Show a message box if there was an error during the merge operation (instead of crashing). Fixes ticket #2342

mhugent · mhugent · commit 1aae46860a5a · 2010-01-05T16:06:18.000Z
git-svn-id: http://svn.osgeo.org/qgis/trunk/qgis@12673 c8812cc2-4d05-0410-92ff-de0c093fc19c
diff --git a/src/app/qgisapp.cpp b/src/app/qgisapp.cpp
@@ -3635,8 +3635,9 @@ void QgisApp::deletePart()
   mMapCanvas->setMapTool( mMapTools.mDeletePart );
 }
 
-QgsGeometry* QgisApp::unionGeometries( const QgsVectorLayer* vl, QgsFeatureList& featureList )
+QgsGeometry* QgisApp::unionGeometries( const QgsVectorLayer* vl, QgsFeatureList& featureList, bool& canceled )
 {
+  canceled = false;
   if ( !vl || featureList.size() < 2 )
   {
     return 0;
@@ -3660,6 +3661,7 @@ QgsGeometry* QgisApp::unionGeometries( const QgsVectorLayer* vl, QgsFeatureList&
     {
       delete unionGeom;
       QApplication::restoreOverrideCursor();
+      canceled = true;
       return 0;
     }
     progress.setValue( i );
@@ -3668,6 +3670,12 @@ QgsGeometry* QgisApp::unionGeometries( const QgsVectorLayer* vl, QgsFeatureList&
     {
       backupPtr = unionGeom;
       unionGeom = unionGeom->combine( currentGeom );
+      if ( !unionGeom )
+      {
+        delete backupPtr;
+        QApplication::restoreOverrideCursor();
+        return 0;
+      }
       if ( i > 1 ) //delete previous intermediate results
       {
         delete backupPtr;
@@ -3798,9 +3806,14 @@ void QgisApp::mergeSelectedFeatures()
 
   //get initial selection (may be altered by attribute merge dialog later)
   QgsFeatureList featureList = vl->selectedFeatures();  //get QList<QgsFeature>
-  QgsGeometry* unionGeom = unionGeometries( vl, featureList );
+  bool canceled;
+  QgsGeometry* unionGeom = unionGeometries( vl, featureList, canceled );
   if ( !unionGeom )
   {
+    if ( !canceled )
+    {
+      QMessageBox::critical( 0, tr( "Merge failed" ), tr( "An error occured during the merge operation" ) );
+    }
     return;
   }
 
@@ -3835,9 +3848,14 @@ void QgisApp::mergeSelectedFeatures()
   if ( featureList.size() != featureListAfter.size() )
   {
     delete unionGeom;
-    unionGeom = unionGeometries( vl, featureListAfter );
+    bool canceled;
+    unionGeom = unionGeometries( vl, featureListAfter, canceled );
     if ( !unionGeom )
     {
+      if ( !canceled )
+      {
+        QMessageBox::critical( 0, tr( "Merge failed" ), tr( "An error occured during the merge operation" ) );
+      }
       return;
     }
 
diff --git a/src/app/qgisapp.h b/src/app/qgisapp.h
@@ -710,8 +710,8 @@ class QgisApp : public QMainWindow
     //! check to see if file is dirty and if so, prompt the user th save it
     bool saveDirty();
     /** Helper function to union several geometries together (used in function mergeSelectedFeatures)
-      @return 0 in case of error*/
-    QgsGeometry* unionGeometries( const QgsVectorLayer* vl, QgsFeatureList& featureList );
+      @return 0 in case of error or if canceled*/
+    QgsGeometry* unionGeometries( const QgsVectorLayer* vl, QgsFeatureList& featureList, bool& canceled );
 
     /**Deletes all the composer objects and clears mPrintComposers*/
     void deletePrintComposers();

