QTreeView: speedup more QTreeViewPrivate::layout(-1)

Specially when called from expandAll

Reviewed-by: Gabriel

2 files changed, 27 insertions, 16 deletions

diff --git a/src/gui/itemviews/qtreeview.cpp b/src/gui/itemviews/qtreeview.cpp
index 0a7ffb7fbc..18ee5d3d9b 100644
--- a/src/gui/itemviews/qtreeview.cpp
+++ b/src/gui/itemviews/qtreeview.cpp
@@ -2662,17 +2662,8 @@ void QTreeView::expandAll()
 {
     Q_D(QTreeView);
     d->viewItems.clear();
-    d->expandedIndexes.clear();
     d->interruptDelayedItemsLayout();
-    d->layout(-1);
-    for (int i = 0; i < d->viewItems.count(); ++i) {
-        if (d->viewItems[i].expanded)
-            continue;
-        d->viewItems[i].expanded = true;
-        d->layout(i);
-        QModelIndex idx = d->viewItems.at(i).index;
-        d->expandedIndexes.insert(idx);
-    }
+    d->layout(-1, true);
     updateGeometries();
     d->viewport->update();
 }
@@ -3155,7 +3146,14 @@ void QTreeViewPrivate::_q_columnsRemoved(const QModelIndex &parent, int start, i
     QAbstractItemViewPrivate::_q_columnsRemoved(parent, start, end);
 }
 
-void QTreeViewPrivate::layout(int i)
+/** \internal
+    creates and initialize the viewItem structure of the children of the element \i
+
+    set \a recursiveExpanding if the function has to expand all the children (called from expandAll)
+    \a afterIsUninitialized is when we recurse from layout(-1), it means all the items after 'i' are
+    not yet initialized and need not to be moved
+ */
+void QTreeViewPrivate::layout(int i, bool recursiveExpanding, bool afterIsUninitialized)
 {
     Q_Q(QTreeView);
     QModelIndex current;
@@ -3182,8 +3180,12 @@ void QTreeViewPrivate::layout(int i)
             defaultItemHeight = q->indexRowSizeHint(index);
         }
         viewItems.resize(count);
+        afterIsUninitialized = true;
     } else if (viewItems[i].total != (uint)count) {
+        if (!afterIsUninitialized)
             insertViewItems(i + 1, count, QTreeViewItem()); // expand
+        else if (count > 0)
+            viewItems.resize(viewItems.count() + count);
     } else {
         expanding = false;
     }
@@ -3212,9 +3214,11 @@ void QTreeViewPrivate::layout(int i)
             item->expanded = false;
             item->total = 0;
             item->hasMoreSiblings = false;
-            if (isIndexExpanded(current)) {
+            if (recursiveExpanding || isIndexExpanded(current)) {
+                if (recursiveExpanding)
+                    expandedIndexes.insert(current);
                 item->expanded = true;
-                layout(last);
+                layout(last, recursiveExpanding, afterIsUninitialized);
                 item = &viewItems[last];
                 children += item->total;
                 item->hasChildren = item->total > 0;
@@ -3226,8 +3230,12 @@ void QTreeViewPrivate::layout(int i)
     }
 
     // remove hidden items
-    if (hidden > 0)
-        removeViewItems(last + 1, hidden); // collapse
+    if (hidden > 0) {
+        if (!afterIsUninitialized)
+            removeViewItems(last + 1, hidden);
+        else
+            viewItems.resize(viewItems.size() - hidden);
+    }
 
     if (!expanding)
         return; // nothing changed
diff --git a/src/gui/itemviews/qtreeview_p.h b/src/gui/itemviews/qtreeview_p.h
index 7893e04067..48997b7162 100644
--- a/src/gui/itemviews/qtreeview_p.h
+++ b/src/gui/itemviews/qtreeview_p.h
@@ -55,6 +55,7 @@
 
 #include "private/qabstractitemview_p.h"
 #include <QtCore/qvariantanimation.h>
+#include <QtCore/qabstractitemmodel.h>
 
 #ifndef QT_NO_TREEVIEW
 
@@ -75,6 +76,8 @@ struct QTreeViewItem
     int height : 16; // row height
 };
 
+Q_DECLARE_TYPEINFO(QTreeViewItem, Q_MOVABLE_TYPE);
+
 class QTreeViewPrivate : public QAbstractItemViewPrivate
 {
     Q_DECLARE_PUBLIC(QTreeView)
@@ -124,7 +127,7 @@ public:
     void _q_sortIndicatorChanged(int column, Qt::SortOrder order);
     void _q_modelDestroyed();
 
-    void layout(int item);
+    void layout(int item, bool recusiveExpanding = false, bool afterIsUninitialized = false);
 
     int pageUp(int item) const;
     int pageDown(int item) const;