SWT:如何在后台"渲染"Widget到屏幕外缓冲区

import org.eclipse.swt.SWT;
import org.eclipse.swt.graphics.GC;
import org.eclipse.swt.graphics.Image;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Shell;
import org.eclipse.swt.widgets.Text;

public class SWTBackgroundRendering {
    public static void main(String[] args) {
        Display display = new Display();
        Shell shell = new Shell(display);
        shell.setText("Background Rendering Example");

        Text text = new Text(shell, SWT.BORDER);
        text.setText("Hello, SWT!");

        // 创建一个屏幕外缓冲区
        Image offscreenBuffer = new Image(display, shell.getSize().x, shell.getSize().y);

        // 使用 GC 类在后台渲染 Widget 到屏幕外缓冲区
        GC gc = new GC(offscreenBuffer);
        shell.print(gc);
        gc.dispose();

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