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-rw-r--r--doc/src/snippets/code/src_gui_effects_qgraphicseffect.cpp33
1 files changed, 33 insertions, 0 deletions
diff --git a/doc/src/snippets/code/src_gui_effects_qgraphicseffect.cpp b/doc/src/snippets/code/src_gui_effects_qgraphicseffect.cpp
new file mode 100644
index 0000000..6265c80
--- /dev/null
+++ b/doc/src/snippets/code/src_gui_effects_qgraphicseffect.cpp
@@ -0,0 +1,33 @@
+//! [0]
+MyGraphicsOpacityEffect::draw(QPainter *painter, QGraphicsEffectSource *source)
+{
+ // Fully opaque; draw directly without going through a pixmap.
+ if (qFuzzyCompare(m_opacity, 1)) {
+ source->draw(painter);
+ return;
+ }
+ ...
+}
+//! [0]
+
+//! [1]
+MyGraphicsEffect::draw(QPainter *painter, QGraphicsEffectSource *source)
+{
+ ...
+ QPoint offset;
+ if (source->isPixmap()) {
+ // No point in drawing in device coordinates (pixmap will be scaled anyways).
+ const QPixmap pixmap = source->pixmap(Qt::LogicalCoordinates, &offset);
+ ...
+ painter->drawPixmap(offset, pixmap);
+ } else {
+ // Draw pixmap in device coordinates to avoid pixmap scaling;
+ const QPixmap pixmap = source->pixmap(Qt::DeviceCoordinates, &offset);
+ painter->setWorldTransform(QTransform());
+ ...
+ painter->drawPixmap(offset, pixmap);
+ }
+ ...
+}
+//! [1]
+