Applied patch from ticket #767 by Florian El Ahdab.

Thanks for the contribution!

I've slightly modified the patch to simplify some pieces of code.


git-svn-id: http://svn.osgeo.org/qgis/trunk/qgis@10065 c8812cc2-4d05-0410-92ff-de0c093fc19c

Author: wonder

CONTRIBUTORS

@@ -11,6 +11,7 @@ Carlos Dávila
 Christian Ferreira
 Faunalia (http://www.faunalia.it)
 Fernando Pacheco
+Florian El Ahdab
 Frank Warmerdam
 Hyao (IRC nickname)
 Jean-Denis Giguere 

src/app/CMakeLists.txt

@@ -39,6 +39,7 @@ SET(QGIS_APP_SRCS
   qgsmeasuretool.cpp
   qgsnewhttpconnection.cpp
   qgsnumericsortlistviewitem.cpp
+  qgsogrsublayersdialog.cpp
   qgsoptions.cpp
   qgspastetransformations.cpp
   qgspluginitem.cpp
@@ -113,6 +114,7 @@ SET (QGIS_APP_MOC_HDRS
   qgsmeasuredialog.h
   qgsnewhttpconnection.h
   qgsoptions.h
+  qgsogrsublayersdialog.h
   qgspastetransformations.h
   qgspluginmanager.h
   qgspythondialog.h

src/app/qgisapp.cpp

@@ -98,6 +98,7 @@
 #include "qgscursors.h"
 #include "qgscustomprojectiondialog.h"
 #include "qgsencodingfiledialog.h"
+#include "qgsogrsublayersdialog.h"
 #include "qgsexception.h"
 #include "qgsfeature.h"
 #include "qgsgeomtypedialog.h"
@@ -800,7 +801,7 @@ void QgisApp::createActions()
   mActionLayerSelectionSaveAs->setStatusTip( tr( "Save the selection as a shapefile" ) );
   connect( mActionLayerSelectionSaveAs, SIGNAL( triggered() ), this, SLOT( saveSelectionAsShapefile() ) );
   mActionLayerSelectionSaveAs->setEnabled( false );
-
+  
   mActionRemoveLayer = new QAction( getThemeIcon( "mActionRemoveLayer.png" ), tr( "Remove Layer" ), this );
   mActionRemoveLayer->setShortcut( tr( "Ctrl+D", "Remove a Layer" ) );
   mActionRemoveLayer->setStatusTip( tr( "Remove a Layer" ) );
@@ -2168,11 +2169,25 @@ bool QgisApp::addVectorLayers( QStringList const & theLayerQStringList, const QS
     {
       layer->setProviderEncoding( enc );
 
-      // Register this layer with the layers registry
-      QgsMapLayerRegistry::instance()->addMapLayer( layer );
-      // notify the project we've made a change
-      QgsProject::instance()->dirty( true );
+      QStringList sublayers = layer->dataProvider()->subLayers();
+
+      // If the newly created layer has more than 1 layer of data available, we show the
+      // sublayers selection dialog so the user can select the sublayers to actually load.
+			if ( sublayers.count() > 1)
+			{
+        askUserForSublayers(layer);				
+
+        // The first layer loaded is not usefull in that case. The user can select it in 
+        // the list if he wants to load it.
+        delete layer;
 
+			}else  // there is 1 layer of data available
+      {
+        // Register this layer with the layers registry
+        QgsMapLayerRegistry::instance()->addMapLayer( layer );
+        // notify the project we've made a change
+        QgsProject::instance()->dirty( true );
+      }
     }
     else
     {
@@ -2203,7 +2218,59 @@ bool QgisApp::addVectorLayers( QStringList const & theLayerQStringList, const QS
   return true;
 } // QgisApp::addVectorLayer()
 
