/*!
Zoom in/out the axes scales
\param factor A value < 1.0 zooms in, a value > 1.0 zooms out.
*/
void QwtPlotMagnifier::rescale(double factor)
{
factor = qwtAbs(factor);
if ( factor == 1.0 || factor == 0.0 )
return;
bool doReplot = false;
QwtPlot* plt = plot();
const bool autoReplot = plt->autoReplot();
plt->setAutoReplot(false);
for ( int axisId = 0; axisId < QwtPlot::axisCnt; axisId++ )
{
const QwtScaleDiv *scaleDiv = plt->axisScaleDiv(axisId);
if ( isAxisEnabled(axisId) && scaleDiv->isValid() )
{
const double center =
scaleDiv->lowerBound() + scaleDiv->range() / 2;
const double width_2 = scaleDiv->range() / 2 * factor;
plt->setAxisScale(axisId, center - width_2, center + width_2);
doReplot = true;
}
}
plt->setAutoReplot(autoReplot);
if ( doReplot )
plt->replot();
}
/*!
Adjust the enabled axes according to dx/dy
\param dx Pixel offset in x direction
\param dy Pixel offset in y direction
\sa QwtPanner::panned()
*/
void QwtPlotPanner::moveCanvas( int dx, int dy )
{
if ( dx == 0 && dy == 0 )
return;
QwtPlot *plot = this->plot();
if ( plot == NULL )
return;
const bool doAutoReplot = plot->autoReplot();
plot->setAutoReplot( false );
for ( int axisPos = 0; axisPos < QwtAxis::PosCount; axisPos++ )
{
const int axesCount = plot->axesCount( axisPos );
for ( int i = 0; i < axesCount; i++ )
{
const QwtAxisId axisId( axisPos, i );
if ( !isAxisEnabled( axisId ) )
continue;
const QwtScaleMap map = plot->canvasMap( axisId );
const double p1 = map.transform( plot->axisScaleDiv( axisId ).lowerBound() );
const double p2 = map.transform( plot->axisScaleDiv( axisId ).upperBound() );
double d1, d2;
if ( QwtAxis::isXAxis( axisPos ) )
{
d1 = map.invTransform( p1 - dx );
d2 = map.invTransform( p2 - dx );
}
else
{
d1 = map.invTransform( p1 - dy );
d2 = map.invTransform( p2 - dy );
}
plot->setAxisScale( axisId, d1, d2 );
}
}
plot->setAutoReplot( doAutoReplot );
plot->replot();
}
void PlotMagnifier::rescale( double factor, AxisMode axis )
{
factor = qAbs( 1.0/factor );
QwtPlot* plt = plot();
if ( plt == nullptr || factor == 1.0 ){
return;
}
bool doReplot = false;
const bool autoReplot = plt->autoReplot();
plt->setAutoReplot( false );
const int axis_list[2] = {QwtPlot::xBottom, QwtPlot::yLeft};
QRectF new_rect;
for ( int i = 0; i <2; i++ )
{
double temp_factor = factor;
if( i==1 && axis == X_AXIS)
{
temp_factor = 1.0;
}
if( i==0 && axis == Y_AXIS)
{
temp_factor = 1.0;
}
int axisId = axis_list[i];
if ( isAxisEnabled( axisId ) )
{
const QwtScaleMap scaleMap = plt->canvasMap( axisId );
double v1 = scaleMap.s1();
double v2 = scaleMap.s2();
double center = _mouse_position.x();
if( axisId == QwtPlot::yLeft){
center = _mouse_position.y();
}
if ( scaleMap.transformation() )
{
// the coordinate system of the paint device is always linear
v1 = scaleMap.transform( v1 ); // scaleMap.p1()
v2 = scaleMap.transform( v2 ); // scaleMap.p2()
}
const double width = ( v2 - v1 );
const double ratio = (v2-center)/ (width);
v1 = center - width*temp_factor*(1-ratio);
v2 = center + width*temp_factor*(ratio);
if( v1 > v2 ) std::swap( v1, v2 );
if ( scaleMap.transformation() )
{
v1 = scaleMap.invTransform( v1 );
v2 = scaleMap.invTransform( v2 );
}
if( v1 < _lower_bounds[axisId]) v1 = _lower_bounds[axisId];
if( v2 > _upper_bounds[axisId]) v2 = _upper_bounds[axisId];
plt->setAxisScale( axisId, v1, v2 );
if( axisId == QwtPlot::xBottom)
{
new_rect.setLeft( v1 );
new_rect.setRight( v2 );
}
else{
new_rect.setBottom( v1 );
new_rect.setTop( v2 );
}
doReplot = true;
}
}
plt->setAutoReplot( autoReplot );
if ( doReplot ){
emit rescaled( new_rect );
}
}