keep old contents of resized windows with Skia (tdf#131952)
It seems this is necessary in rare cases.
Change-Id: Id7557a069bc0adf61b34068f00761e16b961fbc5
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/92258
Tested-by: Jenkins
Reviewed-by: Luboš Luňák <l.lunak@collabora.com>
diff --git a/vcl/skia/gdiimpl.cxx b/vcl/skia/gdiimpl.cxx
index 6f7c2b7..e20d630 100644
--- a/vcl/skia/gdiimpl.cxx
+++ b/vcl/skia/gdiimpl.cxx
@@ -432,7 +432,22 @@
if (!avoidRecreateByResize())
{
Size oldSize(mSurface->width(), mSurface->height());
// Recreating a surface means that the old SkSurface contents will be lost.
// But if a window has been resized the windowing system may send repaint events
// only for changed parts and VCL would not repaint the whole area, assuming
// that some parts have not changed (this is what seems to cause tdf#131952).
// So carry over the old contents for windows, even though generally everything
// will be usually repainted anyway.
sk_sp<SkImage> snapshot;
if (!isOffscreen())
snapshot = mSurface->makeImageSnapshot();
recreateSurface();
if (snapshot)
{
SkPaint paint;
paint.setBlendMode(SkBlendMode::kSrc); // copy as is
mSurface->getCanvas()->drawImage(snapshot, 0, 0, &paint);
}
SAL_INFO("vcl.skia.trace", "recreate(" << this << "): old " << oldSize << " new "
<< Size(mSurface->width(), mSurface->height())
<< " requested "
