ItemViews: make it possible for chekcable items to get partiallyChecked

Previously it was only switching between checked and unchecked.

Task-number: 259008
Reviewed-by: ogoffart

1 files changed, 6 insertions, 1 deletions

diff --git a/src/gui/itemviews/qstyleditemdelegate.cpp b/src/gui/itemviews/qstyleditemdelegate.cpp
index 8faf0be426..34667ee6ce 100644
--- a/src/gui/itemviews/qstyleditemdelegate.cpp
+++ b/src/gui/itemviews/qstyleditemdelegate.cpp
@@ -746,8 +746,13 @@ bool QStyledItemDelegate::editorEvent(QEvent *event,
         return false;
     }
 
-    Qt::CheckState state = (static_cast<Qt::CheckState>(value.toInt()) == Qt::Checked
+    Qt::CheckState state;
+    if ( flags & Qt::ItemIsTristate ) {
+        state = static_cast<Qt::CheckState>( (value.toInt() + 1) % 3 );
+    } else {
+        state = (static_cast<Qt::CheckState>(value.toInt()) == Qt::Checked
                             ? Qt::Unchecked : Qt::Checked);
+    }
     return model->setData(index, state, Qt::CheckStateRole);
 }