用于textField的Groovy swingbuilder事件

Question

我有以下守则：

textField(id: 'programfilter', actionPerformed: { println("execute some action") })

但是，actionPerform-闭包只在textField有焦点并按下enter时才调用。为了在不同的事件上调用闭包，我必须做什么?例如，单击textField，在其中选择文本，或者简单地对文本的每次更新进行选择？

Answer 1

你可以利用http://docs.groovy-lang.org/latest/html/documentation/core-semantics.html#closure-coercion来做到这一点。仅举一个简单的例子来演示：

import groovy.swing.SwingBuilder
import java.awt.event.*
import javax.swing.event.*
import javax.swing.WindowConstants as WC

SwingBuilder.build() {
    frame(title:'Swing Listener example', size:[300,100], 
            visible:true, defaultCloseOperation:WC.EXIT_ON_CLOSE) {
        gridLayout(cols: 2, rows: 0)
        label 'Input text: '
        input = textField(columns:10, actionPerformed: { echo.text = input.text.toUpperCase() })        
        label 'Echo: '
        echo = label()
        input.document.addDocumentListener(
            [insertUpdate: { echo.text = input.text },
             removeUpdate: { echo.text = input.text },
             changedUpdate: { e -> println e }] as DocumentListener)

        input.addFocusListener(
            [focusGained: { e -> println "Focus gained: $e.cause"},
             focusLost: {e -> println "Focus lost: $e.cause"}] as FocusListener)

        input.addCaretListener({ e ->  println "Caret event: $e"})
    }
}