diff options
author | Ivan Komissarov <ABBAPOH@gmail.com> | 2015-05-27 15:12:54 +0300 |
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committer | Ivan Komissarov <ABBAPOH@gmail.com> | 2015-05-28 11:02:22 +0000 |
commit | bccdb62340659cfdf4e0f8b53180fb73fda6ea39 (patch) | |
tree | 254e9786afcf093b53b7455397dedcaeaa4665f6 /src | |
parent | 22ecebcc72e418b6bf22562bd8a247261a7a4a37 (diff) |
Improve QHeaderView::sectionsInserted performance
Old implementation had complexity O(oldSectionCount); replace it with
O(hiddenSectionCount) algorithm. This boosts performance in case of the
vertical headers for models with big row count.
Change-Id: I7bb02f5579ce83fbdecf5f8c3aa7dcc0ac60dd40
Reviewed-by: Olivier Goffart (Woboq GmbH) <ogoffart@woboq.com>
Diffstat (limited to 'src')
-rw-r--r-- | src/widgets/itemviews/qheaderview.cpp | 14 |
1 files changed, 7 insertions, 7 deletions
diff --git a/src/widgets/itemviews/qheaderview.cpp b/src/widgets/itemviews/qheaderview.cpp index 66ff472724..bca315f80b 100644 --- a/src/widgets/itemviews/qheaderview.cpp +++ b/src/widgets/itemviews/qheaderview.cpp @@ -1879,13 +1879,13 @@ void QHeaderView::sectionsInserted(const QModelIndex &parent, // insert sections into hiddenSectionSize QHash<int, int> newHiddenSectionSize; // from logical index to section size - for (int i = 0; i < logicalFirst; ++i) - if (isSectionHidden(i)) - newHiddenSectionSize[i] = d->hiddenSectionSize[i]; - for (int j = logicalLast + 1; j < d->sectionCount(); ++j) - if (isSectionHidden(j)) - newHiddenSectionSize[j] = d->hiddenSectionSize[j - insertCount]; - d->hiddenSectionSize = newHiddenSectionSize; + for (QHash<int, int>::const_iterator it = d->hiddenSectionSize.cbegin(), + end = d->hiddenSectionSize.cend(); it != end; ++it) { + const int oldIndex = it.key(); + const int newIndex = (oldIndex < logicalFirst) ? oldIndex : oldIndex + insertCount; + newHiddenSectionSize[newIndex] = it.value(); + } + d->hiddenSectionSize.swap(newHiddenSectionSize); d->doDelayedResizeSections(); emit sectionCountChanged(oldCount, count()); |