🚀 go-pugleaf

Superthanks for your input. Some of it I understand and some of it I don't.
I have followed multiple tutorials and and implemented to fit my need.

This is what I have:
An application where using a tree to display what is in the DB and used 
for selection (that then triggers actions). A tree is used in a couple 
of different screens. The tree is only to show values and enable easy 
navigation and selection.

My tree implementation:

public class MyTree extends JPanel  implements TreeSelectionListener {

   static final int USED_AT_A = 0; // where tree is implemented
   static final int USED_AT_B = 1;

   public MyTree(nodeInfo topNode,int type) {

   public void valueChanged(TreeSelectionEvent e) {
   // this then determine what type it is and use "a ststic method"
   // to set selected values. The method to used is determined by
   // USED_AT_A or USED_AT_B

   public String[] getSelEquip() {
   // used from mainFrame to get values

   public clear(nodeInfo top) {
   // clear the tree and start a new one with top as root

   public DefaultMutableTreeNode insertNode (
   // used from mainFrame to build the tree
   // (i.e. getting data from DB is outside the tree)

   public static class nodeInfo {
   // My different types of nodes
         public String id;
         public String ttype;
         public String what;

         public nodeInfo(String nID, String t, String w) {
             id = nID;
             ttype = t;
             what = w;
         }
         public String toString() { return id; }
         public String getType() { return ttype; }
         public String getWhat() { return what; }
     } // end nodeInfo

     private class MyRenderer extends DefaultTreeCellRenderer {
     // used to set cirrect Icons and tooltip depending on type

} // end MyTree

So i create in my panel where I want to work with my tree:

public class mainFrame extends JFrame {

  MyTree firstTree;

...

  firstTRee = new MyTree(new MyTree.nodeInfo(
                 "Empty","C", "C"), MyTree.USED_AT_A);

  //this creates my empty tree that can be seen in designer.

  buildTree(firstTree) { // a method to get DB from DB and to build tree.

Here is where I fail:
1) The listener is iplemented in MyTree (as I thought it should)
2) When a tree selection happens - the listener updates values in the 
panel where "firstTree" is implemented. The update use a method that
"must" be static since I can't create a
    mainFrame frame = new mainFrame();
within MyTree. (since I in frame have created firstTree) ...
3) Since method used by firstTree.<my static method> is static it 
ripples through all functions and GUI components that then will be 
updated by a selection in the tree.

So, where have I gone wrong ? How to fix this?

Thanks in advance,

Magnus

Paul Furbacher [TeamB] wrote:
> Magnus wrote:
> 
>> I did have a problem with a customized tree that was built with values 
>> from a DB. 
> 
> 
> Shouldn't be designed this way.  Your component should stand
> on its own without data.  The classes that use it are the only
> ones which should put data into it -- all it should know
> how to do is to display the data other classes put into it.
> It should not access databases; it should not read files; it
> should just sit there like a lump until something else provides
> data to it.
>