double QgsComposerItem::horizontalViewScaleFactor() const
{
double result = -1;
if ( scene() )
{
QList<QGraphicsView *> viewList = scene()->views();
if ( !viewList.isEmpty() ) //if not, probably this function was called from non-gui code
{
QGraphicsView *currentView = viewList.at( 0 );
if ( currentView->isVisible() )
{
result = currentView->transform().m11();
mLastValidViewScaleFactor = result;
}
}
}
return result;
}
void QgsPaperGrid::paint( QPainter* painter, const QStyleOptionGraphicsItem* itemStyle, QWidget* pWidget )
{
Q_UNUSED( itemStyle );
Q_UNUSED( pWidget );
//draw grid
if ( mComposition )
{
if ( mComposition->gridVisible() && mComposition->plotStyle() == QgsComposition::Preview
&& mComposition->snapGridResolution() > 0 )
{
int gridMultiplyX = ( int )( mComposition->snapGridOffsetX() / mComposition->snapGridResolution() );
int gridMultiplyY = ( int )( mComposition->snapGridOffsetY() / mComposition->snapGridResolution() );
double currentXCoord = mComposition->snapGridOffsetX() - gridMultiplyX * mComposition->snapGridResolution();
double currentYCoord;
double minYCoord = mComposition->snapGridOffsetY() - gridMultiplyY * mComposition->snapGridResolution();
painter->save();
//turn of antialiasing so grid is nice and sharp
painter->setRenderHint( QPainter::Antialiasing, false );
if ( mComposition->gridStyle() == QgsComposition::Solid )
{
painter->setPen( mComposition->gridPen() );
//draw vertical lines
for ( ; currentXCoord <= rect().width(); currentXCoord += mComposition->snapGridResolution() )
{
painter->drawLine( QPointF( currentXCoord, 0 ), QPointF( currentXCoord, rect().height() ) );
}
//draw horizontal lines
currentYCoord = minYCoord;
for ( ; currentYCoord <= rect().height(); currentYCoord += mComposition->snapGridResolution() )
{
painter->drawLine( QPointF( 0, currentYCoord ), QPointF( rect().width(), currentYCoord ) );
}
}
else //'Dots' or 'Crosses'
{
QPen gridPen = mComposition->gridPen();
painter->setPen( gridPen );
painter->setBrush( QBrush( gridPen.color() ) );
double halfCrossLength = 1;
if ( mComposition->gridStyle() == QgsComposition::Dots )
{
//dots are actually drawn as tiny crosses a few pixels across
//check QGraphicsView to get current transform
if ( scene() )
{
QList<QGraphicsView*> viewList = scene()->views();
if ( viewList.size() > 0 )
{
QGraphicsView* currentView = viewList.at( 0 );
if ( currentView->isVisible() )
{
//set halfCrossLength to equivalent of 1 pixel
halfCrossLength = 1 / currentView->transform().m11();
}
}
}
}
else if ( mComposition->gridStyle() == QgsComposition::Crosses )
{
halfCrossLength = mComposition->snapGridResolution() / 6;
}
for ( ; currentXCoord <= rect().width(); currentXCoord += mComposition->snapGridResolution() )
{
currentYCoord = minYCoord;
for ( ; currentYCoord <= rect().height(); currentYCoord += mComposition->snapGridResolution() )
{
painter->drawLine( QPointF( currentXCoord - halfCrossLength, currentYCoord ), QPointF( currentXCoord + halfCrossLength, currentYCoord ) );
painter->drawLine( QPointF( currentXCoord, currentYCoord - halfCrossLength ), QPointF( currentXCoord, currentYCoord + halfCrossLength ) );
}
}
}
painter->restore();
}
}
}