composite within a composite - swt

Question

Does anybody know how or if you can place a smaller composite inside a larger composite.
For example I want the smaller composite to be in the centre of the large composite and visible and when a button is pressed in the larger composite a picture appears in the smaller composite?
Would be extremely glad of your help.
Ann.

Answer 1

I'm not sure if I understand your question, you meant something like this..?
import java.net.URL;
import org.eclipse.swt.SWT;
import org.eclipse.swt.events.PaintEvent;
import org.eclipse.swt.events.PaintListener;
import org.eclipse.swt.events.SelectionAdapter;
import org.eclipse.swt.events.SelectionEvent;
import org.eclipse.swt.graphics.Image;
import org.eclipse.swt.layout.FillLayout;
import org.eclipse.swt.widgets.Button;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Shell;
public class CompositeInComposite {
private Display display = null;
private Shell shell = null;
private Composite composite = null;
private Image img = null;
private URL dog = null;
private URL cat = null;
public CompositeInComposite() {
display = new Display();
shell = new Shell(display);
shell.setLayout(new FillLayout(SWT.VERTICAL));
shell.setSize(300, 300);
Button btn = new Button(shell, SWT.PUSH);
btn.setText("show cat");
btn.addSelectionListener(new SelectionAdapter() {
#Override
public void widgetSelected(SelectionEvent e) {
try {
img = new Image(display, cat.openStream());
composite.redraw();
} catch(Exception ex) {
ex.printStackTrace();
}
}
});
try {
cat = new URL("http://upload.wikimedia.org/wikipedia/commons/thumb/6/64/Collage_of_Six_Cats-02.jpg/250px-Collage_of_Six_Cats-02.jpg");
dog = new URL("http://upload.wikimedia.org/wikipedia/commons/thumb/2/26/YellowLabradorLooking_new.jpg/260px-YellowLabradorLooking_new.jpg");
img = new Image(display, dog.openStream());
} catch (Exception e) {
e.printStackTrace();
}
composite = new Composite(shell, SWT.BORDER);
composite.addPaintListener(new PaintListener() {
#Override
public void paintControl(PaintEvent e) {
e.gc.drawImage(img, 0, 0);
}
});
// shell.pack();
shell.open();
while (!shell.isDisposed()) {
if (!display.readAndDispatch())
display.sleep();
}
display.dispose();
}
public static void main(String[] args) {
new CompositeInComposite();
}
}
The alignment of the button, it's size, etc. is just a proper configuration of layout manager, I would recommend MigLayout as IMO best layout manager that exists.