Make QPen default to 1-width non-cosmetic.

Use the Qt4CompatiblePainting render hint when painting with QPainter to
treat default constructed QPens as cosmetic still.

The NonCosmeticDefaultPen render hint gets documented as obsolete, since
it was in any case not respected by the raster nor OpenGL paint engine.

Change-Id: I04d910e9700baf7f13a8aac07a3633014bb9283e
Reviewed-by: Jens Bache-Wiig <jens.bache-wiig@digia.com>

3 files changed, 5 insertions, 16 deletions

diff --git a/src/widgets/graphicsview/qgraphicsitem.cpp b/src/widgets/graphicsview/qgraphicsitem.cpp
index 375aa9b6ca..c432902fc2 100644
--- a/src/widgets/graphicsview/qgraphicsitem.cpp
+++ b/src/widgets/graphicsview/qgraphicsitem.cpp
@@ -8030,7 +8030,7 @@ QAbstractGraphicsShapeItem::~QAbstractGraphicsShapeItem()
 
 /*!
     Returns the item's pen. If no pen has been set, this function returns
-    QPen(), a default black solid line pen with 0 width.
+    QPen(), a default black solid line pen with 1 width.
 */
 QPen QAbstractGraphicsShapeItem::pen() const
 {
@@ -8204,7 +8204,7 @@ QRectF QGraphicsPathItem::boundingRect() const
 {
     Q_D(const QGraphicsPathItem);
     if (d->boundingRect.isNull()) {
-        qreal pw = pen().widthF();
+        qreal pw = pen().style() == Qt::NoPen ? qreal(0) : pen().widthF();
         if (pw == 0.0)
             d->boundingRect = d->path.controlPointRect();
         else {
@@ -8434,7 +8434,7 @@ QRectF QGraphicsRectItem::boundingRect() const
 {
     Q_D(const QGraphicsRectItem);
     if (d->boundingRect.isNull()) {
-        qreal halfpw = pen().widthF() / 2;
+        qreal halfpw = pen().style() == Qt::NoPen ? qreal(0) : pen().widthF() / 2;
         d->boundingRect = d->rect;
         if (halfpw > 0.0)
             d->boundingRect.adjust(-halfpw, -halfpw, halfpw, halfpw);
@@ -8723,7 +8723,7 @@ QRectF QGraphicsEllipseItem::boundingRect() const
 {
     Q_D(const QGraphicsEllipseItem);
     if (d->boundingRect.isNull()) {
-        qreal pw = pen().widthF();
+        qreal pw = pen().style() == Qt::NoPen ? qreal(0) : pen().widthF();
         if (pw == 0.0 && d->spanAngle == 360 * 16)
             d->boundingRect = d->rect;
         else
@@ -8959,7 +8959,7 @@ QRectF QGraphicsPolygonItem::boundingRect() const
 {
     Q_D(const QGraphicsPolygonItem);
     if (d->boundingRect.isNull()) {
-        qreal pw = pen().widthF();
+        qreal pw = pen().style() == Qt::NoPen ? qreal(0) : pen().widthF();
         if (pw == 0.0)
             d->boundingRect = d->polygon.boundingRect();
         else
diff --git a/src/widgets/graphicsview/qgraphicsproxywidget.cpp b/src/widgets/graphicsview/qgraphicsproxywidget.cpp
index 6dd03e76b0..762f93f55b 100644
--- a/src/widgets/graphicsview/qgraphicsproxywidget.cpp
+++ b/src/widgets/graphicsview/qgraphicsproxywidget.cpp
@@ -1485,17 +1485,7 @@ void QGraphicsProxyWidget::paint(QPainter *painter, const QStyleOptionGraphicsIt
     if (exposedWidgetRect.isEmpty())
         return;
 
-    // Disable QPainter's default pen being cosmetic. This allows widgets and
-    // styles to follow Qt's existing defaults without getting ugly cosmetic
-    // lines when scaled.
-    bool restore = !(painter->renderHints() & QPainter::NonCosmeticDefaultPen);
-    painter->setRenderHints(QPainter::NonCosmeticDefaultPen, true);
-
     d->widget->render(painter, exposedWidgetRect.topLeft(), exposedWidgetRect);
-
-    // Restore the render hints if necessary.
-    if (restore)
-        painter->setRenderHints(QPainter::NonCosmeticDefaultPen, false);
 }
 
 /*!
diff --git a/src/widgets/graphicsview/qgraphicswidget.cpp b/src/widgets/graphicsview/qgraphicswidget.cpp
index 05ae51c630..859f07a36b 100644
--- a/src/widgets/graphicsview/qgraphicswidget.cpp
+++ b/src/widgets/graphicsview/qgraphicswidget.cpp
@@ -2299,7 +2299,6 @@ void QGraphicsWidget::paintWindowFrame(QPainter *painter, const QStyleOptionGrap
             painter->fillRect(windowFrameRect, palette().window());
         }
     }
-    painter->setRenderHint(QPainter::NonCosmeticDefaultPen);
 
     // Draw title
     int height = (int)d->titleBarHeight(bar);