Hack #2 for measuring. Localized numbers, added hectares (ha),

centralized pretty printing of units and made special cases for
projection on and projection off.


git-svn-id: http://svn.osgeo.org/qgis/trunk/qgis@6450 c8812cc2-4d05-0410-92ff-de0c093fc19c

Author: homann

src/app/qgsmaptoolidentify.cpp

@@ -215,7 +215,7 @@ void QgsMapToolIdentify::identifyVectorLayer(QgsVectorLayer* layer, const QgsPoi
 
   // init distance/area calculator
   QgsDistanceArea calc;
-  calc.setProjectionsEnabled(TRUE); // always project
+  calc.setProjectionsEnabled(mCanvas->projectionsEnabled()); // project?
   calc.setEllipsoid(ellipsoid);
   calc.setSourceSRS(layer->srs().srsid());
 
@@ -265,15 +265,13 @@ void QgsMapToolIdentify::identifyVectorLayer(QgsVectorLayer* layer, const QgsPoi
       if (layer->vectorType() == QGis::Line)
       {
         double dist = calc.measure(feat.geometry());
-        QString str = QString::number(dist/1000, 'f', 3);
-        str += " km";
+        QString str = calc.textUnit(dist, 3, mCanvas->mapUnits(), false);
         mResults->addDerivedAttribute(featureNode, QObject::tr("Length"), str);
       }
       else if (layer->vectorType() == QGis::Polygon)
       {
         double area = calc.measure(feat.geometry());
-        QString str = QString::number(area/1000000, 'f', 3);
-        str += " km^2";
+        QString str = calc.textUnit(area, 3, mCanvas->mapUnits(), true);
         mResults->addDerivedAttribute(featureNode, QObject::tr("Area"), str);
       }
 

src/app/qgsmeasure.cpp

@@ -27,6 +27,7 @@
 
 #include "QMessageBox"
 #include <QSettings>
+#include <QLocale>
 #include <iostream>
 
 
@@ -184,12 +185,11 @@ void QgsMeasure::addPoint(QgsPoint &point)
       editTotal->setText(formatDistance(mTotal));
 
 
-	    int row = mPoints.size()-2;
-      mTable->setText(row, 0, QString::number(d, 'f',1));
-      //mTable->setText ( row, 1, QString::number(mTotal) );
+      int row = mPoints.size()-2;
+      mTable->setText(row, 0, QLocale::system().toString(d, 'f', 2));
       mTable->setNumRows ( mPoints.size() );
 
-      mTable->setText(row + 1, 0, QString::number(0, 'f',1));
+      mTable->setText(row + 1, 0, QLocale::system().toString(0.0, 'f', 2));
       mTable->ensureCellVisible(row + 1,0);
     }
 
@@ -232,7 +232,8 @@ void QgsMeasure::mouseMove(QgsPoint &point)
     QgsPoint p1 = tmpPoints[last], p2 = tmpPoints[last+1];
 
     double d = mCanvas->mapRender()->distArea()->measureLine(p1,p2);
-    mTable->setText(last, 0, QString::number(d, 'f',1));
+    //mTable->setText(last, 0, QString::number(d, 'f',1));
+    mTable->setText(last, 0, QLocale::system().toString(d, 'f', 2));
     editTotal->setText(formatDistance(mTotal + d));
   }
 }
@@ -299,66 +300,13 @@ QString QgsMeasure::formatDistance(double distance)
   QString unitLabel;
 
   QGis::units myMapUnits = mCanvas->mapUnits();
-  switch (myMapUnits)
-  {
-    case QGis::METERS: 
-      if (distance > 1000.0)
-      {
-	unitLabel=tr(" km");
-	distance = distance/1000;
-      }
-      else if (distance < 0.01)
-      {
-	unitLabel=tr(" mm");
-	distance = distance*1000;
-      }
-      else if (distance < 0.1)
-      {
-        unitLabel=tr(" cm");
-        distance = distance*100;
-      }
-      else
-	unitLabel=tr(" m"); 
-      break;
-    case QGis::FEET:
-      if (distance == 1.0)
-	unitLabel=tr(" foot"); 
-      else
-	unitLabel=tr(" feet"); 
-      break;
-    case QGis::DEGREES:
-      if (distance == 1.0)
-	unitLabel=tr(" degree"); 
-      else
-	unitLabel=tr(" degrees"); 
-      break;
-    case QGis::UNKNOWN:
-      unitLabel=tr(" unknown");
-    default: 
-      std::cout << "Error: not picked up map units - actual value = " 
-		<< myMapUnits << std::endl;
-  };
-
-  txt = QString::number(distance,'f',1);
-  txt += unitLabel;
-
-  return txt;
+  return QgsDistanceArea::textUnit(distance, 2, myMapUnits, false);
 }
 
