Bug 351933

Description Ludwig Moser 2011-07-13 05:37:04 EDT

Build Identifier: 20110218-0911

when you exclude a component from the layout without setting the visibility of the component to false, the wrong component gets excluded.
if you set visibility of the component you excluded in the layout data to false, then the correct one gets excluded.

Reproducible: Always

Steps to Reproduce:
i have sample code for you.
if you enable the outcommented stuff.. it works.

package listTests;

import org.eclipse.swt.SWT;

public class TestGui {

	protected Shell shell;
	private Button btn3;
	private Button btn2;
	private Button btn1;

	/**
	 * Launch the application.
	 * 
	 * @param args
	 */
	public static void main(String[] args) {
		try {
			TestGui window = new TestGui();
			window.open();
		} catch (Exception e) {
			e.printStackTrace();
		}
	}

	/**
	 * Open the window.
	 */
	public void open() {
		Display display = Display.getDefault();
		createContents();
		shell.open();
		shell.layout();
		while (!shell.isDisposed()) {
			if (!display.readAndDispatch()) {
				display.sleep();
			}
		}
	}

	/**
	 * Create contents of the window.
	 */
	protected void createContents() {
		shell = new Shell();
		shell.setSize(450, 300);
		shell.setText("SWT Application");
		shell.setLayout(new GridLayout(1, false));


		btn1 = new Button(shell, SWT.NONE);
		btn1.setLayoutData(new GridData(SWT.FILL, SWT.CENTER, true, false,
				1, 1));
		btn1.setText("Show ALL");
		btn1.addSelectionListener(new SelectionAdapter() {
			@Override
			public void widgetSelected(SelectionEvent e) {
				GridData gd = (GridData) btn2.getLayoutData();
				gd.exclude = false;
//				btn2.setVisible(!gd.exclude);
				btn2.setLayoutData(gd);
				shell.layout();
			}
		});

		btn2 = new Button(shell, SWT.NONE);
		btn2.setLayoutData(new GridData(SWT.FILL, SWT.CENTER, true, false,
				1, 1));
		btn2.setText("Press me to hide");
		btn2.addSelectionListener(new SelectionAdapter() {
			@Override
			public void widgetSelected(SelectionEvent e) {
				GridData gd = (GridData) btn2.getLayoutData();
				gd.exclude = true;
//				btn2.setVisible(!gd.exclude);
				btn2.setLayoutData(gd);
				shell.layout();
			}
		});

		btn3 = new Button(shell, SWT.NONE);
		btn3.addSelectionListener(new SelectionAdapter() {
			@Override
			public void widgetSelected(SelectionEvent e) {
				System.out.println("try to move");
				Object data = btn2.getData();
				Composite parent = btn2.getParent();
				int style = btn2.getStyle();
				btn2.dispose();
				btn2 = new Button(parent, style);
				btn2.setData(data);
				shell.layout();
			}
		});
		btn3.setLayoutData(new GridData(SWT.FILL, SWT.CENTER, true, false,
				1, 1));
		btn3.setText("move me above btn2");
	}
}

NOTE: i bugfixed the code in GridLayout

simply change:
for (int i=0; i<children.length; i++) {
		Control control = children [i];
		GridData data = (GridData) control.getLayoutData ();
		if (data == null || !data.exclude) {
			children [count++] = children [i];
		} 
	}

to

for (int i = 0; i < children.length; i++) {
			Control control = children[i];
			GridData data = (GridData) control.getLayoutData();
			if (data != null) {
				children[i].setVisible(!data.exclude);
				if (!data.exclude) {
					children[count++] = children[i];
				}
			}
		}