A quick hack to investigate measurements when projection is off.

Feedback welcome!


git-svn-id: http://svn.osgeo.org/qgis/trunk@6446 c8812cc2-4d05-0410-92ff-de0c093fc19c

src/app/qgsmeasure.cpp

@@ -52,7 +52,7 @@ QgsMeasure::QgsMeasure(bool measureArea, QgsMapCanvas *mc, Qt::WFlags f)
     mTable->setNumRows(1);
     mTable->setText(0, 0, QString::number(0, 'f',1));
 
-    mTable->horizontalHeader()->setLabel( 0, tr("Segments (in meters)") );
+    //mTable->horizontalHeader()->setLabel( 0, tr("Segments (in meters)") );
     //mTable->horizontalHeader()->setLabel( 1, tr("Total") );
     //mTable->horizontalHeader()->setLabel( 2, tr("Azimuth") );
 
@@ -64,7 +64,7 @@ QgsMeasure::QgsMeasure(bool measureArea, QgsMapCanvas *mc, Qt::WFlags f)
 
     connect( mMapCanvas, SIGNAL(renderComplete(QPainter*)), this, SLOT(mapCanvasChanged()) );
 
-    mCalc = new QgsDistanceArea;
+    //mCalc = new QgsDistanceArea;
 
     mRubberBand = new QgsRubberBand(mMapCanvas, mMeasureArea);
 
@@ -84,7 +84,7 @@ void QgsMeasure::activate()
 
   // If we suspect that they have data that is projected, yet the
   // map SRS is set to a geographic one, warn them.
-  if (mCalc->geographic() &&
+  if (mCanvas->mapRender()->distArea()->geographic() &&
       (mMapCanvas->extent().height() > 360 || 
        mMapCanvas->extent().width() > 720))
   {
@@ -119,7 +119,7 @@ void QgsMeasure::setMeasureArea(bool measureArea)
 
 QgsMeasure::~QgsMeasure()
 {
-  delete mCalc;
+//  delete mCalc;
   delete mRubberBand;
 }
 
@@ -169,7 +169,7 @@ void QgsMeasure::addPoint(QgsPoint &point)
 
     if (mMeasureArea && mPoints.size() > 2)
     {
-      double area = mCalc->measurePolygon(mPoints);
+      double area = mCanvas->mapRender()->distArea()->measurePolygon(mPoints);
       editTotal->setText(formatArea(area));
     }
     else if (!mMeasureArea && mPoints.size() > 1)
@@ -178,7 +178,7 @@ void QgsMeasure::addPoint(QgsPoint &point)
 
       QgsPoint p1 = mPoints[last], p2 = mPoints[last+1];
 
-      double d = mCalc->measureLine(p1,p2);
+      double d = mCanvas->mapRender()->distArea()->measureLine(p1,p2);
 
       mTotal += d;
       editTotal->setText(formatDistance(mTotal));
@@ -223,15 +223,15 @@ void QgsMeasure::mouseMove(QgsPoint &point)
   tmpPoints.push_back(point);
   if (mMeasureArea && tmpPoints.size() > 2)
   {
-    double area = mCalc->measurePolygon(tmpPoints);
+    double area = mCanvas->mapRender()->distArea()->measurePolygon(tmpPoints);
     editTotal->setText(formatArea(area));
   }
   else if (!mMeasureArea && tmpPoints.size() > 1)
   {
     int last = tmpPoints.size()-2;
     QgsPoint p1 = tmpPoints[last], p2 = tmpPoints[last+1];
 
-    double d = mCalc->measureLine(p1,p2);
+    double d = mCanvas->mapRender()->distArea()->measureLine(p1,p2);
     mTable->setText(last, 0, QString::number(d, 'f',1));
     editTotal->setText(formatDistance(mTotal + d));
   }
@@ -296,16 +296,52 @@ void QgsMeasure::on_btnHelp_clicked()
 QString QgsMeasure::formatDistance(double distance)
 {
   QString txt;
-  if (distance < 1000)
-  {
-    txt = QString::number(distance,'f',0);
-    txt += " m";
-  }
-  else
+  QString unitLabel;
+
+  QGis::units myMapUnits = mCanvas->mapUnits();
+  switch (myMapUnits)
   {
-    txt = QString::number(distance/1000,'f',1);
-    txt += " km";
-  }
+    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;
 }
 
@@ -327,6 +363,23 @@ QString QgsMeasure::formatArea(double area)
 
 void QgsMeasure::updateUi()
 {
+
+  QGis::units myMapUnits = mCanvas->mapUnits();
+  switch (myMapUnits)
+  {
+    case QGis::METERS: 
+      mTable->horizontalHeader()->setLabel( 0, tr("Segments (in meters)") );
+      break;
+    case QGis::FEET:
+      mTable->horizontalHeader()->setLabel( 0, tr("Segments (in feet)") );
+      break;
+    case QGis::DEGREES:
+      mTable->horizontalHeader()->setLabel( 0, tr("Segments (in degrees)") );
+      break;
+    case QGis::UNKNOWN:
+      mTable->horizontalHeader()->setLabel( 0, tr("Segments") );
+  };
+
   if (mMeasureArea)
   {
     mTable->hide();
@@ -344,14 +397,14 @@ void QgsMeasure::updateProjection()
 {
   // set ellipsoid
   QSettings settings;
-  QString ellipsoid = settings.readEntry("/qgis/measure/ellipsoid", "WGS84");
-  mCalc->setEllipsoid(ellipsoid);
+  // QString ellipsoid = settings.readEntry("/qgis/measure/ellipsoid", "WGS84");
+  // mCalc->setEllipsoid(ellipsoid);
 