+// This method is the method that does the real job. If the layer given in
+// parameter is NULL, then the method tries to act on the activeLayer. 
+void QgisApp::askUserForSublayers(QgsVectorLayer *layer)
+{
+  if (layer == NULL)
+  {
+    if (activeLayer() == NULL || activeLayer()->type() != QgsMapLayer::VectorLayer)
+      return;
+    
+    layer = (QgsVectorLayer*) activeLayer();
+    if (layer->dataProvider()->name() != "ogr")
+      return;
+  }
+  
+  QStringList sublayers = layer->dataProvider()->subLayers();
+
+  // We initialize a selection dialog and display it.
+  QgsOGRSublayersDialog chooseSublayersDialog( this );
+  chooseSublayersDialog.populateLayerTable( sublayers );
+  
+  if (chooseSublayersDialog.exec())
+  {
+    QString uri = layer->source();
+    if ( uri.contains('&', Qt::CaseSensitive) )
+    {
+      // If we get here, there are some options added to the filename.
+      // A valid uri is of the form: filename&option1=value1&option2=value2,...
+      // We want only the filename here, so we get the first part of the split.
+      QStringList theURIParts = uri.split("&");
+      uri = theURIParts.at( 0 );
+    }
+    
+    // the user has done his choice
+    loadOGRSublayers(uri, chooseSublayersDialog.getSelection());
+  }
+}
 
+// This method will load with OGR the layers  in parameter. 
+// This method has been conceived to use the new URI
+// format of the ogrprovider so as to give precisions about which
+// sublayer to load into QGIS. It is normally triggered by the
+// sublayer selection dialog.
+void QgisApp::loadOGRSublayers( QString uri, QStringList list)
+{
+  // The uri must contain the actual uri of the vectorLayer from which we are
+  // going to load the sublayers.
+  QString fileName = QFileInfo(uri).baseName();
+	for (int i = 0; i < list.size(); i++)
+	{
+		QString composedURI=uri+"&layername="+list.at(i);
+		QgsVectorLayer *layer=addVectorLayer(composedURI,fileName+":"+list.at(i),"ogr");
+	}
+}
 
 /** This helper checks to see whether the file name appears to be a valid vector file name */
 bool QgisApp::isValidVectorFileName( QString theFileNameQString )

src/app/qgisapp.h

@@ -63,6 +63,7 @@ class QgsVectorLayer;
 #include "qgsconfig.h"
 #include "qgspoint.h"
 
+
 /*! \class QgisApp
  * \brief Main window for the Qgis application
  */
@@ -342,6 +343,8 @@ class QgisApp : public QMainWindow
      */
     void editPaste( QgsMapLayer * destinationLayer = 0 );
 
+    void loadOGRSublayers( QString uri, QStringList list );
+
   protected:
 
     //! Handle state changes (WindowTitleChange)
@@ -594,6 +597,10 @@ class QgisApp : public QMainWindow
     void bookmarkAdded();
 
   private:
+    /** This method will open a dialog so the user can select the sublayers
+    * to load
+    */
+    void askUserForSublayers(QgsVectorLayer *layer);
     /** Add a raster layer to the map (passed in as a ptr).
      * It won't force a refresh.
      */

src/app/qgsogrsublayersdialog.cpp

@@ -0,0 +1,54 @@
+/***************************************************************************
+    qgsogrsublayersdialog.cpp  - dialog for selecting ogr sublayers
+    ---------------------
+    begin                : January 2009
+    copyright            : (C) 2009 by Florian El Ahdab
+    email                : felahdab at gmail dot com
+ ***************************************************************************
+ *                                                                         *
+ *   This program is free software; you can redistribute it and/or modify  *
+ *   it under the terms of the GNU General Public License as published by  *
+ *   the Free Software Foundation; either version 2 of the License, or     *
+ *   (at your option) any later version.                                   *
+ *                                                                         *
+ ***************************************************************************/
+/* $Id$ */
+
+#include "qgsogrsublayersdialog.h"
+
+#include <QTableWidgetItem>
+
+
+QgsOGRSublayersDialog::QgsOGRSublayersDialog( QWidget* parent, Qt::WFlags fl )
+    : QDialog( parent, fl )
+{
+  setupUi( this );
+  QStringList labels=QStringList() << "Layer ID" << "Layer name" << "Nb of features" << "Geometry type";
+	layersTable->setHeaderLabels(labels);
+}
+
+QgsOGRSublayersDialog::~QgsOGRSublayersDialog()
+{
+}
+
+QStringList QgsOGRSublayersDialog::getSelection()
+{
+  QStringList list=QStringList();
+  for (int i = 0; i < layersTable-> selectedItems().size(); i++)
+  {
+    QString theItem =layersTable-> selectedItems().at(i)->text(1);
+    list.append(theItem);
+  }
+  return list;
+}
+
+void QgsOGRSublayersDialog::populateLayerTable (QStringList theList)
+{
+	for (int i =0; i< theList.size(); i++){
+		QString ligne = theList.at(i);
+		QStringList elements = ligne.split(":");
+    QStringList item=QStringList();
+    item << elements.at(0) << elements.at(1) << elements.at(2) << elements.at(3);
+    layersTable -> addTopLevelItem(new QTreeWidgetItem(item));
+	}	
+}

