QGraphicsAnchorLayoutPrivate: Removing item from layout when there are no more anchors

Now the removeAnchor() method has returned and it is ready for being use in the API for ensure
that items are removed from the layout when they have no more external anchors.

Signed-off-by: Jesus Sanchez-Palencia <jesus.palencia@openbossa.org>
Reviewed-by: Eduardo M. Fleury <eduardo.fleury@openbossa.org>

2 files changed, 77 insertions, 0 deletions

diff --git a/src/gui/graphicsview/qgraphicsanchorlayout_p.cpp b/src/gui/graphicsview/qgraphicsanchorlayout_p.cpp
index f1b9fe5..f2eddde 100644
--- a/src/gui/graphicsview/qgraphicsanchorlayout_p.cpp
+++ b/src/gui/graphicsview/qgraphicsanchorlayout_p.cpp
@@ -1181,6 +1181,82 @@ QGraphicsAnchor *QGraphicsAnchorLayoutPrivate::getAnchor(QGraphicsLayoutItem *fi
     return graphicsAnchor;
 }
 
+/*!
+ * \internal
+ *
+ * Implements the high level "removeAnchor" feature. Called by
+ * the QAnchorData destructor.
+ */
+void QGraphicsAnchorLayoutPrivate::removeAnchor(AnchorVertex *firstVertex,
+                                                AnchorVertex *secondVertex)
+{
+    Q_Q(QGraphicsAnchorLayout);
+
+    // Actually delete the anchor
+    removeAnchor_helper(firstVertex, secondVertex);
+
+    QGraphicsLayoutItem *firstItem = firstVertex->m_item;
+    QGraphicsLayoutItem *secondItem = secondVertex->m_item;
+
+    // Checking if the item stays in the layout or not
+    bool keepFirstItem = false;
+    bool keepSecondItem = false;
+
+    QPair<AnchorVertex *, int> v;
+    int refcount = -1;
+
+    if (firstItem != q) {
+        for (int i = Qt::AnchorLeft; i <= Qt::AnchorBottom; ++i) {
+            v = m_vertexList.value(qMakePair(firstItem, static_cast<Qt::AnchorPoint>(i)));
+            if (v.first) {
+                if (i == Qt::AnchorHorizontalCenter || i == Qt::AnchorVerticalCenter)
+                    refcount = 2;
+                else
+                    refcount = 1;
+
+                if (v.second > refcount) {
+                    keepFirstItem = true;
+                    break;
+                }
+            }
+        }
+    } else
+        keepFirstItem = true;
+
+    if (secondItem != q) {
+        for (int i = Qt::AnchorLeft; i <= Qt::AnchorBottom; ++i) {
+            v = m_vertexList.value(qMakePair(secondItem, static_cast<Qt::AnchorPoint>(i)));
+            if (v.first) {
+                if (i == Qt::AnchorHorizontalCenter || i == Qt::AnchorVerticalCenter)
+                    refcount = 2;
+                else
+                    refcount = 1;
+
+                if (v.second > refcount) {
+                    keepSecondItem = true;
+                    break;
+                }
+            }
+        }
+    } else
+        keepSecondItem = true;
+
+    if (!keepFirstItem)
+        q->removeAt(items.indexOf(firstItem));
+
+    if (!keepSecondItem)
+        q->removeAt(items.indexOf(secondItem));
+
+    // Removing anchors invalidates the layout
+    q->invalidate();
+}
+
+/*
+  \internal
+
+  Implements the low level "removeAnchor" feature. Called by
+  private methods.
+*/
 void QGraphicsAnchorLayoutPrivate::removeAnchor_helper(AnchorVertex *v1, AnchorVertex *v2)
 {
     Q_ASSERT(v1 && v2);
diff --git a/src/gui/graphicsview/qgraphicsanchorlayout_p.h b/src/gui/graphicsview/qgraphicsanchorlayout_p.h
index 89b49af..5a91baa 100644
--- a/src/gui/graphicsview/qgraphicsanchorlayout_p.h
+++ b/src/gui/graphicsview/qgraphicsanchorlayout_p.h
@@ -420,6 +420,7 @@ public:
     QGraphicsAnchor *getAnchor(QGraphicsLayoutItem *firstItem, Qt::AnchorPoint firstEdge,
                                QGraphicsLayoutItem *secondItem, Qt::AnchorPoint secondEdge);
 
+    void removeAnchor(AnchorVertex *firstVertex, AnchorVertex *secondVertex);
     void removeAnchor_helper(AnchorVertex *v1, AnchorVertex *v2);
     void deleteAnchorData(AnchorData *data);
     void setAnchorSize(AnchorData *data, const qreal *anchorSize);