Expose QQuickPath::pointAtPercent as Q_INVOKABLE

So it can be used in QML. Useful in combination with ShapePath,
in order to add graphics along a Shape.

[ChangeLog][QtQuick][Shapes] Exposed QQuickPath::pointAtPercent
as invokable in QML.

Change-Id: Ia8aeb2b74003410ce16d9d2a0c62d79a021530af
Reviewed-by: Shawn Rutledge <shawn.rutledge@qt.io>
 

3 files changed, 26 insertions, 7 deletions

diff --git a/src/quick/items/qquickpathview.cpp b/src/quick/items/qquickpathview.cpp
index e4480b335a..4e81573356 100644
--- a/src/quick/items/qquickpathview.cpp
+++ b/src/quick/items/qquickpathview.cpp
@@ -438,7 +438,7 @@ void QQuickPathViewPrivate::updateItem(QQuickItem *item, qreal percent)
         att->setOnPath(percent < 1.0);
     }
     QQuickItemPrivate::get(item)->setCulled(percent >= 1.0);
-    QPointF pf = path->pointAt(qMin(percent, qreal(1.0)));
+    QPointF pf = path->pointAtPercent(qMin(percent, qreal(1.0)));
     item->setX(pf.x() - item->width()/2);
     item->setY(pf.y() - item->height()/2);
 }
@@ -1584,12 +1584,12 @@ QPointF QQuickPathViewPrivate::pointNear(const QPointF &point, qreal *nearPercen
     qreal res = pathLength / samples;
 
     qreal mindist = 1e10; // big number
-    QPointF nearPoint = path->pointAt(0);
+    QPointF nearPoint = path->pointAtPercent(0);
     qreal nearPc = 0;
 
     // get rough pos
     for (qreal i=1; i < samples; i++) {
-        QPointF pt = path->pointAt(i/samples);
+        QPointF pt = path->pointAtPercent(i/samples);
         QPointF diff = pt - point;
         qreal dist = diff.x()*diff.x() + diff.y()*diff.y();
         if (dist < mindist) {
@@ -1602,7 +1602,7 @@ QPointF QQuickPathViewPrivate::pointNear(const QPointF &point, qreal *nearPercen
     // now refine
     qreal approxPc = nearPc;
     for (qreal i = approxPc-1.0; i < approxPc+1.0; i += 1/(2*res)) {
-        QPointF pt = path->pointAt(i/samples);
+        QPointF pt = path->pointAtPercent(i/samples);
         QPointF diff = pt - point;
         qreal dist = diff.x()*diff.x() + diff.y()*diff.y();
         if (dist < mindist) {
diff --git a/src/quick/util/qquickpath.cpp b/src/quick/util/qquickpath.cpp
index f0705d19bd..840a8c6a2c 100644
--- a/src/quick/util/qquickpath.cpp
+++ b/src/quick/util/qquickpath.cpp
@@ -900,9 +900,28 @@ QPointF QQuickPath::backwardsPointAt(const QPainterPath &path, const qreal &path
     return QPointF(0,0);
 }
 
-QPointF QQuickPath::pointAt(qreal p) const
+/*!
+   \qmlmethod point Path::pointAtPercent(real t)
+
+    Returns the point at the percentage \a t of the current path.
+    The argument \a t has to be between 0 and 1.
+
+    \note Similarly to other percent methods in \l QPainterPath,
+    the percentage measurement is not linear with regards to the length,
+    if curves are present in the path.
+    When curves are present, the percentage argument is mapped to the \c t
+    parameter of the Bezier equations.
+
+   \sa QPainterPath::pointAt
+
+   \since QtQuick 2.14
+*/
+QPointF QQuickPath::pointAtPercent(qreal t) const
 {
     Q_D(const QQuickPath);
+    if (d->isShapePath)                     // this since ShapePath does not calculate the length at all,
+        return d->_path.pointAtPercent(t);  // in order to be faster.
+
     if (d->_pointCache.isEmpty()) {
         createPointCache();
         if (d->_pointCache.isEmpty())
@@ -910,7 +929,7 @@ QPointF QQuickPath::pointAt(qreal p) const
     }
 
     const int segmentCount = d->_pointCache.size() - 1;
-    qreal idxf = p*segmentCount;
+    qreal idxf = t*segmentCount;
     int idx1 = qFloor(idxf);
     qreal delta = idxf - idx1;
     if (idx1 > segmentCount)
diff --git a/src/quick/util/qquickpath_p.h b/src/quick/util/qquickpath_p.h
index 5a939f49cb..998f4e3123 100644
--- a/src/quick/util/qquickpath_p.h
+++ b/src/quick/util/qquickpath_p.h
@@ -488,7 +488,7 @@ public:
     QPainterPath path() const;
     QStringList attributes() const;
     qreal attributeAt(const QString &, qreal) const;
-    QPointF pointAt(qreal) const;
+    Q_REVISION(14) Q_INVOKABLE QPointF pointAtPercent(qreal t) const;
     QPointF sequentialPointAt(qreal p, qreal *angle = nullptr) const;
     void invalidateSequentialHistory() const;