Bug 65276 [Preferences] Preference dialog should disable OK when okPressed
bundles/org.eclipse.jface/src/org/eclipse/jface/preference/PreferenceDialog.java
public Point computeSize(Composite composite, int wHint, int hHint,
				boolean force) {
			if (wHint != SWT.DEFAULT && hHint != SWT.DEFAULT)
				return new Point(wHint, hHint);
			int x = minimumPageSize.x;
			int y = minimumPageSize.y;
			Control[] children = composite.getChildren();
			for (int i = 0; i < children.length; i++) {
				Point size = children[i].computeSize(SWT.DEFAULT, SWT.DEFAULT,
						force);
				x = Math.max(x, size.x);
				y = Math.max(y, size.y);
			}
			if (wHint != SWT.DEFAULT)
				x = wHint;
			if (hHint != SWT.DEFAULT)
				y = hHint;
			return new Point(x, y);
		}
		public void layout(Composite composite, boolean force) {
			Rectangle rect = composite.getClientArea();
			Control[] children = composite.getChildren();
			for (int i = 0; i < children.length; i++) {
				children[i].setSize(rect.width, rect.height);
			}
		}
	}