1 files changed, 277 insertions, 163 deletions

diff --git a/src/gui/graphicsview/qgraphicsitem.cpp b/src/gui/graphicsview/qgraphicsitem.cpp
index 7b885df..fc81f39 100644
--- a/src/gui/graphicsview/qgraphicsitem.cpp
+++ b/src/gui/graphicsview/qgraphicsitem.cpp
@@ -522,6 +522,11 @@
 #include <private/qtextdocumentlayout_p.h>
 #include <private/qtextengine_p.h>
 
+#ifdef Q_WS_X11
+#include <private/qt_x11_p.h>
+#include <private/qpixmap_x11_p.h>
+#endif
+
 #include <math.h>
 
 QT_BEGIN_NAMESPACE
@@ -562,29 +567,6 @@ Q_GLOBAL_STATIC(QGraphicsItemCustomDataStore, qt_dataStore)
 /*!
     \internal
 
-    Removes the first instance of \a child from \a children. This is a
-    heuristic approach that assumes that it's common to remove items from the
-    start or end of the list.
-*/
-static void qt_graphicsitem_removeChild(QGraphicsItem *child, QList<QGraphicsItem *> *children)
-{
-    const int n = children->size();
-    for (int i = 0; i < (n + 1) / 2; ++i) {
-        if (children->at(i) == child) {
-            children->removeAt(i);
-            return;
-        }
-        int j = n - i - 1;
-        if (children->at(j) == child) {
-            children->removeAt(j);
-            return;
-        }
-    }
-}
-
-/*!
-    \internal
-
     Returns a QPainterPath of \a path when stroked with the \a pen.
     Ignoring dash pattern.
 */
@@ -783,6 +765,131 @@ QVariant QGraphicsItemPrivate::inputMethodQueryHelper(Qt::InputMethodQuery query
 /*!
     \internal
 
+    If \a deleting is true, then this item is being deleted, and \a parent is
+    null. Make sure not to trigger any pure virtual function calls (e.g.,
+    prepareGeometryChange).
+*/
+void QGraphicsItemPrivate::setParentItemHelper(QGraphicsItem *newParent, bool deleting)
+{
+    Q_Q(QGraphicsItem);
+    if (newParent == q) {
+        qWarning("QGraphicsItem::setParentItem: cannot assign %p as a parent of itself", this);
+        return;
+    }
+    if (newParent == parent)
+        return;
+
+    QVariant variant;
+    qVariantSetValue<QGraphicsItem *>(variant, newParent);
+    newParent = qVariantValue<QGraphicsItem *>(q->itemChange(QGraphicsItem::ItemParentChange, variant));
+    if (newParent == parent)
+        return;
+
+    if (QGraphicsWidget *w = isWidget ? static_cast<QGraphicsWidget *>(q) : q->parentWidget()) {
+        // Update the child focus chain; when reparenting a widget that has a
+        // focus child, ensure that that focus child clears its focus child
+        // chain from our parents before it's reparented.
+        if (QGraphicsWidget *focusChild = w->focusWidget())
+            focusChild->clearFocus();
+    }
+
+    // We anticipate geometry changes. If the item is deleted, it will be
+    // removed from the index at a later stage, and the whole scene will be
+    // updated.
+    if (!deleting)
+        q_ptr->prepareGeometryChange();
+
+    if (parent) {
+        // Remove from current parent
+        parent->d_ptr->removeChild(q);
+        qVariantSetValue<QGraphicsItem *>(variant, q);
+        parent->itemChange(QGraphicsItem::ItemChildRemovedChange, variant);
+    }
+
+    // Update toplevelitem list. If this item is being deleted, its parent
+    // will be 0 but we don't want to register/unregister it in the TLI list.
+    if (scene && !deleting) {
+        if (parent && !newParent) {
+            scene->d_func()->registerTopLevelItem(q);
+        } else if (!parent && newParent) {
+            scene->d_func()->unregisterTopLevelItem(q);
+        }
+    }
+
+    if ((parent = newParent)) {
+        bool implicitUpdate = false;
+        if (parent->d_func()->scene && parent->d_func()->scene != scene) {
+            // Move this item to its new parent's scene
+            parent->d_func()->scene->addItem(q);
+            implicitUpdate = true;
+        } else if (!parent->d_func()->scene && scene) {
+            // Remove this item from its former scene
+            scene->removeItem(q);
+        }
+
+        parent->d_ptr->addChild(q);
+        qVariantSetValue<QGraphicsItem *>(variant, q);
+        parent->itemChange(QGraphicsItem::ItemChildAddedChange, variant);
+        if (!implicitUpdate)
+            updateHelper();
+
+        // Inherit ancestor flags from the new parent.
+        updateAncestorFlag(QGraphicsItem::GraphicsItemFlag(-1));
+        updateAncestorFlag(QGraphicsItem::ItemClipsChildrenToShape);
+        updateAncestorFlag(QGraphicsItem::ItemIgnoresTransformations);
+
+        // Update item visible / enabled.
+        if (parent->isVisible() != visible) {
+            if (!parent->isVisible() || !explicitlyHidden)
+                setVisibleHelper(parent->isVisible(), /* explicit = */ false, /* update = */ !implicitUpdate);
+        }
+        if (parent->isEnabled() != enabled) {
+            if (!parent->isEnabled() || !explicitlyDisabled)
+                setEnabledHelper(parent->isEnabled(), /* explicit = */ false, /* update = */ !implicitUpdate);
+        }
+
+    } else {
+        // Inherit ancestor flags from the new parent.
+        updateAncestorFlag(QGraphicsItem::GraphicsItemFlag(-1));
+        updateAncestorFlag(QGraphicsItem::ItemClipsChildrenToShape);
+        updateAncestorFlag(QGraphicsItem::ItemIgnoresTransformations);
+
+        // Update item visible / enabled.
+        if (!visible && !explicitlyHidden)
+            setVisibleHelper(true, /* explicit = */ false);
+        if (!enabled && !explicitlyDisabled)
+            setEnabledHelper(true, /* explicit = */ false);
+
+        // If the item is being deleted, the whole scene will be updated.
+        if (!deleting)
+            updateHelper();
+    }
+
+    if (scene) {
+        // Invalidate any sort caching; arrival of a new item means we need to
+        // resort.
+        scene->d_func()->invalidateSortCache();
+    }
+
+    // Resolve opacity.
+    if (parent)
+        resolveEffectiveOpacity(parent->effectiveOpacity());
+    else
+        resolveEffectiveOpacity(1.0);
+
+    // Resolve depth.
+    resolveDepth(parent ? parent->d_ptr->depth : -1);
+
+    // Invalidate transform cache.
+    invalidateSceneTransformCache();
+
+    // Deliver post-change notification
+    q->itemChange(QGraphicsItem::ItemParentHasChanged, qVariantFromValue<QGraphicsItem *>(parent));
+}
+
+/*!
+    \internal
+
     Empty all cached pixmaps from the pixmap cache.
 */
 void QGraphicsItemCache::purge()
@@ -855,24 +962,17 @@ QGraphicsItem::QGraphicsItem(QGraphicsItemPrivate &dd, QGraphicsItem *parent,
 */
 QGraphicsItem::~QGraphicsItem()
 {
+    if (d_ptr->scene && !d_ptr->parent)
+        d_ptr->scene->d_func()->unregisterTopLevelItem(this);
+
     clearFocus();
-    d_ptr->removeExtraItemCache();
 
-    QVariant variant;
-    foreach (QGraphicsItem *child, d_ptr->children) {
-        if (QGraphicsItem *parent = child->parentItem()) {
-            qVariantSetValue<QGraphicsItem *>(variant, child);
-            parent->itemChange(ItemChildRemovedChange, variant);
-        }
-        delete child;
-    }
-    d_ptr->children.clear();
+    d_ptr->removeExtraItemCache();
+    QList<QGraphicsItem *> oldChildren = d_ptr->children;
+    qDeleteAll(oldChildren);
+    Q_ASSERT(d_ptr->children.isEmpty());
 
-    if (QGraphicsItem *parent = parentItem()) {
-        qVariantSetValue<QGraphicsItem *>(variant, this);
-        parent->itemChange(ItemChildRemovedChange, variant);
-        qt_graphicsitem_removeChild(this, &parent->d_func()->children);
-    }
+    d_ptr->setParentItemHelper(0, /* deleting = */ true);
     if (d_ptr->scene)
         d_ptr->scene->d_func()->_q_removeItemLater(this);
 
@@ -1017,103 +1117,7 @@ QGraphicsWidget *QGraphicsItem::window() const
 */
 void QGraphicsItem::setParentItem(QGraphicsItem *parent)
 {
-    if (parent == this) {
-        qWarning("QGraphicsItem::setParentItem: cannot assign %p as a parent of itself", this);
-        return;
-    }
-    if (parent == d_ptr->parent)
-        return;
-    QVariant variant;
-    qVariantSetValue<QGraphicsItem *>(variant, parent);
-    parent = qVariantValue<QGraphicsItem *>(itemChange(ItemParentChange, variant));
-    if (parent == d_ptr->parent)
-        return;
-
-    if (QGraphicsWidget *w = d_ptr->isWidget ? static_cast<QGraphicsWidget *>(this) : parentWidget()) {
-        // Update the child focus chain; when reparenting a widget that has a
-        // focus child, ensure that that focus child clears its focus child
-        // chain from our parents before it's reparented.
-        if (QGraphicsWidget *focusChild = w->focusWidget())
-            focusChild->clearFocus();
-    }
-
-    // We anticipate geometry changes
-    prepareGeometryChange();
-
-    if (d_ptr->parent) {
-        // Remove from current parent
-        qt_graphicsitem_removeChild(this, &d_ptr->parent->d_func()->children);
-        qVariantSetValue<QGraphicsItem *>(variant, this);
-        d_ptr->parent->itemChange(ItemChildRemovedChange, variant);
-    }
-
-    if ((d_ptr->parent = parent)) {
-        bool implicitUpdate = false;
-        if (parent->d_func()->scene && parent->d_func()->scene != d_ptr->scene) {
-            // Move this item to its new parent's scene
-            parent->d_func()->scene->addItem(this);
-            implicitUpdate = true;
-        } else if (!parent->d_func()->scene && d_ptr->scene) {
-            // Remove this item from its former scene
-            d_ptr->scene->removeItem(this);
-        }
-
-        d_ptr->parent->d_func()->children << this;
-        qVariantSetValue<QGraphicsItem *>(variant, this);
-        d_ptr->parent->itemChange(ItemChildAddedChange, variant);
-        if (!implicitUpdate)
-            d_ptr->updateHelper();
-
-        // Inherit ancestor flags from the new parent.
-        d_ptr->updateAncestorFlag(QGraphicsItem::GraphicsItemFlag(-1));
-        d_ptr->updateAncestorFlag(ItemClipsChildrenToShape);
-        d_ptr->updateAncestorFlag(ItemIgnoresTransformations);
-
-        // Update item visible / enabled.
-        if (d_ptr->parent->isVisible() != d_ptr->visible) {
-            if (!d_ptr->parent->isVisible() || !d_ptr->explicitlyHidden)
-                d_ptr->setVisibleHelper(d_ptr->parent->isVisible(), /* explicit = */ false, /* update = */ !implicitUpdate);
-        }
-        if (d_ptr->parent->isEnabled() != d_ptr->enabled) {
-            if (!d_ptr->parent->isEnabled() || !d_ptr->explicitlyDisabled)
-                d_ptr->setEnabledHelper(d_ptr->parent->isEnabled(), /* explicit = */ false, /* update = */ !implicitUpdate);
-        }
-
-    } else {
-        // Inherit ancestor flags from the new parent.
-        d_ptr->updateAncestorFlag(QGraphicsItem::GraphicsItemFlag(-1));
-        d_ptr->updateAncestorFlag(ItemClipsChildrenToShape);
-        d_ptr->updateAncestorFlag(ItemIgnoresTransformations);
-
-        // Update item visible / enabled.
-        if (!d_ptr->visible && !d_ptr->explicitlyHidden)
-            d_ptr->setVisibleHelper(true, /* explicit = */ false);
-        if (!d_ptr->enabled && !d_ptr->explicitlyDisabled)
-            d_ptr->setEnabledHelper(true, /* explicit = */ false);
-
-        d_ptr->updateHelper();
-    }
-
-    if (d_ptr->scene) {
-        // Invalidate any sort caching; arrival of a new item means we need to
-        // resort.
-        d_ptr->scene->d_func()->invalidateSortCache();
-    }
-
-    // Resolve opacity.
-    if (QGraphicsItem *p = d_ptr->parent)
-        d_ptr->resolveEffectiveOpacity(p->effectiveOpacity());
-    else
-        d_ptr->resolveEffectiveOpacity(1.0);
-
-    // Resolve depth.
-    d_ptr->resolveDepth(parent ? parent->d_ptr->depth : -1);
-
-    // Invalidate transform cache.
-    d_ptr->invalidateSceneTransformCache();
-
-    // Deliver post-change notification
-    itemChange(QGraphicsItem::ItemParentHasChanged, qVariantFromValue<QGraphicsItem *>(parent));
+    d_ptr->setParentItemHelper(parent, /* deleting = */ false);
 }
 
 /*!
@@ -2930,11 +2934,11 @@ qreal QGraphicsItem::zValue() const
 /*!
     Sets the Z-value, or the elevation, of the item, to \a z. The elevation
     decides the stacking order of sibling (neighboring) items. An item of high
-    Z-value will be drawn on top of an item with a lower Z-value if they
-    share the same parent item. In addition, children of an item will always be drawn
-    on top of the parent, regardless of the child's Z-value. Sibling items
-    that share the same Z-value will be drawn in an undefined order, although
-    the order will stay the same for as long as the items live.
+    Z-value will be drawn on top of an item with a lower Z-value if they share
+    the same parent item. In addition, children of an item will always be
+    drawn on top of the parent, regardless of the child's Z-value. Sibling
+    items that share the same Z-value will be drawn in order of insertion; the
+    last inserted child is stacked above previous children.
 
     \img graphicsview-zorder.png
 
@@ -2961,7 +2965,7 @@ void QGraphicsItem::setZValue(qreal z)
     qreal newZ = qreal(itemChange(ItemZValueChange, double(z)).toDouble());
     if (newZ == d_ptr->z)
         return;
-    d_ptr->z = z;
+    d_ptr->z = newZ;
     d_ptr->fullUpdateHelper();
 
     if (d_ptr->scene) {
@@ -3589,15 +3593,27 @@ void QGraphicsItem::setBoundingRegionGranularity(qreal granularity)
     only case where the item's background should be marked as dirty even when
     the item isn't visible.
 */
-void QGraphicsItemPrivate::updateHelper(const QRectF &rect, bool force)
+void QGraphicsItemPrivate::updateHelper(const QRectF &rect, bool force, bool updateCache)
 {
     // No scene, or if the scene is updating everything, means we have nothing
     // to do. The only exception is if the scene tracks the growing scene rect.
-    if (dirty)
+    QGraphicsItemCache *cache = maybeExtraItemCache();
+    if (dirty && (!updateCache || !cache || cache->allExposed))
         return;
+
     if (!scene || (scene && scene->d_func()->updateAll && scene->d_func()->hasSceneRect))
         return;
-    if (scene && (visible || force)) {
+
+    if (updateCache && QGraphicsItem::CacheMode(cacheMode) != QGraphicsItem::NoCache) {
+        if (rect.isNull()) {
+            cache->allExposed = true;
+            cache->exposed.clear();
+        } else {
+            cache->exposed.append(rect);
+        }
+    }
+
+    if (!dirty && scene && (visible || force)) {
         if (rect.isNull())
             dirty = 1;
         scene->itemUpdated(q_ptr, rect);
@@ -3706,6 +3722,41 @@ void QGraphicsItemPrivate::invalidateSceneTransformCache()
         children.at(i)->d_ptr->invalidateSceneTransformCache();
 }
 
+/*!
+    \internal
+*/
+void QGraphicsItemPrivate::addChild(QGraphicsItem *child)
+{
+    child->d_ptr->siblingIndex = children.size();
+    children.append(child);
+}
+
+/*!
+    \internal
+*/
+void QGraphicsItemPrivate::removeChild(QGraphicsItem *child)
+{
+    int idx = child->d_ptr->siblingIndex;
+    int size = children.size();
+    for (int i = idx; i < size - 1; ++i) {
+        QGraphicsItem *p = children[i + 1];
+        children[i] = p;
+        p->d_ptr->siblingIndex = i;
+    }
+    children.removeLast();
+}
+
+/*!
+    \internal
+*/
+QGraphicsItemCache *QGraphicsItemPrivate::maybeExtraItemCache() const
+{
+    return (QGraphicsItemCache *)qVariantValue<void *>(extra(ExtraCacheData));
+}
+
+/*!
+    \internal
+*/
 QGraphicsItemCache *QGraphicsItemPrivate::extraItemCache() const
 {
     QGraphicsItemCache *c = (QGraphicsItemCache *)qVariantValue<void *>(extra(ExtraCacheData));
@@ -3717,6 +3768,9 @@ QGraphicsItemCache *QGraphicsItemPrivate::extraItemCache() const
     return c;
 }
 
+/*!
+    \internal
+*/
 void QGraphicsItemPrivate::removeExtraItemCache()
 {
     QGraphicsItemCache *c = (QGraphicsItemCache *)qVariantValue<void *>(extra(ExtraCacheData));
@@ -3757,22 +3811,48 @@ bool QGraphicsItemPrivate::isProxyWidget() const
 */
 void QGraphicsItem::update(const QRectF &rect)
 {
-    if (d_ptr->dirty)
-        return;
-    if (d_ptr->scene && isVisible()) {
-        if (CacheMode(d_ptr->cacheMode) != NoCache) {
-            QGraphicsItemCache *cache = d_ptr->extraItemCache();
-            if (rect.isNull()) {
-                cache->allExposed = true;
-                cache->exposed.clear();
-            } else {
-                cache->exposed.append(rect);
-            }
-        }
-        d_ptr->updateHelper(rect);
-    }
+    d_ptr->updateHelper(rect, /* force = */ false, /* updateCache = */ true);
 }
 
+/*!
+    \internal
+
+    Scrolls \a rect in \a pix by \a dx, \a dy.
+
+    ### This can be done much more efficiently by using XCopyArea on X11 with
+    the same dst and src, and through moving pixels in the raster engine. It
+    can probably also be done much better on the other paint engines.
+*/
+void _q_scrollPixmap(QPixmap *pix, const QRect &rect, int dx, int dy)
+{
+#if 0
+    QPainter painter(pix);
+    painter.setClipRect(rect);
+    painter.drawPixmap(rect.translated(dx, dy), *pix, rect);
+    painter.end();
+#elif defined Q_WS_X11
+    GC gc = XCreateGC(X11->display, pix->handle(), 0, 0);
+
+    XRectangle xrect;
+    xrect.x = rect.x();
+    xrect.y = rect.y();
+    xrect.width = rect.width();
+    xrect.height = rect.height();
+    XSetClipRectangles(X11->display, gc, 0, 0, &xrect, 1, YXBanded);
+
+    XCopyArea(X11->display, pix->handle(), pix->handle(), gc,
+              rect.x(), rect.y(), rect.width(), rect.height(),
+              rect.x()+dx, rect.y()+dy);
+    XFreeGC(X11->display, gc);
+#else
+    QPixmap newPix = *pix;
+    QPainter painter(&newPix);
+    painter.setClipRect(rect);
+    painter.drawPixmap(rect.translated(dx, dy), *pix, rect);
+    painter.end();
+    *pix = newPix;
+#endif
+}
 
 /*!
     \since 4.4
@@ -3801,11 +3881,45 @@ void QGraphicsItem::scroll(qreal dx, qreal dy, const QRectF &rect)
     if (!d->scene)
         return;
     if (d->cacheMode != NoCache) {
-        // ### This is very slow, and can be done much better. If the cache is
-        // local and matches the below criteria for rotation and scaling, we
-        // can easily scroll. And if the cache is in device coordinates, we
-        // can scroll both the viewport and the cache.
-        update(rect);
+        QGraphicsItemCache *c;
+        bool scrollCache = qFuzzyCompare(dx - int(dx), qreal(0.0)) && qFuzzyCompare(dy - int(dy), qreal(0.0))
+                           && (c = (QGraphicsItemCache *)qVariantValue<void *>(d_ptr->extra(QGraphicsItemPrivate::ExtraCacheData)))
+                           && (d->cacheMode == ItemCoordinateCache && !c->fixedSize.isValid());
+        if (scrollCache) {
+            QPixmap pix;
+            if (QPixmapCache::find(c->key, pix)) {
+                // Adjust with 2 pixel margin. Notice the loss of precision
+                // when converting to QRect.
+                int adjust = 2;
+                QRectF br = boundingRect().adjusted(-adjust, -adjust, adjust, adjust);
+                QRect irect = rect.toRect().translated(-br.x(), -br.y());
+
+                _q_scrollPixmap(&pix, irect, dx, dy);
+
+                QPixmapCache::insert(c->key, pix);
+
+                // Translate the existing expose.
+                foreach (QRectF exposedRect, c->exposed)
+                    c->exposed += exposedRect.translated(dx, dy) & rect;
+
+                // Calculate exposure.
+                QRegion exposed;
+                QRect r = rect.toRect();
+                exposed += r;
+                exposed -= r.translated(dx, dy);
+                foreach (QRect rect, exposed.rects())
+                    update(rect);
+                d_ptr->updateHelper();
+            } else {
+                update(rect);
+            }
+        } else {
+            // ### This is very slow, and can be done much better. If the cache is
+            // local and matches the below criteria for rotation and scaling, we
+            // can easily scroll. And if the cache is in device coordinates, we
+            // can scroll both the viewport and the cache.
+            update(rect);
+        }
         return;
     }