QGAL: clean up interpolation code

Now the interpolation doesn't need to know how to traverse complex
anchors, since when it runs, the graph is not simplified anymore.
This commit removes unnecessary code for dealing with that.

Signed-off-by: Caio Marcelo de Oliveira Filho <caio.oliveira@openbossa.org>
Reviewed-by: Eduardo M. Fleury <eduardo.fleury@openbossa.org>

2 files changed, 16 insertions, 95 deletions

diff --git a/src/gui/graphicsview/qgraphicsanchorlayout_p.cpp b/src/gui/graphicsview/qgraphicsanchorlayout_p.cpp
index 5b1e36c..7646d4c 100644
--- a/src/gui/graphicsview/qgraphicsanchorlayout_p.cpp
+++ b/src/gui/graphicsview/qgraphicsanchorlayout_p.cpp
@@ -2564,21 +2564,6 @@ void QGraphicsAnchorLayoutPrivate::setItemsGeometries(const QRectF &geom)
 }
 
 /*!
-    \internal
-
-    Fill the distance in the vertex and in the sub-vertices if its a combined vertex.
-*/
-static void setVertexDistance(AnchorVertex *v, qreal distance)
-{
-    v->distance = distance;
-    if (v->m_type == AnchorVertex::Pair) {
-        AnchorVertexPair *pair = static_cast<AnchorVertexPair *>(v);
-        setVertexDistance(pair->m_first, distance);
-        setVertexDistance(pair->m_second, distance);
-    }
-}
-
-/*!
   \internal
 
   Calculate the position of each vertex based on the paths to each of
@@ -2593,7 +2578,7 @@ void QGraphicsAnchorLayoutPrivate::calculateVertexPositions(
     // Get root vertex
     AnchorVertex *root = layoutFirstVertex[orientation];
 
-    setVertexDistance(root, 0);
+    root->distance = 0;
     visited.insert(root);
 
     // Add initial edges to the queue
@@ -2604,16 +2589,12 @@ void QGraphicsAnchorLayoutPrivate::calculateVertexPositions(
     // Do initial calculation required by "interpolateEdge()"
     setupEdgesInterpolation(orientation);
 
-    // Traverse the graph and calculate vertex positions, we need to
-    // visit all pairs since each of them could have a sequential
-    // anchor inside, which hides more vertices.
+    // Traverse the graph and calculate vertex positions
     while (!queue.isEmpty()) {
         QPair<AnchorVertex *, AnchorVertex *> pair = queue.dequeue();
         AnchorData *edge = graph[orientation].edgeData(pair.first, pair.second);
 
-        // Both vertices were interpolated, and the anchor itself can't have other
-        // anchors inside (it's not a complex anchor).
-        if (edge->type == AnchorData::Normal && visited.contains(pair.second))
+        if (visited.contains(pair.second))
             continue;
 
         visited.insert(pair.second);
@@ -2653,24 +2634,20 @@ void QGraphicsAnchorLayoutPrivate::setupEdgesInterpolation(
 }
 
 /*!
-  \internal
-
-  Calculate the current Edge size based on the current Layout size and the
-  size the edge is supposed to have when the layout is at its:
+    \internal
 
-   - minimum size,
-   - preferred size,
-   - maximum size.
+    Calculate the current Edge size based on the current Layout size and the
+    size the edge is supposed to have when the layout is at its:
 
-   These three key values are calculated in advance using linear
-   programming (more expensive) or the simplification algorithm, then
-   subsequential resizes of the parent layout require a simple
-   interpolation.
+    - minimum size,
+    - preferred size,
+    - maximum size.
 
