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Tree leaves [message #1412880]

Wed, 27 August 2014 05:25

Eclipse User

Having trouble adding leaves to my tree. Developing a stand alone Java app using mainly SWT and Eclipse JavaEE on Windows.

The tree is like this:

root
------parentA
--------------childA1
--------------childA2
--------------childA3
------parentB
------parentC
--------------childC1
--------------childC2

My requirement: when a child is selected/clicked I want to create a grandchild (there could be from zero to say 12 grandchildren added by user action at different times).

Thus if user clicks/selects childA2:

root
------parentA
--------------childA1
--------------childA2
----------------------grandchildA21
--------------childA3
------parentB
------parentC
--------------childC1
--------------childC2

Codewise I have:

import org.eclipse.swt.widgets.Tree;  
import org.eclipse.swt.widgets.TreeItem;

Question one: do I need any further tree related imports to get this to work?

.  
final Tree tree = new Tree(shell, SWT.VIRTUAL | SWT.BORDER | SWT.CHECK | SWT.V_SCROLL | SWT.H_SCROLL | SWT.SINGLE );  
        tree.setHeaderVisible(true);  
        tree.setBounds(975, 00, 375, 600);  
.  
.  
 void populate_tree() {  
                for(int x=1;x<number_of_lines;x++) {  
                    if ( script_type[x].matches("S")) {  
                                final TreeItem itemI = new TreeItem(tree, SWT.NULL);  
                        itemI.setText(script_type[x] + "=" + x + "=" + script_item[x]);  
                        x++;  
                        while (! script_type[x].equals("S")) {  
                            if ( script_type[x].equals("AB1")||script_type[x].equals("DB1")) {  
                                TreeItem itemJ = new TreeItem(itemI, SWT.NULL);  
                                itemJ.setText(script_type[x] + "=" + x + "=" + script_itemnumber[x] + "=" + script_item[x]);   
                                x++;  
                                TreeItem itemK = new TreeItem(itemI, SWT.NULL);  
                                itemK.setText(script_type[x] + "=" + x + "=" + script_itemnumber[x] + "=" + script_item[x]);  
                            }    
                            x++;  
                            if(x>number_of_lines) break;  
                                }  
                        x--;       
                    }   
                }  
            }  
  
        }

Tree displays, is expandable, has all the right text.

 
.  
                tree.addListener(SWT.Selection, new Listener() {  
            public void handleEvent(Event event) {  
.

And it is here I've tried lots of options but it's like bleak mid winter - no new leaves What seems odd is that I can see the selected/clicked child text item.getText() but if I look at the index it is always -1. And I thought the index would let me create the leaf.

Question 2: If anyone can give me any guidance or link to a good example that actually works while I still have hair it would be greatly appreciated.

Cheers

Re: Tree leaves [message #1412979 is a reply to message #1412880]

Wed, 27 August 2014 09:40

Eclipse User

Please refer the Tree section on SWT Snippets page:
http://eclipse.org/swt/snippets/

-Niraj

Re: Tree leaves [message #1443179 is a reply to message #1412979]

Sun, 12 October 2014 04:59

Eclipse User

Been playing sometime with this and maybe I was expecting too much sophistication from a SWT tree (and SWT table for that matter).

To get it to work I have found that walking the tree is the best if not only approach.

However I still have one issue that someone who uses SWT trees might help with. The following code adds leaves at a certain node in the tree.

            	// Create directive leaves
            	for(int z=0; z<dirbits.length; z++) {
            		final TreeItem itemDir = new TreeItem( itemDBAB1, SWT.NULL);
            		itemDir.setText(dirbits[z]);
            		itemDir.setForeground(green);
            								
            	}

As presented it appends values to the tree leaf but what I want is distinct tree leaves. Because I'm looping I'm using the same treeitem so thus the append and not create. If anyone could suggest if my code is simply wrong or could be easily changed before I go for a more convoluted solution I'd very much appreciate it.

Many thanks

Re: Tree leaves [message #1444455 is a reply to message #1443179]

Tue, 14 October 2014 01:17

Eclipse User

Apologies to all who read this but it turned out to be a symptom of another problem related to incompatibilities between Swing and SWT.

I don't have the details as I had to get someone to fix this for me.

Mods do you want to delete this hread as I doubt it helps anyone?

Again sorry

Re: Tree leaves [message #1456118 is a reply to message #1444455]

Wed, 29 October 2014 23:35

Eclipse User

Nigel i got also a problem with Tree Leaves. though a bit different.

I want to catch an event a Tree Item child is selected

ParentItem
-- ChildItem

when Child Item is selected i want to do some actions

here is the listener I added:

            selectedForm.getTreeWidget().addSelectionListener(new SelectionListener()
            {
               
               @Override
               public void widgetSelected(SelectionEvent event)
               {
                  // TODO Auto-generated method stub
                  TreeItem[] treeItems = selectedForm.getTreeWidget().getItems();
                  final TreeItem item = (TreeItem)event.item;
                  
                  if (item != null && item.toString().equals(treeItems[0].toString()))
                  {
                     //selectedForm.getDvTextForm().forceFocus();
                     selectedForm.setDvTextFormStyledDVText("gaga");
                  }
               }
               
               @Overrid
               public void widgetDefaultSelected(SelectionEvent e)
               {
                  // TODO Auto-generated method stub
                  
               }
            });

The problem is that

 TreeItem[] treeItems = selectedForm.getTreeWidget().getItems();

returns only 1 item, the "ParentItem"
I can't find a way to get the Children of ParentItem

if i set treeItems[0] to treeItems[1] it get's an OutOfBound Exception

 if (item != null && item.toString().equals(treeItems[0].toString()))

btw. the snippets do not help on such questions as the Tree snippets mostly cover tables and trees only with a parent

[Updated on: Wed, 29 October 2014 23:37] by Moderator

Re: Tree leaves [message #1456128 is a reply to message #1456118]

Wed, 29 October 2014 23:48

Eclipse User

sorry for the question
solved it. sometimes asking questions helps finding solutions Smile

                  TreeItem[] treeItems = selectedForm.getTreeWidget().getItems();
                  TreeItem[] childItems = treeItems[0].getItems();
                  final TreeItem item = (TreeItem)event.item;

                  if (item != null && item.toString().equals(childItems[0].toString()))

Re: Tree leaves [message #1456405 is a reply to message #1456128]

Thu, 30 October 2014 06:20

Eclipse User

Charlie just for interest I found this was useful for my tree with leaves that could be checked or selected. The tree was:

final Tree g8_tree = new Tree(g8_main_script_tree, SWT.BORDER | SWT.CHECK | SWT.V_SCROLL | SWT.H_SCROLL );

and the listener:

 g8_tree.addListener(SWT.Selection, new Listener() {
    	public void handleEvent(Event event) {

    		TreeItem item = (TreeItem) event.item;
    		
    		String string = event.detail == SWT.CHECK ? "Checked" : "Selected";
    		
    		if (string.matches("Selected")) {
    			System.out.println(" was selected.");
    		
.....................................

                 if (string.matches("Checked")) {
    			 System.out.println(" was checked.");

My outstanding SWT tree issue at the moment is can I have a tree with say level one leaves/branches with check boxes and say level two without?

Cheers Nigel

Re: Tree leaves [message #1459966 is a reply to message #1456405]

Sun, 02 November 2014 22:56

Eclipse User

Hi Nigel

Thx for sharing. interesting listener.

About your issue. I do not know, So far I do not use checkboxes in tree items.
but theoretically this should be possible, as you can set checked or not checked for each tree item.

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