Merge pull request #208 from homann/issue1969

Issue1969 - Improvements to use of measurement functionality

Author: timlinux

i18n/qgis_sv.ts

@@ -14,10 +14,12 @@ class QgsDistanceArea
     ~QgsDistanceArea();
 
     //! sets whether coordinates must be projected to ellipsoid before measuring
-    void setProjectionsEnabled(bool flag);
+    void setEllipsoidalMode(bool flag);
+    void setProjectionsEnabled(bool flag) /Deprecated/;
 
     //! returns projections enabled flag
-    bool hasCrsTransformEnabled();
+    bool ellipsoidalEnabled();
+    bool hasCrsTransformEnabled() /Deprecated/;
 
     //! sets source spatial reference system (by QGIS CRS)
     void setSourceCrs(long srsid);
@@ -67,4 +69,7 @@ class QgsDistanceArea
 
     static QString textUnit( double value, int decimals, QGis::UnitType u, bool isArea, bool keepBaseUnit = false );
 
+    //! Helper for conversion between physical units
+    void convertMeasurement( double &measure, QGis::UnitType &measureUnits, QGis::UnitType displayUnits, bool isArea );
+
 };

python/core/qgsdistancearea.sip

@@ -46,7 +46,7 @@ class ANALYSIS_EXPORT QgsGraphBuilderInterface
     {
       mDa.setSourceCrs( mCrs.srsid() );
       mDa.setEllipsoid( ellipsoidID );
-      mDa.setProjectionsEnabled( ctfEnabled );
+      mDa.setEllipsoidalMode( ctfEnabled );
     }
 
     //! Destructor

src/analysis/network/qgsgraphbuilderintr.h

@@ -245,7 +245,7 @@ bool QgsMapToolIdentify::identifyVectorLayer( QgsVectorLayer *layer, int x, int
   QgsDistanceArea calc;
   if ( !featureList.count() == 0 )
   {
-    calc.setProjectionsEnabled( mCanvas->hasCrsTransformEnabled() ); // project?
+    calc.setEllipsoidalMode( mCanvas->hasCrsTransformEnabled() );
     calc.setEllipsoid( ellipsoid );
     calc.setSourceCrs( layer->crs().srsid() );
   }
@@ -387,43 +387,23 @@ void QgsMapToolIdentify::convertMeasurement( QgsDistanceArea &calc, double &meas
   // Helper for converting between meters and feet
   // The parameter &u is out only...
 
+  // Get the canvas units
   QGis::UnitType myUnits = mCanvas->mapUnits();
-  if (( myUnits == QGis::Degrees || myUnits == QGis::Feet ) &&
-      calc.ellipsoid() != "NONE" &&
-      calc.hasCrsTransformEnabled() )
-  {
-    // Measuring on an ellipsoid returns meters, and so does using projections???
-    myUnits = QGis::Meters;
-    QgsDebugMsg( "We're measuring on an ellipsoid or using projections, the system is returning meters" );
-  }
 
   // Get the units for display
   QSettings settings;
   QString myDisplayUnitsTxt = settings.value( "/qgis/measure/displayunits", "meters" ).toString();
 
-  // Only convert between meters and feet
-  if ( myUnits == QGis::Meters && myDisplayUnitsTxt == "feet" )
+  QGis::UnitType displayUnits;
+  if ( myDisplayUnitsTxt == "feet" )
   {
-    QgsDebugMsg( QString( "Converting %1 meters" ).arg( QString::number( measure ) ) );
-    measure /= 0.3048;
-    if ( isArea )
-    {
-      measure /= 0.3048;
-    }
-    QgsDebugMsg( QString( "to %1 feet" ).arg( QString::number( measure ) ) );
-    myUnits = QGis::Feet;
+    displayUnits = QGis::Feet;
   }
-  if ( myUnits == QGis::Feet && myDisplayUnitsTxt == "meters" )
+  else
   {
-    QgsDebugMsg( QString( "Converting %1 feet" ).arg( QString::number( measure ) ) );
-    measure *= 0.3048;
-    if ( isArea )
-    {
-      measure *= 0.3048;
-    }
-    QgsDebugMsg( QString( "to %1 meters" ).arg( QString::number( measure ) ) );
-    myUnits = QGis::Meters;
+    displayUnits = QGis::Meters;
   }
 
