From d01b1b174f4e18b8bef23f7409d4e9cf4f07d232 Mon Sep 17 00:00:00 2001
From: Szymon Kłos <eszkadev@gmail.com>
Date: Mon, 31 Jan 2022 17:15:21 +0100
Subject: lok: render image preview with lower resolution
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

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>
---
 filter/source/svg/svgexport.cxx |  6 +++++-
 filter/source/svg/svgfilter.cxx | 10 ++++++++++
 filter/source/svg/svgfilter.hxx |  1 +
 filter/source/svg/svgwriter.cxx | 22 +++++++++++++++++++++-
 filter/source/svg/svgwriter.hxx |  2 ++
 5 files changed, 39 insertions(+), 2 deletions(-)

(limited to 'filter')

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),
@@ -111,6 +112,15 @@ sal_Bool SAL_CALL SVGFilter::filter( const Sequence< PropertyValue >& rDescripto
 
     if(mxSrcDoc.is())
     {
+        for (const PropertyValue& rProp : rDescriptor)
+        {
+            if (rProp.Name == "IsPreview")
+            {
+                rProp.Value >>= mbIsPreview;
+                break;
+            }
+        }
+
         for (const PropertyValue& rProp : rDescriptor)
         {
             if (rProp.Name == "FilterName")
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; }
 };
 
 
-- 
cgit