[FEATURE]: Start implementation of native dxf export

Author: mhugent

python/core/core.sip

@@ -27,6 +27,7 @@
 %Include qgsdatasourceuri.sip
 %Include qgsdbfilterproxymodel.sip
 %Include qgsdistancearea.sip
+%Include qgsdxfexport.sip
 %Include qgserror.sip
 %Include qgsexpression.sip
 %Include qgsfeature.sip

python/core/qgsdxfexport.sip

@@ -0,0 +1,29 @@
+/***************************************************************************
+                         qgsdxfexport.sip
+                         ----------------
+    begin                : September 2013
+    copyright            : (C) 2013 by Marco Hugentobler
+    email                : marco at sourcepole dot ch
+ ***************************************************************************/
+
+/***************************************************************************
+ *                                                                         *
+ *   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.                                   *
+ *                                                                         *
+ ***************************************************************************/
+
+class QgsDxfExport
+{
+%TypeHeaderCode
+#include <qgsdxfexport.h>
+%End
+    public:
+        QgsDxfExport();
+        ~QgsDxfExport();
+
+        void addLayers( QList< QgsMapLayer* >& layers );
+        int writeToFile( QIODevice* d );
+};

src/core/CMakeLists.txt

@@ -62,6 +62,7 @@ SET(QGIS_CORE_SRCS
   qgsdbfilterproxymodel.cpp
   qgsdiagramrendererv2.cpp
   qgsdistancearea.cpp
+  qgsdxfexport.cpp
   qgserror.cpp
   qgsexpression.cpp
   qgsexpression_texts.cpp

src/core/qgsdxfexport.cpp

@@ -0,0 +1,52 @@
+/***************************************************************************
+                         qgsdxfexport.cpp
+                         ----------------
+    begin                : September 2013
+    copyright            : (C) 2013 by Marco Hugentobler
+    email                : marco at sourcepole dot ch
+ ***************************************************************************/
+
+/***************************************************************************
+ *                                                                         *
+ *   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.                                   *
+ *                                                                         *
+ ***************************************************************************/
+
+#include "qgsdxfexport.h"
+#include <QIODevice>
+#include <QTextStream>
+
+QgsDxfExport::QgsDxfExport()
+{
+}
+
+QgsDxfExport::~QgsDxfExport()
+{
+
+}
+
+int QgsDxfExport::writeToFile( QIODevice* d )
+{
+  if ( !d )
+  {
+    return 1;
+  }
+
+  if ( !d->open( QIODevice::WriteOnly ) )
+  {
+    return 2;
+  }
+
+  QTextStream outStream( d );
+  writeHeader( outStream );
+  return 0;
+}
+
+int QgsDxfExport::writeHeader( QTextStream& stream )
+{
+  stream << "Hello, dxf!";
+  return 0; //soon...
+}

src/core/qgsdxfexport.h

@@ -0,0 +1,47 @@
+/***************************************************************************
+                         qgsdxfexport.h
+                         --------------
+    begin                : September 2013
+    copyright            : (C) 2013 by Marco Hugentobler
+    email                : marco at sourcepole dot ch
+ ***************************************************************************/
+
+/***************************************************************************
+ *                                                                         *
+ *   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.                                   *
+ *                                                                         *
+ ***************************************************************************/
+
+#ifndef QGSDXFEXPORT_H
+#define QGSDXFEXPORT_H
+
+#include <QList>
+
+class QgsMapLayer;
+class QIODevice;
+class QTextStream;
+
+class QgsDxfExport
+{
+  public:
+    QgsDxfExport();
+    ~QgsDxfExport();
+
+    void addLayers( QList< QgsMapLayer* >& layers ) { mLayers = layers; }
+    int writeToFile( QIODevice* d );  //maybe add progress dialog? //other parameters (e.g. scale, dpi)?
+
+  private:
+
+    QList< QgsMapLayer* > mLayers;
+
+    int writeHeader( QTextStream& stream );
+    //collect styles
+    //writeEntities
+
+    //Option: export feature once / multiple export (considering symbol layers / symbol levels)
+};
+
+#endif // QGSDXFEXPORT_H