add base for master element feature

git-svn-id: svn+ssh://svn.tuxfamily.org/svnroot/qet/qet/trunk@2863 bfdf4180-ca20-0410-9c96-a3a8aa849046

sources/qetgraphicsitem/masterelement.cpp

@@ -0,0 +1,67 @@
+#include "masterelement.h"
+
+/**
+ * @brief MasterElement::MasterElement
+ * Default constructor
+ * @param location location of xml definition
+ * @param qgi parent QGraphicItem
+ * @param s parent diagram
+ * @param state int used to know if the creation of element have error
+ */
+MasterElement::MasterElement(const ElementsLocation &location, QGraphicsItem *qgi, Diagram *s, int *state) :
+	CustomElement(location, qgi, s, state)
+{
+	link_type_ = Master;
+}
+
+/**
+ * @brief MasterElement::~MasterElement
+ * default destructor
+ */
+MasterElement::~MasterElement() {
+	unlinkAllElements();
+}
+
+/**
+ * @brief MasterElement::linkToElement
+ * Link this master to another element
+ * For this class element must be a slave
+ * @param elmt
+ */
+void MasterElement::linkToElement(Element *elmt) {
+	// check if this element is already linked
+	if (connected_elements.contains(elmt)) return;
+	
+	//check if elmt is a slave
+	if (elmt->linkType() == SlaveNO || elmt->linkType() == SlaveNC) {
+		///TODO create the cross ref and connection
+		connected_elements << elmt;
+		elmt->linkToElement(this);
+	}
+}
+
+/**
+ * @brief MasterElement::unlinkAllElements
+ * Unlink all of the element in the QList connected_elements
+ */
+void MasterElement::unlinkAllElements() {
+	// if this element is free no need to do something
+	if (!isFree()) {
+		foreach(Element *elmt, connected_elements) {
+			unlinkElement(elmt);
+		}	
+	}
+}
+
+/**
+ * @brief MasterElement::unlinkElement
+ * Unlink the given elmt in parametre
+ * @param elmt element to unlink from this
+ */
+void MasterElement::unlinkElement(Element *elmt) {
+	//Ensure elmt is linked to this element
+	if (connected_elements.contains(elmt)) {
+		connected_elements.removeOne(elmt);
+		elmt->unlinkElement(this);
+	}
+}