1 files changed, 57 insertions, 0 deletions
diff --git a/app/qcheapruler.hpp b/app/qcheapruler.hpp
new file mode 100644
index 0000000..9e9c664
--- /dev/null
+++ b/app/qcheapruler.hpp
@@ -0,0 +1,57 @@
+#pragma once
+
+#include <QGeoCoordinate>
+#include <QJSValue>
+#include <QObject>
+#include <QtCore>
+
+#include <mapbox/cheap_ruler.hpp>   /* BSD3 LICENSE */
+
+namespace cr = mapbox::cheap_ruler;
+
+class QCheapRuler : public QObject{
+    Q_OBJECT
+    //registy the read write&notify function for qml
+    //the distance from start point to end point(read only)
+    Q_PROPERTY(double distance READ distance)
+    //the distance from start point to current postion along the route(read notify)
+    Q_PROPERTY(double currentDistance READ currentDistance NOTIFY currentDistanceChanged)
+    //the coordinate info of current postion(read)
+    Q_PROPERTY(QGeoCoordinate currentPosition READ currentPosition NOTIFY currentPositionChanged)
+    //the route path info postion(read write&notify)
+    Q_PROPERTY(QJSValue path READ path WRITE setPath NOTIFY pathChanged)
+
+public:
+    QCheapRuler();
+     ~QCheapRuler();
+
+    //read write&notify function  for qml
+    double distance() const;
+    double currentDistance() const;
+    QGeoCoordinate currentPosition() const;
+    QJSValue path() const;
+    void setPath(const QJSValue &value);
+
+    //functions that can called by qml(Q_INVOKABLE)
+    Q_INVOKABLE void initRouteInfo();
+    Q_INVOKABLE void setCurrentPosition(double, double);
+    Q_INVOKABLE void setCurrentDistance(double);
+
+signals:
+    //notify signals to  qml
+    //notify signal when the distance from start point to current postion changed
+    void currentDistanceChanged();
+    //notify signal when currentPosition changed
+    void currentPositionChanged();
+    //notify signal when the distance from start point to current postion changed
+    void pathChanged();
+
+private:
+    cr::CheapRuler ruler() const;
+
+    double m_distance = 0.;
+    double m_currentDistance = 0.;
+    QGeoCoordinate m_currentPosition;
+
+    cr::line_string m_path;
+};