Add Skeleton for DataProvider Class

DataProvider class serves as an abstraction of various External
Data Importing Techniques we have and the others which
could be implemented in the future.

Change-Id: I9fc9455f7fbf9025aace4c3248df9b32f522ce52
Reviewed-on: https://gerrit.libreoffice.org/30906
Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Jaskaran singh <jvsg1303@gmail.com>

sc/Library_sc.mk

@@ -427,6 +427,7 @@ $(eval $(call gb_Library_add_exception_objects,sc,\
     sc/source/ui/docshell/docsh8 \
     sc/source/ui/docshell/documentlinkmgr \
     sc/source/ui/docshell/editable \
+    sc/source/ui/docshell/dataprovider \
     sc/source/ui/docshell/externalrefmgr \
     sc/source/ui/docshell/impex \
     sc/source/ui/docshell/macromgr \

sc/source/ui/docshell/dataprovider.cxx

@@ -0,0 +1,11 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * This file is part of the LibreOffice project.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+#include <dataprovider.hxx>
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */

sc/source/ui/inc/dataprovider.hxx

@@ -0,0 +1,80 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * This file is part of the LibreOffice project.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+#ifndef INCLUDED_SC_SOURCE_UI_INC_DATAPROVIDER_HXX
+#define INCLUDED_SC_SOURCE_UI_INC_DATAPROVIDER_HXX
+
+#include <salhelper/thread.hxx>
+#include <tools/stream.hxx>
+#include <rtl/ustring.hxx>
+#include <address.hxx>
+
+namespace sc {
+
+class CSVFetchThread : public salhelper::Thread
+{
+    SvStream *mpStream;
+    bool mbTerminate;
+
+    virtual void execute() override;
+
+public:
+    CSVFetchThread();
+    virtual ~CSVFetchThread() override;
+
+    void RequestTerminate();
+    void IsRequestedTerminate();
+    void Terminate();
+    void EndThread();
+};
+
+class DataProvider
+{
+    virtual ~DataProvider() = 0;
+
+    virtual void StartImport() = 0;
+    virtual void StopImport() = 0;
+    virtual void Refresh() = 0;
+    virtual void SetUrl(OUString) = 0;
+    virtual void SetRefreshRate(double) = 0;
+
+    virtual ScRange GetRange() const = 0;
+    virtual const OUString& GetURL() const = 0;
+
+protected:
+    virtual void DecodeURL() = 0;
+};
+
+class CSVDataProvider : public DataProvider
+{
+    OUString maURL;
+    double mnRefreshRate;
+
+    bool mbImportUnderway;
+
+public:
+    CSVDataProvider (OUString& rUrl);
+    virtual ~CSVDataProvider() override;
+
+    virtual void StartImport() override;
+    virtual void StopImport() override;
+    virtual void Refresh() override;
+    virtual void SetUrl(OUString) override;
+    virtual void SetRefreshRate(double mnRefreshRate) override;
+
+    ScRange GetRange() const override;
+    const OUString& GetURL() const override { return maURL; }
+
+private:
+    virtual void DecodeURL() override;
+};
+
+}
+#endif
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */