使用两个TextField：texMin和texMax，我想限制我的 doubleSlider 控件的最小值和最大值（参见DoubleSlider此处的自定义 ui 控件：http ://code.google.com/p/javafx-widgets/source/browse/#svn%2Ftrunk% 2FDoubleSlider%2Fsrc%2Fdouble_slider )
带有 StringConverter 的 DoubleBinded（双精度字符串）完美地工作，但现在我不知道如何过滤以在按键TextField后仅获取用户在两者中输入的正确值。ENTER
我不知道setOnKeyReleasedEvent用户输入的值的过滤器是否可以与bindBidirectionalon 属性一起使用。我认为bindBidirectional绕过我的过滤器（每次文本更改时触发一个事件），但我不确定。
def sliderBlockFactory(slider: DoubleSlider): HBox = {
val minText = new TextField()
val maxText = new TextField()
minText.setText(slider.getValue1().toString)
maxText.setText(slider.getValue2().toString)
slider.value1Property().addListener(
new ChangeListener[Number]() {
override def changed(ov: ObservableValue[_ <: Number], old_val: Number, new_val: Number) {
if (new_val.doubleValue() == null) {
minText.setText("")
} else {
minText.setText(new_val.doubleValue().toString())
}
}
})
slider.value2Property().addListener(
new ChangeListener[Number]() {
override def changed(ov: ObservableValue[_ <: Number], old_val: Number, new_val: Number) {
if (new_val.doubleValue() == null) {
maxText.setText("")
} else {
maxText.setText(new_val.doubleValue().toString())
}
}
})
minText.setPrefWidth(40)
maxText.setPrefWidth(40)
val converter: StringConverter[_ <: Number] = new DoubleStringConverter()
Bindings.bindBidirectional(minText.textProperty(), slider.value1Property(), converter.asInstanceOf[StringConverter[Number]])
Bindings.bindBidirectional(maxText.textProperty(), slider.value2Property(), converter.asInstanceOf[StringConverter[Number]])
val uiSliderBlock = new HBox()
uiSliderBlock.getChildren.addAll(minText, slider, maxText)
uiSliderBlock
}
def doubleSliderFactory(min: Double, max: Double): DoubleSlider = {
val slider = new DoubleSlider()
slider.setMin(min)
slider.setMax(max)
slider.setShowTickLabels(true)
slider.setShowTickMarks(true)
slider.setMajorTickUnit(50)
slider.setMinorTickCount(25)
slider.setSnapToTicks(true)
slider.setPrefWidth(100)
slider.setBlockIncrement(10)
slider
}
val myDoubleSlider = sliderBlockFactory(doubleSliderFactory(0.0, 100.0))
更新 1：
感谢评论，我修改了我的代码源。我放弃了 DoubleStringConverter，因为我的用例太复杂了。我还将评论 url 中给出的 java 源代码翻译成 scala ：
class DoubleTextField(var minValue: Double, var maxValue: Double, val initialValue: Double) extends TextField {
require(minValue < maxValue, "DoubleField min value " + minValue + " greater than max value " + maxValue)
require(maxValue > minValue, "DoubleField max value " + minValue + " less than min value " + maxValue)
//require(!((minValue <= initialValue) && (initialValue <= maxValue)), "DoubleField initialValue " + initialValue + " not between " + minValue + " and " + maxValue)
val value: DoubleProperty = new SimpleDoubleProperty(initialValue)
//scala parsing
def parseDouble(s: String) = try {
Some(s.toDouble)
} catch {
case _ ⇒ None
}
def getValue() = value.getValue()
def setValue(newValue: Double) = value.setValue(newValue)
def valueProperty(): DoubleProperty = value
setText(initialValue.toString())
val doubleField: DoubleTextField = this
// make sure the value property is clamped to the required range
// and update the field's text to be in sync with the value.
value.addListener(new ChangeListener[Number]() {
override def changed(observableValue: ObservableValue[_ <: Number], oldValue: Number, newValue: Number) {
if (newValue == null) {
doubleField.setText("")
} else {
if (newValue.doubleValue() < doubleField.minValue) {
value.setValue(doubleField.minValue)
return
}
if (newValue.doubleValue() > doubleField.maxValue) {
value.setValue(doubleField.maxValue)
return
}
if (newValue.doubleValue() == 0 && (textProperty().get() == null || "".equals(textProperty().get()))) {
// no action required, text property is already blank, we don't need to set it to 0.