+  calc.convertMeasurement( measure, myUnits, displayUnits, isArea );
   u = myUnits;
 }

src/app/qgsmaptoolidentify.cpp

@@ -183,7 +183,7 @@ void QgsMapToolMeasureAngle::configureDistanceArea()
   QString ellipsoidId = settings.value( "/qgis/measure/ellipsoid", "WGS84" ).toString();
   mDa.setSourceCrs( mCanvas->mapRenderer()->destinationCrs().srsid() );
   mDa.setEllipsoid( ellipsoidId );
-  mDa.setProjectionsEnabled( mResultDisplay->projectionEnabled() );
+  mDa.setEllipsoidalMode( mResultDisplay->projectionEnabled() ); // FIXME (not when proj is turned off)
 }
 
 

src/app/qgsmaptoolmeasureangle.cpp

@@ -59,6 +59,12 @@ QgsMeasureDialog::QgsMeasureDialog( QgsMeasureTool* tool, Qt::WFlags f )
 
   connect( mcbProjectionEnabled, SIGNAL( stateChanged( int ) ),
            this, SLOT( changeProjectionEnabledState() ) );
+  // Update when project wide transformation has changed
+  connect( mTool->canvas()->mapRenderer(), SIGNAL( hasCrsTransformEnabled( bool ) ),
+           this, SLOT( changeProjectionEnabledState() ) );
+  // Update when project CRS has changed
+  connect( mTool->canvas()->mapRenderer(), SIGNAL( destinationSrsChanged() ),
+           this, SLOT( changeProjectionEnabledState() ) );
 
   updateUi();
 }
@@ -118,6 +124,7 @@ void QgsMeasureDialog::mouseMove( QgsPoint &point )
     convertMeasurement( d, myDisplayUnits, false );
     QTreeWidgetItem *item = mTable->topLevelItem( mTable->topLevelItemCount() - 1 );
     item->setText( 0, QLocale::system().toString( d, 'f', decimalPlaces ) );
+    QgsDebugMsg( QString( "Final result is %1" ).arg( item->text( 0 ) ) );
   }
 }
 
@@ -214,29 +221,50 @@ QString QgsMeasureDialog::formatArea( double area, int decimalPlaces )
 
 void QgsMeasureDialog::updateUi()
 {
+  // Only enable checkbox when project wide transformation is on
+  mcbProjectionEnabled->setEnabled( mTool->canvas()->hasCrsTransformEnabled() );
+
+  configureDistanceArea();
+
   QSettings settings;
-  int decimalPlaces = settings.value( "/qgis/measure/decimalplaces", "3" ).toInt();
 
-  double dummy = 1.0;
-  QGis::UnitType myDisplayUnits;
-  // The dummy distance is ignored
-  convertMeasurement( dummy, myDisplayUnits, false );
+  // Set tooltip to indicate how we calculate measurments
+  QGis::UnitType mapUnits = mTool->canvas()->mapUnits();
+  QGis::UnitType displayUnits = QGis::fromLiteral( settings.value( "/qgis/measure/displayunits", QGis::toLiteral( QGis::Meters ) ).toString() );
 
-  switch ( myDisplayUnits )
+  QString toolTip = tr( "The calculations are based on:" );
+  if ( ! mTool->canvas()->hasCrsTransformEnabled() )
   {
-    case QGis::Meters:
-      mTable->setHeaderLabels( QStringList( tr( "Segments (in meters)" ) ) );
-      break;
-    case QGis::Feet:
-      mTable->setHeaderLabels( QStringList( tr( "Segments (in feet)" ) ) );
-      break;
-    case QGis::Degrees:
-      mTable->setHeaderLabels( QStringList( tr( "Segments (in degrees)" ) ) );
-      break;
-    case QGis::UnknownUnit:
-      mTable->setHeaderLabels( QStringList( tr( "Segments" ) ) );
+    toolTip += "<br> * " + tr( "Project CRS transformation is turned off." ) + " ";
+    toolTip += tr( "Canvas units setting is taken from project properties setting (%1)." ).arg( QGis::tr( mapUnits ) );
+    toolTip += "<br> * " + tr( "Ellipsoidal calculation is not possible, as project CRS is undefined." );
+  }
+  else
+  {
+    if ( mDa.ellipsoidalEnabled() )
+    {
+      toolTip += "<br> * " + tr( "Project CRS transformation is turned on and ellipsoidal calculation is selected." ) + " ";
+      toolTip += "<br> * " + tr( "The coordinates are transformed to the chosen ellipsoid (%1), and the result is in meters" ).arg( mDa.ellipsoid() );
+    }
+    else
+    {
+      toolTip += "<br> * " + tr( "Project CRS transformation is turned on but ellipsoidal calculation is not selected." );
+      toolTip += "<br> * " + tr( "The canvas units setting is taken from the project CRS (%1)." ).arg( QGis::tr( mapUnits ) );
+    }
   }
 
