Discussion :

[QuentinS]

Hi all,

I am doing my first RCP application development using Lotus Expeditor.

Anyway, so far, here is what I have:
- A View (ViewPart) that displays a list of buttons depending on the content of a table in a database
- A class that is aware of the network status: when it detects that the application is online again, it will replicate the database (from a remote server, I am using DB2 Everyplace here)... that's working fine, but I would like also to refresh my View with the new data after replicating (without clicking on a "refresh" button on the view... I have tried this, and it's working fine, but I would like to have an automatic refresh).

So here are my questions:
- First, a design question: how should I do if I want a class to have access to my View? Indeed, my NetworkAwareImpl class needs to have access to it, but I can not pass the View object to the constructor the NetworkAwareImpl, since I create this object before creating the view (in the bundle activator class, so that the application is listening from the very start to the network status). So, what I did, is implement my View as a kind of singleton, so that my NetworkAwareImpl can call DesktopView.getDefault().updateView() for instance...

- Please take a look to my DesktopView class... for some reason, when I call the updateView method from my NetworkAwareImpl class, the method stops on the container.dispose() call... without any errors but it stops!

My DesktopView:

Code :

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public class DesktopView extends ViewPart implements SelectionListener{
 
	private MessageGeneratorSupport msgGenService;
	private DatabaseSupport dsService;
	private DatabaseSyncSupport dssService;
	private PreferencesService prefService;
 
	private static DesktopView view;
 
	private UI ui;
	private Composite parent;
	private Composite container;
	private boolean disposed = false;
 
	public DesktopView()
	{
		view = this;
		BundleContext context = Activator.getDefault().getContext();
		ServiceReference refMsgGen = context.getServiceReference(MessageGeneratorSupport.class.getName());
		msgGenService = (MessageGeneratorSupport) context.getService(refMsgGen);
		ServiceReference refDS = context.getServiceReference(DatabaseSupport.class.getName());
		dsService = (DatabaseSupport) context.getService(refDS);
		ServiceReference refDSS = context.getServiceReference(DatabaseSyncSupport.class.getName());
		dssService = (DatabaseSyncSupport) context.getService(refDSS);
		ServiceReference refPref = context.getServiceReference(PreferencesService.class.getName());
		prefService = (PreferencesService) context.getService(refPref);
	}
 
	public void createPartControl(Composite parent) {
		this.parent = parent;
		parent.setLayout(new FillLayout());
		Vector activities = new Vector();
		try
		{
			activities = dsService.getActivitiesList();
		}
		catch(Exception e)
		{
			System.err.println(e.toString());
		}
		createContainer(parent, activities);
	}
 
	public void createContainer(Composite parent, Vector activities)
	{	
		System.out.println("createContainer");
		if(parent.isDisposed())
		{
			System.out.println("HERE");
			return;
		}
		container = new Composite(parent, SWT.NONE);
		container.setBounds(parent.getBounds());
		GridLayout gl = new GridLayout();
		gl.numColumns = 1;
		container.setLayout(gl);
 
		for(int i=0; i<activities.size(); i++)
		{
			System.out.println(i);
			Button btn = new Button(container, SWT.NONE);
			btn.setText((String)activities.elementAt(i));
		}
 
		Button btn = new Button(container, SWT.NONE);
		btn.setText("refresh");
		btn.setData("button");
		btn.addSelectionListener(this);
 
		container.layout();
	}
 
	public void setFocus() {
		// TODO Auto-generated method stub
	}
 
	public void widgetDefaultSelected(SelectionEvent arg0) {
		// TODO Auto-generated method stub
 
	}
 
	public void updateView()
	{
		System.out.println("UpdateView");
		if(!isDisposed()) {
			if(!container.isDisposed())
			{
				System.out.println("about to dispose");
				container.dispose();
				disposed = true;
				System.out.println("Disposed");
			}
		}
 
		Vector activities = new Vector();
 
		System.out.println("new Vector");
 
		try
		{
			activities = dsService.getActivitiesList();
		}
		catch(Exception e)
		{
			System.err.println(e.toString());
		}
 
		createContainer(parent, activities);
		disposed = false;
	}
 
	public void widgetSelected(SelectionEvent e) {
		if(((String) e.widget.getData()).equals("button")) {
			if(!isDisposed()) {
				updateView();
			}
		}	
	}
 
	public boolean isDisposed()
	{
		return disposed;
	}
 
	public void dispose() {
		disposed = true;
		super.dispose();
	}
 
	public static DesktopView getDefault()
	{
		return view;
	}
}

Note: for now, I added a refresh button, and this is working fine.

And my NetworkAwareImpl :

Code :

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public class NetworkAwareImpl implements INetworkAware {
 
	IOfflineServiceHelper _helper; 
	private DatabaseSyncSupport dssService;
	private DatabaseSupport dsService;
	private PreferencesService prefService;
 
	public NetworkAwareImpl()
	{
		BundleContext context = Activator.getDefault().getContext();
		ServiceReference refDS = context.getServiceReference(DatabaseSupport.class.getName());
		dsService = (DatabaseSupport) context.getService(refDS);
		ServiceReference refDSS = context.getServiceReference(DatabaseSyncSupport.class.getName());
		dssService = (DatabaseSyncSupport) context.getService(refDSS);
		ServiceReference refPref = context.getServiceReference(PreferencesService.class.getName());
		prefService = (PreferencesService) context.getService(refPref);
	}
 
    public INetworkAware init() {
        _helper = IOfflineServiceHelperFactory.INSTANCE.create(this);
        return this;
    }
	public IOfflineServiceHelper getOfflineServiceHelper() {
            return _helper;
    }
 
		public void disconnected(){
			System.out.println("DISCONNECTED");
            //do things accordingly if the system state changed to offline. e.g if the network connectivity is lost.
            //e.g if application calls IOfflineManager.disconnected(), IOfflineManager will
            // fire an DISCONNECTED event, which directly call INetworkAware.disconnected() method here.
            // no intermediate states.
    }
 
    public void reconnected(){
    	System.out.println("RECONNECTED");
            //do things accordingly if the system state changed to online.e.g. if the network connectivity is back.
            //e.g if application calls IOfflineManager.reconnected(), IOfflineManager will
            // fire an RECONNECTED event, which directly call INetworkAware.reconnected() method here.
            // no intermediate states.
    	dssService.synchronizeDatabase(prefService.getUsername(), prefService.getPassword(), prefService.getHost());
    	System.out.println("replicated");
    	DesktopView.getDefault().updateView();
    }
...

Last question: is it ok to invoke other plugins in the DesktopView, as I did it? Since it's a view, it doesn't look nice to me... can you advice me also on this?

Thanks a LOT !

[QuentinS]

LOL je viens de voir que j'avais posté cette question en anglais, sur une forum plutot français... désolé, déformation professionnelle!

Si quelqu'un a besoin de la traduction pr me répondre... je la lui donnerai volontiers

Merci!