在eclipse-rcp / swt中创建多个相同的文本验证侦听器 [英] Creating multiple identical text verify listeners in eclipse-rcp/swt

问题描述

我正在尝试验证多个文本框的输入（即它们应该是一个数字），并在。

I'm trying to validate the input of multiple text boxes (i.e. they should be a number), and found the useful code snippet below here.

但是，如果我有三个文本框（文本， moreText 和 evenMoreText ），如何对每个应用具有相同功能的验证侦听器，而不必重复（ .addVerifyListener（new VerifyListener（）{... ）代码三遍？

However, if I have three text boxes (text, moreText and evenMoreText), how can I apply a verify listener with the same functionality to each, without having to repeat the (.addVerifyListener(new VerifyListener() {...) code three times?

我不想实现switch语句或类似语句（决定哪个文本框以将其应用于），我想要更通用的东西（将来也许可以将其提供给其他类使用）。

I don't want to implement a switch statement or similar (to decide which text box to apply it to), I want something more generic (that I can perhaps make available for other classes to use in the future).

text.addVerifyListener(new VerifyListener() {
  @Override
  public void verifyText(VerifyEvent e) {
    final String oldS = text.getText();
    final String newS = oldS.substring(0, e.start) + e.text + oldS.substring(e.end);

    try {
      BigDecimal bd = new BigDecimal(newS);
      // value is decimal
      // Test value range
    } catch (final NumberFormatException numberFormatException) {
      // value is not decimal
      e.doit = false;
    }
  }
});

推荐答案

定义 VerifyListener 并从 VerifyEvent 获取实际的文本：

VerifyListener listener = new VerifyListener()
{
    @Override
    public void verifyText(VerifyEvent e)
    {
        // Get the source widget
        Text source = (Text) e.getSource();

        // Get the text
        final String oldS = source.getText();
        final String newS = oldS.substring(0, e.start) + e.text + oldS.substring(e.end);

        try
        {
            BigDecimal bd = new BigDecimal(newS);
            // value is decimal
            // Test value range
        }
        catch (final NumberFormatException numberFormatException)
        {
            // value is not decimal
            e.doit = false;
        }
    }
};

// Add listener to both texts
text.addVerifyListener(listener);
anotherText.addVerifyListener(listener);

---

如果您想在其他地方使用它好了，创建一个新类：

---

If you want to use it in other places as well, create a new class:

public class MyVerifyListener implements VerifyListener
{
    // The above code in here
}

然后使用：

MyVerifyListener listener = new MyVerifyListener();

text.addVerifyListener(listener);
anotherText.addVerifyListener(listener);

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