} else {
doubleField.setText(newValue.toString())
}
}
}
})
// restrict key input to numerals.
this.addEventFilter(KeyEvent.KEY_TYPED, new EventHandler[KeyEvent]() {
override def handle(keyEvent: KeyEvent) {
if (!"0123456789".contains(keyEvent.getCharacter())) {
keyEvent.consume()
}
}
})
// i don't want a realtime change on my textfield,
// so i prefer a validate method like focusedProperty (see below)
/*this.textProperty().addListener(
new ChangeListener[String]() {
override def changed(observableValue: ObservableValue[_ <: String], oldValue: String, newValue: String) {
if (newValue == null || "".equals(newValue)) {
value.setValue(0)
return
}
parseDouble(newValue) match {
case Some(d: Double) ⇒
if (doubleField.minValue > d || d > doubleField.maxValue) {
textProperty().setValue(oldValue)
value.set(oldValue.toDouble)
} else {
value.set(d)
}
case _ ⇒ oldValue //reset to old value
}
}
})*/
// Detect a change in focus on the text field.. If we lose the focus we take appropriate action
// problem with boolean : https://stackoverflow.com/questions/11377350/scala-java-interop-class-type-not-converted
this.focusedProperty().addListener(
new ChangeListener[java.lang.Boolean]() { db ⇒
override def changed(observable: ObservableValue[_ <: java.lang.Boolean], oldValue: java.lang.Boolean, newValue: java.lang.Boolean) {
if (!newValue) {
parseDouble(doubleField.textProperty().get()) match {
case Some(d: Double) ⇒
if (doubleField.minValue > d || d > doubleField.maxValue) {
textProperty().setValue(doubleField.minValue.toString)
value.set(textProperty().get().toDouble)
} else {
value.set(d)
}
case _ ⇒ println("error") //reset to old value
}
}
}
})
}
DoubleSlider更新的更正代码源DoubleTextField：
// inspired by :
// https://gist.github.com/1962045
// https://stackoverflow.com/questions/14138082/java-fx-bidirectional-bindings-of-different-properties
// https://forums.oracle.com/forums/thread.jspa?threadID=2311243
def sliderBlockFactory(slider: DoubleSlider): HBox = {
val minText = new DoubleTextField(slider.getMin, slider.getMax, slider.getMin)
val maxText = new DoubleTextField(slider.getMin, slider.getMax, slider.getMax)
slider.value1Property().addListener(
new ChangeListener[Number]() {
override def changed(ov: ObservableValue[_ <: Number], old_val: Number, new_val: Number) {
if (new_val.doubleValue() == null) {
minText.setText("")
} else {
//set new min value of maxText
maxText.minValue = new_val.doubleValue()
}
}
})
slider.value2Property().addListener(
new ChangeListener[Number]() {
override def changed(ov: ObservableValue[_ <: Number], old_val: Number, new_val: Number) {
if (new_val.doubleValue() == null) {
maxText.setText("")
} else {
//set new max value of minText
minText.maxValue = new_val.doubleValue()
}
}
})
minText.setPrefWidth(40)
maxText.setPrefWidth(40)
/*val converter: StringConverter[_ <: Number] = new DoubleStringConverter()
Bindings.bindBidirectional(minText.textProperty(), slider.value1Property(), converter.asInstanceOf[StringConverter[Number]])
Bindings.bindBidirectional(maxText.textProperty(), slider.value2Property(), converter.asInstanceOf[StringConverter[Number]])
*/
minText.valueProperty().bindBidirectional(slider.value1Property())
maxText.valueProperty().bindBidirectional(slider.value2Property())
val uiSliderBlock = new HBox()
uiSliderBlock.getChildren.addAll(minText, slider, maxText)
uiSliderBlock
}
def doubleSliderFactory(min: Double, max: Double): DoubleSlider = {
val slider = new DoubleSlider()
slider.setMin(min)
slider.setMax(max)
slider.setShowTickLabels(true)
slider.setShowTickMarks(true)
slider.setMajorTickUnit(50)
slider.setMinorTickCount(25)
slider.setSnapToTicks(true)
slider.setPrefWidth(100)
slider.setBlockIncrement(10)
slider
}
val myDoubleSlider = sliderBlockFactory(doubleSliderFactory(0.0, 100.0))
结果 ：）
此代码有效，每个滑块控件的 min 和 max 值已正确更新，但如您所见，当焦点离开且值错误时，我无法使用焦点事件检索旧值。我的问题很简单，有没有办法在不使用changeListeneron的情况下获取 textField 中的旧值textProperty？
更新 2：
我在这里找到了答案：