From 65f32bc137993485cf6d1c88a4df6d5ad0c04908 Mon Sep 17 00:00:00 2001
From: "Juergen E. Fischer" <jef@norbit.de>
Date: Sat, 28 Jan 2012 14:28:58 +0100
Subject: [PATCH] reproject canvas extent on crs change with OTFR enabled

---
 src/core/qgscoordinatetransform.cpp |  4 ++--
 src/core/qgsmaprenderer.cpp         | 14 ++++++++++++++
 src/core/raster/qgsrasterlayer.cpp  |  4 ++--
 src/gui/qgsmapcanvas.cpp            | 19 +++++++++++++++----
 src/gui/qgsmapcanvas.h              |  3 +++
 5 files changed, 36 insertions(+), 8 deletions(-)

diff --git a/src/core/qgscoordinatetransform.cpp b/src/core/qgscoordinatetransform.cpp
index 45ed92f8cc03..1bed402aa0ef 100644
--- a/src/core/qgscoordinatetransform.cpp
+++ b/src/core/qgscoordinatetransform.cpp
@@ -494,11 +494,11 @@ QgsRectangle QgsCoordinateTransform::transformBoundingBox( const QgsRectangle re
       bb_rect.combineExtentWith( x[i], y[i] );
   }
 
-  QgsDebugMsg( "Projected extent: " + QString(( bb_rect.toString() ).toLocal8Bit().data() ) );
+  QgsDebugMsg( "Projected extent: " + bb_rect.toString() );
 
   if ( bb_rect.isEmpty() )
   {
-    QgsMessageLog::logMessage( tr( "Reprojected extent is empty. Original extent: %1" ).arg( rect.toString() ), tr( "CRS" ) );
+    QgsDebugMsg( "Original extent: " + rect.toString() );
   }
 
   return bb_rect;
diff --git a/src/core/qgsmaprenderer.cpp b/src/core/qgsmaprenderer.cpp
index eaaae6387fe3..34b21128a1f8 100644
--- a/src/core/qgsmaprenderer.cpp
+++ b/src/core/qgsmaprenderer.cpp
@@ -666,6 +666,7 @@ void QgsMapRenderer::setProjectionsEnabled( bool enabled )
     QgsDebugMsg( "Adjusting DistArea projection on/off" );
     mDistArea->setProjectionsEnabled( enabled );
     updateFullExtent();
+    mLastExtent.setMinimal();
     emit hasCrsTransformEnabled( enabled );
   }
 }
@@ -681,11 +682,24 @@ void QgsMapRenderer::setDestinationCrs( const QgsCoordinateReferenceSystem& crs
   QgsDebugMsg( "* DestCRS.srsid() = " + QString::number( crs.srsid() ) );
   if ( *mDestCRS != crs )
   {
+    QgsRectangle rect;
+    if ( hasCrsTransformEnabled() && !mExtent.isEmpty() )
+    {
+      QgsCoordinateTransform transform( *mDestCRS, crs );
+      rect = transform.transformBoundingBox( mExtent );
+    }
+
     invalidateCachedLayerCrs();
     QgsDebugMsg( "Setting DistArea CRS to " + QString::number( crs.srsid() ) );
     mDistArea->setSourceCrs( crs.srsid() );
     *mDestCRS = crs;
     updateFullExtent();
+
+    if ( !rect.isEmpty() )
+    {
+      setExtent( rect );
+    }
+
     emit destinationSrsChanged();
   }
 }
diff --git a/src/core/raster/qgsrasterlayer.cpp b/src/core/raster/qgsrasterlayer.cpp
index 0e28e1a2a28a..78c24130dccd 100644
--- a/src/core/raster/qgsrasterlayer.cpp
+++ b/src/core/raster/qgsrasterlayer.cpp
@@ -656,7 +656,7 @@ bool QgsRasterLayer::draw( QgsRenderContext& rendererContext )
     catch ( QgsCsException &cs )
     {
       QgsMessageLog::logMessage( tr( "Could not reproject view extent: %1" ).arg( cs.what() ), tr( "Raster" ) );
-      myProjectedViewExtent = rendererContext.extent();
+      myProjectedViewExtent.setMinimal();
     }
 
     try
@@ -666,7 +666,7 @@ bool QgsRasterLayer::draw( QgsRenderContext& rendererContext )
     catch ( QgsCsException &cs )
     {
       QgsMessageLog::logMessage( tr( "Could not reproject layer extent: %1" ).arg( cs.what() ), tr( "Raster" ) );
-      myProjectedLayerExtent = mLayerExtent;
+      myProjectedViewExtent.setMinimal();
     }
   }
   else
diff --git a/src/gui/qgsmapcanvas.cpp b/src/gui/qgsmapcanvas.cpp
index 894afc7aa7ed..6e3676896279 100644
--- a/src/gui/qgsmapcanvas.cpp
+++ b/src/gui/qgsmapcanvas.cpp
@@ -123,8 +123,10 @@ QgsMapCanvas::QgsMapCanvas( QWidget * parent, const char *name )
 
   moveCanvasContents( true );
 
-  //connect(mMapRenderer, SIGNAL(updateMap()), this, SLOT(updateMap()));
   connect( mMapRenderer, SIGNAL( drawError( QgsMapLayer* ) ), this, SLOT( showError( QgsMapLayer* ) ) );
+  connect( mMapRenderer, SIGNAL( hasCrsTransformEnabled( bool ) ), this, SLOT( crsTransformEnabled( bool ) ) );
+
+  crsTransformEnabled( hasCrsTransformEnabled() );
 
   // project handling
   connect( QgsProject::instance(), SIGNAL( readProject( const QDomDocument & ) ),
@@ -1491,7 +1493,6 @@ void QgsMapCanvas::readProject( const QDomDocument & doc )
   {
     QgsDebugMsg( "Couldn't read mapcanvas information from project" );
   }
-
 }
 
 void QgsMapCanvas::writeProject( QDomDocument & doc )
@@ -1509,8 +1510,6 @@ void QgsMapCanvas::writeProject( QDomDocument & doc )
   QDomElement mapcanvasNode = doc.createElement( "mapcanvas" );
   qgisNode.appendChild( mapcanvasNode );
   mMapRenderer->writeXML( mapcanvasNode, doc );
-
-
 }
 
 void QgsMapCanvas::zoomByFactor( double scaleFactor )
@@ -1541,3 +1540,15 @@ void QgsMapCanvas::dragEnterEvent( QDragEnterEvent * e )
   // parent (e.g. QgisApp) to handle drops of map layers etc.
   e->ignore();
 }
+
+void QgsMapCanvas::crsTransformEnabled( bool enabled )
+{
+  if ( enabled )
+  {
+    QgsDebugMsg( "refreshing after reprojection was enabled" );
+    refresh();
+    connect( mMapRenderer, SIGNAL( destinationSrsChanged() ), this, SLOT( refresh() ) );
+  }
+  else
+    disconnect( mMapRenderer, SIGNAL( destinationSrsChanged() ), this, SLOT( refresh() ) );
+}
diff --git a/src/gui/qgsmapcanvas.h b/src/gui/qgsmapcanvas.h
index aa8a3896a55c..465ebc379ca8 100644
--- a/src/gui/qgsmapcanvas.h
+++ b/src/gui/qgsmapcanvas.h
@@ -395,6 +395,9 @@ class GUI_EXPORT QgsMapCanvas : public QGraphicsView
     /// Handle pattern for implementation object
     std::auto_ptr<CanvasProperties> mCanvasProperties;
 
+  private slots:
+    void crsTransformEnabled( bool );
+
   private:
     /// this class is non-copyable
     /**