Java Development

[jtp5120]

I have the following code that is ran in a thread that does not have the event lock. I get the event lock by running invokeLater.

UiApplication.getUiApplication().invokeLater(
new Runnable() {
public void run() {
Screen mScreen = UiApplication
        .getUiApplication().getActiveScreen();
if (mScreen instanceof MyScreen) {
	try {
        VerticalFieldManager oldVfm = ((MyScreen) mScreen)
                .getVfm();
        mScreen.replace(oldVfm, newVfm);

        UiApplication.getUiApplication()
                .updateDisplay();

    } catch (IllegalArgumentException e) {
        Logger
                .debug("Illegal argument: "
                        + e.getMessage());
        e.printStackTrace();
    } catch (IllegalStateException e) {
        Logger
                .debug("Illegal state: "
                        + e.getMessage());
        e.printStackTrace();
    }
}
}
});

I am receiving an IllegalArgumentException: "oldField is not a child" when the invokeLater is ran. The "oldVfm" is added to the active screen with:

public MyScreen() {
  super();

  this.cfm = new VerticalFieldManager();
  add(this.cfm);
}

So how is "oldField" (VerticalFieldManger oldVfm) not a child of the MyScreen class that extends MainScreen?

I don't have to nest the "oldVfm" inside another Manager - that wouldn't make sense...

[jprofitt]

Is getVfm() a method you've made?

[simon_hain]

a problem like this can easily be traced by assigning the field in question to a variable and checking it with the debugger.

[jtp5120]

Yes.

public MyScreen() {
  super();

  this.cfm = new VerticalFieldManager();
  add(this.cfm);
}

public VerticalFieldManager getVfm(){
  return this.cfm;
}

[jtp5120]

@simon_hain

To clarify, assign my "oldVfm" to a field within my class before I pass it to Manager.replace, correct?

[simon_hain]

you already assign it correctly. set a breakpoint at the replace line and check the attributes of the oldVfm, especially the manager which it is assigned to. you can also use getManager to check which manager the field belongs to.

[jtp5120]

Alright, I believe this makes sense.

oldVfm.getManager() returns null because oldVfm is the top most Manager (Field) in my class that extends MainScreen.

So I can't replace my VerticalFieldManager because it is the only one on the screen. In other words, I cannot replace the old Field on a Screen with a new Field when there is only one Field added to the screen.

Screen -> VerticalFieldManager (old)

Screen -> VerticalFieldManager (new)

I will try to delete the oldVfm and add the newVfm, but I thought replace() would have done that?

[jtp5120]

Now I've tried nested managers and I still receive an Illegal argument: oldField is not a child.

I'm stumped here, I've tried:

Screen -> Manager

Screen -> Manager -> Manager

Either way, I am unable to replace the Screen's Field (Manager in these cases) with another Field?

Replace just performances what delete plus add does.

[jtp5120]

This is ridiculous.

All I am trying to do is replace a screen's only manager with another manager.

1. Screen has a Manager [oldVfm]
2. Create a new Manager [newVfm]
3. Loop through a table in a database and output each value to a LabelField
4. Add each LabelField to a the new Manager [newVfm]
5. Replace the Screen's Manager [oldVfm] with Manager [newVfm]

That's it...

However, if I check the oldVfm Manager it is always null since Manager [oldVfm] is the only manager added to the Screen.

Manager m = oldVfm.getManager();
if (m != null) {
  mycard.replace(oldVfm, newVfm);
  mycard.invalidate();
} else {
  Logger.debug("oldVfm has no manager.");
}

How can I design a solution?

Plus what I really don't understand is Screen extends Manager extends Field. So I would think this would be somewhat of a simple solution.

[simon_hain]

The main manager of a mainscreen cannot be replaced i think. you can add a manager for the whole screen and replace this one.