Function to load graphic swapped out (loaded on demand)

When a document is loaded it takes a lot of time and memory to
load the graphic that are in the documet, so avoid that and just
store the compressed graphic into a temporary file (handeled by
GfxLink) and load when we really need to show the graphic.

GraphicObject cached some attributes from Graphic, but this
attributes now aren't available immediately so this attributes
are removed form GraphicObject and now delegate to the Graphic
itself. GetSizeBytes attribute however was removed as it is
only used in some tests.

GfxLink initial values were moved to the constructor and are
not set in the header file anymore (as it is the recommended
way to do it).

The SdImportTest::testDocumentLayout failed as it looks like the
dump sometimes didn't include the width and height of the null
bitmap (which is set to 32x32) of the FillBitmap in some
situations, but then in other situations it did include this
attributes. With this change the width and height are always
included for the FillBitmap which looks like it is more correct.

Reviewed-on: https://gerrit.libreoffice.org/53016
Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Tomaž Vajngerl <quikee@gmail.com>
(cherry picked from commit 7b355669c6ddeab2e6cec692d6afdff41c61d0fb)

Change-Id: Ia1218f93b1735402b7828404f65660e2d4acf32f

2 files changed, 14 insertions, 9 deletions

diff --git a/svx/source/svdraw/svdograf.cxx b/svx/source/svdraw/svdograf.cxx
index 2aced9a3227f..0415cfbe3eb2 100644
--- a/svx/source/svdraw/svdograf.cxx
+++ b/svx/source/svdraw/svdograf.cxx
@@ -288,7 +288,7 @@ sdr::contact::ViewContact* SdrGrafObj::CreateObjectSpecificViewContact()
 
 void SdrGrafObj::onGraphicChanged()
 {
-    if (!pGraphic || pGraphic->IsSwappedOut()) // don't force swap-in for this
+    if (!pGraphic || !pGraphic->GetGraphic().isAvailable())
         return;
 
     const SvgDataPtr& rSvgDataPtr = pGraphic->GetGraphic().getSvgData();
@@ -552,12 +552,12 @@ bool SdrGrafObj::IsSwappedOut() const
     return mbIsPreview || pGraphic->IsSwappedOut();
 }
 
-const MapMode& SdrGrafObj::GetGrafPrefMapMode() const
+MapMode SdrGrafObj::GetGrafPrefMapMode() const
 {
     return pGraphic->GetPrefMapMode();
 }
 
-const Size& SdrGrafObj::GetGrafPrefSize() const
+Size SdrGrafObj::GetGrafPrefSize() const
 {
     return pGraphic->GetPrefSize();
 }
@@ -1338,7 +1338,7 @@ IMPL_LINK( SdrGrafObj, ImpSwapHdl, const GraphicObject*, pO, SvStream* )
 
     if( pO->IsInSwapOut() )
     {
-        if( pModel && !mbIsPreview && pModel->IsSwapGraphics() && pGraphic->GetSizeBytes() > 20480 )
+        if( pModel && !mbIsPreview && pModel->IsSwapGraphics() && pGraphic->GetGraphic().GetSizeBytes() > 20480 )
         {
             // test if this object is visualized from someone
             // ## test only if there are VOCs other than the preview renderer
diff --git a/svx/source/xml/xmlgrhlp.cxx b/svx/source/xml/xmlgrhlp.cxx
index 1add678a67b1..53b4f60dbecb 100644
--- a/svx/source/xml/xmlgrhlp.cxx
+++ b/svx/source/xml/xmlgrhlp.cxx
@@ -499,15 +499,20 @@ OUString SvXMLGraphicHelper::ImplGetGraphicMimeType( const OUString& rFileName )
 Graphic SvXMLGraphicHelper::ImplReadGraphic( const OUString& rPictureStorageName,
                                              const OUString& rPictureStreamName )
 {
-    Graphic             aGraphic;
+    Graphic aReturnGraphic;
     SvxGraphicHelperStream_Impl aStream( ImplGetGraphicStream( rPictureStorageName, rPictureStreamName ) );
-    if( aStream.xStream.is() )
+    if (aStream.xStream.is())
     {
-        std::unique_ptr<SvStream> pStream(utl::UcbStreamHelper::CreateStream( aStream.xStream ));
-        GraphicFilter::GetGraphicFilter().ImportGraphic( aGraphic, "", *pStream );
+        GraphicFilter& rGraphicFilter = GraphicFilter::GetGraphicFilter();
+        std::unique_ptr<SvStream> pStream(utl::UcbStreamHelper::CreateStream(aStream.xStream));
+        Graphic aGraphic = rGraphicFilter.ImportUnloadedGraphic(*pStream);
+        if (aGraphic)
+            aReturnGraphic = aGraphic;
+        else
+            rGraphicFilter.ImportGraphic(aReturnGraphic, "", *pStream);
     }
 
-    return aGraphic;
+    return aReturnGraphic;
 }
 
 bool SvXMLGraphicHelper::ImplWriteGraphic( const OUString& rPictureStorageName,