Implement the functions we added in the API review:

Those are:
  * setAnchorSpacing()
  * anchorSpacing()
  * unsetAnchorSpacing()

Autotests for the two last ones are missing though..

4 files changed, 95 insertions, 26 deletions

diff --git a/src/gui/graphicsview/qgraphicsanchorlayout.cpp b/src/gui/graphicsview/qgraphicsanchorlayout.cpp
index db79dae..5032dc6 100644
--- a/src/gui/graphicsview/qgraphicsanchorlayout.cpp
+++ b/src/gui/graphicsview/qgraphicsanchorlayout.cpp
@@ -138,18 +138,6 @@ void QGraphicsAnchorLayout::addAnchor(QGraphicsLayoutItem *firstItem, Qt::Anchor
     invalidate();
 }
 
-void QGraphicsAnchorLayout::setAnchorSpacing(const QGraphicsLayoutItem *firstItem, Qt::AnchorPoint firstEdge,
-                                             const QGraphicsLayoutItem *secondItem, Qt::AnchorPoint secondEdge,
-                                             qreal spacing)
-{
-    Q_D(QGraphicsAnchorLayout);
-
-    if (!d->setAnchorSize(firstItem, firstEdge, secondItem, secondEdge, spacing)) {
-        qWarning("setAnchorSpacing: The anchor does not exist.");
-    }
-    invalidate();
-}
-
 /*!
  * Creates two anchors between \a firstItem and \a secondItem, where one is for the horizontal
  * edge and another one for the vertical edge that the corners \a firstCorner and \a
@@ -225,17 +213,52 @@ void QGraphicsAnchorLayout::addCornerAnchors(QGraphicsLayoutItem *firstItem,
     \endcode
 */
 
+/*!
+  Set the spacing between the anchor point defined by \a firstItem and \a firstEdge and
+  \a secondItem and \a secondEdge to be \a spacing.
+*/
+void QGraphicsAnchorLayout::setAnchorSpacing(const QGraphicsLayoutItem *firstItem, Qt::AnchorPoint firstEdge,
+                                             const QGraphicsLayoutItem *secondItem, Qt::AnchorPoint secondEdge,
+                                             qreal spacing)
+{
+    Q_D(QGraphicsAnchorLayout);
+
+    if (!d->setAnchorSize(firstItem, firstEdge, secondItem, secondEdge, &spacing)) {
+        qWarning("setAnchorSpacing: The anchor does not exist.");
+    }
+    invalidate();
+}
+
+/*!
+  Returns the spacing between the anchor point defined by \a firstItem and \a firstEdge and
+  \a secondItem and \a secondEdge. The anchor must exist.
+*/
 qreal QGraphicsAnchorLayout::anchorSpacing(const QGraphicsLayoutItem *firstItem, Qt::AnchorPoint firstEdge,
                                            const QGraphicsLayoutItem *secondItem, Qt::AnchorPoint secondEdge) const
 {
-    qWarning("// ### TO BE IMPLEMENTED");
-    return 0;
+    Q_D(const QGraphicsAnchorLayout);
+    qreal size = 0;
+    if (!d->anchorSize(firstItem, firstEdge, secondItem, secondEdge, 0, &size)) {
+        qWarning("anchorSpacing: The anchor does not exist.");
+    }
+    return size;
 }
 
+/*!
+  Resets the spacing between the anchor point defined by \a firstItem and \a firstEdge and
+  \a secondItem and \a secondEdge to be the default spacing. Depending on the anchor type, the
+  default spacing is either 0 or a value returned from the style.
+
+  \sa setAnchorSpacing, anchorSpacing, addAnchor
+*/
 void QGraphicsAnchorLayout::unsetAnchorSpacing(const QGraphicsLayoutItem *firstItem, Qt::AnchorPoint firstEdge,
                                                const QGraphicsLayoutItem *secondItem, Qt::AnchorPoint secondEdge)
 {
-    qWarning("// ### TO BE IMPLEMENTED");
+    Q_D(QGraphicsAnchorLayout);
+
+    if (!d->setAnchorSize(firstItem, firstEdge, secondItem, secondEdge, 0)) {
+        qWarning("unsetAnchorSpacing: The anchor does not exist.");
+    }
     invalidate();
 }
 
diff --git a/src/gui/graphicsview/qgraphicsanchorlayout.h b/src/gui/graphicsview/qgraphicsanchorlayout.h
index f2335a8..3de9ae5 100644
--- a/src/gui/graphicsview/qgraphicsanchorlayout.h
+++ b/src/gui/graphicsview/qgraphicsanchorlayout.h
@@ -65,10 +65,6 @@ public:
     void addAnchor(QGraphicsLayoutItem *firstItem, Qt::AnchorPoint firstEdge,
                    QGraphicsLayoutItem *secondItem, Qt::AnchorPoint secondEdge);
 
-    void setAnchorSpacing(const QGraphicsLayoutItem *firstItem, Qt::AnchorPoint firstEdge,
-                          const QGraphicsLayoutItem *secondItem, Qt::AnchorPoint secondEdge,
-                          qreal spacing);
-
     void addCornerAnchors(QGraphicsLayoutItem *firstItem, Qt::Corner firstCorner,
                           QGraphicsLayoutItem *secondItem, Qt::Corner secondCorner);
 
@@ -81,8 +77,13 @@ public:
     inline void addAllAnchors(QGraphicsLayoutItem *firstItem,
                               QGraphicsLayoutItem *secondItem);
 
+    void setAnchorSpacing(const QGraphicsLayoutItem *firstItem, Qt::AnchorPoint firstEdge,
+                          const QGraphicsLayoutItem *secondItem, Qt::AnchorPoint secondEdge,
+                          qreal spacing);
+
     qreal anchorSpacing(const QGraphicsLayoutItem *firstItem, Qt::AnchorPoint firstEdge,
                         const QGraphicsLayoutItem *secondItem, Qt::AnchorPoint secondEdge) const;
+
     void unsetAnchorSpacing(const QGraphicsLayoutItem *firstItem, Qt::AnchorPoint firstEdge,
                             const QGraphicsLayoutItem *secondItem, Qt::AnchorPoint secondEdge);
 
diff --git a/src/gui/graphicsview/qgraphicsanchorlayout_p.cpp b/src/gui/graphicsview/qgraphicsanchorlayout_p.cpp
index 436ce2c..ffece0d 100644
--- a/src/gui/graphicsview/qgraphicsanchorlayout_p.cpp
+++ b/src/gui/graphicsview/qgraphicsanchorlayout_p.cpp
@@ -1125,17 +1125,49 @@ bool QGraphicsAnchorLayoutPrivate::setAnchorSize(const QGraphicsLayoutItem *firs
                                                  Qt::AnchorPoint firstEdge,
                                                  const QGraphicsLayoutItem *secondItem,
                                                  Qt::AnchorPoint secondEdge,
-                                                 qreal anchorSize)
+                                                 const qreal *anchorSize)
 {
-    // ### we can avoid restoration if we really want to
+    // ### we can avoid restoration if we really want to, but we would have to
+    // search recursively through all composite anchors
     restoreSimplifiedGraph(edgeOrientation(firstEdge));
     AnchorVertex *v1 = internalVertex(firstItem, firstEdge);
     AnchorVertex *v2 = internalVertex(secondItem, secondEdge);
 
     AnchorData *data = graph[edgeOrientation(firstEdge)].edgeData(v1, v2);
-    if (data)
-        data->setFixedSize(anchorSize);
+    if (data) {
+        if (anchorSize) {
+            data->setFixedSize(*anchorSize);
+        } else {
+            data->unsetSize();
+        }
+    }
+
+    return data;
+}
 
+bool QGraphicsAnchorLayoutPrivate::anchorSize(const QGraphicsLayoutItem *firstItem,
+                                              Qt::AnchorPoint firstEdge,
+                                              const QGraphicsLayoutItem *secondItem,
+                                              Qt::AnchorPoint secondEdge,
+                                              qreal *minSize,
+                                              qreal *prefSize,
+                                              qreal *maxSize) const
+{
+    Q_ASSERT(minSize || prefSize || maxSize);
+    QGraphicsAnchorLayoutPrivate *that = const_cast<QGraphicsAnchorLayoutPrivate *>(this);
+    that->restoreSimplifiedGraph(edgeOrientation(firstEdge));
+    AnchorVertex *v1 = internalVertex(firstItem, firstEdge);
+    AnchorVertex *v2 = internalVertex(secondItem, secondEdge);
+
+    AnchorData *data = that->graph[edgeOrientation(firstEdge)].edgeData(v1, v2);
+    if (data) {
+        if (minSize)
+            *minSize = data->minSize;
+        if (prefSize)
+            *prefSize = data->prefSize;
+        if (maxSize)
+            *maxSize = data->maxSize;
+    }
     return data;
 }
 
diff --git a/src/gui/graphicsview/qgraphicsanchorlayout_p.h b/src/gui/graphicsview/qgraphicsanchorlayout_p.h
index 742108d..e17bd28 100644
--- a/src/gui/graphicsview/qgraphicsanchorlayout_p.h
+++ b/src/gui/graphicsview/qgraphicsanchorlayout_p.h
@@ -176,6 +176,11 @@ struct AnchorData : public QSimplexVariable {
         hasSize = true;
     }
 
+    inline void unsetSize()
+    {
+        hasSize = false;
+    }
+
     // Anchor is semantically directed
     AnchorVertex *from;
     AnchorVertex *to;
@@ -367,7 +372,15 @@ public:
                        Qt::AnchorPoint firstEdge,
                        const QGraphicsLayoutItem *secondItem,
                        Qt::AnchorPoint secondEdge,
-                       qreal anchorSize);
+                       const qreal *anchorSize);
+
+    bool anchorSize(const QGraphicsLayoutItem *firstItem,
+                    Qt::AnchorPoint firstEdge,
+                    const QGraphicsLayoutItem *secondItem,
+                    Qt::AnchorPoint secondEdge,
+                    qreal *minSize = 0,
+                    qreal *prefSize = 0,
+                    qreal *maxSize = 0) const;
 
     void removeAnchors(QGraphicsLayoutItem *item);
 
@@ -394,12 +407,12 @@ public:
     QList<QSimplexConstraint *> constraintsFromSizeHints(const QList<AnchorData *> &anchors);
     QList<QList<QSimplexConstraint *> > getGraphParts(Orientation orientation);
 
-    inline AnchorVertex *internalVertex(const QPair<QGraphicsLayoutItem*, Qt::AnchorPoint> &itemEdge)
+    inline AnchorVertex *internalVertex(const QPair<QGraphicsLayoutItem*, Qt::AnchorPoint> &itemEdge) const
     {
         return m_vertexList.value(itemEdge).first;
     }
 
-    inline AnchorVertex *internalVertex(const QGraphicsLayoutItem *item, Qt::AnchorPoint edge)
+    inline AnchorVertex *internalVertex(const QGraphicsLayoutItem *item, Qt::AnchorPoint edge) const
     {
         return internalVertex(qMakePair(const_cast<QGraphicsLayoutItem *>(item), edge));
     }