Scala-Swing When Dialog accesses parent, parent content clears - swing

Question

I am developing an application with a Scala-swing front-end. I have a MainFrame that is populated and working well. I have a dialog that works well too. But when I access the parent frame from the dialog the contents of the frame clear. The MemuBar is still there.
I only need to centre the dialog on the frame, so I just passed a Point (after trying to do it right) and even that causes the problem. I can set a location point created in the dialog I just can't access the frame to do it. And this I really don't get; I create the point in the frame and send it to the dialog, that is fine, but setting the dialog location to it clears the frame.
I am using "org.scala-lang.modules" % "scala-swing_2.11" % "1.0.2"
Any one have any ideas?
Thanks!
On the other hand this demo code works fine, so it isn't that simple
package hack
import scala.swing.{Action, BorderPanel, Button, Dialog, Dimension, FlowPanel, Frame, MainFrame, Menu, MenuBar, MenuItem, SimpleSwingApplication, TabbedPane}
/**
* Created by bday on 3/31/16.<br>
* <br>
* FrameClearingDialog will do something useful I'm sure
*/
class FrameClearingDialog (parent: Frame) {
val dialog = new Dialog
dialog.contents = new FlowPanel() {
preferredSize = new Dimension(500,500)
}
dialog.open()
dialog.setLocationRelativeTo(parent)
}
class Parent extends SimpleSwingApplication {
override def top: Frame = new MainFrame {
title = "Hack "
preferredSize = new Dimension(1000,1000)
menuBar = new MenuBar() {
contents += new Menu("Menu") {
contents += new MenuItem(Action("Show Dialog") {
createAndShowDialog
})
}
}
val panel = new BorderPanel() {
layout(new Button() {text="button"}) = BorderPanel.Position.North
layout(new Button() {text="button"}) = BorderPanel.Position.Center
layout(new Button() {text="button"}) = BorderPanel.Position.South
}
contents = new TabbedPane() {
pages += new TabbedPane.Page("Page", panel)
}
}
def createAndShowDialog = {
new FrameClearingDialog(top)
}
}
object Starter extends App {
val demo = new Parent
demo.main(args)
}

Answer 1

This is not the answer, but it does explain the issue enough to understand and avoid it.
The problem seems to be scope. If the content is created inside the MainFrame constructor it survives the call from the child, if created outside it does not. Swing does some strange things sometimes and I am not going to spend more time on this now.
If you move the creation of "map" into the MainFrame then this example will work correctly.
package hack
import scala.swing.{Action, BorderPanel, BoxPanel, Button, Dialog, Dimension, FlowPanel, Frame, MainFrame, Menu, MenuBar, MenuItem, Orientation, Panel, Point, RichWindow, SimpleSwingApplication, TabbedPane}
/**
* Created by bday on 3/31/16.<br>
* <br>
* Utils will do something useful I'm sure
*/
object Utils {
def findCenter(window: RichWindow) = {
new Point(window.location.x + window.size.width/2, window.location.y + window.size.height/2)
}
def centerMe(parent: RichWindow, child: RichWindow) = {
val parentCenter = findCenter(parent)
val childCenter = findCenter(child)
new Point(parentCenter.x - childCenter.x, parentCenter.y - childCenter.y)
}
}
/**
* Created by bday on 3/31/16.<br>
* <br>
* FrameClearingDialog will do something useful I'm sure
*/
class FrameClearingDialog (parent: Frame) {
val dialog = new Dialog
dialog.contents = new FlowPanel() {
preferredSize = new Dimension(500, 500)
}
dialog.location = Utils.centerMe(parent, dialog)
dialog.open()
}
class Parent extends SimpleSwingApplication {
val map = {
var map = Map.empty[Int, Panel]
for (x <- 1 to 5) {
map += x -> createPanel(x)
}
map
}
override def top: Frame = new MainFrame {
title = "Hack "
preferredSize = new Dimension(1000,1000)
menuBar = new MenuBar() {
contents += new Menu("Menu") {
contents += new MenuItem(Action("Show Dialog") {
createAndShowDialog
})
}
}
contents = new TabbedPane() {
for (x <- 1 to 5) {
pages += new TabbedPane.Page(s"Page $x", map(x))
}
}
}
def createPanel(x: Int) = {
new BoxPanel(Orientation.Vertical) {
contents += new Button() {text=s"button $x"}
}
}
def createAndShowDialog = {
new FrameClearingDialog(top)
}
}
object Starter extends App {
val demo = new Parent
demo.main(args)
}