tdf#108608 Draw file unresponsive on large text pasted into textbox

We have O(n^2) algorithm here.

The stack trace looks like:
ImpEditEngine::CalcTextWidth
EditEngine::CalcTextWidth
Outliner::CalcTextSize
SvxOutlinerForwarder::GetParaBounds
SvxAccessibleTextAdapter::GetParaBounds
accessibility::AccessibleEditableTextPara::getBounds
...
OutlinerView::PasteSpecial
where AccessibleEditableTextPara::getBounds iterates over all
paragraphs, and so does ImpEditEngine::CalcTextWidth.

To solve this, push the logic down from
SvxOutlinerForwarder::GetParaBounds, to new logic in EditEngine and
ImpEditEngine, where we can optimise the width calculation.

Note that this means that the width returned for a specific paragraph is
no longer the maximum width of all paragraphs, lets hope that does not
cause regressions.

Change-Id: I9f879d9a67b16a4aec08915328c99961b7313c2f
Reviewed-on: https://gerrit.libreoffice.org/52369
Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>

1 files changed, 1 insertions, 0 deletions

diff --git a/include/editeng/outliner.hxx b/include/editeng/outliner.hxx
index 5ef2a56ac05c..ee856b9e6b35 100644
--- a/include/editeng/outliner.hxx
+++ b/include/editeng/outliner.hxx
@@ -931,6 +931,7 @@ public:
 
     sal_uLong       GetTextHeight() const;
     sal_uLong       GetTextHeight( sal_Int32 nParagraph ) const;
+    tools::Rectangle GetParaBounds( sal_Int32 nParagraph ) const;
     Point           GetDocPosTopLeft( sal_Int32 nParagraph );
     Point           GetDocPos( const Point& rPaperPos ) const;
     bool            IsTextPos( const Point& rPaperPos, sal_uInt16 nBorder );