svx: cache PNG export of graphic shapes

One scenario where this is useful is: manipulate a JPEG photo in
Online's Impress, e.g. resize it multiple times. Each time we generate
an SVG preview of the shape, which includes the PNG export of the bitmap
itself.

This helps with a desktop CPU:

debug:9976:9974: SVGFilter::filter finished in 3422 ms
debug:9976:9974: SVGFilter::filter finished in 176 ms

But it is meant to help on mobile, too, where writing such a bitmap as
PNG takes 16-17 seconds without this.

(This works because SVG writes the original bitmap, even if it's scaled.
If that invariant will be broken in the future, we still emit correct
output, but then the cache will be less useful.)

Change-Id: I7204b04efeeb42c6eec67f04dfdb8a4ed50443a9
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/89377
Reviewed-by: Miklos Vajna <vmiklos@collabora.com>
Tested-by: Jenkins

1 files changed, 22 insertions, 0 deletions

diff --git a/svx/source/svdraw/svdograf.cxx b/svx/source/svdraw/svdograf.cxx
index 127de6a0c6f5..f7c089d2232e 100644
--- a/svx/source/svdraw/svdograf.cxx
+++ b/svx/source/svdraw/svdograf.cxx
@@ -1276,4 +1276,26 @@ void SdrGrafObj::addCropHandles(SdrHdlList& rTarget) const
     rTarget.AddHdl(std::make_unique<SdrCropHdl>(Point(basegfx::fround(aPos.getX()), basegfx::fround(aPos.getY())), SdrHdlKind::LowerRight, fShearX, fRotate));
 }
 
+void SdrGrafObj::SetPNGPreviewChecksum(BitmapChecksum nPNGPreviewChecksum)
+{
+    mnPNGPreviewChecksum = nPNGPreviewChecksum;
+}
+
+BitmapChecksum SdrGrafObj::GetPNGPreviewChecksum() const
+{
+    return mnPNGPreviewChecksum;
+}
+
+void SdrGrafObj::SetPNGPreviewData(SvMemoryStream& rPNGPreviewData)
+{
+    rPNGPreviewData.Seek(0);
+    maPNGPreviewData.resize(rPNGPreviewData.remainingSize());
+    rPNGPreviewData.ReadBytes(maPNGPreviewData.data(), maPNGPreviewData.size());
+}
+
+const std::vector<sal_Int8>& SdrGrafObj::GetPNGPreviewData() const
+{
+    return maPNGPreviewData;
+}
+
 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */