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authorBjoern Erik Nilsen <bjorn.nilsen@nokia.com>2009-05-08 14:00:57 (GMT)
committerBjørn Erik Nilsen <bjorn.nilsen@nokia.com>2009-05-15 15:55:44 (GMT)
commit59cc08796bfb88bc0010006f365f1361462761aa (patch)
tree44eebedc40e44546a5788cfb3ac497f1bab7e7d6 /src/gui/graphicsview/qgraphicsitem.cpp
parentb0095f7f8925cf571224d348124f08c56f7f46e9 (diff)
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Graphics View Optimization: Use a simple style option by default.
QStyleOptionGraphicsItem extends QStyleOption with three values: 1) matrix, 2) levelOfDetail, 3) exposedRect, and they all involve expensive QTranform operations when calculated. We pass style option(s) to drawItems() and paint(), but the extended values are usually not in use. We can therefore gain quite some nice speedup by making them opt-in with the QGraphicsItem::ItemUsesExtendedStyleOption flag. Additionally, QStyleOptionGraphicsItem::levelOfDetail has been obsoleted, and a new function QStyleOptionGraphicsItem:: levelOfDetailFromTransform(const QTransform &) has been added. Me and Andreas don't consider this change to be too controversial even though it changes the behavior. Auto tests still pass. Reviewed-by: Andreas
Diffstat (limited to 'src/gui/graphicsview/qgraphicsitem.cpp')
-rw-r--r--src/gui/graphicsview/qgraphicsitem.cpp67
1 files changed, 63 insertions, 4 deletions
diff --git a/src/gui/graphicsview/qgraphicsitem.cpp b/src/gui/graphicsview/qgraphicsitem.cpp
index aa55908..ec08aaf 100644
--- a/src/gui/graphicsview/qgraphicsitem.cpp
+++ b/src/gui/graphicsview/qgraphicsitem.cpp
@@ -274,6 +274,15 @@
this flag, the child will be stacked behind it. This flag is useful for
drop shadow effects and for decoration objects that follow the parent
item's geometry without drawing on top of it.
+
+ \value ItemUsesExtendedStyleOption The item makes use of either
+ QStyleOptionGraphicsItem::exposedRect or QStyleOptionGraphicsItem::matrix.
+ By default, the exposedRect is initialized to the item's boundingRect and
+ the matrix is untransformed. Enable this flag for more fine-grained values.
+ Note that QStyleOptionGraphicsItem::levelOfDetail is unaffected by this flag
+ and is always initialized to 1.
+ Use QStyleOptionGraphicsItem::levelOfDetailFromTransform for a more
+ fine-grained value.
*/
/*!
@@ -914,6 +923,53 @@ void QGraphicsItemPrivate::childrenBoundingRectHelper(QTransform *x, QRectF *rec
}
}
+void QGraphicsItemPrivate::initStyleOption(QStyleOptionGraphicsItem *option, const QTransform &worldTransform,
+ const QRegion &exposedRegion, bool allItems) const
+{
+ Q_ASSERT(option);
+ Q_Q(const QGraphicsItem);
+
+ // Initialize standard QStyleOption values.
+ const QRectF brect = q->boundingRect();
+ option->state = QStyle::State_None;
+ option->rect = brect.toRect();
+ option->levelOfDetail = 1;
+ option->exposedRect = brect;
+ if (selected)
+ option->state |= QStyle::State_Selected;
+ if (enabled)
+ option->state |= QStyle::State_Enabled;
+ if (q->hasFocus())
+ option->state |= QStyle::State_HasFocus;
+ if (scene) {
+ if (scene->d_func()->hoverItems.contains(q_ptr))
+ option->state |= QStyle::State_MouseOver;
+ if (q == scene->mouseGrabberItem())
+ option->state |= QStyle::State_Sunken;
+ }
+
+ if (!(flags & QGraphicsItem::ItemUsesExtendedStyleOption))
+ return;
+
+ // Initialize QStyleOptionGraphicsItem specific values (matrix, exposedRect).
+
+ const QTransform itemToViewportTransform = q->deviceTransform(worldTransform);
+ option->matrix = itemToViewportTransform.toAffine(); //### discards perspective
+
+ if (!allItems) {
+ // Determine the item's exposed area
+ option->exposedRect = QRectF();
+ const QTransform reverseMap = itemToViewportTransform.inverted();
+ const QVector<QRect> exposedRects(exposedRegion.rects());
+ for (int i = 0; i < exposedRects.size(); ++i) {
+ option->exposedRect |= reverseMap.mapRect(exposedRects.at(i));
+ if (option->exposedRect.contains(brect))
+ break;
+ }
+ option->exposedRect &= brect;
+ }
+}
+
/*!
\internal
@@ -3671,7 +3727,7 @@ void QGraphicsItem::setBoundingRegionGranularity(qreal granularity)
All painting is done in local coordinates.
- \sa setCacheMode(), QPen::width(), {Item Coordinates}
+ \sa setCacheMode(), QPen::width(), {Item Coordinates}, ItemUsesExtendedStyleOption
*/
/*!
@@ -7635,9 +7691,7 @@ void QGraphicsPixmapItem::paint(QPainter *painter, const QStyleOptionGraphicsIte
painter->setRenderHint(QPainter::SmoothPixmapTransform,
(d->transformationMode == Qt::SmoothTransformation));
- QRectF exposed = option->exposedRect.adjusted(-1, -1, 1, 1);
- exposed &= QRectF(d->offset.x(), d->offset.y(), d->pixmap.width(), d->pixmap.height());
- painter->drawPixmap(exposed, d->pixmap, exposed.translated(-d->offset));
+ painter->drawPixmap(d->offset, d->pixmap);
if (option->state & QStyle::State_Selected)
qt_graphicsItem_highlightSelected(this, painter, option);
@@ -7803,6 +7857,7 @@ QGraphicsTextItem::QGraphicsTextItem(const QString &text, QGraphicsItem *parent
setPlainText(text);
setAcceptDrops(true);
setAcceptHoverEvents(true);
+ setFlags(ItemUsesExtendedStyleOption);
}
/*!
@@ -7822,6 +7877,7 @@ QGraphicsTextItem::QGraphicsTextItem(QGraphicsItem *parent
dd->qq = this;
setAcceptDrops(true);
setAcceptHoverEvents(true);
+ setFlag(ItemUsesExtendedStyleOption);
}
/*!
@@ -9167,6 +9223,9 @@ QDebug operator<<(QDebug debug, QGraphicsItem::GraphicsItemFlag flag)
case QGraphicsItem::ItemStacksBehindParent:
str = "ItemStacksBehindParent";
break;
+ case QGraphicsItem::ItemUsesExtendedStyleOption:
+ str = "ItemUsesExtendedStyleOption";
+ break;
}
debug << str;
return debug;