+  if (( mapUnits == QGis::Meters && displayUnits == QGis::Feet ) || ( mapUnits == QGis::Feet && displayUnits == QGis::Meters ) )
+  {
+    toolTip += "<br> * " + tr( "Finally, the value is converted from %2 to %3." ).arg( QGis::tr( mapUnits ) ).arg( QGis::tr( displayUnits ) );
+  }
+
+  editTotal->setToolTip( toolTip );
+  mTable->setToolTip( toolTip );
+
+  int decimalPlaces = settings.value( "/qgis/measure/decimalplaces", "3" ).toInt();
+
+  mTable->setHeaderLabels( QStringList( tr( "Segments [%1]" ).arg( QGis::tr( displayUnits ) ) ) );
+
   if ( mMeasureArea )
   {
     mTable->hide();
@@ -247,52 +275,23 @@ void QgsMeasureDialog::updateUi()
     mTable->show();
     editTotal->setText( formatDistance( 0, decimalPlaces ) );
   }
-
-  configureDistanceArea();
 }
 
 void QgsMeasureDialog::convertMeasurement( double &measure, QGis::UnitType &u, bool isArea )
 {
   // Helper for converting between meters and feet
   // The parameter &u is out only...
 
+  // Get the canvas units
   QGis::UnitType myUnits = mTool->canvas()->mapUnits();
-  if (( myUnits == QGis::Degrees || myUnits == QGis::Feet )  &&
-      mcbProjectionEnabled->isChecked() )
-  {
-    // Measuring on an ellipsoid returns meters, and so does using projections???
-    myUnits = QGis::Meters;
-    QgsDebugMsg( "We're measuring on an ellipsoid or using projections, the system is returning meters" );
-  }
 
   // Get the units for display
   QSettings settings;
-  QString myDisplayUnitsTxt = settings.value( "/qgis/measure/displayunits", "meters" ).toString();
+  QGis::UnitType displayUnits = QGis::fromLiteral( settings.value( "/qgis/measure/displayunits", QGis::toLiteral( QGis::Meters ) ).toString() );
 
-  // Only convert between meters and feet
-  if ( myUnits == QGis::Meters && myDisplayUnitsTxt == "feet" )
-  {
-    QgsDebugMsg( QString( "Converting %1 meters" ).arg( QString::number( measure ) ) );
-    measure /= 0.3048;
-    if ( isArea )
-    {
-      measure /= 0.3048;
-    }
-    QgsDebugMsg( QString( "to %1 feet" ).arg( QString::number( measure ) ) );
-    myUnits = QGis::Feet;
-  }
-  if ( myUnits == QGis::Feet && myDisplayUnitsTxt == "meters" )
-  {
-    QgsDebugMsg( QString( "Converting %1 feet" ).arg( QString::number( measure ) ) );
-    measure *= 0.3048;
-    if ( isArea )
-    {
-      measure *= 0.3048;
-    }
-    QgsDebugMsg( QString( "to %1 meters" ).arg( QString::number( measure ) ) );
-    myUnits = QGis::Meters;
-  }
+  QgsDebugMsg( QString( "Preferred display units are %1" ).arg( QGis::toLiteral( displayUnits ) ) );
 
+  mDa.convertMeasurement( measure, myUnits, displayUnits, isArea );
   u = myUnits;
 }
 
@@ -301,9 +300,13 @@ void QgsMeasureDialog::changeProjectionEnabledState()
   // store value
   QSettings settings;
   if ( mcbProjectionEnabled->isChecked() )
+  {
     settings.setValue( "/qgis/measure/projectionEnabled", 2 );
+  }
   else
+  {
     settings.setValue( "/qgis/measure/projectionEnabled", 0 );
+  }
 
   // clear interface
   mTable->clear();
@@ -362,5 +365,6 @@ void QgsMeasureDialog::configureDistanceArea()
   QString ellipsoidId = settings.value( "/qgis/measure/ellipsoid", "WGS84" ).toString();
   mDa.setSourceCrs( mTool->canvas()->mapRenderer()->destinationCrs().srsid() );
   mDa.setEllipsoid( ellipsoidId );
-  mDa.setProjectionsEnabled( mcbProjectionEnabled->isChecked() );
+  // Only use ellipsoidal calculation when project wide transformation is enabled.
+  mDa.setEllipsoidalMode( mcbProjectionEnabled->isChecked() && mTool->canvas()->hasCrsTransformEnabled() );
 }

src/app/qgsmeasuredialog.cpp

@@ -62,8 +62,8 @@ class QgsMeasureDialog : public QDialog, private Ui::QgsMeasureBase
 
