如何使用SWT更改组件的父级？

Question

我的窗口应该允许两种不同的布局(这是一个更好地说明它的简单示例),例如

+-------------+-------------+-------------+
| Component 1 | Component 2 | Component 3 |
|             |             |             |
|             |             |             |
|             |             |             |
|             |             |             |
+-------------+-------------+-------------+

和

+-------------+---------------------------+
| Component 1 | Component 2               |
|             |                           |
|             +---------------------------+
|             | Component 3               |
|             |                           |
+-------------+---------------------------+

用户可以在两者之间切换,例如,使用菜单项.

使用SWT,您需要在创建组件时提供父级.但我们需要(1)重用组件,(2)将它们放在不同的父组件中(类似于对接框架).SWT如何实现这一目标？

Answer 1

您可以通过更改组件的父级来执行此操作.

setParent()如果底层操作系统支持,则更改控件的父级.然后,您可以layout()复合,以便显示更改.

假设您有三个控件:

• c1包含垂直控件的复合材料
• c2包含水平控件的复合材料
• 一个标签 lbl
• 一个按钮 btn

这是代码:

public class ControlSwitcher {
    public static void main(String[] args) {
        Display display = new Display();
        final Shell shell = new Shell(display);
        GridLayout gl = new GridLayout();
        gl.marginWidth = gl.marginHeight = 20;
        shell.setLayout(gl);

        final Composite c1 = new Composite(shell, SWT.NONE);
        c1.setBackground(new Color(display, 255, 160, 160));
        RowLayout layout = new RowLayout(SWT.VERTICAL);
        c1.setLayout(layout);

        final Composite c2 = new Composite(c1, SWT.NONE);
        c2.setBackground(new Color(display, 160, 255, 160));
        c2.setLayout(new RowLayout());

        final Label lbl = new Label(c2, SWT.NORMAL);
        lbl.setText("Hello world");

        final Button btn = new Button(c2, SWT.PUSH);
        btn.setText("Switch");
        btn.addSelectionListener(new SelectionListener() {
            @Override
            public void widgetSelected(SelectionEvent arg0) {
                Composite target;
                if (btn.getParent().equals(c2)) {
                    target = c1;
                } else {
                    target = c2;
                }
                boolean success = btn.setParent(target);
                if (success) {
                    target.pack();
                    shell.pack();
                } else {
                    throw new RuntimeException("Not supported by this platform");
                }
            }

            @Override
            public void widgetDefaultSelected(SelectionEvent arg0) {
            }
        });

        shell.pack();
        shell.open();
        while (!shell.isDisposed()) {
            if (!display.readAndDispatch()) {
                display.sleep();
            }
        }
        display.dispose();
    }
}