树的事件展开收缩 多选

原来例子：Snippet61

 

public class Snippet61 {

	public static void main (String [] args) {
		Display display = new Display ();
		Shell shell = new Shell (display);
		shell.setLayout (new FillLayout ());
		final Tree tree = new Tree (shell, SWT.BORDER | SWT.MULTI | SWT.V_SCROLL);
		for (int i=0; i<4; i++) {
			TreeItem item0 = new TreeItem (tree, 0);
			item0.setText ("Item " + i);
			for (int j=0; j<4; j++) {
				TreeItem item1 = new TreeItem (item0, 0);
				item1.setText ("SubItem " + i + " " + j);
				for (int k=0; k<4; k++) {
					TreeItem item2 = new TreeItem (item1, 0);
					item2.setText ("SubItem " + i + " " + j + " " + k);
				}	
			}
		}
		tree.addListener (SWT.Selection, new Listener () {
			public void handleEvent (Event e) {
				String string = "";
				TreeItem [] selection = tree.getSelection ();
				for (int i=0; i<selection.length; i++) string += selection [i] + " ";
				System.out.println ("Selection={" + string + "}");
			}
		});
		tree.addListener (SWT.DefaultSelection, new Listener () {
			public void handleEvent (Event e) {
				String string = "";
				TreeItem [] selection = tree.getSelection ();
				for (int i=0; i<selection.length; i++) string += selection [i] + " ";
				System.out.println ("DefaultSelection={" + string + "}");
			}
		});
		tree.addListener (SWT.Expand, new Listener () {
			public void handleEvent (Event e) {
				System.out.println ("Expand={" + e.item + "}");
			}
		});
		tree.addListener (SWT.Collapse, new Listener () {
			public void handleEvent (Event e) {
				System.out.println ("Collapse={" + e.item + "}");
			}
		});
		tree.getItems()[0].setExpanded (true);
		shell.pack ();
		shell.open ();
		while (!shell.isDisposed ()) {
			if (!display.readAndDispatch ()) display.sleep ();
		}
		display.dispose ();
	}
} 

 

《Eclipse插件笔记》P149，树中的SWT.FULL_SELECTION，也是其效果的，因为现在的书，是可以增加到多列的。从Eclipse3.1开始，TableTree和Tree的功能在Tree中都具有了，也就是说这里的Tree也可以使多列的。

《Eclipse插件笔记》P151，对于Expand和Collapse事件：是在树展开或折起的动作发生之后才发送出去的，因此无法试图通过将事件类TreeEvent的doit属性设置为false来取消这个动作。另外，调用TreeItem.setExpanded方法来展开或折起不会触发这个事件。