Fix #3800 Connect TD export to FC Gui Export

- TD did not define export types for the general Export
  command in Gui.

src/Mod/TechDraw/Gui/AppTechDrawGuiPy.cpp

@@ -41,10 +41,12 @@
 #include <App/DocumentObject.h>
 #include <App/DocumentObjectPy.h>
 #include <Gui/Application.h>
+#include <Gui/Document.h>
 #include <Gui/ViewProvider.h>
 
 
 #include <Mod/Part/App/OCCError.h>
+#include <Mod/TechDraw/App/DrawPage.h>
 
 #include "MDIViewPage.h"
 #include "ViewProviderPage.h"
@@ -60,7 +62,10 @@ class Module : public Py::ExtensionModule<Module>
 public:
     Module() : Py::ExtensionModule<Module>("TechDrawGui")
     {
-        add_varargs_method("exportPageAsPdf",&Module::exportPageAsPdf,
+       add_varargs_method("export",&Module::exporter,
+            "TechDraw hook for FC Gui exporter."
+       );
+       add_varargs_method("exportPageAsPdf",&Module::exportPageAsPdf,
             "exportPageAsPdf(DrawPageObject,FilePath) -- print page as Pdf to file."
         );
         add_varargs_method("exportPageAsSvg",&Module::exportPageAsSvg,
@@ -104,6 +109,53 @@ class Module : public Py::ExtensionModule<Module>
         }
     }
 
+//! hook for FC Gui export function
+    Py::Object exporter(const Py::Tuple& args)
+    {
+        PyObject* object;
+        char* Name;
+        if (!PyArg_ParseTuple(args.ptr(), "Oet",&object,"utf-8",&Name))
+            throw Py::Exception();
+
+        std::string EncodedName = std::string(Name);
+        PyMem_Free(Name);
+
+        TechDraw::DrawPage* page = nullptr;
+        Py::Sequence list(object);
+        for (Py::Sequence::iterator it = list.begin(); it != list.end(); ++it) {
+            PyObject* item = (*it).ptr();
+            if (PyObject_TypeCheck(item, &(App::DocumentObjectPy::Type))) {
+                App::DocumentObject* obj = static_cast<App::DocumentObjectPy*>(item)->getDocumentObjectPtr();
+                if (obj->getTypeId().isDerivedFrom(TechDraw::DrawPage::getClassTypeId())) {
+                    page = static_cast<TechDraw::DrawPage*>(obj);
+                    Gui::Document* activeGui = Gui::Application::Instance->getDocument(page->getDocument());
+                    Gui::ViewProvider* vp = activeGui->getViewProvider(obj);
+                    ViewProviderPage* dvp = dynamic_cast<ViewProviderPage*>(vp);
+                    if ( !(dvp  && dvp->getMDIViewPage()) ) {
+                        throw Py::TypeError("TechDraw can not find Page");
+                    }
+
+                    Base::FileInfo fi_out(EncodedName.c_str());
+
+                    if (fi_out.hasExtension("svg")) {
+                        dvp->getMDIViewPage()->saveSVG(EncodedName);
+                    } else if (fi_out.hasExtension("dxf")) {
+                        dvp->getMDIViewPage()->saveDXF(EncodedName);
+                    } else if (fi_out.hasExtension("pdf")) {
+                        dvp->getMDIViewPage()->savePDF(EncodedName);
+                    } else {
+                        throw Py::TypeError("TechDraw can not export this file format");
+                    }
+                }
+                else {
+                    throw Py::TypeError("Export of this object type is not supported by TechDraw module");
+                }
+            }
+        }
+
+        return Py::None();
+    }
+
 //!exportPageAsPdf(PageObject,FullPath)
     Py::Object exportPageAsPdf(const Py::Tuple& args)
     {

src/Mod/TechDraw/Gui/MDIViewPage.cpp

@@ -118,6 +118,12 @@ MDIViewPage::MDIViewPage(ViewProviderPage *pageVp, Gui::Document* doc, QWidget*
     m_exportSVGAction = new QAction(tr("&Export SVG"), this);
     connect(m_exportSVGAction, SIGNAL(triggered()), this, SLOT(saveSVG()));
 
