Java Tray Icon messages SOMETIMES don't show up.

jamie marchant · 04-28-2017, 03:39 PM

Hi:
I am writing a Java program that uses a TrayIcon. On XFCE the displayMessage() method shows the message but only occasionally, does anyone know why this would be?
-Jamie

hydrurga · 04-29-2017, 08:19 AM

Hi Jamie,

Can you confirm that the *exact same message* is shown only intermittently?

If that is not the case, then it might be that the content of the message (control characters, message length etc) is the determining factor.

BW-userx · 04-29-2017, 08:34 AM

the code block would be nice to see,
does it have a time limit that has to be met before message is shown?
is the pointer where it has to be in order for it to register an 'on_focus' event (I don't now what the actual event name is) if that is even how you're implementing it, or if it is to show a message for some other reason.

What is suppose to be triggering the function call to show Message?

here is the Java docs (?) on it

Code:

java.awt
Class TrayIcon

    java.lang.Object
        java.awt.TrayIcon

https://docs.oracle.com/javase/7/doc.../TrayIcon.html

jamie marchant · 04-29-2017, 10:06 AM

I am using this method in many parts of my code:

Code:

/**
* Displays a tooltip above the icon for a  short period of time.
* 
* @param message The message to be displayed
* @param title The title.
* @param icon The icon to use.
*/
public void notifyUser(String message, String title, TrayIcon.MessageType icon) {
   _ni.displayMessage(title, message, icon);
   S_lastMessage = message; 
}

_ni is an instance of TrayIcon. (Used to be "NoteifyIcon" before I ported this too Java). Ther is no time limit. It's connected to the tray like this:
BufferedImage iconForTray = null;

Code:

try {
    iconForTray = ImageIO.read(new File("cr.png"));// Forgot about recouces, we never got them to work in the C# ver.
} catch (IOException e1) {
    JOptionPane.showMessageDialog(null, "This program has been damaged, please re-download it!", 
    "Oh darn!", JOptionPane.ERROR_MESSAGE);
    // We assume, it's damage since they should be no reason why 
    // We can't read the icon otherwise. 
    System.err.println(e1.getMessage());
    System.exit(9);
}
gram._ni = new TrayIcon(iconForTray);
gram._ni.addActionListener(gram);
    	
SystemTray theTray = SystemTray.getSystemTray();

BW-userx · 04-29-2017, 10:35 AM

1. displayMessage() method shows the message but only occasionally.
that is a function call, yes?

2. notifyUser(String message, String title, TrayIcon.MessageType icon)
that is a different function call, yes?

3. in your catch error to call to print a message,
System.err.println(e1.getMessage());

that is to print line - does that not come out on a command line and not message "box"?

I do not see anywhere in the other two code blocks you calling displayMessage(e1.getMessage());

something like that maybe?

in this one

JOptionPane.showMessageDialog(null, "This program has been damaged, please re-download it!",
"Oh darn!", JOptionPane.ERROR_MESSAGE);

that is only when their is an error ... maybe it is not seeing that "test" error as an error all of the time?

it is a test error yes?

jamie marchant · 04-29-2017, 10:55 AM

Quote:

1. displayMessage() method shows the message but only occasionally.
that is a function call, yes?

Correct.

Quote:

2. notifyUser(String message, String title, TrayIcon.MessageType icon)
that is a different function call, yes?

The notifyUser() method calls the displayMessage() method. The displayMessage() method is in the official Java API.

Quote:

3. in your catch error to call to print a message,
System.err.println(e1.getMessage());

that is to print line - does that not come out on a command line and not message "box"?

That is correct. I am in pre-alpha stages at the moment so I am running my program from an IDE which has a "command line".

Quote:

I do not see anywhere in the other two code blocks you calling displayMessage.

That is correct, it is used in several locations throughout the program but never for crashes. Here is an example where it's used:

Code:

gram.notifyUser("Double-click the icon for volume control.", "Your reader is ready!", TrayIcon.MessageType.INFO);
//Application.Run(gram); 
System.out.println("[DEBUG]: Last instruction ran, program should now run in the background.");

The debug statement IS printed.

Quote:

that is only when there is an error ... maybe it is not seeing that "test" error as an error all of the time?

Is it a test error yes?

If it was seeing that error all the time I would get a message and the program would quite. Notice the line:
"System.exit(9);"

It is not a 'test', Java will execute that code if it can't read the icon file of my disk.

BW-userx · 04-29-2017, 11:13 AM

OK I'm missing something here.

Quote:

I am using this method in many parts of my code:

public void notifyUser(String message, String title, TrayIcon.MessageType icon) {
_ni.displayMessage(title, message, icon);
S_lastMessage = message;
}

what conditions need to be met before the message shows? just an arrow over?

maybe a look over on this
System Tray Icon Example
may help

because it is only showing sometimes. means their has to be a 'short' in your line of code connections. All of the 'wires' are not connected properly to the 'switch' analogy.

one call is connected properly so it does works
another call is not connected properly so it does not work.

That is what I'd be looking in to. Making sure all of your connections are set up properly . have it println("this is where I am being called from") for every displayMessage() that is to be called then look at your terminal out put to find which ones are not being called/working.

jamie marchant · 04-29-2017, 11:38 AM

That's a good idea. I've already noticed the same message called from the same place will usually not show up. I'm not sure what is different in the tray when it does. It seems to be consistent when using Gnome-shell or KDE, even though those desktop environments have their own bugs with Java tray icons.

Hmm... this gives me an idea, I wonder if there is an alternative class I can use, that is less buggy.

I have asked about this here:
https://stackoverflow.com/questions/...a-awt-trayicon

Ok, I've found out that the message only shows up when the tray is visible. So the question is how do I force the tray to show?