Fixes QTreeView: stylesheet :has-children pseudo selector doesn't works for the ::item pseudo-class

The State_Children was not set on the QStyleOption.
Refactorized a little bit the way it was computed.

Reviewed-by: Thierry
Task-number: 234930
Task-number: QTBUG-3129

3 files changed, 50 insertions, 16 deletions

diff --git a/src/gui/itemviews/qtreeview.cpp b/src/gui/itemviews/qtreeview.cpp
index f37d8c7..49c8e34 100644
--- a/src/gui/itemviews/qtreeview.cpp
+++ b/src/gui/itemviews/qtreeview.cpp
@@ -1422,8 +1422,8 @@ void QTreeView::drawTree(QPainter *painter, const QRegion &region) const
         for (; i < viewItems.count() && y <= area.bottom(); ++i) {
             const int itemHeight = d->itemHeight(i);
             option.rect.setRect(0, y, viewportWidth, itemHeight);
-            option.state = state | (viewItems.at(i).expanded
-                                    ? QStyle::State_Open : QStyle::State_None);
+            option.state = state | (viewItems.at(i).expanded ? QStyle::State_Open : QStyle::State_None)
+                                 | (viewItems.at(i).hasChildren ? QStyle::State_Children : QStyle::State_None );
             d->current = i;
             d->spanning = viewItems.at(i).spanning;
             if (!multipleRects || !drawn.contains(i)) {
@@ -1748,8 +1748,7 @@ void QTreeView::drawBranches(QPainter *painter, const QRect &rect,
         opt.rect = primitive;
 
         const bool expanded = viewItem.expanded;
-        const bool children = (((expanded && viewItem.total > 0)) // already laid out and has children
-                                || d->hasVisibleChildren(index)); // not laid out yet, so we don't know
+        const bool children = viewItem.hasChildren;
         bool moreSiblings = false;
         if (d->hiddenIndexes.isEmpty())
             moreSiblings = (d->model->rowCount(parent) - 1 > index.row());
@@ -3135,17 +3134,22 @@ void QTreeViewPrivate::layout(int i)
             last = j - hidden + children;
         } else {
             last = j - hidden + children;
-            viewItems[last].index = current;
-            viewItems[last].level = level;
-            viewItems[last].height = 0;
-            viewItems[last].spanning = q->isFirstColumnSpanned(current.row(), parent);
-            viewItems[last].expanded = false;
-            viewItems[last].total = 0;
+            QTreeViewItem *item = &viewItems[last];
+            item->index = current;
+            item->level = level;
+            item->height = 0;
+            item->spanning = q->isFirstColumnSpanned(current.row(), parent);
+            item->expanded = false;
+            item->total = 0;
             if (isIndexExpanded(current)) {
-                viewItems[last].expanded = true;
+                item->expanded = true;
                 layout(last);
-                children += viewItems[last].total;
+                item = &viewItems[last];
+                children += item->total;
+                item->hasChildren = item->total > 0;
                 last = j - hidden + children;
+            } else {
+                item->hasChildren = hasVisibleChildren(current);
             }
         }
     }
diff --git a/src/gui/itemviews/qtreeview_p.h b/src/gui/itemviews/qtreeview_p.h
index def8253..f89c328 100644
--- a/src/gui/itemviews/qtreeview_p.h
+++ b/src/gui/itemviews/qtreeview_p.h
@@ -66,7 +66,8 @@ struct QTreeViewItem
     QModelIndex index; // we remove items whenever the indexes are invalidated
     uint expanded : 1;
     uint spanning : 1;
-    uint total : 30; // total number of children visible
+    uint hasChildren : 1; // if the item has visible children (even if collapsed)
+    uint total : 29; // total number of children visible
     uint level : 16; // indentation
     int height : 16; // row height
 };
diff --git a/tests/auto/qtreeview/tst_qtreeview.cpp b/tests/auto/qtreeview/tst_qtreeview.cpp
index da58725..8d824cb 100644
--- a/tests/auto/qtreeview/tst_qtreeview.cpp
+++ b/tests/auto/qtreeview/tst_qtreeview.cpp
@@ -2891,7 +2891,8 @@ void tst_QTreeView::styleOptionViewItem()
 
