QHeaderView - add parameter to control sizeHint precision

Currently Qt looks at 1000 rows when scaling a column.
That can be slow in some situations and too inaccurate in others.

With this patch we leave it up to the user to decide how precise
e.g resizeToContents should be.

Change-Id: I6ef60f9a3bb40fc331ce1a1544fdc77488d20ca3
Reviewed-by: Stephen Kelly <stephen.kelly@kdab.com>

1 files changed, 19 insertions, 4 deletions

diff --git a/src/widgets/itemviews/qtableview.cpp b/src/widgets/itemviews/qtableview.cpp
index d72e19114d..41ecd3b48f 100644
--- a/src/widgets/itemviews/qtableview.cpp
+++ b/src/widgets/itemviews/qtableview.cpp
@@ -2208,7 +2208,7 @@ void QTableView::updateGeometries()
     if a larger row height is required by either the vertical header or
     the item delegate, that width will be used instead.
 
-    \sa QWidget::sizeHint, verticalHeader()
+    \sa QWidget::sizeHint, verticalHeader(), QHeaderView::resizeContentsPrecision()
 */
 int QTableView::sizeHintForRow(int row) const
 {
@@ -2218,7 +2218,8 @@ int QTableView::sizeHintForRow(int row) const
         return -1;
 
     ensurePolished();
-    const int maximumProcessCols = 1000; // To avoid this to take forever.
+    const int maximumProcessCols = d->verticalHeader->resizeContentsPrecision();
+
 
     int left = qMax(0, d->horizontalHeader->visualIndexAt(0));
     int right = d->horizontalHeader->visualIndexAt(d->viewport->width());
@@ -2253,6 +2254,9 @@ int QTableView::sizeHintForRow(int row) const
     int idxLeft = left;
     int idxRight = column - 1;
 
+    if (maximumProcessCols == 0)
+        columnsProcessed = 0; // skip the while loop
+
     while (columnsProcessed != maximumProcessCols && (idxLeft > 0 || idxRight < actualRight)) {
         int logicalIdx  = -1;
 
@@ -2306,7 +2310,7 @@ int QTableView::sizeHintForRow(int row) const
     required by either the horizontal header or the item delegate, the larger
     width will be used instead.
 
-    \sa QWidget::sizeHint, horizontalHeader()
+    \sa QWidget::sizeHint, horizontalHeader(), QHeaderView::resizeContentsPrecision()
 */
 int QTableView::sizeHintForColumn(int column) const
 {
@@ -2316,7 +2320,7 @@ int QTableView::sizeHintForColumn(int column) const
         return -1;
 
     ensurePolished();
-    const int maximumProcessRows = 1000; // To avoid this to take forever.
+    const int maximumProcessRows = d->horizontalHeader->resizeContentsPrecision();
 
     int top = qMax(0, d->verticalHeader->visualIndexAt(0));
     int bottom = d->verticalHeader->visualIndexAt(d->viewport->height());
@@ -2345,6 +2349,9 @@ int QTableView::sizeHintForColumn(int column) const
     int idxTop = top;
     int idxBottom = row - 1;
 
+    if (maximumProcessRows == 0)
+        rowsProcessed = 0;  // skip the while loop
+
     while (rowsProcessed != maximumProcessRows && (idxTop > 0 || idxBottom < actualBottom)) {
         int logicalIdx  = -1;
 
@@ -3038,6 +3045,8 @@ void QTableView::showColumn(int column)
 /*!
     Resizes the given \a row based on the size hints of the delegate
     used to render each item in the row.
+
+    \sa resizeRowsToContents(), sizeHintForRow(), QHeaderView::resizeContentsPrecision()
 */
 void QTableView::resizeRowToContents(int row)
 {
@@ -3050,6 +3059,8 @@ void QTableView::resizeRowToContents(int row)
 /*!
     Resizes all rows based on the size hints of the delegate
     used to render each item in the rows.
+
+    \sa resizeRowToContents(), sizeHintForRow(), QHeaderView::resizeContentsPrecision()
 */
 void QTableView::resizeRowsToContents()
 {
@@ -3063,6 +3074,8 @@ void QTableView::resizeRowsToContents()
 
     \note Only visible columns will be resized. Reimplement sizeHintForColumn()
     to resize hidden columns as well.
+
+    \sa resizeColumnsToContents(), sizeHintForColumn(), QHeaderView::resizeContentsPrecision()
 */
 void QTableView::resizeColumnToContents(int column)
 {
@@ -3075,6 +3088,8 @@ void QTableView::resizeColumnToContents(int column)
 /*!
     Resizes all columns based on the size hints of the delegate
     used to render each item in the columns.
+
+    \sa resizeColumnToContents(), sizeHintForColumn(), QHeaderView::resizeContentsPrecision()
 */
 void QTableView::resizeColumnsToContents()
 {