Create a SWT tree (lazy)
/*
* Tree example snippet: create a tree (lazy)
*
* For a list of all SWT example snippets see
* http://dev.eclipse.org/viewcvs/index.cgi/%7Echeckout%7E/platform-swt-home/dev.html#snippets
*/
import java.io.File;
import org.eclipse.swt.SWT;
import org.eclipse.swt.graphics.Point;
import org.eclipse.swt.layout.FillLayout;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Event;
import org.eclipse.swt.widgets.Listener;
import org.eclipse.swt.widgets.Shell;
import org.eclipse.swt.widgets.Tree;
import org.eclipse.swt.widgets.TreeItem;
public class Snippet8 {
public static void main(String[] args) {
final Display display = new Display();
final Shell shell = new Shell(display);
shell.setText("Lazy Tree");
shell.setLayout(new FillLayout());
final Tree tree = new Tree(shell, SWT.BORDER);
File[] roots = File.listRoots();
for (int i = 0; i < roots.length; i++) {
TreeItem root = new TreeItem(tree, 0);
root.setText(roots[i].toString());
root.setData(roots[i]);
new TreeItem(root, 0);
}
tree.addListener(SWT.Expand, new Listener() {
public void handleEvent(final Event event) {
final TreeItem root = (TreeItem) event.item;
TreeItem[] items = root.getItems();
for (int i = 0; i < items.length; i++) {
if (items[i].getData() != null)
return;
items[i].dispose();
}
File file = (File) root.getData();
File[] files = file.listFiles();
if (files == null)
return;
for (int i = 0; i < files.length; i++) {
TreeItem item = new TreeItem(root, 0);
item.setText(files[i].getName());
item.setData(files[i]);
if (files[i].isDirectory()) {
new TreeItem(item, 0);
}
}
}
});
Point size = tree.computeSize(300, SWT.DEFAULT);
int width = Math.max(300, size.x);
int height = Math.max(300, size.y);
shell.setSize(shell.computeSize(width, height));
shell.open();
while (!shell.isDisposed()) {
if (!display.readAndDispatch())
display.sleep();
}
display.dispose();
}
}
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