AuroraMiddleware/qt5base-lts
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

QTextMarkdownImporter: Fix performance for non-trivial documents

Browse Source 
While parsing the markdown document, each addition of text and
formats was triggering a relayout of the so far existing document,
leading to quadratic behavior and very bad performance for any
non-trivial markdown document.

Guard the changes while parsing with a begin/endEditBlock to
avoid these intermediate updates.

The performance impact can for example be observed with the
markdown editor in Qt Creator (11+).

Pick-to: 6.5
Change-Id: I5f89441ea41bc3c6281b616f0c5528b49b48e432
Reviewed-by: Shawn Rutledge <shawn.rutledge@qt.io>
This commit is contained in:
Eike Ziller 2023-05-05 15:46:51 +02:00
parent e21c4be5d6
commit 9f0b4e18cd
1 changed files with 2 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
src/gui/text/qtextmarkdownimporter.cpp
View File

@ -138,7 +138,9 @@ void QTextMarkdownImporter::import(QTextDocument *doc, const QString &markdown)
m_monoFont.setPixelSize(doc->defaultFont().pixelSize()); m_monoFont.setPixelSize(doc->defaultFont().pixelSize());
qCDebug(lcMD) << "default font" << doc->defaultFont() << "mono font" << m_monoFont; qCDebug(lcMD) << "default font" << doc->defaultFont() << "mono font" << m_monoFont;
QByteArray md = markdown.toUtf8(); QByteArray md = markdown.toUtf8();
m_cursor->beginEditBlock();
md_parse(md.constData(), MD_SIZE(md.size()), &callbacks, this); md_parse(md.constData(), MD_SIZE(md.size()), &callbacks, this);
m_cursor->endEditBlock();
delete m_cursor; delete m_cursor;
m_cursor = nullptr; m_cursor = nullptr;
} }