Refactor ExportSpecctraFile to be usable in API

Currently there is pcbnew.ExportSpecctraDSN() but it needs a pcbnew
frame set which makes it unusable outside of the scripting window or a
plugin.

This refactors actual exporting logic into separate helper and adds an
overload to ExportSpecctraDSN(board, filename) that doesn't need pcbnew
window.

pcbnew/python/scripting/pcbnew_scripting_helpers.cpp

@@ -46,6 +46,7 @@
 #include <pcbnew_scripting_helpers.h>
 #include <project.h>
 #include <settings/settings_manager.h>
+#include <specctra.h>
 #include <project/project_local_settings.h>
 #include <wildcards_and_files_ext.h>
 #include <locale_io.h>
@@ -270,6 +271,22 @@ bool ExportSpecctraDSN( wxString& aFullFilename )
     }
 }
 
+
+bool ExportSpecctraDSN( BOARD* aBoard, wxString& aFullFilename )
+{
+    try
+    {
+        ExportBoardToSpecctraFile( aBoard, aFullFilename );
+    }
+    catch( ... )
+    {
+        return false;
+    }
+
+    return true;
+}
+
+
 bool ExportVRML( const wxString& aFullFileName, double aMMtoWRMLunit, bool aExport3DFiles,
                  bool aUseRelativePaths, const wxString& a3D_Subdir, double aXRef, double aYRef )
 {

pcbnew/python/scripting/pcbnew_scripting_helpers.h

@@ -83,6 +83,17 @@ wxArrayString GetFootprints( const wxString& aNickName );
  */
 bool ExportSpecctraDSN( wxString& aFullFilename );
 
+/**
+ * Will export the BOARD to a specctra dsn file.
+ * Unlike first overload doesn't need a valid PCB_EDIT_FRAME set and can be used
+ * in a standalone python script.
+ *
+ * See http://www.autotraxeda.com/docs/SPECCTRA/SPECCTRA.pdf for the specification.
+ *
+ * @return true if OK
+ */
+bool ExportSpecctraDSN( BOARD* aBoard, wxString& aFullFilename );
+
 /**
  * Export the current BOARD to a VRML (wrl) file.
  *

pcbnew/specctra_import_export/specctra.h

@@ -48,6 +48,15 @@ class SHAPE_POLY_SET;
 typedef DSN::T  DSN_T;
 
 
+/**
+ * @brief Helper method to export board to DSN file
+ *
+ * @param aBoard board object
+ * @param aFullFilename specctra file name
+ */
+void ExportBoardToSpecctraFile( BOARD* aBoard, const wxString& aFullFilename );
+
+
 /**
  * This source file implements export and import capabilities to the
  * specctra dsn file format.  The grammar for that file format is documented

pcbnew/specctra_import_export/specctra_export.cpp

@@ -85,36 +85,14 @@ static const double safetyMargin = 0.1;
 
 bool PCB_EDIT_FRAME::ExportSpecctraFile( const wxString& aFullFilename )
 {
-    SPECCTRA_DB     db;
-    bool            ok = true;
-    wxString        errorText;
-
-    BASE_SCREEN*    screen = GetScreen();
-    bool            wasModified = screen->IsContentModified();
-
-    db.SetPCB( SPECCTRA_DB::MakePCB() );
-
-    LOCALE_IO       toggle;     // Switch the locale to standard C
-
-    // Build the board outlines *before* flipping footprints
-    if( !db.BuiltBoardOutlines( GetBoard() ) )
-    {
-        wxLogWarning( _( "Board outline is malformed. Run DRC for a full analysis." ) );
-    }
-
-    // DSN Images (=KiCad FOOTPRINTs and PADs) must be presented from the top view.  So we
-    // temporarily flip any footprints which are on the back side of the board to the front,
-    // and record this in the FOOTPRINT's flag field.
-    db.FlipFOOTPRINTs( GetBoard() );
+    BASE_SCREEN* screen = GetScreen();
+    bool         wasModified = screen->IsContentModified();
+    wxString     errorText;
+    bool         ok = true;
 
     try
     {
-        GetBoard()->SynchronizeNetsAndNetClasses();
-        db.FromBOARD( GetBoard() );
-        db.ExportPCB( aFullFilename, true );
-
-        // if an exception is thrown by FromBOARD or ExportPCB(), then
-        // ~SPECCTRA_DB() will close the file.
+        ExportBoardToSpecctraFile( GetBoard(), aFullFilename );
     }
     catch( const IO_ERROR& ioe )
     {
@@ -124,10 +102,7 @@ bool PCB_EDIT_FRAME::ExportSpecctraFile( const wxString& aFullFilename )
         errorText = ioe.What();
     }
 
-    // done assuredly, even if an exception was thrown and caught.
-    db.RevertFOOTPRINTs( GetBoard() );
-
-    // The two calls below to FOOTPRINT::Flip(), both set the
+    // The two calls to FOOTPRINT::Flip() in ExportBoardToSpecctraFile both set the
     // modified flag, yet their actions cancel each other out, so it should
     // be ok to clear the modify flag.
     if( !wasModified )
@@ -139,15 +114,48 @@ bool PCB_EDIT_FRAME::ExportSpecctraFile( const wxString& aFullFilename )
     }
     else
     {
-        DisplayErrorMessage( this,
-                             _( "Unable to export, please fix and try again" ),
-                             errorText );
+        DisplayErrorMessage( this, _( "Unable to export, please fix and try again" ), errorText );
     }
 
     return ok;
 }
 
 
+void ExportBoardToSpecctraFile( BOARD* aBoard, const wxString& aFullFilename )
+{
+    SPECCTRA_DB db;
+
+    db.SetPCB( SPECCTRA_DB::MakePCB() );
+
+    LOCALE_IO toggle; // Switch the locale to standard C
+
+    // Build the board outlines *before* flipping footprints
+    if( !db.BuiltBoardOutlines( aBoard ) )
+        wxLogWarning( _( "Board outline is malformed. Run DRC for a full analysis." ) );
+
+    // DSN Images (=KiCad FOOTPRINTs and PADs) must be presented from the top view.  So we
+    // temporarily flip any footprints which are on the back side of the board to the front,
+    // and record this in the FOOTPRINT's flag field.
+    db.FlipFOOTPRINTs( aBoard );
+
+    try
+    {
+        aBoard->SynchronizeNetsAndNetClasses();
+        db.FromBOARD( aBoard );
+        db.ExportPCB( aFullFilename, true );
+        db.RevertFOOTPRINTs( aBoard );
+
+        // if an exception is thrown by FromBOARD or ExportPCB(), then
+        // ~SPECCTRA_DB() will close the file.
+    }
+    catch( ... )
+    {
+        db.RevertFOOTPRINTs( aBoard );
+        throw;
+    }
+}
+
+
 namespace DSN {
 
 const KICAD_T SPECCTRA_DB::scanPADs[] = { PCB_PAD_T, EOT };