 QString QgsMeasure::formatArea(double area)
 {
-  QString txt;
-  if (area < 10000)
-  {
-    txt = QString::number(area,'f',0);
-    txt += " m2";
-  }
-  else
-  {
-    txt = QString::number(area/1000000,'f',3);
-    txt += " km2";
-  }
-  return txt;
+  QGis::units myMapUnits = mCanvas->mapUnits();
+  return QgsDistanceArea::textUnit(area, 2, myMapUnits, true);
 }
 
 void QgsMeasure::updateUi()

src/core/qgsdistancearea.cpp

@@ -17,6 +17,9 @@
 #include <cmath>
 #include <sqlite3.h>
 #include <QDir>
+#include <QString>
+#include <QLocale>
+#include <QObject>
 
 #include "qgis.h"
 #include "qgspoint.h"
@@ -529,6 +532,10 @@ double QgsDistanceArea::computePolygonArea(const std::vector<QgsPoint>& points)
   double Qbar1, Qbar2;
   double area;
 
+  if (! mProjectionsEnabled)
+  {
+    return computePolygonFlatArea(points);
+  }
   int n = points.size();
   x2 = DEG2RAD(points[n-1].x());
   y2 = DEG2RAD(points[n-1].y());
@@ -573,3 +580,109 @@ double QgsDistanceArea::computePolygonArea(const std::vector<QgsPoint>& points)
   return area;
 }
 
+double QgsDistanceArea::computePolygonFlatArea(const std::vector<QgsPoint>& points)
+{
+  // Normal plane area calculations.
+  double area = 0.0;
+  int i, size;
+  
+  size = points.size();
+
+  // QgsDebugMsg("New area calc, nr of points: " + QString::number(size));
+  for(i = 0; i < size; i++)
+  {
+    // QgsDebugMsg("Area from point: " + (points[i]).stringRep(2));
+    // Using '% size', so that we always end with the starting point
+    // and thus close the polygon.
+    area = area + points[i].x()*points[(i+1) % size].y() - points[(i+1) % size].x()*points[i].y();
+  }
+  // QgsDebugMsg("Area from point: " + (points[i % size]).stringRep(2));
+  area = area / 2.0;
+  return area;
+}
+
+QString QgsDistanceArea::textUnit(double value, int decimals, QGis::units u, bool isArea)
+{
+  QString unitLabel;
+
+
+  switch (u)
+  {
+  case QGis::METERS: 
+    if (isArea)
+    {
+      if (value > 1000000.0)
+      {
+	unitLabel = QObject::tr(" km2");
+	value = value / 1000000.0;
+      }
+      else if (value > 1000.0)
+      {
+	unitLabel = QObject::tr(" ha");
+	value = value / 10000.0;
+      }
+      else
+      {
+	unitLabel = QObject::tr(" m2");
+      }
+    }
+    else
+    {
+      if (value > 1000.0)
+      {
+	unitLabel=QObject::tr(" km");
+	value = value/1000;
+      }
+      else if (value < 0.01)
+      {
+	unitLabel=QObject::tr(" mm");
+	value = value*1000;
+      }
+      else if (value < 0.1)
+      {
+	unitLabel=QObject::tr(" cm");
+	value = value*100;
+      }
+      else
+      {
+	unitLabel=QObject::tr(" m"); 
+      }
+    }
+    break;
+  case QGis::FEET:
+    if (isArea)
+    {
+      unitLabel = QObject::tr(" sq ft");
+    }
+    else
+    {
+      if (value == 1.0)
+	unitLabel=QObject::tr(" foot"); 
+      else
+	unitLabel=QObject::tr(" feet"); 
+    }
+    break;
+  case QGis::DEGREES:
+    if (isArea)
+    {
+      unitLabel = QObject::tr(" sq.deg.");
+    }
+    else
+    {
+      if (value == 1.0)
+	unitLabel=QObject::tr(" degree"); 
+      else
+	unitLabel=QObject::tr(" degrees"); 
+    }
+    break;
+  case QGis::UNKNOWN:
+    unitLabel=QObject::tr(" unknown");
+  default: 
+    std::cout << "Error: not picked up map units - actual value = " 
+	      << u << std::endl;
+  };
+
+
+  return QLocale::system().toString(value, 'f', decimals) + unitLabel;
+
+}

src/core/qgsdistancearea.h

@@ -84,6 +84,8 @@ class CORE_EXPORT QgsDistanceArea
     //! compute bearing - in radians
     double getBearing(const QgsPoint& p1, const QgsPoint& p2);
 
+    static QString textUnit(double value, int decimals, QGis::units u, bool isArea);
+
   protected:
 
     //! measures line distance, line points are extracted from WKB
@@ -111,6 +113,8 @@ class CORE_EXPORT QgsDistanceArea
     
     */
     double computePolygonArea(const std::vector<QgsPoint>& points);
+
+    double computePolygonFlatArea(const std::vector<QgsPoint>& points);
 
     /**
       precalculates some values