peerlist.java

J2ME MIDP_Example_Applications

//
// Copyright 2002 Nokia Corporation.
//
// THIS SOURCE CODE IS PROVIDED 'AS IS', WITH NO WARRANTIES WHATSOEVER,
// EXPRESS OR IMPLIED, INCLUDING ANY WARRANTY OF MERCHANTABILITY, FITNESS
// FOR ANY PARTICULAR PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE
// OR TRADE PRACTICE, RELATING TO THE SOURCE CODE OR ANY WARRANTY OTHERWISE
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// RIGHTS GRANTED HEREUNDER DOES NOT INFRINGE OR MAY NOT CAUSE INFRINGEMENT
// OF ANY PATENT OR OTHER INTELLECTUAL PROPERTY RIGHTS OWNED OR CONTROLLED
// BY THIRD PARTIES
//
// Furthermore, information provided in this source code is preliminary,
// and may be changed substantially prior to final release. Nokia Corporation
// retains the right to make changes to this source code at any time,
// without notice. This source code is provided for informational
// purposes only.
//
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// Corporation. Java and all Java-based marks are trademarks or registered
// trademarks of Sun Microsystems, Inc. Other product and company names
// mentioned herein may be trademarks or trade names of their respective owners.
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// A non-exclusive, non-transferable, worldwide, limited license is hereby
// granted to the Licensee to download, print, reproduce and modify the
// source code. The licensee has the right to market, sell, distribute and
// make available the source code in original or modified form only when
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//


import javax.microedition.lcdui.*;


class PeerList
     extends Form
     implements CommandListener, ItemStateListener
{
    private final ChatMIDlet parent;
    private final ChoiceGroup peers;
    private final Command okCommand, backCommand, newCommand;
    private final Command editCommand, removeCommand;

    private boolean isElementSelected = false;


    PeerList(ChatMIDlet parent, String[] peerNames)
    {
        super("Choose Peers");
        this.parent = parent;

        peers = new ChoiceGroup("", List.MULTIPLE, peerNames, null);
        append(peers);

        okCommand = new Command("OK", Command.OK, 1);
        backCommand = new Command("Back", Command.BACK, 2);
        newCommand = new Command("New", Command.SCREEN, 2);
        editCommand = new Command("Edit", Command.SCREEN, 2);
        removeCommand = new Command("Remove", Command.SCREEN, 2);
        addCommand(backCommand);
        addCommand(newCommand);

        setCommandListener(this);
        setItemStateListener(this);
    }


    void init(String[] names)
    {
        while (peers.size() > 0)
        {
            peers.delete(0);
        }
        for (int i = 0; i < names.length; i++)
        {
            peers.append(names[i], null);
        }
        elementUnselected();
    }


    public void itemStateChanged(Item item)
    {
        for (int i = 0; i < peers.size(); i++)
        {
            if (peers.isSelected(i))
            {
                if (!isElementSelected)
                {
                    elementSelected();
                }
                return;
            }
        }
        elementUnselected();
    }


    private void elementUnselected()
    {
        removeCommand(newCommand);
        removeCommand(okCommand);
        removeCommand(editCommand);
        removeCommand(removeCommand);
        addCommand(newCommand);
        isElementSelected = false;
    }


    private void elementSelected()
    {
        removeCommand(okCommand);
        removeCommand(editCommand);
        removeCommand(removeCommand);
        removeCommand(newCommand);
        addCommand(okCommand);
        addCommand(editCommand);
        addCommand(removeCommand);
        isElementSelected = true;
    }


    public void commandAction(Command c, Displayable d)
    {
        if (c == okCommand || c == removeCommand)
        {
            // get selected names and put them to an array
            int peerNum = 0;
            int i;

            for (i = 0; i < peers.size(); i++)
            {
                peerNum += peers.isSelected(i) ? 1 : 0;
            }

            String[] peerNames = new String[peerNum];
            int k = 0;

            for (i = 0; i < peers.size() && k < peerNum; i++)
            {
                if (peers.isSelected(i))
                {
                    peerNames[k] = peers.getString(i);
                    k++;
                }
            }

            if (c == okCommand)
            {
                parent.peerListDone(peerNames);
            }
            else
            {
                // removeCommand

                for (i = peers.size() - 1, k = peerNum; i >= 0 && k > 0; i--)
                {
                    if (peers.isSelected(i))
                    {
                        peers.delete(i);
                        k--;
                    }
                }
                elementUnselected();
                parent.peerListRemove(peerNames);
            }
        }
        else if (c == newCommand)
        {
            parent.peerListNew();
        }
        else if (c == editCommand)
        {
            int i = 0;

            for (; i < peers.size() - 1 && !peers.isSelected(i); i++)
            {
                ;
            }
            parent.peerListEdit(peers.getString(i));
        }
        else
        {
            // backCommand
            parent.peerListBack();
        }
    }


    public int size()
    {
        return peers.size();
    }
}