ui: Group graph nodes by file or namespace (issues #171, #439, #522)

* added buttons to enable grouping by file or namespace
* last used group settings saved to ApplicationSettings
* made groups hoverable/clickable on label only
* improved node hatching and override edge colors
* group overview lists

fortune cookie message = Seen with the eyes of love, everything gets a new meaning.

src/lib_gui/qt/view/graphElements/QtGraphNode.cpp

@@ -61,13 +61,13 @@ QtGraphNode* QtGraphNode::getParent() const
 	return m_parentNode;
 }
 
-QtGraphNode* QtGraphNode::getLastParent() const
+QtGraphNode* QtGraphNode::getLastParent(bool noGroups) const
 {
 	QtGraphNode* node = const_cast<QtGraphNode*>(this);
 	while (true)
 	{
 		QtGraphNode* parent = dynamic_cast<QtGraphNode*>(node->parentItem());
-		if (!parent)
+		if (!parent || (noGroups && parent->isGroupNode()))
 		{
 			break;
 		}
@@ -76,6 +76,11 @@ QtGraphNode* QtGraphNode::getLastParent() const
 	return node;
 }
 
+QtGraphNode* QtGraphNode::getLastNonGroupParent() const
+{
+	return getLastParent(true);
+}
+
 void QtGraphNode::setParent(QtGraphNode* parentNode)
 {
 	m_parentNode = parentNode;
@@ -86,7 +91,7 @@ void QtGraphNode::setParent(QtGraphNode* parentNode)
 	}
 }
 
-std::list<QtGraphNode*> QtGraphNode::getSubNodes() const
+const std::list<QtGraphNode*>& QtGraphNode::getSubNodes() const
 {
 	return m_subNodes;
 }
@@ -142,11 +147,6 @@ Vec4i QtGraphNode::getBoundingRect() const
 	return Vec4i(pos.x, pos.y, pos.x + size.x, pos.y + size.y);
 }
 
-Vec4i QtGraphNode::getParentBoundingRect() const
-{
-	return getLastParent()->getBoundingRect();
-}
-
 void QtGraphNode::addOutEdge(QtGraphEdge* edge)
 {
 	m_outEdges.push_back(edge);
@@ -348,7 +348,7 @@ void QtGraphNode::addSubNode(QtGraphNode* node)
 	if (node->getIsActive())
 	{
 		QtGraphNode* parent = this;
-		while (parent)
+		while (parent && !parent->isGroupNode())
 		{
 			parent->setZValue(-10.0f);
 			parent->m_text->setZValue(-9.0f);