Catch datum transform request signal in QgsMapCanvas

qgis · Oct 18, 2013 · a2e0a1a · a2e0a1a
1 parent c82606c
commit a2e0a1a
Show file tree

Hide file tree

Showing 4 changed files with 69 additions and 11 deletions.
diff --git a/src/core/qgscoordinatetransform.cpp b/src/core/qgscoordinatetransform.cpp
@@ -785,7 +785,7 @@ QList< QList< int > > QgsCoordinateTransform::datumTransformations( const QgsCoo
   }
 
   QList<int> directTransforms;
-  searchDatumTransform( QString( "SELECT coord_op_code FROM tbl_datum_transform WHERE source_crs_code = %1 AND dest_crs_code = %2" ).arg( srcAuthCode ).arg( destAuthCode ),
+  searchDatumTransform( QString( "SELECT coord_op_code FROM tbl_datum_transform WHERE source_crs_code = %1 AND target_crs_code = %2" ).arg( srcAuthCode ).arg( destAuthCode ),
                         directTransforms );
   QList<int> srcToWgs84;
   searchDatumTransform( QString( "SELECT coord_op_code FROM tbl_datum_transform WHERE ( source_crs_code = %1 AND target_crs_code = %2 ) OR ( source_crs_code = %2 AND target_crs_code = %1 )" ).arg( srcAuthCode ).arg( 4326 ),

diff --git a/src/core/qgsmaprenderer.cpp b/src/core/qgsmaprenderer.cpp
@@ -792,17 +792,23 @@ bool QgsMapRenderer::splitLayersExtent( QgsMapLayer* layer, QgsRectangle& extent
       // extent separately.
       static const double splitCoord = 180.0;
 
+      const QgsCoordinateTransform* transform = tr( layer );
       if ( layer->crs().geographicFlag() )
       {
         // Note: ll = lower left point
         //   and ur = upper right point
-        QgsPoint ll = tr( layer )->transform( extent.xMinimum(), extent.yMinimum(),
-                                              QgsCoordinateTransform::ReverseTransform );
 
-        QgsPoint ur = tr( layer )->transform( extent.xMaximum(), extent.yMaximum(),
-                                              QgsCoordinateTransform::ReverseTransform );
+        QgsPoint ll( extent.xMinimum(), extent.yMinimum() );
+        QgsPoint ur( extent.xMaximum(), extent.yMaximum() );
 
-        extent = tr( layer )->transformBoundingBox( extent, QgsCoordinateTransform::ReverseTransform );
+        if ( transform )
+        {
+          ll = transform->transform( ll.x(), ll.y(),
+                                     QgsCoordinateTransform::ReverseTransform );
+          ur = transform->transform( ur.x(), ur.y(),
+                                     QgsCoordinateTransform::ReverseTransform );
+          extent = transform->transformBoundingBox( extent, QgsCoordinateTransform::ReverseTransform );
+        }
 
         if ( ll.x() > ur.x() )
         {
@@ -814,7 +820,10 @@ bool QgsMapRenderer::splitLayersExtent( QgsMapLayer* layer, QgsRectangle& extent
       }
       else // can't cross 180
       {
-        extent = tr( layer )->transformBoundingBox( extent, QgsCoordinateTransform::ReverseTransform );
+        if ( transform )
+        {
+          extent = transform->transformBoundingBox( extent, QgsCoordinateTransform::ReverseTransform );
+        }
       }
     }
     catch ( QgsCsException &cse )
@@ -830,14 +839,18 @@ bool QgsMapRenderer::splitLayersExtent( QgsMapLayer* layer, QgsRectangle& extent
 
 QgsRectangle QgsMapRenderer::layerExtentToOutputExtent( QgsMapLayer* theLayer, QgsRectangle extent )
 {
-  QgsDebugMsg( QString( "sourceCrs = " + tr( theLayer )->sourceCrs().authid() ) );
-  QgsDebugMsg( QString( "destCRS = " + tr( theLayer )->destCRS().authid() ) );
-  QgsDebugMsg( QString( "extent = " + extent.toString() ) );
+  //QgsDebugMsg( QString( "sourceCrs = " + tr( theLayer )->sourceCrs().authid() ) );
+  //QgsDebugMsg( QString( "destCRS = " + tr( theLayer )->destCRS().authid() ) );
+  //QgsDebugMsg( QString( "extent = " + extent.toString() ) );
   if ( hasCrsTransformEnabled() )
   {
     try
     {
-      extent = tr( theLayer )->transformBoundingBox( extent );
+      const QgsCoordinateTransform* transform = tr( theLayer );
+      if ( transform )
+      {
+        extent = transform->transformBoundingBox( extent );
+      }
     }
     catch ( QgsCsException &cse )
     {
@@ -1250,6 +1263,11 @@ const QgsCoordinateTransform* QgsMapRenderer::tr( QgsMapLayer *layer )
     return 0;
   }
 