src/app/qgsogrsublayersdialog.h

@@ -0,0 +1,36 @@
+/***************************************************************************
+    qgsogrsublayersdialog.h  - dialog for selecting ogr sublayers
+    ---------------------
+    begin                : January 2009
+    copyright            : (C) 2009 by Florian El Ahdab
+    email                : felahdab at gmail dot com
+ ***************************************************************************
+ *                                                                         *
+ *   This program is free software; you can redistribute it and/or modify  *
+ *   it under the terms of the GNU General Public License as published by  *
+ *   the Free Software Foundation; either version 2 of the License, or     *
+ *   (at your option) any later version.                                   *
+ *                                                                         *
+ ***************************************************************************/
+/* $Id$ */
+
+#ifndef QGSOGRSUBLAYERSDIALOG_H
+#define QGSOGRSUBLAYERSDIALOG_H
+
+#include <QDialog>
+#include <ui_qgsogrsublayersdialogbase.h>
+
+
+
+class QgsOGRSublayersDialog : public QDialog, private Ui::QgsOGRSublayersDialogBase
+{
+    Q_OBJECT
+  public:
+    QgsOGRSublayersDialog( QWidget* parent = 0, Qt::WFlags fl = 0 );
+    ~QgsOGRSublayersDialog();
+		void populateLayerTable(QStringList theList);
+		QStringList getSelection();
+
+};
+
+#endif

src/providers/ogr/qgsogrprovider.cpp

@@ -73,14 +73,61 @@ QgsOgrProvider::QgsOgrProvider( QString const & uri )
   // try to open for update, but disable error messages to avoid a
   // message if the file is read only, because we cope with that
   // ourselves.
+
+  // This part of the code parses the uri transmitted to the ogr provider to 
+  // get the options the client wants us to apply
+
+  QString mFilePath;
+  QString theLayerName;
+  int theLayerIndex=0;
+
+  // If there is no & in the uri, then the uri is just the filename. The loaded
+  // layer will be layer 0.
+  if ( ! uri.contains('&', Qt::CaseSensitive))
+  {
+    mFilePath = uri;
+  }
+  else
+  {
+  // If we get here, there are some options added to the filename. We must parse
+  // the different parts separated by &, and among each option, the name and the
+  // value around the =.
+  // A valid uri is of the form: filename&option1=value1&option2=value2,...
+
+ 	  QStringList theURIParts = uri.split("&");
+    mFilePath = theURIParts.at( 0 );
+
+    for (int i = 1 ; i < theURIParts.size(); i++ )
+    {
+      QStringList theInstruction = theURIParts.at( i ).split( "=" );
+      if ( theInstruction.at( 0 ) == QString( "layerid" ) )
+      {
+        bool ok;
+        theLayerIndex = theInstruction.at( 1 ).toInt( &ok );
+        if ( ! ok )
+        {
+          theLayerIndex = 0;
+        }
+      }
+      if ( theInstruction.at( 0 ) == QString( "layername" ) )
+      {
+        theLayerName = theInstruction.at( 1 );
+      }				
+    }
+  }
+
+  QgsDebugMsg("mFilePath: " + mFilePath);
+  QgsDebugMsg("theLayerIndex: "+theLayerIndex);
+  QgsDebugMsg("theLayerName: "+theLayerName);
+	
   CPLPushErrorHandler( CPLQuietErrorHandler );
-  ogrDataSource = OGROpen( QFile::encodeName( uri ).constData(), TRUE, &ogrDriver );
+  ogrDataSource = OGROpen( QFile::encodeName( mFilePath ).constData(), TRUE, &ogrDriver );
   CPLPopErrorHandler();
 
