Fix sorting bug and ensure render functions work. Make direct default.

Mark the children list for sorting when the Z value for items changes.
Change the signature of the recursive draw function slightly so that
the expose region is optional, and ensure we don't intersect with this
region if it's not available.

This change also flips the direct painting so that the default is to
use the recursive approach.

4 files changed, 15 insertions, 16 deletions

diff --git a/src/gui/graphicsview/qgraphicsitem.cpp b/src/gui/graphicsview/qgraphicsitem.cpp
index e1389b5..17cab45 100644
--- a/src/gui/graphicsview/qgraphicsitem.cpp
+++ b/src/gui/graphicsview/qgraphicsitem.cpp
@@ -3151,6 +3151,7 @@ void QGraphicsItem::setZValue(qreal z)
     if (newZ == d_ptr->z)
         return;
     d_ptr->z = newZ;
+    d_ptr->needSortChildren = 1;
 
     if (d_ptr->scene) {
         d_ptr->scene->d_func()->markDirty(this, QRectF(), /*invalidateChildren=*/true);
diff --git a/src/gui/graphicsview/qgraphicsscene.cpp b/src/gui/graphicsview/qgraphicsscene.cpp
index b1d1742..fcb6352 100644
--- a/src/gui/graphicsview/qgraphicsscene.cpp
+++ b/src/gui/graphicsview/qgraphicsscene.cpp
@@ -2522,7 +2522,6 @@ QList<QGraphicsItem *> QGraphicsScene::items(const QPointF &pos) const
     return d->items_helper(pos);
 }
 
-
 /*!
     \fn QList<QGraphicsItem *> QGraphicsScene::items(const QRectF &rectangle, Qt::ItemSelectionMode mode) const
 
@@ -5046,7 +5045,7 @@ void QGraphicsScenePrivate::drawItemHelper(QGraphicsItem *item, QPainter *painte
 
 void QGraphicsScenePrivate::drawSubtreeRecursive(QGraphicsItem *item, QPainter *painter, const QTransform &parentTransform,
                                                  const QTransform &viewTransform,
-                                                 const QRegion &exposedRegion, QWidget *widget,
+                                                 QRegion *exposedRegion, QWidget *widget,
                                                  QGraphicsView::OptimizationFlags optimizationFlags,
                                                  QList<QGraphicsItem *> *topLevelItems,
                                                  qreal parentOpacity)
@@ -5084,10 +5083,11 @@ void QGraphicsScenePrivate::drawSubtreeRecursive(QGraphicsItem *item, QPainter *
         if (!brect.size().isNull()) {
             // ### This does not take the clip into account.
             _q_adjustRect(&brect);
-            const QRect paintedViewBoundingRect = transform.mapRect(brect).toRect().adjusted(-1, -1, 1, 1);
-            item->d_ptr->paintedViewBoundingRects.insert(widget, paintedViewBoundingRect);
-            viewBoundingRect = paintedViewBoundingRect & exposedRegion.boundingRect();
-        }
+            viewBoundingRect = transform.mapRect(brect).toRect().adjusted(-1, -1, 1, 1);
+            item->d_ptr->paintedViewBoundingRects.insert(widget, viewBoundingRect);
+            if (exposedRegion)
+                viewBoundingRect &= exposedRegion->boundingRect();
+         }
     }
 
     bool childClip = (item && (item->d_ptr->flags & QGraphicsItem::ItemClipsChildrenToShape));
@@ -5132,7 +5132,7 @@ void QGraphicsScenePrivate::drawSubtreeRecursive(QGraphicsItem *item, QPainter *
     // Draw item
     if (!dontDrawItem) {
         QStyleOptionGraphicsItem option;
-        item->d_ptr->initStyleOption(&option, transform, exposedRegion);
+        item->d_ptr->initStyleOption(&option, transform, exposedRegion ? *exposedRegion : QRegion(), exposedRegion == 0);
 
         bool clipsToShape = (item->d_ptr->flags & QGraphicsItem::ItemClipsToShape);
         bool savePainter = clipsToShape || !(optimizationFlags & QGraphicsView::DontSavePainterState);
@@ -5143,7 +5143,6 @@ void QGraphicsScenePrivate::drawSubtreeRecursive(QGraphicsItem *item, QPainter *
         if (clipsToShape)
             painter->setClipPath(item->shape(), Qt::IntersectClip);
         painter->setOpacity(opacity);
-
         drawItemHelper(item, painter, &option, widget, false);
 
         if (savePainter)
@@ -5318,20 +5317,19 @@ void QGraphicsScene::drawItems(QPainter *painter,
 
     // Determine view, expose and flags.
     QGraphicsView *view = widget ? qobject_cast<QGraphicsView *>(widget->parentWidget()) : 0;
-    QRegion expose;
+    QRegion *expose = 0;
     QGraphicsView::OptimizationFlags flags;
     if (view) {
-        expose = view->d_func()->exposedRegion;
+        expose = &view->d_func()->exposedRegion;
         flags = view->optimizationFlags();
     }
 
-    // Draw each toplevel recursively.
+    // Find all toplevels, they are already sorted.
     QList<QGraphicsItem *> topLevelItems;
     for (int i = 0; i < numItems; ++i) {
         QGraphicsItem *item = items[i]->topLevelItem();
-        topLevelItems << item;
-
         if (!item->d_ptr->itemDiscovered) {
+            topLevelItems << item;
             item->d_ptr->itemDiscovered = 1;
             d->drawSubtreeRecursive(item, painter, viewTransform, viewTransform,
                                     expose, widget, flags);
diff --git a/src/gui/graphicsview/qgraphicsscene_p.h b/src/gui/graphicsview/qgraphicsscene_p.h
index 2a036e3..2e82a4a 100644
--- a/src/gui/graphicsview/qgraphicsscene_p.h
+++ b/src/gui/graphicsview/qgraphicsscene_p.h
@@ -256,7 +256,7 @@ public:
     
     void drawSubtreeRecursive(QGraphicsItem *item, QPainter *painter, const QTransform &parentTransform,
                               const QTransform &viewTransform,
-                              const QRegion &exposedRegion, QWidget *widget, QGraphicsView::OptimizationFlags optimizationFlags,
+                              QRegion *exposedRegion, QWidget *widget, QGraphicsView::OptimizationFlags optimizationFlags,
                               QList<QGraphicsItem *> *topLevelItems = 0, qreal parentOpacity = qreal(1.0));
     void markDirty(QGraphicsItem *item, const QRectF &rect = QRectF(), bool invalidateChildren = false,
                    bool maybeDirtyClipPath = false, bool force = false, bool ignoreOpacity = false);
diff --git a/src/gui/graphicsview/qgraphicsview.cpp b/src/gui/graphicsview/qgraphicsview.cpp
index d410a53..caa3ffc 100644
--- a/src/gui/graphicsview/qgraphicsview.cpp
+++ b/src/gui/graphicsview/qgraphicsview.cpp
@@ -3300,8 +3300,8 @@ void QGraphicsView::paintEvent(QPaintEvent *event)
     }
 
     // Items
-    if ((d->optimizationFlags & IndirectPainting)) {
-        d->scene->d_func()->drawSubtreeRecursive(0, &painter, viewTransform, viewTransform, d->exposedRegion,
+    if (!(d->optimizationFlags & IndirectPainting)) {
+        d->scene->d_func()->drawSubtreeRecursive(0, &painter, viewTransform, viewTransform, &d->exposedRegion,
                                                  viewport(), d->optimizationFlags, 0);
     } else {
         // Find all exposed items