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>

1 files changed, 29 insertions, 15 deletions

diff --git a/src/gui/painting/qpen.cpp b/src/gui/painting/qpen.cpp
index d86a5f0392..6b71c3818f 100644
--- a/src/gui/painting/qpen.cpp
+++ b/src/gui/painting/qpen.cpp
@@ -86,7 +86,7 @@ typedef QPenPrivate QPenData;
 
     \snippet code/src_gui_painting_qpen.cpp 1
 
-    The default pen is a solid black brush with 0 width, square
+    The default pen is a solid black brush with 1 width, square
     cap style (Qt::SquareCap), and  bevel join style (Qt::BevelJoin).
 
     In addition QPen provides the color() and setColor()
@@ -230,9 +230,9 @@ typedef QPenPrivate QPenData;
   \internal
 */
 inline QPenPrivate::QPenPrivate(const QBrush &_brush, qreal _width, Qt::PenStyle penStyle,
-                                Qt::PenCapStyle _capStyle, Qt::PenJoinStyle _joinStyle)
+                                Qt::PenCapStyle _capStyle, Qt::PenJoinStyle _joinStyle, bool _defaultWidth)
     : ref(1), dashOffset(0), miterLimit(2),
-      cosmetic(false)
+      cosmetic(false), defaultWidth(_defaultWidth)
 {
     width = _width;
     brush = _brush;
@@ -261,12 +261,12 @@ public:
 };
 
 Q_GLOBAL_STATIC_WITH_ARGS(QPenDataHolder, defaultPenInstance,
-                          (Qt::black, 0, Qt::SolidLine, qpen_default_cap, qpen_default_join))
+                          (Qt::black, 1, Qt::SolidLine, qpen_default_cap, qpen_default_join))
 Q_GLOBAL_STATIC_WITH_ARGS(QPenDataHolder, nullPenInstance,
-                          (Qt::black, 0, Qt::NoPen, qpen_default_cap, qpen_default_join))
+                          (Qt::black, 1, Qt::NoPen, qpen_default_cap, qpen_default_join))
 
 /*!
-    Constructs a default black solid line pen with 0 width.
+    Constructs a default black solid line pen with 1 width.
 */
 
 QPen::QPen()
@@ -276,7 +276,7 @@ QPen::QPen()
 }
 
 /*!
-    Constructs a black pen with 0 width and the given \a style.
+    Constructs a black pen with 1 width and the given \a style.
 
     \sa setStyle()
 */
@@ -287,20 +287,20 @@ QPen::QPen(Qt::PenStyle style)
         d = nullPenInstance()->pen;
         d->ref.ref();
     } else {
-        d = new QPenData(Qt::black, 0, style, qpen_default_cap, qpen_default_join);
+        d = new QPenData(Qt::black, 1, style, qpen_default_cap, qpen_default_join);
     }
 }
 
 
 /*!
-    Constructs a solid line pen with 0 width and the given \a color.
+    Constructs a solid line pen with 1 width and the given \a color.
 
     \sa setBrush(), setColor()
 */
 
 QPen::QPen(const QColor &color)
 {
-    d = new QPenData(color, 0, Qt::SolidLine, qpen_default_cap, qpen_default_join);
+    d = new QPenData(color, 1, Qt::SolidLine, qpen_default_cap, qpen_default_join);
 }
 
 
@@ -315,7 +315,7 @@ QPen::QPen(const QColor &color)
 
 QPen::QPen(const QBrush &brush, qreal width, Qt::PenStyle s, Qt::PenCapStyle c, Qt::PenJoinStyle j)
 {
-    d = new QPenData(brush, width, s, c, j);
+    d = new QPenData(brush, width, s, c, j, false);
 }
 
 /*!
@@ -655,12 +655,15 @@ void QPen::setWidth(int width)
 
 void QPen::setWidthF(qreal width)
 {
-    if (width < 0.f)
+    if (width < 0.f) {
         qWarning("QPen::setWidthF: Setting a pen width with a negative value is not defined");
+        return;
+    }
     if (qAbs(d->width - width) < 0.00000001f)
         return;
     detach();
     d->width = width;
+    d->defaultWidth = false;
 }
 
 
@@ -785,8 +788,7 @@ bool QPen::isSolid() const
     used with. Drawing a shape with a cosmetic pen ensures that its
     outline will have the same thickness at different scale factors.
 
-    A zero width pen is cosmetic by default; pens with a non-zero width
-    are non-cosmetic.
+    A zero width pen is cosmetic by default.
 
     \sa setCosmetic(), widthF()
 */
@@ -848,7 +850,8 @@ bool QPen::operator==(const QPen &p) const
                 || (qFuzzyCompare(pdd->dashOffset, dd->dashOffset) &&
                     pdd->dashPattern == dd->dashPattern))
             && p.d->brush == d->brush
-            && pdd->cosmetic == dd->cosmetic);
+            && pdd->cosmetic == dd->cosmetic
+            && pdd->defaultWidth == dd->defaultWidth);
 }
 
 
@@ -910,6 +913,8 @@ QDataStream &operator<<(QDataStream &s, const QPen &p)
         }
         if (s.version() >= 9)
             s << double(p.dashOffset());
+        if (s.version() >= QDataStream::Qt_5_0)
+            s << bool(dd->defaultWidth);
     }
     return s;
 }
@@ -935,6 +940,7 @@ QDataStream &operator>>(QDataStream &s, QPen &p)
     QVector<qreal> dashPattern;
     double dashOffset = 0;
     bool cosmetic = false;
+    bool defaultWidth = false;
     if (s.version() < QDataStream::Qt_4_3) {
         quint8 style8;
         s >> style8;
@@ -967,6 +973,13 @@ QDataStream &operator>>(QDataStream &s, QPen &p)
             s >> dashOffset;
     }
 
+    if (s.version() >= QDataStream::Qt_5_0) {
+        s >> defaultWidth;
+    } else {
+        // best we can do for legacy pens
+        defaultWidth = qFuzzyIsNull(width);
+    }
+
     p.detach();
     QPenData *dd = static_cast<QPenData *>(p.d);
     dd->width = width;
@@ -978,6 +991,7 @@ QDataStream &operator>>(QDataStream &s, QPen &p)
     dd->miterLimit = miterLimit;
     dd->dashOffset = dashOffset;
     dd->cosmetic = cosmetic;
+    dd->defaultWidth = defaultWidth;
 
     return s;
 }