* add API docu to the methods i added

* add a resetLayout() so layouts can release LayoutItems on deletion, avoiding dangling pointers and possible crashes

svn path=/trunk/KDE/kdebase/workspace/plasma/lib/; revision=668931

widgets/layoutitem.cpp

@@ -70,6 +70,11 @@ qreal LayoutItem::widthForHeight(qreal h) const
 	return 0.0;
 }
 
+void LayoutItem::resetLayout()
+{
+    d->layout = 0;
+}
+
 void LayoutItem::setLayout(Layout* layout)
 {
     if (d->layout) {

widgets/layoutitem.h

@@ -54,7 +54,27 @@ class KDE_EXPORT LayoutItem
 
         virtual QSizeF sizeHint() const = 0;
 
+        /**
+         * Resets the layout to 0 and doesn't notify the previous layout.
+         * Should only be used by the current layout when relinquishing the item,
+         * e.g. during layout destruction.
+         */
+        void resetLayout();
+
+        /**
+         * Sets the layout so that the LayoutItem may inform the layout of its
+         * deletion. Should only be used by the layout it is added to.
+         *
+         * If the layout item is currently associated with another layout, it will
+         * first remove itself from that layout.
+         *
+         * @param layout The Layout that this LayoutItem will be managed by.
+         */
         void setLayout(Layout* layout);
+
+        /**
+         * Returns the layout this item is currently associated with
+         */
         Layout* layout();
 
     private:

widgets/vboxlayout.cpp

@@ -44,6 +44,9 @@ VBoxLayout::VBoxLayout(LayoutItem *parent)
 
 VBoxLayout::~VBoxLayout()
 {
+    foreach (LayoutItem *l, d->childList) {
+        l->resetLayout();
+    }
 }
 
 Qt::Orientations VBoxLayout::expandingDirections() const