IconEditApp.java

// Copyright (c) 2015 Andrzej Borucki, see LICENSE file
package com.blogspot.borneq;

import java.util.ArrayList;
import java.util.List;

import org.eclipse.swt.widgets.Display;

/**
 * Start application class with static {@code main} method
 * which creates {@code Display} object and call main window constructor
 * @author Andrzej Borucki
 * @version 1.0
 * @since   2015-07-13
 */
public class IconEditApp {
    static private List<ShellMain> shellList;
    private static Display display;
    static public void registerShell(ShellMain shell) {
        shellList.add(shell);
    }

    static private int getWaitingShellCount()
    {
        int countWaiting = 0;
        int startSize = shellList.size();
        //this for loop it gives me more control than
        //for (: shellList) where was error for empty list
        for (int i=startSize-1; i>=0; i--)
        {
            ShellMain shell = shellList.get(i);
            if (!shell.isDisposed())
                countWaiting++;
            else
                shellList.remove(i); //enable GC dispose memory
        }
        return countWaiting;
    }

    static private void startEventLoop() {
        while (getWaitingShellCount()>0) {
            if (!display.readAndDispatch())
                display.sleep();
        }
    }

    /**
     * Entry point of application
     * @param args list of arguments
     */
    public static void main(String[] args) {
        shellList = new ArrayList<ShellMain>();
        display = new Display();
        registerShell(new ShellMain());
        startEventLoop();
        display.dispose();
    }
}