Description Lakshmi P Shanmugam 2011-01-07 09:27:44 EST

In a Tree with TreeEditors expanding or collapsing a TreeItem causes all the editors in the tree to be redrawn. This causes lot of flickering. 
We should (atleast) prevent the editors above the expanding/collapsing item from being affected.

Snippet to show the problem:-
public class TreeEditorFlicker {
public static void main(String[] args) {
	Display display = new Display ();
	Shell shell = new Shell (display);
	shell.setLayout (new FillLayout ());
	Tree tree = new Tree (shell, SWT.BORDER | SWT.MULTI|SWT.V_SCROLL|SWT.FULL_SELECTION);
	tree.setLinesVisible (true);
	for (int i=0; i<3; i++) {
		TreeColumn column = new TreeColumn(tree, SWT.NONE);
		column.setWidth (100);
	}
	for (int i=0; i<10; i++) {
		TreeItem item = new TreeItem (tree, SWT.NONE);
		for (int j = 0; j < 5; j++) {
			new TreeItem (item, SWT.NONE);
		}
	}
	TreeItem [] items = tree.getItems ();
	for (int i=0; i<items.length; i++) {
		createEditors(tree, items[i], i);
		TreeItem [] children = items[i].getItems();
		for (int j = 0; j < children.length; j++) {
			createEditors(tree, children[j], i+j);
		}
		
	}
	tree.pack();
	shell.pack ();
	shell.open ();
	while (!shell.isDisposed ()) {
		if (!display.readAndDispatch ()) display.sleep ();
	}
	display.dispose ();
}

static void createEditors(Tree tree, TreeItem child, int i) {
	TreeEditor editor = new TreeEditor (tree);
	Text text = new Text (tree, SWT.NONE);
	text.setText("Text" + i);
	editor.grabHorizontal = true;
	editor.setEditor(text, child, 0);
	editor = new TreeEditor (tree);
	Combo combo = new Combo (tree, SWT.NONE);
	combo.setText("Combo" + i);
	combo.add("item 1");
	combo.add("item 2");
	editor.grabHorizontal = true;
	editor.setEditor(combo, child, 1);
	editor = new TreeEditor (tree);
	Button button = new Button(tree, SWT.CHECK);
	editor.grabHorizontal = true;
	editor.setEditor(button, child, 2);
	editor = new TreeEditor (tree);
}
}