     //! Show the help for the dialog
     void on_buttonBox_helpRequested() { QgsContextHelp::run( metaObject()->className() ); }
-  private slots:
-    //! on change state projection enable
+
+    //! on change state projection/ellipsoid enable
     void changeProjectionEnabledState();
 
   private:

src/app/qgsmeasuredialog.h

@@ -187,7 +187,7 @@ double QgsComposerScaleBar::mapWidth() const
   else
   {
     QgsDistanceArea da;
-    da.setProjectionsEnabled( true );
+    da.setEllipsoidalMode( mComposerMap->mapRenderer()->hasCrsTransformEnabled() );
     da.setSourceCrs( mComposerMap->mapRenderer()->destinationCrs().srsid() );
     QSettings s;
     da.setEllipsoid( s.value( "/qgis/measure/ellipsoid", "WGS84" ).toString() );

src/core/composer/qgscomposerscalebar.cpp

@@ -19,7 +19,7 @@
 #ifndef QGSVERSION
 #include "qgsversion.h"
 #endif
-
+#include <QCoreApplication>
 #include "qgsconfig.h"
 
 #include <ogr_api.h>
@@ -67,5 +67,40 @@ const char* QGis::qgisFeatureTypes[] =
   "WKBMultiPolygon"
 };
 
+
 const double QGis::DEFAULT_IDENTIFY_RADIUS = 0.5;
 
+// description strings for units
+// Order must match enum indices
+const char* QGis::qgisUnitTypes[] =
+{
+  QT_TRANSLATE_NOOP( "QGis::UnitType", "meters" ),
+  QT_TRANSLATE_NOOP( "QGis::UnitType", "feet" ),
+  QT_TRANSLATE_NOOP( "QGis::UnitType", "degrees" ),
+  QT_TRANSLATE_NOOP( "QGis::UnitType", "<unknown>" ),
+  QT_TRANSLATE_NOOP( "QGis::UnitType", "degrees" ),
+  QT_TRANSLATE_NOOP( "QGis::UnitType", "degrees" ),
+  QT_TRANSLATE_NOOP( "QGis::UnitType", "degrees" )
+};
+
+QGis::UnitType QGis::fromLiteral( QString literal, QGis::UnitType defaultType )
+{
+  for ( unsigned int i = 0; i < ( sizeof( qgisUnitTypes ) / sizeof( qgisUnitTypes[0] ) ); i++ )
+  {
+    if ( literal == qgisUnitTypes[ i ] )
+    {
+      return static_cast<UnitType>( i );
+    }
+  }
+  return defaultType;
+}
+
+QString QGis::toLiteral( QGis::UnitType unit )
+{
+  return QString( qgisUnitTypes[ static_cast<int>( unit )] );
+}
+
+QString QGis::tr( QGis::UnitType unit )
+{
+  return QCoreApplication::translate( "QGis::UnitType", qPrintable( toLiteral( unit ) ) );
+}

src/core/qgis.cpp

@@ -20,6 +20,7 @@
 
 #include <QEvent>
 #include <QString>
+#include <QMetaType>
 #include <cfloat>
 #include <cmath>
 #include <qnumeric.h>
@@ -96,6 +97,13 @@ class CORE_EXPORT QGis
       DegreesDecimalMinutes = 2,  // was 5
     };
 
+    // Provides the canonical name of the type value
+    static QString toLiteral( QGis::UnitType unit );
+    // Converts from the canonical name to the type value
+    static UnitType fromLiteral( QString  literal, QGis::UnitType defaultType = UnknownUnit );
+    // Provides translated version of the type value
+    static QString tr( QGis::UnitType unit );
+
     //! User defined event types
     enum UserEvent
     {
@@ -109,6 +117,11 @@ class CORE_EXPORT QGis
     };
 
     static const double DEFAULT_IDENTIFY_RADIUS;
+
+  private:
+    // String representation of unit types (set in qgis.cpp)
+    static const char *qgisUnitTypes[];
+
 };
 
 // hack to workaround warnings when casting void pointers