removed dnd bug

Author: PiaFlessner

src/main/java/backend_data/Header.java

@@ -349,7 +349,8 @@ public int getTotalSubTreeCount() {
      * @return true means, the this Element is a parent, false means its not a parent.
      */
     public boolean isHeaderInParentHeader(Header targetHeader){
-        if(targetHeader.isRoot) return false;
+        if(targetHeader.parentElement == null) return false;
+        if(targetHeader.parentElement.isRoot) return false;
         if(targetHeader.parentElement == this) return true;
         return this.isHeaderInParentHeader(targetHeader.parentElement);
     }

src/main/java/visual_components/header/HeaderComponent.java

@@ -2,6 +2,7 @@
 
 import javax.swing.JLabel;
 import javax.swing.JMenuItem;
+import javax.swing.JOptionPane;
 import javax.swing.JPanel;
 
 import main.java.backend_data.Direction;
@@ -959,12 +960,13 @@ private void removeDnDTargetElements() {
         private void moveHeaderUp(HeaderComponent sourceHeaderComponent) {
             Header targetParent = connectedHeader.getParentElement();
             Header sourceParent = sourceHeaderComponent.connectedHeader.getParentElement();
-            // Backend
-            // remove from source
-            sourceParent.deleteSubheader(sourceHeaderComponent.connectedHeader);
-            int newNr = connectedHeader.getOwnNr();
 
+            
             if (isShiftingAllowed(sourceHeaderComponent.connectedHeader)) {
+                // Backend
+                // remove from source
+                sourceParent.deleteSubheader(sourceHeaderComponent.connectedHeader);
+                int newNr = connectedHeader.getOwnNr();
                 // Insert Start
                 if (newNr == 1) {
                     targetParent.insertNewSubheaderStart(sourceHeaderComponent.connectedHeader);
@@ -976,8 +978,8 @@ private void moveHeaderUp(HeaderComponent sourceHeaderComponent) {
                     assert sourceHeaderComponent.connectedHeader.getOwnNr() == newNr;
                 }
                 assert connectedHeader.getParentElement().equals(targetParent);
-                reloadComponents();
             }
+            reloadComponents();
 
         }
 
@@ -991,11 +993,12 @@ private void moveHeaderUp(HeaderComponent sourceHeaderComponent) {
         private void moveHeaderDown(HeaderComponent sourceHeaderComponent) {
             Header targetParent = connectedHeader.getParentElement();
             Header sourceParent = sourceHeaderComponent.connectedHeader.getParentElement();
-            // remove from source
-            sourceParent.deleteSubheader(sourceHeaderComponent.connectedHeader);
-            int newNr = connectedHeader.getOwnNr();
+            
 
             if (isShiftingAllowed(sourceHeaderComponent.connectedHeader)) {
+                // remove from source
+                sourceParent.deleteSubheader(sourceHeaderComponent.connectedHeader);
+                int newNr = connectedHeader.getOwnNr();
                 // Insert at End
                 if (newNr > targetParent.getSubheaderSize()) {
                     targetParent.insertNewSubheaderEnd(sourceHeaderComponent.connectedHeader);
@@ -1007,8 +1010,8 @@ private void moveHeaderDown(HeaderComponent sourceHeaderComponent) {
                     assert sourceHeaderComponent.connectedHeader.getOwnNr() == newNr + 1;
                 }
                 assert connectedHeader.getParentElement().equals(targetParent);
-                reloadComponents();
             }
+            reloadComponents();
         }
 
         /**
@@ -1024,9 +1027,9 @@ private void moveHeaderSub(HeaderComponent sourceHeaderComponent) {
             if (isShiftingAllowed(sourceHeaderComponent.connectedHeader)) {
                 sourceParent.deleteSubheader(sourceHeaderComponent.connectedHeader);
                 connectedHeader.insertNewSubheaderStart(sourceHeaderComponent.connectedHeader);
-                assert connectedHeader.getParentElement().equals(connectedHeader);
-                reloadComponents();
+                assert connectedHeader.getParentElement().equals(connectedHeader);    
             }
+            reloadComponents();
         }
 
         /**
@@ -1039,8 +1042,10 @@ private void moveHeaderSub(HeaderComponent sourceHeaderComponent) {
          * @return true= shifting allowed | false = shifting is not allowed.
          */
         private boolean isShiftingAllowed(Header sourceHeader) {
-            if (connectedHeader == sourceHeader || sourceHeader.isHeaderInParentHeader(connectedHeader))
+            if (connectedHeader == sourceHeader || sourceHeader.isHeaderInParentHeader(connectedHeader)) {
+                JOptionPane.showMessageDialog(null,"Actions from header to subheader are not allowed.");
                 return false;
+            }
             else
                 return true;
         }