新增qwt源码版本

qwtdemo/qwt/qwt_sampling_thread.h

@@ -0,0 +1,50 @@
+#ifndef _QWT_SAMPLING_THREAD_H_
+#define _QWT_SAMPLING_THREAD_H_
+
+#include "qwt_global.h"
+#include <qthread.h>
+
+/*!
+  \brief A thread collecting samples at regular intervals.
+
+  Continuous signals are converted into a discrete signal by
+  collecting samples at regular intervals. A discrete signal
+  can be displayed by a QwtPlotSeriesItem on a QwtPlot widget.
+
+  QwtSamplingThread starts a thread calling periodically sample(),
+  to collect and store ( or emit ) a single sample.
+
+  \sa QwtPlotCurve, QwtPlotSeriesItem
+*/
+class QWT_EXPORT QwtSamplingThread: public QThread
+{
+    Q_OBJECT
+
+public:
+    virtual ~QwtSamplingThread();
+
+    double interval() const;
+    double elapsed() const;
+
+public Q_SLOTS:
+    void setInterval( double interval );
+    void stop();
+
+protected:
+    explicit QwtSamplingThread( QObject *parent = NULL );
+
+    virtual void run();
+
+    /*!
+       Collect a sample
+
+       \param elapsed Time since the thread was started in milliseconds
+     */
+    virtual void sample( double elapsed ) = 0;
+
+private:
+    class PrivateData;
+    PrivateData *d_data;
+};
+
+#endif