The user must select points in a clockwise direction

--HG--
branch : feature

src/libs/vlayout/vabstractdetail.cpp

@@ -506,3 +506,33 @@ QPointF VAbstractDetail::SingleParallelPoint(const QLineF &line, const qreal &an
     pLine.setLength( width );
     return pLine.p2();
 }
+
+//---------------------------------------------------------------------------------------------------------------------
+qreal VAbstractDetail::SumTrapezoids(int n, QVector<qreal> x, QVector<qreal> y) const
+{
+    // Calculation a polygon area through the sum of the areas of trapezoids
+    qreal s, res = 0;
+
+    for (int i = 0; i < n; ++i)
+    {
+        if (i == 0)
+        {
+            s = x.at(i)*(y.at(n-1) - y.at(i+1)); //if i == 0, then y[i-1] replace on y[n-1]
+            res += s;
+        }
+        else
+        {
+            if (i == n-1)
+            {
+                s = x.at(i)*(y.at(i-1) - y.at(0)); // if i == n-1, then y[i+1] replace on y[0]
+                res += s;
+            }
+            else
+            {
+                s = x.at(i)*(y.at(i-1) - y.at(i+1));
+                res += s;
+            }
+        }
+    }
+    return res;
+}

src/libs/vlayout/vabstractdetail.h

@@ -65,6 +65,8 @@ public:
     void    setWidth(const qreal &value);
 
     static QVector<QPointF> Equidistant(const QVector<QPointF> &points, const EquidistantType &eqv, qreal width);
+    qreal SumTrapezoids(int n,  QVector<qreal> x,  QVector<qreal> y) const;
+
 
 protected:
     static QVector<QPointF> RemoveDublicates(const QVector<QPointF> &points);

src/libs/vlayout/vlayoutdetail.cpp

@@ -289,7 +289,6 @@ qint64 VLayoutDetail::Square() const
     }
 
     const int n = d->layoutAllowence.count();
-    qreal s, res = 0;
     qint64 sq = 0;
 
     QVector<qreal> x;
@@ -301,28 +300,8 @@ qint64 VLayoutDetail::Square() const
         y.append(d->layoutAllowence.at(i).y());
     }
 
-    // Calculation a polygon area through the sum of the areas of trapezoids
-    for (int i = 0; i < n; ++i)
-    {
-        if (i == 0)
-        {
-            s = x.at(i)*(y.at(n-1) - y.at(i+1)); //if i == 0, then y[i-1] replace on y[n-1]
-            res += s;
-        }
-        else
-        {
-            if (i == n-1)
-            {
-                s = x.at(i)*(y.at(i-1) - y.at(0)); // if i == n-1, then y[i+1] replace on y[0]
-                res += s;
-            }
-            else
-            {
-                s = x.at(i)*(y.at(i-1) - y.at(i+1));
-                res += s;
-            }
-        }
-    }
+    qreal res = this->SumTrapezoids(n, x, y);
+
     sq = qFloor(qAbs(res/2.0));
     return sq;
 }

src/libs/vtools/dialogs/tools/dialogdetail.cpp

@@ -473,6 +473,12 @@ bool DialogDetail::DetailIsValid() const
     }
     else
     {
+        if(not DetailIsClockwise())
+        {
+            url += QString(" ") +tr("You have to choose points in a clockwise direction!");
+            ui.helpLabel->setText(url);
+            return false;
+        }
         if (FirstPointEqualLast())
         {
             url += QString(" ") +tr("First point can not equal the last point!");
@@ -518,3 +524,35 @@ bool DialogDetail::FirstPointEqualLast() const
     }
     return false;
 }
+
+//---------------------------------------------------------------------------------------------------------------------
+bool DialogDetail::DetailIsClockwise() const
+{
+    VDetail detail;
+    if(ui.listWidget->count() < 3)
+    {
+        return true;
+    }
+    for (qint32 i = 0; i < ui.listWidget->count(); ++i)
+    {
+        QListWidgetItem *item = ui.listWidget->item(i);
+        detail.append( qvariant_cast<VNodeDetail>(item->data(Qt::UserRole)));
+    }
+    QVector<QPointF> points = detail.ContourPoints(data);
+
+    QVector<qreal> x;
+    QVector<qreal> y;
+    const int n = points.size();
+    for (int i=0; i < n; ++i)
+    {
+        x.append(points.at(i).x());
+        y.append(points.at(i).y());
+    }
+
+    qreal res = detail.SumTrapezoids(n, x, y);
+    if (res < 0)
+    {
+        return true;
+    }
+    return false;
+}

src/libs/vtools/dialogs/tools/dialogdetail.h

@@ -78,6 +78,7 @@ private:
     bool             flagWidth;
     bool             DetailIsValid() const;
     bool             FirstPointEqualLast() const;
+    bool             DetailIsClockwise() const;
 
     void             NewItem(quint32 id, const Tool &typeTool, const NodeDetail &typeNode,
                              qreal mx = 0, qreal my = 0, bool reverse = false);