From 5f3e64235e8d0ed70e93fa6bf379296e0324751b Mon Sep 17 00:00:00 2001
From: Christian Ehrlicher <ch.ehrlicher@gmx.de>
Date: Thu, 31 Oct 2024 18:58:35 +0100
Subject: [PATCH] Itemviews: avoid unneeded calls to rowCount()

Avoid unneeded calls to rowCount() in a for loop as this might get
expensive for large models.

Change-Id: Ic949ba64f5068b4e6ca0d0c9bc51f181e220da70
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>
(cherry picked from commit 4280e4c12e289aeb0ed28f07b0036e89bc8fb35f)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>
---
 src/widgets/itemviews/qlistview.cpp    | 3 ++-
 src/widgets/itemviews/qtablewidget.cpp | 8 ++++----
 2 files changed, 6 insertions(+), 5 deletions(-)

diff --git a/src/widgets/itemviews/qlistview.cpp b/src/widgets/itemviews/qlistview.cpp
index 91f32a14e15..b07032a11c5 100644
--- a/src/widgets/itemviews/qlistview.cpp
+++ b/src/widgets/itemviews/qlistview.cpp
@@ -583,7 +583,8 @@ void QListViewPrivate::selectAll(QItemSelectionModel::SelectionFlags command)
     QModelIndex topLeft;
     int row = 0;
     const int colCount = model->columnCount(root);
-    for(; row < model->rowCount(root); ++row) {
+    const int rowCount = model->rowCount(root);
+    for ( ; row < rowCount; ++row) {
         if (isHidden(row)) {
             //it might be the end of a selection range
             if (topLeft.isValid()) {
diff --git a/src/widgets/itemviews/qtablewidget.cpp b/src/widgets/itemviews/qtablewidget.cpp
index 2c1a95f6c8b..a2d9153c913 100644
--- a/src/widgets/itemviews/qtablewidget.cpp
+++ b/src/widgets/itemviews/qtablewidget.cpp
@@ -498,11 +498,12 @@ void QTableModel::sort(int column, Qt::SortOrder order)
 {
     QList<QPair<QTableWidgetItem *, int>> sortable;
     QList<int> unsortable;
+    const int numRows = rowCount();
 
-    sortable.reserve(rowCount());
-    unsortable.reserve(rowCount());
+    sortable.reserve(numRows);
+    unsortable.reserve(numRows);
 
-    for (int row = 0; row < rowCount(); ++row) {
+    for (int row = 0; row < numRows; ++row) {
         if (QTableWidgetItem *itm = item(row, column))
             sortable.append(QPair<QTableWidgetItem*,int>(itm, row));
         else
@@ -515,7 +516,6 @@ void QTableModel::sort(int column, Qt::SortOrder order)
     QList<QTableWidgetItem *> sorted_table(tableItems.size());
     QModelIndexList from;
     QModelIndexList to;
-    const int numRows = rowCount();
     const int numColumns = columnCount();
     from.reserve(numRows * numColumns);
     to.reserve(numRows * numColumns);