void QgsMapToolZoom::canvasReleaseEvent( QMouseEvent * e )
{
if ( e->button() != Qt::LeftButton )
return;
// We are not really dragging in this case. This is sometimes caused by
// a pen based computer reporting a press, move, and release, all the
// one point.
if ( mDragging && ( mZoomRect.topLeft() == mZoomRect.bottomRight() ) )
{
mDragging = false;
delete mRubberBand;
mRubberBand = 0;
}
if ( mDragging )
{
mDragging = false;
delete mRubberBand;
mRubberBand = 0;
// store the rectangle
mZoomRect.setRight( e->pos().x() );
mZoomRect.setBottom( e->pos().y() );
const QgsMapToPixel* coordinateTransform = mCanvas->getCoordinateTransform();
// set the extent to the zoomBox
QgsPoint ll = coordinateTransform->toMapCoordinates( mZoomRect.left(), mZoomRect.bottom() );
QgsPoint ur = coordinateTransform->toMapCoordinates( mZoomRect.right(), mZoomRect.top() );
QgsRectangle r;
r.setXMinimum( ll.x() );
r.setYMinimum( ll.y() );
r.setXMaximum( ur.x() );
r.setYMaximum( ur.y() );
r.normalize();
// prevent zooming to an empty extent
if ( r.width() == 0 || r.height() == 0 )
{
return;
}
if ( mZoomOut )
{
QgsPoint cer = r.center();
QgsRectangle extent = mCanvas->extent();
double sf;
if ( mZoomRect.width() > mZoomRect.height() )
{
sf = extent.width() / r.width();
}
else
{
sf = extent.height() / r.height();
}
r.expand( sf );
QgsDebugMsg( QString( "Extent scaled by %1 to %2" ).arg( sf ).arg( r.toString().toLocal8Bit().constData() ) );
QgsDebugMsg( QString( "Center of currentExtent after scaling is %1" ).arg( r.center().toString().toLocal8Bit().constData() ) );
}
mCanvas->setExtent( r );
mCanvas->refresh();
}
else // not dragging
{
// change to zoom in/out by the default multiple
mCanvas->zoomWithCenter( e->x(), e->y(), !mZoomOut );
}
}
