Question

我发现在谈到JTextPanes主题时，缺乏互联网上有用的文档/教程。我正在尝试做一个简单的文本处理器，我希望它能够从JComboBox中选择一个字体系列，它根据用户在系统上安装的字体填充自己。但是，无论我尝试什么样的实验，我都无法弄清楚如何让它发挥作用。

我所拥有的是一个基于JTextPane构建的工具栏类。目前，它有一堆样式按钮，用于设置对齐和粗体，斜体和下划线。

这是我的代码：

/**
* The StyleBar is used to customize styles in a Styled Document. It will take a
* JTextPane as an argument for its constructor and then all actions to be taken
* will affect the text in it.
*
* @author Andrew
*/
public class StyleBar extends JToolBar {

    private JLabel fontLbl;
    private JComboBox fontBox;

        // ...Irrelevant stuff to the problem at hand.

    /**
    * The initEvents method is used to initialize the necessary events for the
    * tool bar to actually do its job. It establishes the focus listener to the
    * buttons on the bar, and gives each one its individual functionality. It 
    * also establishes the Font Selection interface.
    */
    public void initEvents() {
        //For each item in the tool bar, add the focus listener as well as the
        //formatting listeners:
        boldFormat.addActionListener(new StyledEditorKit.BoldAction()); //boldFormat is
        boldFormat.addActionListener(resetFocus);                       //a JButton

        //Ditto for my italicsFormat and underlineFormat button(s) in the toolbar

        leftAlign.addActionListener(new StyledEditorKit.AlignmentAction(null,
                StyleConstants.ALIGN_LEFT));
        leftAlign.addActionListener(resetFocus);    //This listener just resets focus
                                                    //back onto the TextPane.

        //Ditto for my right and centerAlign buttons

        //Set up the Font list, and add a listener to the combo box
        buildFontMenu();
    }

    /**
    * The buildFontMenu detects all of the SYstem's available fonts and adds 
    * them to the Font Selection box.
    */
    public void buildFontMenu(){
        GraphicsEnvironment ge = 
                GraphicsEnvironment.getLocalGraphicsEnvironment();
        final String[] fontNames = ge.getAvailableFontFamilyNames();
        for (int i = 0; i < fontNames.length; i++){
            //What do I do here to take the entry at String[i] and make it so that when
            //the user selects it it sets the font Family in a similar way to that of
            //pressing the boldFormat button or the leftAlign button?
        }
    }

    //Everything else is irrelevant

所以总结一下我的问题：我不知道如何正确地将侦听器设置为ComboBox，以便a）它对所选择的单个字体敏感，并且b）以某种方式使用StyledEditorKit.FontFamilyAction来简化生活？

斜线，如果我以错误的方式接近这个，我很想听到正确的方法。正如我所说，我在互联网上的消息来源在这个问题上并不十分清楚。

非常感谢！

Answer 1

StyledEditorTest将Action放入JToolBar，但想法是一样的。另见Charles Bell的HTMLDocumentEditor，提及here。例如，

bar.add(new StyledEditorKit.FontFamilyAction("Serif", Font.SERIF));
bar.add(new StyledEditorKit.FontFamilyAction("SansSerif", Font.SANS_SERIF));

附录：当您使用JComboBox时，您可以将事件转发到相应的StyledEditorKit Action，默认情况下会对当前选择进行操作。

JComboBox combo = new JComboBox();
combo.addItem("Serif");
combo.addItem("Sans");
combo.addActionListener(new ActionListener() {

    Action serif = new StyledEditorKit.FontFamilyAction("Serif", Font.SERIF);
    Action sans = new StyledEditorKit.FontFamilyAction("Sans", Font.SANS_SERIF);

    @Override
    public void actionPerformed(ActionEvent e) {
        if ("Sans".equals(e.getActionCommand())) {
            sans.actionPerformed(e);
        } else {
            serif.actionPerformed(e);
        }
    }
});

Answer 2

这可能有点晚了，但我发现自己陷入了类似的问题，虽然之前的回答确实有帮助，但是当你想要使用计算机上可用的所有字体时，这里有一个更完整的答案。 / p>

其中“fonts”是一个字符串数组，包含程序中使用的所有所需字体

        final JComboBox jcb = new JComboBox(fonts);

    final Action [] actions = new Action[fonts.length];

    for (int i = 0; i < actions.length; i++)
    {
        actions[i] = new StyledEditorKit.FontFamilyAction(fonts[i], fonts[i]);
    }

    jcb.addActionListener(new ActionListener()
        {
            public void actionPerformed(ActionEvent event) 
            {
                for (int i = 0; i < actions.length; i++)
                {
                    if (fonts[i].equals((String)jcb.getSelectedItem()))
                    {
                        actions[i].actionPerformed(event);
                        break;
                    }
                }
            }
        });

如何允许用户使用JComboBox在JTextPane中更改其字体？

2 个答案: