1 files changed, 130 insertions, 68 deletions

diff --git a/src/gui/graphicsview/qgraphicsanchorlayout_p.h b/src/gui/graphicsview/qgraphicsanchorlayout_p.h
index 7dd0d658bf..5f50c85d99 100644
--- a/src/gui/graphicsview/qgraphicsanchorlayout_p.h
+++ b/src/gui/graphicsview/qgraphicsanchorlayout_p.h
@@ -78,66 +78,30 @@ QT_BEGIN_NAMESPACE
   Represents a vertex (anchorage point) in the internal graph
 */
 struct AnchorVertex {
+    enum Type {
+        Normal = 0,
+        Pair
+    };
+
     AnchorVertex(QGraphicsLayoutItem *item, Qt::AnchorPoint edge)
-        : m_item(item), m_edge(edge) {}
+        : m_item(item), m_edge(edge), m_type(Normal) {}
 
     AnchorVertex()
-        : m_item(0), m_edge(Qt::AnchorPoint(0)) {}
+        : m_item(0), m_edge(Qt::AnchorPoint(0)), m_type(Normal) {}
 
 #ifdef QT_DEBUG
     inline QString toString() const;
 #endif
+
     QGraphicsLayoutItem *m_item;
     Qt::AnchorPoint m_edge;
+    uint m_type : 1;
 
     // Current distance from this vertex to the layout edge (Left or Top)
     // Value is calculated from the current anchors sizes.
     qreal distance;
 };
 
-#ifdef QT_DEBUG
-inline QString AnchorVertex::toString() const
-{
-    if (!this || !m_item) {
-        return QLatin1String("NULL");
-    }
-    QString edge;
-    switch (m_edge) {
-    case Qt::AnchorLeft:
-        edge = QLatin1String("Left");
-        break;
-    case Qt::AnchorHorizontalCenter:
-        edge = QLatin1String("HorizontalCenter");
-        break;
-    case Qt::AnchorRight:
-        edge = QLatin1String("Right");
-        break;
-    case Qt::AnchorTop:
-        edge = QLatin1String("Top");
-        break;
-    case Qt::AnchorVerticalCenter:
-        edge = QLatin1String("VerticalCenter");
-        break;
-    case Qt::AnchorBottom:
-        edge = QLatin1String("Bottom");
-        break;
-    default:
-        edge = QLatin1String("None");
-        break;
-    }
-    QString itemName;
-    if (m_item->isLayout()) {
-        itemName = QLatin1String("layout");
-    } else {
-        if (QGraphicsItem *item = m_item->graphicsItem()) {
-            itemName = item->data(0).toString();
-        }
-    }
-    edge.insert(0, QLatin1String("%1_"));
-    return edge.arg(itemName);
-}
-#endif
-
 /*!
   \internal
 
@@ -150,14 +114,21 @@ struct AnchorData : public QSimplexVariable {
         Parallel
     };
 
+    enum Dependency {
+        Independent = 0,
+        Master,
+        Slave
+    };
+
     AnchorData()
         : QSimplexVariable(), item(0), from(0), to(0),
-          minSize(0), prefSize(0), expSize(0), maxSize(0),
+          minSize(0), prefSize(0), maxSize(0),
           sizeAtMinimum(0), sizeAtPreferred(0),
-          sizeAtExpanding(0), sizeAtMaximum(0),
+          sizeAtMaximum(0),
           graphicsAnchor(0), skipInPreferred(0),
           type(Normal), hasSize(true), isLayoutAnchor(false),
-          isCenterAnchor(false), orientation(0) {}
+          isCenterAnchor(false), orientation(0),
+          dependency(Independent) {}
 
     virtual void updateChildrenSizes() {}
     virtual bool refreshSizeHints(const QLayoutStyleInfo *styleInfo);
@@ -194,7 +165,6 @@ struct AnchorData : public QSimplexVariable {
     // size.
     qreal minSize;
     qreal prefSize;
-    qreal expSize;
     qreal maxSize;
 
     // These attributes define which sizes should that anchor be in when the
@@ -202,7 +172,6 @@ struct AnchorData : public QSimplexVariable {
     // calculated by the Simplex solver based on the current layout setup.
     qreal sizeAtMinimum;
     qreal sizeAtPreferred;
-    qreal sizeAtExpanding;
     qreal sizeAtMaximum;
     QGraphicsAnchor *graphicsAnchor;
 
@@ -212,6 +181,7 @@ struct AnchorData : public QSimplexVariable {
     uint isLayoutAnchor : 1;  // if this anchor is an internal layout anchor
     uint isCenterAnchor : 1;
     uint orientation : 1;
+    uint dependency : 2;      // either Independent, Master or Slave
 };
 
 #ifdef QT_DEBUG
@@ -250,10 +220,11 @@ struct ParallelAnchorData : public AnchorData
         type = AnchorData::Parallel;
         orientation = first->orientation;
 
-        // ### Those asserts force that both child anchors have the same direction,
-        // but can't we simplify a pair of anchors in opposite directions?
-        Q_ASSERT(first->from == second->from);
-        Q_ASSERT(first->to == second->to);
+        // This assert whether the child anchors share their vertices
+        Q_ASSERT(((first->from == second->from) && (first->to == second->to)) ||
+                 ((first->from == second->to) && (first->to == second->from)));
+
+        // We arbitrarily choose the direction of the first child as "our" direction
         from = first->from;
         to = first->to;
 #ifdef QT_DEBUG
@@ -268,8 +239,73 @@ struct ParallelAnchorData : public AnchorData
 
     AnchorData* firstEdge;
     AnchorData* secondEdge;
+
+    QList<QSimplexConstraint *> m_firstConstraints;
+    QList<QSimplexConstraint *> m_secondConstraints;
 };
 
+struct AnchorVertexPair : public AnchorVertex {
+    AnchorVertexPair(AnchorVertex *v1, AnchorVertex *v2, AnchorData *data)
+        : AnchorVertex(), m_first(v1), m_second(v2), m_removedAnchor(data) {
+        m_type = AnchorVertex::Pair;
+    }
+
+    AnchorVertex *m_first;
+    AnchorVertex *m_second;
+
+    AnchorData *m_removedAnchor;
+    QList<AnchorData *> m_firstAnchors;
+    QList<AnchorData *> m_secondAnchors;
+};
+
+#ifdef QT_DEBUG
+inline QString AnchorVertex::toString() const
+{
+    if (!this) {
+        return QLatin1String("NULL");
+    } else if (m_type == Pair) {
+        const AnchorVertexPair *vp = static_cast<const AnchorVertexPair *>(this);
+        return QString::fromAscii("(%1, %2)").arg(vp->m_first->toString()).arg(vp->m_second->toString());
+    } else if (!m_item) {
+        return QString::fromAscii("NULL_%1").arg(quintptr(this));
+    }
+    QString edge;
+    switch (m_edge) {
+    case Qt::AnchorLeft:
+        edge = QLatin1String("Left");
+        break;
+    case Qt::AnchorHorizontalCenter:
+        edge = QLatin1String("HorizontalCenter");
+        break;
+    case Qt::AnchorRight:
+        edge = QLatin1String("Right");
+        break;
+    case Qt::AnchorTop:
+        edge = QLatin1String("Top");
+        break;
+    case Qt::AnchorVerticalCenter:
+        edge = QLatin1String("VerticalCenter");
+        break;
+    case Qt::AnchorBottom:
+        edge = QLatin1String("Bottom");
+        break;
+    default:
+        edge = QLatin1String("None");
+        break;
+    }
+    QString itemName;
+    if (m_item->isLayout()) {
+        itemName = QLatin1String("layout");
+    } else {
+        if (QGraphicsItem *item = m_item->graphicsItem()) {
+            itemName = item->data(0).toString();
+        }
+    }
+    edge.insert(0, QLatin1String("%1_"));
+    return edge.arg(itemName);
+}
+#endif
+
 /*!
   \internal
 
@@ -337,8 +373,7 @@ public:
     // Interval represents which interpolation interval are we operating in.
     enum Interval {
         MinToPreferred = 0,
-        PreferredToExpanding,
-        ExpandingToMax
+        PreferredToMax
     };
 
     // Several structures internal to the layout are duplicated to handle
@@ -427,20 +462,33 @@ public:
 
     QLayoutStyleInfo &styleInfo() const;
 
-    // Activation methods
-    bool simplifyGraph(Orientation orientation);
-    bool simplifyGraphIteration(Orientation orientation, bool *feasible);
-    void restoreSimplifiedGraph(Orientation orientation);
+    AnchorData *addAnchorMaybeParallel(AnchorData *newAnchor, bool *feasible);
 
+    // Activation
     void calculateGraphs();
     void calculateGraphs(Orientation orientation);
 
+    // Simplification
+    bool simplifyGraph(Orientation orientation);
+    bool simplifyVertices(Orientation orientation);
+    bool simplifyGraphIteration(Orientation orientation, bool *feasible);
+
+    bool replaceVertex(Orientation orientation, AnchorVertex *oldV,
+                       AnchorVertex *newV, const QList<AnchorData *> &edges);
+
+
+    void restoreSimplifiedGraph(Orientation orientation);
+    void restoreSimplifiedAnchor(AnchorData *edge);
+    void restoreSimplifiedConstraints(ParallelAnchorData *parallel);
+    void restoreVertices(Orientation orientation);
+
     bool calculateTrunk(Orientation orientation, const GraphPath &trunkPath,
                         const QList<QSimplexConstraint *> &constraints,
                         const QList<AnchorData *> &variables);
     bool calculateNonTrunk(const QList<QSimplexConstraint *> &constraints,
                            const QList<AnchorData *> &variables);
 
+    // Support functions for calculateGraph()
     bool refreshAllSizeHints(Orientation orientation);
     void findPaths(Orientation orientation);
     void constraintsFromPaths(Orientation orientation);
@@ -460,6 +508,17 @@ public:
         return internalVertex(qMakePair(const_cast<QGraphicsLayoutItem *>(item), edge));
     }
 
+    inline void changeLayoutVertex(Orientation orientation, AnchorVertex *oldV, AnchorVertex *newV)
+    {
+        if (layoutFirstVertex[orientation] == oldV)
+            layoutFirstVertex[orientation] = newV;
+        else if (layoutCentralVertex[orientation] == oldV)
+            layoutCentralVertex[orientation] = newV;
+        else if (layoutLastVertex[orientation] == oldV)
+            layoutLastVertex[orientation] = newV;
+    }
+
+
     AnchorVertex *addInternalVertex(QGraphicsLayoutItem *item, Qt::AnchorPoint edge);
     void removeInternalVertex(QGraphicsLayoutItem *item, Qt::AnchorPoint edge);
 
@@ -468,19 +527,15 @@ public:
 
     void calculateVertexPositions(Orientation orientation);
     void setupEdgesInterpolation(Orientation orientation);
-    void interpolateEdge(AnchorVertex *base, AnchorData *edge, Orientation orientation);
-    void interpolateSequentialEdges(AnchorVertex *base, SequentialAnchorData *edge,
-                                    Orientation orientation);
-    void interpolateParallelEdges(AnchorVertex *base, ParallelAnchorData *edge,
-                                  Orientation orientation);
+    void interpolateEdge(AnchorVertex *base, AnchorData *edge);
+    void interpolateSequentialEdges(SequentialAnchorData *edge);
+    void interpolateParallelEdges(ParallelAnchorData *edge);
 
     // Linear Programming solver methods
     bool solveMinMax(const QList<QSimplexConstraint *> &constraints,
                      GraphPath path, qreal *min, qreal *max);
     bool solvePreferred(const QList<QSimplexConstraint *> &constraints,
                         const QList<AnchorData *> &variables);
-    void solveExpanding(const QList<QSimplexConstraint *> &constraints,
-                        const QList<AnchorData *> &variables);
     bool hasConflicts() const;
 
 #ifdef QT_DEBUG
@@ -491,7 +546,6 @@ public:
     qreal spacings[NOrientations];
     // Size hints from simplex engine
     qreal sizeHints[2][3];
-    qreal sizeAtExpanding[2];
 
     // Items
     QVector<QGraphicsLayoutItem *> items;
@@ -504,6 +558,14 @@ public:
     // Internal graph of anchorage points and anchors, for both orientations
     Graph<AnchorVertex, AnchorData> graph[2];
 
+    AnchorVertex *layoutFirstVertex[2];
+    AnchorVertex *layoutCentralVertex[2];
+    AnchorVertex *layoutLastVertex[2];
+
+    // Combined anchors in order of creation
+    QList<AnchorVertexPair *> simplifiedVertices[2];
+    QList<AnchorData *> anchorsFromSimplifiedVertices[2];
+
     // Graph paths and constraints, for both orientations
     QMultiHash<AnchorVertex *, GraphPath> graphPaths[2];
     QList<QSimplexConstraint *> constraints[2];