System Tray

To show, hide a System Tray on task bar

Introduction

If you want to show a System Tray on task bar, to do integration is required.

You can show, hide a System Tray, popup a menu and receive the mouse event through integration API.

API Classes

There are 3 API classes to integrate with System Tray:

public class SystemTray;
public class SystemTrayMenu;
public interface SystemTrayCallback;

The class SystemTray stands for a System Tray instance, it is used to control the System Tray's appearance:

public class SystemTray
{
    /**
     * Constructor.
     * The second is to construct System Tray with a windows 2000 style balloon info.
     */
    public SystemTray(int nIcon, String szTip);
    public SystemTray(int nIcon, String szTip, 
                           String szInfo, String szInfoTitle, int nInfoType);

    /**
     * Change the system tray. The usage is the same as constructor.
     * Any int argument < 0 means not to change.
     * Any String argument == null means not to change.
     */
    public void Change(int nIcon, String szTip);
    public void Change(int nIcon, String szTip,
                            String szInfo, String szInfoTitle, int nInfoType);

    /** Show and hide */
    public void Show();
    public void Hide();
    
    /**
     * Set the mouse event callback handler, to receive mouse event and menu event
     */
    public static void setSystemTrayCallback(SystemTrayCallback callback);
}

The second class SystemTrayMenu stands for a menu, you can popup it in the mouse event callback:

public class SystemTrayMenu
{    
    /**
     * Append a menu item to current menu
     */
    public void Append(String title, int itemid);
    
    /**
     * Append a sub-menu to current menu
     */
    public void Append(String title, SystemTrayMenu popup);

    /**
     * Append a separator line to current menu
     */
    public void AppendSeparator();
    
    /**
     * Show current menu
     */
    public void Popup();
}

The interface SystemTrayCallback is to receive System Tray event:

public interface SystemTrayCallback
{
    /**
     * If mouse event occurs, this method will be called.
     */
    public void OnMouseClick(SystemTray tray, int mouseEvent);
    
    /**
     * When popup menu selected.
     */
    public void OnMenuCommand(int menuid);
}

Demo Code

Typical usage of System Tray:

1. Call constructor to create a System Tray instance:

systemTray = new SystemTray(
    1,                     // 1 - the first 'icon image', 2 - the second, etc
    "Hello System Tray"    // the tips string
);

2. Create a menu instance:

systemTrayMenu = new SystemTrayMenu();
systemTrayMenu.Append("Hide", 1);
systemTrayMenu.AppendSeparator();
systemTrayMenu.Append("Exit", 2);

3. Set the System Tray event handler:

SystemTray.setSystemTrayCallback(new SystemTrayCallback() {
    
    public void OnMouseClick(SystemTray tray, int mouseEvent) {
        if(mouseEvent == SystemTray.RIGHT_CLICK) {
            systemTrayMenu.Popup();
        }
    }
    
    public void OnMenuCommand(int menuid) {
        if(menuid == 1) {
            systemTray.Hide();
        }
        else if(menuid == 2) {
            System.exit(0);
        }
    }
});

4. Show the System Tray:

systemTray.Show();

5. Call Hide on exit:

systemTray.Hide();

See Also

Add new comment