Add scale property to QQuickPath

With this property, Paths and ShapePaths become scalable.

[ChangeLog][QQuick][Path] Added scale property to scale
a path before sending it in to PathView/Shape.

Change-Id: Id9ce7d1247d55e2cdb0d27a19c86fe0970e66268
Fixes: QTBUG-74456
Reviewed-by: Shawn Rutledge <shawn.rutledge@qt.io>
 

3 files changed, 49 insertions, 2 deletions

diff --git a/src/quick/util/qquickpath.cpp b/src/quick/util/qquickpath.cpp
index 16723b997e..a0f3749552 100644
--- a/src/quick/util/qquickpath.cpp
+++ b/src/quick/util/qquickpath.cpp
@@ -407,6 +407,19 @@ void QQuickPath::processPath()
     emit changed();
 }
 
+inline static void scalePath(QPainterPath &path, const QSizeF &scale)
+{
+    const qreal xscale = scale.width();
+    const qreal yscale = scale.height();
+    if (xscale == 1 && yscale ==  1)
+        return;
+
+    for (int i = 0; i < path.elementCount(); ++i) {
+        const QPainterPath::Element &element = path.elementAt(i);
+        path.setElementPositionAt(i, element.x * xscale, element.y * yscale);
+    }
+}
+
 QPainterPath QQuickPath::createPath(const QPointF &startPoint, const QPointF &endPoint, const QStringList &attributes, qreal &pathLength, QList<AttributePoint> &attributePoints, bool *closed)
 {
     Q_D(QQuickPath);
@@ -465,7 +478,7 @@ QPainterPath QQuickPath::createPath(const QPointF &startPoint, const QPointF &en
         d->_attributePoints.last().values[percentString] = 1;
         interpolate(d->_attributePoints.count() - 1, percentString, 1);
     }
-
+    scalePath(path, d->scale);
 
     // Adjust percent
     qreal length = path.length();
@@ -491,7 +504,7 @@ QPainterPath QQuickPath::createPath(const QPointF &startPoint, const QPointF &en
 
     if (closed) {
         QPointF end = path.currentPosition();
-        *closed = length > 0 && startX == end.x() && startY == end.y();
+        *closed = length > 0 && startX * d->scale.width() == end.x() && startY * d->scale.height() == end.y();
     }
     pathLength = length;
 
@@ -525,6 +538,7 @@ QPainterPath QQuickPath::createShapePath(const QPointF &startPoint, const QPoint
         QPointF end = path.currentPosition();
         *closed = startX == end.x() && startY == end.y();
     }
+    scalePath(path, d->scale);
 
     // Note: Length of paths inside ShapePath is not used, so currently
     // length is always 0. This avoids potentially heavy path.length()
@@ -723,6 +737,33 @@ void QQuickPath::invalidateSequentialHistory() const
     d->prevBez.isValid = false;
 }
 
+/*!
+    \qmlproperty size QtQuick::Path::scale
+
+    This property holds the scale factor for the path.
+    The width and height of \a scale can be different, to
+    achieve anisotropic scaling.
+
+    \note Setting this property will not affect the border width.
+
+    \since QtQuick 2.14
+*/
+QSizeF QQuickPath::scale() const
+{
+    Q_D(const QQuickPath);
+    return d->scale;
+}
+
+void QQuickPath::setScale(const QSizeF &scale)
+{
+    Q_D(QQuickPath);
+    if (scale == d->scale)
+        return;
+    d->scale = scale;
+    emit scaleChanged();
+    processPath();
+}
+
 QPointF QQuickPath::sequentialPointAt(qreal p, qreal *angle) const
 {
     Q_D(const QQuickPath);
diff --git a/src/quick/util/qquickpath_p.h b/src/quick/util/qquickpath_p.h
index 6b9a40fe6d..01f60c34d2 100644
--- a/src/quick/util/qquickpath_p.h
+++ b/src/quick/util/qquickpath_p.h
@@ -445,6 +445,7 @@ class Q_QUICK_PRIVATE_EXPORT QQuickPath : public QObject, public QQmlParserStatu
     Q_PROPERTY(qreal startX READ startX WRITE setStartX NOTIFY startXChanged)
     Q_PROPERTY(qreal startY READ startY WRITE setStartY NOTIFY startYChanged)
     Q_PROPERTY(bool closed READ isClosed NOTIFY changed)
+    Q_PROPERTY(QSizeF scale READ scale WRITE setScale NOTIFY scaleChanged REVISION 14)
     Q_CLASSINFO("DefaultProperty", "pathElements")
     Q_INTERFACES(QQmlParserStatus)
 public:
@@ -470,10 +471,14 @@ public:
     QPointF sequentialPointAt(qreal p, qreal *angle = nullptr) const;
     void invalidateSequentialHistory() const;
 
+    QSizeF scale() const;
+    void setScale(const QSizeF &scale);
+
 Q_SIGNALS:
     void changed();
     void startXChanged();
     void startYChanged();
+    Q_REVISION(14) void scaleChanged();
 
 protected:
     QQuickPath(QQuickPathPrivate &dd, QObject *parent = nullptr);
diff --git a/src/quick/util/qquickpath_p_p.h b/src/quick/util/qquickpath_p_p.h
index 9735d51264..e26001ec77 100644
--- a/src/quick/util/qquickpath_p_p.h
+++ b/src/quick/util/qquickpath_p_p.h
@@ -84,6 +84,7 @@ public:
     QQmlNullableValue<qreal> startX;
     QQmlNullableValue<qreal> startY;
     qreal pathLength = 0;
+    QSizeF scale = QSizeF(1, 1);
     bool closed = false;
     bool componentComplete = true;
     bool isShapePath = false;