+  if ( layer->crs().authid() == mDestCRS->authid() )
+  {
+    return 0;
+  }
+
   QHash< QString, QgsLayerCoordinateTransform >::const_iterator ctIt = mLayerCoordinateTransformInfo.find( layer->id() );
   if ( ctIt != mLayerCoordinateTransformInfo.constEnd() )
   {

diff --git a/src/gui/qgsmapcanvas.cpp b/src/gui/qgsmapcanvas.cpp
@@ -38,6 +38,7 @@ email                : sherman at mrcc.com
 
 #include "qgis.h"
 #include "qgsapplication.h"
+#include "qgscrscache.h"
 #include "qgslogger.h"
 #include "qgsmapcanvas.h"
 #include "qgsmapcanvasmap.h"
@@ -110,6 +111,8 @@ QgsMapCanvas::QgsMapCanvas( QWidget * parent, const char *name )
   setFocusPolicy( Qt::StrongFocus );
 
   mMapRenderer = new QgsMapRenderer;
+  connect( mMapRenderer, SIGNAL( datumTransformInfoRequested( QgsMapLayer*, const QString&, const QString& ) ),
+           this, SLOT( getDatumTransformInfo( QgsMapLayer*, const QString& , const QString& ) ) );
 
   // create map canvas item which will show the map
   mMap = new QgsMapCanvasMap( this );
@@ -1543,6 +1546,40 @@ void QgsMapCanvas::writeProject( QDomDocument & doc )
   mMapRenderer->writeXML( mapcanvasNode, doc );
 }
 
+/**Ask user which datum transform to use*/
+void QgsMapCanvas::getDatumTransformInfo( QgsMapLayer* ml, const QString& srcAuthId, const QString& destAuthId )
+{
+  if ( !ml )
+  {
+    return;
+  }
+
+  //create two crs
+  const QgsCoordinateReferenceSystem& srcCRS = QgsCRSCache::instance()->crsByAuthId( srcAuthId );
+  const QgsCoordinateReferenceSystem& destCRS = QgsCRSCache::instance()->crsByAuthId( destAuthId );
+
+  //get list of datum transforms (QgsCoordinateTransform::datumTransformations
+  QList< QList< int > > dt = QgsCoordinateTransform::datumTransformations( srcCRS, destCRS );
+  if ( dt.size() < 2 )
+  {
+    return; //skip?
+  }
+
+  //if several possibilities:  present dialog
+  //QgsDatumTransformDialog d( dt );
+  //if( d.exec() == QDialog::Accepted )
+  //{
+  //  int srcTransform = -1;
+  //  int destTransform = -1;
+  //  QList<int> t = d.selectedDatumTransform();
+  //  if( t.size() > 0 )
+  //  {
+  //      srcTransform = t.at( 0 );
+  //  }
+  //  QgsMapRenderer::addLayerCoordinateTransform( ml->id(), const QString& srcAuthId, const QString& destAuthId, int srcTransform = -1, int destTransform = -1 )
+  //}
+}
+
 void QgsMapCanvas::zoomByFactor( double scaleFactor )
 {
   if ( mDrawing )

diff --git a/src/gui/qgsmapcanvas.h b/src/gui/qgsmapcanvas.h
@@ -303,6 +303,9 @@ class GUI_EXPORT QgsMapCanvas : public QGraphicsView
     //! called to write map canvas settings to project
     void writeProject( QDomDocument & );
 
+    //! ask user about datum transformation
+    void getDatumTransformInfo( QgsMapLayer* ml, const QString& srcAuthId, const QString& destAuthId );
+
   private slots:
     //! called when current maptool is destroyed
     void mapToolDestroyed();