qt_demoe/qwtdemo/examples/oscilloscope/signaldata.cpp

134 lines
2.6 KiB
C++

#include "signaldata.h"
#include <qvector.h>
#include <qmutex.h>
#include <qreadwritelock.h>
class SignalData::PrivateData
{
public:
PrivateData():
boundingRect( 1.0, 1.0, -2.0, -2.0 ) // invalid
{
values.reserve( 1000 );
}
inline void append( const QPointF &sample )
{
values.append( sample );
// adjust the bounding rectangle
if ( boundingRect.width() < 0 || boundingRect.height() < 0 )
{
boundingRect.setRect( sample.x(), sample.y(), 0.0, 0.0 );
}
else
{
boundingRect.setRight( sample.x() );
if ( sample.y() > boundingRect.bottom() )
boundingRect.setBottom( sample.y() );
if ( sample.y() < boundingRect.top() )
boundingRect.setTop( sample.y() );
}
}
QReadWriteLock lock;
QVector<QPointF> values;
QRectF boundingRect;
QMutex mutex; // protecting pendingValues
QVector<QPointF> pendingValues;
};
SignalData::SignalData()
{
d_data = new PrivateData();
}
SignalData::~SignalData()
{
delete d_data;
}
int SignalData::size() const
{
return d_data->values.size();
}
QPointF SignalData::value( int index ) const
{
return d_data->values[index];
}
QRectF SignalData::boundingRect() const
{
return d_data->boundingRect;
}
void SignalData::lock()
{
d_data->lock.lockForRead();
}
void SignalData::unlock()
{
d_data->lock.unlock();
}
void SignalData::append( const QPointF &sample )
{
d_data->mutex.lock();
d_data->pendingValues += sample;
const bool isLocked = d_data->lock.tryLockForWrite();
if ( isLocked )
{
const int numValues = d_data->pendingValues.size();
const QPointF *pendingValues = d_data->pendingValues.data();
for ( int i = 0; i < numValues; i++ )
d_data->append( pendingValues[i] );
d_data->pendingValues.clear();
d_data->lock.unlock();
}
d_data->mutex.unlock();
}
void SignalData::clearStaleValues( double limit )
{
d_data->lock.lockForWrite();
d_data->boundingRect = QRectF( 1.0, 1.0, -2.0, -2.0 ); // invalid
const QVector<QPointF> values = d_data->values;
d_data->values.clear();
d_data->values.reserve( values.size() );
int index;
for ( index = values.size() - 1; index >= 0; index-- )
{
if ( values[index].x() < limit )
break;
}
if ( index > 0 )
d_data->append( values[index++] );
while ( index < values.size() - 1 )
d_data->append( values[index++] );
d_data->lock.unlock();
}
SignalData &SignalData::instance()
{
static SignalData valueVector;
return valueVector;
}