than reinitializing an existing one with
// QImage::fill( 0 ) or memset()
d_data->rgbaBuffer = ( uchar* )::calloc( width() * height(), 4 );
QImage image( d_data->rgbaBuffer,
width(), height(), qwtMaskImageFormat() );
QPainter painter( &image );
draw( &painter );
painter.end();
mask = qwtAlphaMask( image, hint.rects() );
if ( d_data->renderMode == QwtWidgetOverlay::DrawOverlay )
{
// we don't need the buffer later
d_data->resetRgbaBuffer();
}
}
// A bug in Qt initiates a full repaint of the widget
// when we change the mask, while we are visible !
setVisible( false );
if ( mask.isEmpty() )
clearMask();
else
setMask( mask );
setVisible( true );
}
void Editor::setItemVisible( QwtPlotShapeItem *item, bool on )
{
if ( plot() == NULL || item == NULL || item->isVisible() == on )
return;
const bool doAutoReplot = plot()->autoReplot();
plot()->setAutoReplot( false );
item->setVisible( on );
plot()->setAutoReplot( doAutoReplot );
/*
Avoid replot with a full repaint of the canvas.
For special combinations - f.e. using the
raster paint engine on a remote display -
this makes a difference.
*/
QwtPlotCanvas *canvas =
qobject_cast<QwtPlotCanvas *>( plot()->canvas() );
if ( canvas )
canvas->invalidateBackingStore();
plot()->canvas()->update( maskHint( item ) );
}
QRegion Editor::maskHint() const
{
return maskHint( d_editedItem );
}
