Stopping MouseMoved Event in Java

Question

I'm doing a project in school and I've a distinction feature to implement but have some issues. What I need to do is that I've to check the number of beds left in my SQL database and if it goes below a critical number a JOptionPane appears.

What I'm trying to do is another scenario which is tougher, 2 Frames opened. Eg, first frame user uses the bed, it'll drop to the critical value 10, on the other frame when the user moves his mouse arrow the JOptionPane will pop up showing a message.

I've looked up in this community but I can't seem to implement the codes to make it work. I've got to a point where there's no errors but I can't seem to close the JOptionPane. Basically I would only want this event to fire only when user of either frames go below the bed count.

I'm brand new to this actionevent. I'm doing this project as 3 tier programming with MySQL database.

I've looked at these sites but to no avail:

Stopping mouseMoved

How to temporarily disable event listeners in Swing?

Code for the Frame to show the JOptionPane

public HomePageForm() {
    setTitle("Home");
    setDefaultCloseOperation(WindowConstants.DISPOSE_ON_CLOSE);
    setBounds(100, 100, 640, 428);
    contentPane = new JPanel();
    contentPane.addMouseMotionListener(new MouseMotionAdapter() {
        @Override
        public void mouseMoved(MouseEvent e) {

            String cardioMsg = "Beds are running out for Cardiothoracic Department!";
            String oncoMsg = "Beds are running out for Oncology Department!";
            String orthoMsg = "Beds are running out for Orthopaedic Department!";
            String pediaMsg = "Beds are running out for Pediatric Department!";

            if (ignoreMouseMovedEvents) {
                return;
            }

            ArrayList<ChangeBed> bedList = new ArrayList<ChangeBed>();

            ChangeBedControl cbc8 = new ChangeBedControl();

            bedList = cbc8.processCountBedsAvailableDpt4();

            for (int i = 0; i < bedList.size(); i++) {

                bedsForPediatric = bedList.get(i).getRowCountAvail();

            }

            if (bedsForPediatric <= 3) {

                int valuePedia = JOptionPane.showConfirmDialog(null, pediaMsg, "URGENT", JOptionPane.WARNING_MESSAGE);

                if (valuePedia == 0 || valuePedia == 2) {
                    ignoreMouseMovedEvents = true;
                    valuePedia = JOptionPane.CLOSED_OPTION;
                }

            }   

        }
    });

Codes for Controller Class

public ArrayList<ChangeBed> processCountBedsAvailableDpt4() {

    ChangeBed changeBed = new ChangeBed();

    ArrayList<ChangeBed> bedList = new ArrayList<ChangeBed>();

    bedList = changeBed.countBedsAvailableDpt4();

    return bedList;

}

Entity class to retrieve from SQL DB

public ArrayList<ChangeBed> countBedsAvailableDpt4() {

    ArrayList<ChangeBed> bedList = new ArrayList<ChangeBed>();

    boolean rowBooleanAvail;

    int rowCountAvail;

    try {

        myConn = DriverManager.getConnection("jdbc:mysql://localhost:3306/ooadp?useSSL=false", "root", "root"); 

        Statement myStmt = myConn.createStatement();

        ResultSet myRs = myStmt.executeQuery("SELECT count(*) FROM bed WHERE bedStatus = 'Available' AND department = 'Pediatric'");

        while (myRs.next()) {

            rowBooleanAvail = myRs.last();

            rowCountAvail = myRs.getRow();

            ChangeBed cb = new ChangeBed(myRs.getInt(rowCountAvail), "");

            bedList.add(cb);

           }

        } catch (Exception e) {
            e.printStackTrace();
        }

    return bedList;

}

Basically I also have a Login Frame, upon logging in it opens up the frame I've shown in the above codes. At first showing a JOptionPane upon Mousemoved event showing a warning message. Once I click Ok/Cancel it closes the JOptionPane and stops the mousemoved event.

If I have another login frame whereby I login to the homepage (codes of the frame shown above), the same process will repeat whereby an optionpane will be shown.

So now I'll have 2 homepages opened and both mousemoved event deactivated and it won't fire again.

For frame 2, if I were to hit the critical value of to show the JOptionPane as soon as I move the mouse in the first homepage frame - how can I do that?

Answer 1

Lets answer with a question back to you: why do you want to stop the events?

Meaning: you programmed a listener that reacts to certain events. Now you are saying: at some point; I don't want "reactions"; so how do I prevent those events going into my listener?!

That is one way to look at it.

The other: simply tell your listener(s) that they should ignore incoming events, like:

Class SomeExample {
  private boolean ignoreMouseMovedEvents = false;
  ...
  @Override
  public void mouseMoved(MouseEvent e) {
    if (ignoreMouseMovedEvents) {
      return; 
    }
    ... handle move events 

Now you just need to update that boolean field whenever you want to ignore mouse move events.

But lets be precise here: I am not saying that ignoring events is always the best solution. I am merely expressing: if it is hard for you to prevent events from coming "into your system"; then maybe it is easier to let them coming; but change the way how your system reacts to them.

Finally: there is also a slightly different variation of this: instead of telling your listener to ignore events; you can also de-register your listeners from the event source. In other words: you can simply drop your listener from the frame you attached it to. And you re-add it, when events should be processed again.