Add ITiledRenderable.

We want to have a simple interface that allows access to tiled
rendering without digging into the internals of writer
(and in the future calc/impress/draw).

Change-Id: Ia9c278a48c919333186e5361ff25bb1ab603b846

include/vcl/ITiledRenderable.hxx

@@ -0,0 +1,48 @@
+/* -*- 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_VCL_ITILEDRENDERABLE_HXX
+#define INCLUDED_VCL_ITILEDRENDERABLE_HXX
+
+#include <tools/gen.hxx>
+#include <vcl/virdev.hxx>
+
+namespace vcl
+{
+
+class VCL_DLLPUBLIC ITiledRenderable
+{
+public:
+    virtual ~ITiledRenderable() {};
+
+    /**
+     * Paint a tile to a given VirtualDevice.
+     *
+     * Output parameters are measured in pixels, tile parameters are in
+     * twips.
+     */
+    virtual void paintTile( VirtualDevice &rDevice,
+                            int nOutputWidth,
+                            int nOutputHeight,
+                            int nTilePosX,
+                            int nTilePosY,
+                            long nTileWidth,
+                            long nTileHeight ) = 0;
+
+    /**
+     * Get the document size in twips.
+     */
+    virtual Size getDocumentSize() = 0;
+
+};
+
+} // namespace vcl
+
+#endif // INCLUDED_VCL_ITILEDRENDERABLE_HXX