                 QVERIFY(!opt.text.isEmpty());
                 QCOMPARE(opt.index, index);
-                QCOMPARE(!(opt.features & QStyleOptionViewItemV2::Alternate), !(index.row() % 2));
+                if (allCollapsed)
+                    QCOMPARE(!(opt.features & QStyleOptionViewItemV2::Alternate), !(index.row() % 2));
                 QCOMPARE(!(opt.features & QStyleOptionViewItemV2::HasCheckIndicator), !opt.text.contains("Checkable"));
 
                 if (opt.text.contains("Beginning"))
@@ -2911,12 +2912,15 @@ void tst_QTreeView::styleOptionViewItem()
                 else
                     QCOMPARE(opt.checkState, Qt::Unchecked);
 
+                QCOMPARE(!(opt.state & QStyle::State_Children) , !opt.text.contains("HasChildren"));
+
                 QVERIFY(!opt.text.contains("Assert"));
 
                 QStyledItemDelegate::paint(painter, option, index);
                 count++;
             }
             mutable int count;
+            bool allCollapsed;
     };
 
     QTreeView view;
@@ -2926,8 +2930,9 @@ void tst_QTreeView::styleOptionViewItem()
     view.setItemDelegate(&delegate);
     model.appendRow(QList<QStandardItem*>()
         << new QStandardItem("Beginning") <<  new QStandardItem("Middle") << new QStandardItem("Middle") << new QStandardItem("End") );
+    QStandardItem *par1 = new QStandardItem("Beginning HasChildren");
     model.appendRow(QList<QStandardItem*>()
-        << new QStandardItem("Beginning") <<  new QStandardItem("Middle") << new QStandardItem("Middle") << new QStandardItem("End") );
+        << par1 <<  new QStandardItem("Middle HasChildren") << new QStandardItem("Middle HasChildren") << new QStandardItem("End HasChildren") );
     model.appendRow(QList<QStandardItem*>()
         << new QStandardItem("OnlyOne") <<  new QStandardItem("Assert") << new QStandardItem("Assert") << new QStandardItem("Assert") );
     QStandardItem *checkable = new QStandardItem("Checkable");
@@ -2938,12 +2943,37 @@ void tst_QTreeView::styleOptionViewItem()
     model.appendRow(QList<QStandardItem*>()
         << new QStandardItem("Beginning") <<  checkable << checked << new QStandardItem("End") );
 
+    par1->appendRow(QList<QStandardItem*>()
+        << new QStandardItem("Beginning") <<  new QStandardItem("Middle") << new QStandardItem("Middle") << new QStandardItem("End") );
+    QStandardItem *par2 = new QStandardItem("Beginning HasChildren");
+    par1->appendRow(QList<QStandardItem*>()
+        << par2 <<  new QStandardItem("Middle HasChildren") << new QStandardItem("Middle HasChildren") << new QStandardItem("End HasChildren") );
+    par2->appendRow(QList<QStandardItem*>()
+        << new QStandardItem("Beginning") <<  new QStandardItem("Middle") << new QStandardItem("Middle") << new QStandardItem("End") );
+
+    QStandardItem *par3 = new QStandardItem("Beginning");
+    par1->appendRow(QList<QStandardItem*>()
+        << par3 <<  new QStandardItem("Middle") << new QStandardItem("Middle") << new QStandardItem("End") );
+    par3->appendRow(QList<QStandardItem*>()
+        << new QStandardItem("Beginning") <<  new QStandardItem("Middle") << new QStandardItem("Middle") << new QStandardItem("End") );
+    view.setRowHidden(0, par3->index(), true);
+
     view.setFirstColumnSpanned(2, QModelIndex(), true);
     view.setAlternatingRowColors(true);
 
     delegate.count = 0;
+    delegate.allCollapsed = true;
     view.showMaximized();
+    QApplication::processEvents();
     QTRY_VERIFY(delegate.count >= 13);
+    delegate.count = 0;
+    delegate.allCollapsed = false;
+    view.expandAll();
+    QApplication::processEvents();
+    QTRY_VERIFY(delegate.count >= 13);
+    view.collapse(par2->index());
+    QApplication::processEvents();
+    QTRY_VERIFY(delegate.count >= 4);
 }
 
 class task174627_TreeView : public QTreeView
@@ -3508,6 +3538,5 @@ void tst_QTreeView::task245654_changeModelAndExpandAll()
 }
 
 
-
 QTEST_MAIN(tst_QTreeView)
 #include "tst_qtreeview.moc"