   if ( ogrDataSource == NULL )
   {
     // try to open read-only
-    ogrDataSource = OGROpen( QFile::encodeName( uri ).constData(), FALSE, &ogrDriver );
+    ogrDataSource = OGROpen( QFile::encodeName( mFilePath ).constData(), FALSE, &ogrDriver );
 
     //TODO Need to set a flag or something to indicate that the layer
     //TODO is in read-only mode, otherwise edit ops will fail
@@ -95,8 +142,17 @@ QgsOgrProvider::QgsOgrProvider( QString const & uri )
     valid = true;
 
     ogrDriverName = OGR_Dr_GetName( ogrDriver );
-
-    ogrLayer = OGR_DS_GetLayer( ogrDataSource, 0 );
+		
+    // We get the layer which was requested by the uri. The layername
+    // has precedence over the layerid if both are given.
+    if ( theLayerName.isNull() )
+    {
+      ogrLayer = OGR_DS_GetLayer( ogrDataSource, theLayerIndex );
+    }
+    else
+    {
+      ogrLayer = OGR_DS_GetLayerByName( ogrDataSource, (char*)(theLayerName.toLocal8Bit().data()) );
+    }
 
     // get the extent_ (envelope) of the layer
 
@@ -145,6 +201,44 @@ QgsOgrProvider::~QgsOgrProvider()
   }
 }
 
+QStringList QgsOgrProvider::subLayers() const
+{
+  QStringList theList = QStringList();
+  if (! valid )
+  {
+    return theList;
+  }
+  for ( int i = 0; i < layerCount() ; i++ )
+  {  
+    QString theLayerName = QString(OGR_FD_GetName(OGR_L_GetLayerDefn(OGR_DS_GetLayer( ogrDataSource, i ))));
+    OGRwkbGeometryType layerGeomType = OGR_FD_GetGeomType(OGR_L_GetLayerDefn(OGR_DS_GetLayer( ogrDataSource, i )));
+
+    int theLayerFeatureCount=OGR_L_GetFeatureCount(OGR_DS_GetLayer( ogrDataSource, i ),1) ;
+
+    QString geom;
+    switch (layerGeomType)
+    {
+      case wkbUnknown:            geom = "Unknown"; break;
+      case wkbPoint:              geom="Point"; break;
+      case wkbLineString:         geom="LineString"; break;
+      case wkbPolygon:            geom="Polygon"; break;
+      case wkbMultiPoint:         geom="MultiPoint"; break;
+      case wkbMultiLineString:    geom="MultiLineString"; break;
+      case wkbGeometryCollection: geom = "GeometryCollection"; break;
+      case wkbNone:               geom = "None"; break;
+      case wkbPoint25D:           geom="Point25D"; break;
+      case wkbLineString25D:      geom="LineString25D"; break;
+      case wkbPolygon25D:         geom="Polygon25D"; break;
+      case wkbMultiPoint25D:      geom="MultiPoint25D"; break;
+      case wkbMultiLineString25D: geom="MultiLineString25D"; break;
+      case wkbMultiPolygon25D:    geom="MultiPolygon25D"; break;
+      default: geom="Unknown WKB: " + QString::number(layerGeomType);
+    }
+    theList.append(QString::number(i)+":"+ theLayerName+":"+QString::number(theLayerFeatureCount)+":"+geom);
+  }
+  return theList;
+}
+
 void QgsOgrProvider::setEncoding( const QString& e )
 {
   QgsVectorDataProvider::setEncoding( e );