From da34d9524dc255bfb52afa585d9dbedb7ffdc54d Mon Sep 17 00:00:00 2001
From: Mark Liversedge <liversedge@gmail.com>
Date: Mon, 24 Aug 2015 20:04:41 +0100
Subject: [PATCH] Add Gapped Curve

.. want to mod ride plot to not plot gaps
   in recording, but instead draw a break
   in the curve.
---
 .../qwtcurve/qwt_plot_gapped_curve.cpp        | 63 +++++++++++++++++++
 qtsolutions/qwtcurve/qwt_plot_gapped_curve.h  | 39 ++++++++++++
 src/src.pro                                   |  6 +-
 3 files changed, 107 insertions(+), 1 deletion(-)
 create mode 100644 qtsolutions/qwtcurve/qwt_plot_gapped_curve.cpp
 create mode 100644 qtsolutions/qwtcurve/qwt_plot_gapped_curve.h

diff --git a/qtsolutions/qwtcurve/qwt_plot_gapped_curve.cpp b/qtsolutions/qwtcurve/qwt_plot_gapped_curve.cpp
new file mode 100644
index 000000000..3c198b379
--- /dev/null
+++ b/qtsolutions/qwtcurve/qwt_plot_gapped_curve.cpp
@@ -0,0 +1,63 @@
+#include "qwt_plot_gapped_curve.h"
+
+////////////////////////////////////////////////////////////////////////////////
+QwtPlotGappedCurve::QwtPlotGappedCurve(double gapValue) 
+:	QwtPlotCurve(), 
+	gapValue_(gapValue) 
+{
+}
+
+////////////////////////////////////////////////////////////////////////////////
+QwtPlotGappedCurve::QwtPlotGappedCurve(const QwtText &title, double gapValue)
+:	QwtPlotCurve(title), 
+	gapValue_(gapValue)  
+{
+}
+
+////////////////////////////////////////////////////////////////////////////////
+QwtPlotGappedCurve::QwtPlotGappedCurve(const QString &title, double gapValue)
+:	QwtPlotCurve(title), 
+	gapValue_(gapValue) 
+{
+}
+
+////////////////////////////////////////////////////////////////////////////////
+void QwtPlotGappedCurve::drawSeries(QPainter *painter, const QwtScaleMap &xMap,
+                                                          const QwtScaleMap &yMap, const QRectF &canvRect, int from, int to) const
+{
+    if ( !painter || dataSize() <= 0 )
+        return;
+
+    if (to < 0)
+        to = dataSize() - 1;
+
+    int i = from;
+    while (i < to)
+    {
+        // If data begins with missed values,
+        // we need to find first non-missed point.
+            double y = sample(i).y();
+            while ((i < to) && (y == gapValue_))
+            {
+                ++i;
+                y = sample(i).y();
+            }
+        // First non-missed point will be the start of curve section.
+            int start = i;
+            y = sample(i).y();
+        // Find the last non-missed point, it will be the end of curve section.
+            while ((i < to) && (y != gapValue_))
+            {
+                ++i;
+                y = sample(i).y();
+            }
+        // Correct the end of the section if it is at missed point
+            int end = (y == gapValue_) ? i - 1 : i;
+
+        // Draw the curve section
+            if (start <= end)
+                    QwtPlotCurve::drawSeries(painter, xMap, yMap, canvRect, start, end);
+    }
+}
+
+////////////////////////////////////////////////////////////////////////////////
diff --git a/qtsolutions/qwtcurve/qwt_plot_gapped_curve.h b/qtsolutions/qwtcurve/qwt_plot_gapped_curve.h
new file mode 100644
index 000000000..9d6e6fa37
--- /dev/null
+++ b/qtsolutions/qwtcurve/qwt_plot_gapped_curve.h
@@ -0,0 +1,39 @@
+#ifndef QWT_PLOT_GAPPED_CURVE_H
+#define QWT_PLOT_GAPPED_CURVE_H
+
+#include <QString>
+
+#include "qwt_plot_curve.h"
+#include "qwt_text.h"
+#include "qwt_plot_curve.h"
+#include "qwt_scale_map.h"
+
+////////////////////////////////////////////////////////////////////////////////
+/// This class is a plot curve that can have gaps at points
+/// with specific Y value.
+/// This specific "gap" value can be passed to constructors, 
+/// it's zero by default.  
+class QwtPlotGappedCurve: public QwtPlotCurve
+{
+public:
+	/// gapValue is an Y value which denotes missed data
+    QwtPlotGappedCurve(double gapValue = 0);
+    
+	/// gapValue is an Y value which denotes missed data
+    QwtPlotGappedCurve(const QwtText &title, double gapValue = 0);
+
+	/// gapValue is an Y value which denotes missed data
+    QwtPlotGappedCurve(const QString &title, double gapValue = 0);
+
+    /// Override draw method to create gaps for missed Y values 
+    virtual void drawSeries(QPainter *painter, const QwtScaleMap &xMap,
+                                                const QwtScaleMap &yMap, const QRectF &canvRect, int from, int to) const;
+
+private:
+	/// Value that denotes missed Y data at point
+	double gapValue_;
+};
+
+////////////////////////////////////////////////////////////////////////////////
+
+#endif
diff --git a/src/src.pro b/src/src.pro
index 7744edcae..6e179d046 100644
--- a/src/src.pro
+++ b/src/src.pro
@@ -12,7 +12,7 @@ DEPENDPATH += .
 QMAKE_INFO_PLIST = ./mac/Info.plist.app
 
 ## qwt and libz
-INCLUDEPATH += ../qwt/src ../qxt/src $${LIBZ_INCLUDE} ../qtsolutions/json
+INCLUDEPATH += ../qwt/src ../qxt/src $${LIBZ_INCLUDE} ../qtsolutions/json ../qtsolutions/qwtcurve
 LIBS += ../qwt/lib/libqwt.a
 LIBS += -lm $${LIBZ_LIBS}
 
@@ -266,6 +266,10 @@ HEADERS += TPUpload.h TPUploadDialog.h TPDownload.h TPDownloadDialog.h
 SOURCES += TPUpload.cpp TPUploadDialog.cpp TPDownload.cpp TPDownloadDialog.cpp
 DEFINES += GC_HAVE_SOAP
 
+# gapped curve
+HEADERS += ../qtsolutions/qwtcurve/qwt_plot_gapped_curve.h
+SOURCES +=  ../qtsolutions/qwtcurve/qwt_plot_gapped_curve.cpp
+
 HEADERS += \
         AboutDialog.h \
         AddDeviceWizard.h \