Added functionality to check whether changed data is saved when exiting the program

src/repository/Project.java

@@ -52,7 +52,10 @@ public class Project implements Iterable<Entity>, EntityDrawboxChangedListener,
 	 * */
 	public static final String DEFAULT_XML_PATH = "res/"; //TODO: make an actual path to example objecttypes in the root of the project
 	public static final String DEFAULT_XML_FILENAME = "objecttypes.xml";
-	
+	/**
+	 * Переменная которая отслеживает, были ли произведены изменения XML-Dom-дерева.
+	 * */
+	public static boolean changeOfXmlDOM = false; 
 	static Project thisProject;
 	private List <Entity> listEntity = new ArrayList<Entity>();
 	private String path = DEFAULT_XML_PATH;	
@@ -249,6 +252,7 @@ public class Project implements Iterable<Entity>, EntityDrawboxChangedListener,
 		hitboxProperty.setAttribute("default", "Rectangle 0 0 0 0"); // empty, no hitbox yet
 		objecttypeElement.appendChild(hitboxProperty);
 		
+		changeOfXmlDOM = true;
 		//printXMlToConsole(); //DEBUG!
 	}
 	
@@ -298,10 +302,11 @@ public class Project implements Iterable<Entity>, EntityDrawboxChangedListener,
 			DOMSource source = new DOMSource(document);
 			StreamResult result = new StreamResult(new FileOutputStream(getXMLPath() + getXMLFileName()));
 			transformer.transform(source, result);
-			JOptionPane.showMessageDialog(null, "Бугага, сохранилось!", "Success", JOptionPane.INFORMATION_MESSAGE);
+			JOptionPane.showMessageDialog(null, "Бугагашеньки, сохранилось!", "Success", JOptionPane.INFORMATION_MESSAGE);
 		} catch (TransformerException | FileNotFoundException e) {
 			JOptionPane.showMessageDialog(null, "Saving project is unsuccsessfull! Erorr is: "+e, "Project save unsuccsesfull", JOptionPane.ERROR_MESSAGE);
 		}
+		changeOfXmlDOM = false;
 	}
 		
 	public void PrintEntitys() {
@@ -361,6 +366,7 @@ public class Project implements Iterable<Entity>, EntityDrawboxChangedListener,
 				}
 			}
 		}
+		changeOfXmlDOM = true;
 	}
 	
 	/**
@@ -381,6 +387,7 @@ public class Project implements Iterable<Entity>, EntityDrawboxChangedListener,
 				}
 			}
 		}
+		changeOfXmlDOM = true;
 	}
 	
 	private Node getEntityXMLNodeByName(String name) { //returns entitie's objecttype node