   // set source SRS and projections enabled flag
-  QgsMapRender* mapRender = mCanvas->mapRender();
-  mCalc->setProjectionsEnabled(mapRender->projectionsEnabled());
-  int srsid = mapRender->destinationSrs().srsid();
-  mCalc->setSourceSRS(srsid);
+  // QgsMapRender* mapRender = mCanvas->mapRender();
+  // mCalc->setProjectionsEnabled(mapRender->projectionsEnabled());
+  // int srsid = mapRender->destinationSrs().srsid();
+  // mCalc->setSourceSRS(srsid);
 
   int myRed = settings.value("/qgis/default_measure_color_red", 180).toInt();
   int myGreen = settings.value("/qgis/default_measure_color_green", 180).toInt();

src/app/qgsmeasure.h

@@ -111,7 +111,7 @@ public slots:
   QgsMapCanvas *mMapCanvas;
 
   //! distance/area calculator
-  QgsDistanceArea* mCalc;
+  //QgsDistanceArea* mCalc;
 
   std::vector<QgsPoint> mPoints;
 

src/core/qgsdistancearea.cpp

@@ -279,8 +279,12 @@ double QgsDistanceArea::measureLine(const QgsPoint& p1, const QgsPoint& p2)
     {
       pp1 = mCoordTransform->transform(p1);
       pp2 = mCoordTransform->transform(p2);
+      return computeDistanceBearing(pp1, pp2);
+    }
+    else
+    {
+      return sqrt((p2.x()-p1.x())*(p2.x()-p1.x()) + (p2.y()-p1.y())*(p2.y()-p1.y()));
     }
-    return computeDistanceBearing(pp1, pp2);
   }
   catch (QgsCsException &cse)
   {

src/core/qgsmaprender.cpp

@@ -24,6 +24,7 @@
 #include "qgsmaptopixel.h"
 #include "qgsmaplayer.h"
 #include "qgsmaplayerregistry.h"
+#include "qgsdistancearea.h"
 //#include "qgsspatialrefsys.h"
 
 #include <QDomDocument>
@@ -37,6 +38,7 @@ QgsMapRender::QgsMapRender()
 {
   mCoordXForm = new QgsMapToPixel;
   mScaleCalculator = new QgsScaleCalculator;
+  mDistArea = new QgsDistanceArea;
 
   mDrawing = false;
   mOverview = false;
@@ -55,6 +57,7 @@ QgsMapRender::~QgsMapRender()
 {
   delete mCoordXForm;
   delete mScaleCalculator;
+  delete mDistArea;
   delete mDestSRS;
 }
 
@@ -365,6 +368,8 @@ void QgsMapRender::setProjectionsEnabled(bool enabled)
   if (mProjectionsEnabled != enabled)
   {
     mProjectionsEnabled = enabled;
+    QgsDebugMsg("Adjusting DistArea projection on/off");
+    mDistArea->setProjectionsEnabled(enabled);
     updateFullExtent();
     emit projectionsEnabled(enabled);
   }
@@ -382,7 +387,8 @@ void QgsMapRender::setDestinationSrs(const QgsSpatialRefSys& srs)
   QgsDebugMsg("* DestSRS.proj4() = " + srs.proj4String());
   if (*mDestSRS != srs)
   {
-    QgsDebugMsg("No, changed my mind!");
+    QgsDebugMsg("Setting DistArea SRS to " + QString::number(srs.srsid()));
+    mDistArea->setSourceSRS(srs.srsid());
     *mDestSRS = srs;
     updateFullExtent();
     emit destinationSrsChanged();

src/core/qgsmaprender.h

@@ -32,6 +32,7 @@ class QgsMapToPixel;
 class QgsMapLayer;
 class QgsScaleCalculator;
 class QgsSpatialRefSys;
+class QgsDistanceArea;
 
 /**
  * \class QgsMapRender
@@ -68,6 +69,8 @@ class CORE_EXPORT QgsMapRender : public QObject
     //! Recalculate the map scale
     void updateScale();
 
+    //! Return the measuring object
+    QgsDistanceArea* distArea() { return mDistArea; }
     QGis::units mapUnits() const;
     void setMapUnits(QGis::units u);
 
@@ -191,6 +194,8 @@ class CORE_EXPORT QgsMapRender : public QObject
     //! full extent of the layer set
     QgsRect mFullExtent;
 
+    //! tool for measuring 
+    QgsDistanceArea* mDistArea;
 };
 
 #endif