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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 /demos
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 'demos')
-rw-r--r--demos/chip/chip.cpp17
1 files changed, 9 insertions, 8 deletions
diff --git a/demos/chip/chip.cpp b/demos/chip/chip.cpp
index c2b22da..4b6579e 100644
--- a/demos/chip/chip.cpp
+++ b/demos/chip/chip.cpp
@@ -74,8 +74,9 @@ void Chip::paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWid
if (option->state & QStyle::State_MouseOver)
fillColor = fillColor.light(125);
- if (option->levelOfDetail < 0.2) {
- if (option->levelOfDetail < 0.125) {
+ const qreal lod = option->levelOfDetailFromTransform(painter->worldTransform());
+ if (lod < 0.2) {
+ if (lod < 0.125) {
painter->fillRect(QRectF(0, 0, 110, 70), fillColor);
return;
}
@@ -100,7 +101,7 @@ void Chip::paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWid
painter->drawRect(QRect(14, 14, 79, 39));
painter->setBrush(b);
- if (option->levelOfDetail >= 1) {
+ if (lod >= 1) {
painter->setPen(QPen(Qt::gray, 1));
painter->drawLine(15, 54, 94, 54);
painter->drawLine(94, 53, 94, 15);
@@ -108,7 +109,7 @@ void Chip::paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWid
}
// Draw text
- if (option->levelOfDetail >= 2) {
+ if (lod >= 2) {
QFont font("Times", 10);
font.setStyleStrategy(QFont::ForceOutline);
painter->setFont(font);
@@ -122,17 +123,17 @@ void Chip::paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWid
// Draw lines
QVarLengthArray<QLineF, 36> lines;
- if (option->levelOfDetail >= 0.5) {
- for (int i = 0; i <= 10; i += (option->levelOfDetail > 0.5 ? 1 : 2)) {
+ if (lod >= 0.5) {
+ for (int i = 0; i <= 10; i += (lod > 0.5 ? 1 : 2)) {
lines.append(QLineF(18 + 7 * i, 13, 18 + 7 * i, 5));
lines.append(QLineF(18 + 7 * i, 54, 18 + 7 * i, 62));
}
- for (int i = 0; i <= 6; i += (option->levelOfDetail > 0.5 ? 1 : 2)) {
+ for (int i = 0; i <= 6; i += (lod > 0.5 ? 1 : 2)) {
lines.append(QLineF(5, 18 + i * 5, 13, 18 + i * 5));
lines.append(QLineF(94, 18 + i * 5, 102, 18 + i * 5));
}
}
- if (option->levelOfDetail >= 0.4) {
+ if (lod >= 0.4) {
const QLineF lineData[] = {
QLineF(25, 35, 35, 35),
QLineF(35, 30, 35, 40),