+    m_exportDXFAction = new QAction(tr("Export DXF"), this);
+    connect(m_exportDXFAction, SIGNAL(triggered()), this, SLOT(saveDXF()));
+
+    m_exportPDFAction = new QAction(tr("Export PDF"), this);
+    connect(m_exportPDFAction, SIGNAL(triggered()), this, SLOT(savePDF()));
+
     isSelectionBlocked = false;
 
     QString tabText = QString::fromUtf8(pageVp->getDrawPage()->getNameInDocument());
@@ -763,6 +769,8 @@ void MDIViewPage::contextMenuEvent(QContextMenuEvent *event)
     menu.addAction(m_toggleFrameAction);
     menu.addAction(m_toggleKeepUpdatedAction);
     menu.addAction(m_exportSVGAction);
+    menu.addAction(m_exportDXFAction);
+    menu.addAction(m_exportPDFAction);
     menu.exec(event->globalPos());
 }
 
@@ -809,6 +817,43 @@ void MDIViewPage::saveSVG(std::string file)
     m_view->saveSvg(filename);
 }
 
+void MDIViewPage::saveDXF()
+{
+//    TechDraw::DrawPage* page = m_vpPage->getDrawPage();
+    QString defaultDir;
+    QString fileName = Gui::FileDialog::getSaveFileName(Gui::getMainWindow(),
+                                                   QString::fromUtf8(QT_TR_NOOP("Save Dxf File ")),
+                                                   defaultDir,
+                                                   QString::fromUtf8(QT_TR_NOOP("Dxf (*.dxf)")));
+    if (fileName.isEmpty()) {
+        return;
+    }
+
+    std::string sFileName = fileName.toUtf8().constData();
+    saveDXF(sFileName);
+}
+
+void MDIViewPage::saveDXF(std::string fileName)
+{
+    TechDraw::DrawPage* page = m_vpPage->getDrawPage();
+    std::string PageName = page->getNameInDocument();
+    Gui::Command::openCommand("Save page to dxf");
+    Gui::Command::doCommand(Gui::Command::Doc,"import TechDraw");
+    Gui::Command::doCommand(Gui::Command::Doc,"TechDraw.writeDXFPage(App.activeDocument().%s,u\"%s\")",
+                            PageName.c_str(),(const char*)fileName.c_str());
+    Gui::Command::updateActive();
+    Gui::Command::commitCommand();
+}
+
+void MDIViewPage::savePDF()
+{
+    printPdf();
+}
+
+void MDIViewPage::savePDF(std::string file)
+{
+    printPdf(file);
+}
 
 /////////////// Selection Routines ///////////////////
 // wf: this is never executed???

src/Mod/TechDraw/Gui/MDIViewPage.h

@@ -80,6 +80,8 @@ class TechDrawGuiExport MDIViewPage : public Gui::MDIView, public Gui::Selection
     void printPreview();
 
     void saveSVG(std::string file);
+    void saveDXF(std::string file);
+    void savePDF(std::string file);
 
     void setFrameState(bool state);
     bool getFrameState(void) {return m_frameState;};
@@ -104,6 +106,8 @@ class TechDrawGuiExport MDIViewPage : public Gui::MDIView, public Gui::Selection
 public Q_SLOTS:
     void viewAll();
     void saveSVG(void);
+    void saveDXF(void);
+    void savePDF(void);
     void toggleFrame(void);
     void toggleKeepUpdated(void);
 //    void testAction(void);
@@ -137,6 +141,8 @@ public Q_SLOTS:
     QAction *m_toggleFrameAction;
     QAction *m_toggleKeepUpdatedAction;
     QAction *m_exportSVGAction;
+    QAction *m_exportDXFAction;
+    QAction *m_exportPDFAction;
 //    QAction* m_testAction;
 
     std::string m_objectName;

src/Mod/TechDraw/InitGui.py

@@ -45,3 +45,6 @@ def GetClassName(self):
         return "TechDrawGui::Workbench"
 
 Gui.addWorkbench(TechDrawWorkbench())
+
+# Append the export handler
+FreeCAD.addExportType("Technical Drawing (*.svg *.dxf *.pdf)","TechDrawGui")