Original file line number	Diff line number	Diff line change
`@@ -3635,8 +3635,9 @@ void QgisApp::deletePart()`
`3635`	`3635`	`mMapCanvas->setMapTool( mMapTools.mDeletePart );`
`3636`	`3636`	`}`
`3637`	`3637`
`3638`		`-QgsGeometry* QgisApp::unionGeometries( const QgsVectorLayer* vl, QgsFeatureList& featureList )`
	`3638`	`+QgsGeometry* QgisApp::unionGeometries( const QgsVectorLayer* vl, QgsFeatureList& featureList, bool& canceled )`
`3639`	`3639`	`{`
	`3640`	`+ canceled = false;`
`3640`	`3641`	`if ( !vl \|\| featureList.size() < 2 )`
`3641`	`3642`	`{`
`3642`	`3643`	`return 0;`
`@@ -3660,6 +3661,7 @@ QgsGeometry* QgisApp::unionGeometries( const QgsVectorLayer* vl, QgsFeatureList&`
`3660`	`3661`	`{`
`3661`	`3662`	`delete unionGeom;`
`3662`	`3663`	`QApplication::restoreOverrideCursor();`
	`3664`	`+ canceled = true;`
`3663`	`3665`	`return 0;`
`3664`	`3666`	`}`
`3665`	`3667`	`progress.setValue( i );`
`@@ -3668,6 +3670,12 @@ QgsGeometry* QgisApp::unionGeometries( const QgsVectorLayer* vl, QgsFeatureList&`
`3668`	`3670`	`{`
`3669`	`3671`	`backupPtr = unionGeom;`
`3670`	`3672`	`unionGeom = unionGeom->combine( currentGeom );`
	`3673`	`+ if ( !unionGeom )`
	`3674`	`+ {`
	`3675`	`+ delete backupPtr;`
	`3676`	`+ QApplication::restoreOverrideCursor();`
	`3677`	`+ return 0;`
	`3678`	`+ }`
`3671`	`3679`	`if ( i > 1 ) //delete previous intermediate results`
`3672`	`3680`	`{`
`3673`	`3681`	`delete backupPtr;`
`@@ -3798,9 +3806,14 @@ void QgisApp::mergeSelectedFeatures()`
`3798`	`3806`
`3799`	`3807`	`//get initial selection (may be altered by attribute merge dialog later)`
`3800`	`3808`	`QgsFeatureList featureList = vl->selectedFeatures(); //get QList<QgsFeature>`
`3801`		`- QgsGeometry* unionGeom = unionGeometries( vl, featureList );`
	`3809`	`+ bool canceled;`
	`3810`	`+ QgsGeometry* unionGeom = unionGeometries( vl, featureList, canceled );`
`3802`	`3811`	`if ( !unionGeom )`
`3803`	`3812`	`{`
	`3813`	`+ if ( !canceled )`
	`3814`	`+ {`
	`3815`	`+ QMessageBox::critical( 0, tr( "Merge failed" ), tr( "An error occured during the merge operation" ) );`
	`3816`	`+ }`
`3804`	`3817`	`return;`
`3805`	`3818`	`}`
`3806`	`3819`
`@@ -3835,9 +3848,14 @@ void QgisApp::mergeSelectedFeatures()`
`3835`	`3848`	`if ( featureList.size() != featureListAfter.size() )`
`3836`	`3849`	`{`
`3837`	`3850`	`delete unionGeom;`
`3838`		`- unionGeom = unionGeometries( vl, featureListAfter );`
	`3851`	`+ bool canceled;`
	`3852`	`+ unionGeom = unionGeometries( vl, featureListAfter, canceled );`
`3839`	`3853`	`if ( !unionGeom )`
`3840`	`3854`	`{`
	`3855`	`+ if ( !canceled )`
	`3856`	`+ {`
	`3857`	`+ QMessageBox::critical( 0, tr( "Merge failed" ), tr( "An error occured during the merge operation" ) );`
	`3858`	`+ }`
`3841`	`3859`	`return;`
`3842`	`3860`	`}`
`3843`	`3861`