Scala Swing ListView's Remove / Add Elements Events
With reference to this,
How do I change the contents of a ListView in Scala?
I could change ListView
contents by changing listData
. However, I couldn't get ListView
to开发者_开发知识库 publish these events, ListElementsAdded
, ListElementsAdded
and ListChanged
. From the looks of ListView
source, it would only adds a listener to a read-only empty model. How do I go about this?
Thanks
Later on, I managed to figure out a way to have ListView published these events., please refer to the code.
Is the right to go about it? Is there a better way to do this? Please advise.
Thanks
** code borrowed and modified **
object ListViewTest extends SimpleSwingApplication
{
lazy val top = new MainFrame
{
title = "ListView Test"
contents = new BoxPanel(Orientation.Vertical)
{
border = Swing.EmptyBorder(2, 2, 2, 2)
val listModel = new DefaultListModel
List("First", "Second", "Third", "Fourth", "Fifth").map(listModel.addElement(_))
val myList = ListBuffer()
val listView = new ListView[String](myList)
{
selection.intervalMode = ListView.IntervalMode.Single
peer.setModel(listModel)
//listData = myList
}
listView.peer.getModel.addListDataListener(new ListDataListener {
def contentsChanged(e: ListDataEvent) { publish(ListChanged(listView)) }
def intervalRemoved(e: ListDataEvent) { publish(ListElementsRemoved(listView, e.getIndex0 to e.getIndex1)) }
def intervalAdded(e: ListDataEvent) { publish(ListElementsAdded(listView, e.getIndex0 to e.getIndex1)) }
})
contents += new ScrollPane(listView)
val label = new Label("No selection")
contents += label
val b = new Button("Remove")
contents += b
listenTo(listView.selection, listView, b)
reactions +=
{
case ListSelectionChanged(list, range, live) =>
label.text = "Selection: " + range
case e: ButtonClicked =>
if (listView.listData.isEmpty)
{
b.enabled = false
}
else
{
listView.peer.getModel.asInstanceOf[DefaultListModel].remove(listView.selection.anchorIndex)
}
case ListElementsRemoved(source, range) =>
println("Element at " + (range.start + 1) + " is removed.")
}
}
pack
}
精彩评论