ScrolledComposite不会在TabFolder中显示

Question

我很难找到一个例子，在这个例子中，滚动条可以按预期在TabFolder中工作。下面是示例代码。有人能告诉我我做错了什么吗，或者如果是错误的话？

import org.eclipse.swt.SWT;
import org.eclipse.swt.custom.ScrolledComposite;
import org.eclipse.swt.layout.GridData;
import org.eclipse.swt.layout.GridLayout;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Shell;
import org.eclipse.swt.widgets.TabFolder;
import org.eclipse.swt.widgets.TabItem;
import org.eclipse.swt.widgets.Text;

public class Test {
    public static void main(String[] args) {
        Display display = new Display();

        Shell shell = new Shell(display, SWT.SHELL_TRIM);
        shell.setLayout(new GridLayout(1, false));

        TabFolder tabFolder = new TabFolder(shell, SWT.NULL);

        TabItem tab = new TabItem(tabFolder, SWT.NULL);

        ScrolledComposite scrolledComposite = new ScrolledComposite(tabFolder, 
          SWT.H_SCROLL | SWT.V_SCROLL);
        scrolledComposite.setExpandHorizontal(true);
        scrolledComposite.setExpandVertical(true);
        scrolledComposite.setLayout(new GridLayout(1, false));
        scrolledComposite.setLayoutData(new GridData(SWT.FILL, SWT.FILL,
          true, true));

        Composite innerComposite = new Composite(scrolledComposite, SWT.NULL);
        for (int x = 0; x < 20; x++) {
            Text t = new Text(innerComposite, SWT.BORDER);
            t.setText(x + "");
        }
        innerComposite.setLayout(new GridLayout(2, false));
        innerComposite.setLayoutData(new GridData(SWT.FILL, SWT.FILL, true, 
          true));

        scrolledComposite.setContent(innerComposite);
        scrolledComposite.setMinSize(scrolledComposite.computeSize(SWT.DEFAULT,
          SWT.DEFAULT));
        tab.setControl(scrolledComposite);

        shell.setSize(100, 100);
        shell.open();
        while (!shell.isDisposed()) {
            if (!shell.getDisplay().readAndDispatch()) {
                shell.getDisplay().sleep();
            }
        }
        display.dispose();
    }
}

Answer 1

这方面有若干问题。见守则中的评论：

TabFolder tabFolder = new TabFolder(shell, SWT.NULL);

// Must set layout data for Shell GridLayout
tabFolder.setLayoutData(new GridData(SWT.FILL, SWT.FILL, true, true));

TabItem tab = new TabItem(tabFolder, SWT.NULL);

ScrolledComposite scrolledComposite = new ScrolledComposite(tabFolder, SWT.H_SCROLL | SWT.V_SCROLL);
scrolledComposite.setExpandHorizontal(true);
scrolledComposite.setExpandVertical(true);

// ScrolledComposite ignores setLayout
// scrolledComposite.setLayout(new GridLayout(1, false));
// TabFolder doesn't use GridData
// scrolledComposite.setLayoutData(new GridData(SWT.FILL, SWT.FILL, true, true));

Composite innerComposite = new Composite(scrolledComposite, SWT.NULL);
for (int x = 0; x < 20; x++) {
    final Text t = new Text(innerComposite, SWT.BORDER);
    t.setText(x + "");
}
innerComposite.setLayout(new GridLayout(2, false));
innerComposite.setLayoutData(new GridData(SWT.FILL, SWT.FILL, true, true));

scrolledComposite.setContent(innerComposite);

// MinSize should be the computed size of the inner composite
scrolledComposite.setMinSize(innerComposite.computeSize(SWT.DEFAULT, SWT.DEFAULT)); 

tab.setControl(scrolledComposite);