-   If the edge is sequential or parallel, it's possible to have more
-   vertices to be initalized, so it calls specialized functions that
-   will recurse back to interpolateEdge().
- */
+    These three key values are calculated in advance using linear
+    programming (more expensive) or the simplification algorithm, then
+    subsequential resizes of the parent layout require a simple
+    interpolation.
+*/
 void QGraphicsAnchorLayoutPrivate::interpolateEdge(AnchorVertex *base, AnchorData *edge)
 {
     const Orientation orientation = Orientation(edge->orientation);
@@ -2684,64 +2661,10 @@ void QGraphicsAnchorLayoutPrivate::interpolateEdge(AnchorVertex *base, AnchorDat
 
     // Calculate the distance for the vertex opposite to the base
     if (edge->from == base) {
-        setVertexDistance(edge->to, base->distance + edgeDistance);
+        edge->to->distance = base->distance + edgeDistance;
     } else {
-        setVertexDistance(edge->from, base->distance - edgeDistance);
-    }
-
-    // Process child anchors
-    if (edge->type == AnchorData::Sequential)
-        interpolateSequentialEdges(static_cast<SequentialAnchorData *>(edge));
-    else if (edge->type == AnchorData::Parallel)
-        interpolateParallelEdges(static_cast<ParallelAnchorData *>(edge));
-}
-
-void QGraphicsAnchorLayoutPrivate::interpolateParallelEdges(ParallelAnchorData *data)
-{
-    // In parallels the boundary vertices are already calculate, we
-    // just need to look for sequential groups inside, because only
-    // them may have new vertices associated.
-
-    // First edge
-    if (data->firstEdge->type == AnchorData::Sequential)
-        interpolateSequentialEdges(static_cast<SequentialAnchorData *>(data->firstEdge));
-    else if (data->firstEdge->type == AnchorData::Parallel)
-        interpolateParallelEdges(static_cast<ParallelAnchorData *>(data->firstEdge));
-
-    // Second edge
-    if (data->secondEdge->type == AnchorData::Sequential)
-        interpolateSequentialEdges(static_cast<SequentialAnchorData *>(data->secondEdge));
-    else if (data->secondEdge->type == AnchorData::Parallel)
-        interpolateParallelEdges(static_cast<ParallelAnchorData *>(data->secondEdge));
-}
-
-void QGraphicsAnchorLayoutPrivate::interpolateSequentialEdges(SequentialAnchorData *data)
-{
-    // This method is supposed to handle any sequential anchor, even out-of-order
-    // ones. However, in the current QGAL implementation we should get only the
-    // well behaved ones.
-    Q_ASSERT(data->m_edges.first()->from == data->from);
-    Q_ASSERT(data->m_edges.last()->to == data->to);
-
-    // At this point, the two outter vertices already have their distance
-    // calculated.
-    // We use the first as the base to calculate the internal ones
-
-    AnchorVertex *prev = data->from;
-
-    for (int i = 0; i < data->m_edges.count() - 1; ++i) {
-        AnchorData *edge = data->m_edges.at(i);
-        interpolateEdge(prev, edge);
-
-        // Use the recently calculated vertex as the base for the next one
-        const bool edgeIsForward = (edge->from == prev);
-        prev = edgeIsForward ? edge->to : edge->from;
+        edge->from->distance = base->distance - edgeDistance;
     }
-
-    // Treat the last specially, since we already calculated it's end
-    // vertex, so it's only interesting if it's a complex one
-    if (data->m_edges.last()->type != AnchorData::Normal)
-        interpolateEdge(prev, data->m_edges.last());
 }
 
 bool QGraphicsAnchorLayoutPrivate::solveMinMax(const QList<QSimplexConstraint *> &constraints,
diff --git a/src/gui/graphicsview/qgraphicsanchorlayout_p.h b/src/gui/graphicsview/qgraphicsanchorlayout_p.h
index 7e2e00e..fd82dd9 100644
--- a/src/gui/graphicsview/qgraphicsanchorlayout_p.h
+++ b/src/gui/graphicsview/qgraphicsanchorlayout_p.h
@@ -522,8 +522,6 @@ public:
     void calculateVertexPositions(Orientation orientation);
     void setupEdgesInterpolation(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,