lok: render image preview with lower resolution

renderShapeSelection callback is used to render
image previews which are later used during
eg. rotation.

Do not render preview with original size which
slows down app a lot. Use 1280x720 max.

Change-Id: Ia8365a67d87cea869ef74cb70ce4830439a523b6
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/129376
Tested-by: Jenkins CollaboraOffice <jenkinscollaboraoffice@gmail.com>
Reviewed-by: Szymon Kłos <szymon.klos@collabora.com>

5 files changed, 39 insertions, 2 deletions

diff --git a/filter/source/svg/svgexport.cxx b/filter/source/svg/svgexport.cxx
index fc8de3b18f68..d0eb6b9c6a8c 100644
--- a/filter/source/svg/svgexport.cxx
+++ b/filter/source/svg/svgexport.cxx
@@ -802,7 +802,9 @@ bool SVGFilter::implExportWriterTextGraphic( const Reference< view::XSelectionSu
         const Graphic aOriginalGraphic(xOriginalGraphic);
 
         uno::Reference<graphic::XGraphic> xTransformedGraphic;
-        xPropertySet->getPropertyValue("TransformedGraphic") >>= xTransformedGraphic;
+        xPropertySet->getPropertyValue(
+            mbIsPreview ? OUString("GraphicPreview") : OUString("TransformedGraphic"))
+                >>= xTransformedGraphic;
 
         if (!xTransformedGraphic.is())
             return false;
@@ -978,6 +980,8 @@ bool SVGFilter::implExportDocument()
                 mpSVGWriter->SetEmbeddedBitmapRefs( &maBitmapActionMap );
                 implExportTiledBackground();
             }
+            if( mbIsPreview )
+                mpSVGWriter->SetPreviewMode();
 
             // #i124608# export a given object selection, so no MasterPage export at all
             if (!mbExportShapeSelection)
diff --git a/filter/source/svg/svgfilter.cxx b/filter/source/svg/svgfilter.cxx
index 8025550b5837..67ff2dd80680 100644
--- a/filter/source/svg/svgfilter.cxx
+++ b/filter/source/svg/svgfilter.cxx
@@ -82,6 +82,7 @@ SVGFilter::SVGFilter( const Reference< XComponentContext >& rxCtx ) :
     mbExportShapeSelection(false),
     maFilterData(),
     mxDefaultPage(),
+    mbIsPreview(false),
     mbWriterFilter(false),
     mbCalcFilter(false),
     mbImpressFilter(false),
@@ -113,6 +114,15 @@ sal_Bool SAL_CALL SVGFilter::filter( const Sequence< PropertyValue >& rDescripto
     {
         for (const PropertyValue& rProp : rDescriptor)
         {
+            if (rProp.Name == "IsPreview")
+            {
+                rProp.Value >>= mbIsPreview;
+                break;
+            }
+        }
+
+        for (const PropertyValue& rProp : rDescriptor)
+        {
             if (rProp.Name == "FilterName")
             {
                 OUString sFilterName;
diff --git a/filter/source/svg/svgfilter.hxx b/filter/source/svg/svgfilter.hxx
index aab158971e0b..975eb4ae2d02 100644
--- a/filter/source/svg/svgfilter.hxx
+++ b/filter/source/svg/svgfilter.hxx
@@ -209,6 +209,7 @@ private:
     Sequence< PropertyValue >           maFilterData;
     Reference< css::drawing::XDrawPage > mxDefaultPage;
     std::vector< Reference< css::drawing::XDrawPage > > mSelectedPages;
+    bool                                mbIsPreview;
 
     bool                                mbWriterFilter;
     bool                                mbCalcFilter;
diff --git a/filter/source/svg/svgwriter.cxx b/filter/source/svg/svgwriter.cxx
index f5c96878d4f4..9677c9e092fd 100644
--- a/filter/source/svg/svgwriter.cxx
+++ b/filter/source/svg/svgwriter.cxx
@@ -2949,7 +2949,27 @@ void SVGActionWriter::ImplWriteBmp( const BitmapEx& rBmpEx,
         }
     }
 
-    if( !(bCached || GraphicConverter::Export( aOStm, rBmpEx, ConvertDataFormat::PNG ) == ERRCODE_NONE) )
+    const BitmapEx* pBitmap = &rBmpEx;
+    std::unique_ptr<BitmapEx> pNewBitmap;
+
+    // for preview we generate downscaled images (1280x720 max)
+    if (mbIsPreview)
+    {
+        Size aSize = rBmpEx.GetSizePixel();
+        double fX = static_cast<double>(aSize.getWidth()) / 1280;
+        double fY = static_cast<double>(aSize.getHeight()) / 720;
+        double fFactor = fX > fY ? fX : fY;
+        if (fFactor > 1.0)
+        {
+            aSize.setWidth(aSize.getWidth() / fFactor);
+            aSize.setHeight(aSize.getHeight() / fFactor);
+            pNewBitmap = std::make_unique<BitmapEx>(rBmpEx);
+            pNewBitmap->Scale(aSize);
+            pBitmap = pNewBitmap.get();
+        }
+    }
+
+    if( !(bCached || GraphicConverter::Export( aOStm, *pBitmap, ConvertDataFormat::PNG ) == ERRCODE_NONE) )
         return;
 
     Point                    aPt;
diff --git a/filter/source/svg/svgwriter.hxx b/filter/source/svg/svgwriter.hxx
index a052fba16e87..57c261fad7a5 100644
--- a/filter/source/svg/svgwriter.hxx
+++ b/filter/source/svg/svgwriter.hxx
@@ -319,6 +319,7 @@ private:
     bool                                        mbClipAttrChanged;
     bool                                        mbIsPlaceholderShape;
     const MetaBitmapActionMap*                  mpEmbeddedBitmapsMap;
+    bool                                        mbIsPreview;
 
 
     tools::Long                    ImplMap( sal_Int32 nVal ) const;
@@ -378,6 +379,7 @@ public:
     void                    SetEmbeddedBitmapRefs( const MetaBitmapActionMap* pEmbeddedBitmapsMap );
     void StartMask(const Point& rDestPt, const Size& rDestSize, const Gradient& rGradient,
                    sal_uInt32 nWriteFlags, OUString* pTextStyle = nullptr);
+    void                    SetPreviewMode(bool bState = true) { mbIsPreview = bState; }
 };