Eclipse RAP multi-window/tab - eclipse

I would like to have a multi-tab/windowed Eclipse RAP application.
I am able to open a second window using
UrlLauncher launcher = RWT.getClient().getService(UrlLauncher.class);
launcher.openURL("/gasf?foo=other_perspective");
Where I use the foo paramter to select the perspetive I want. However using this method will create a speparate http session, thus the various listeners and so on won't communicate with my first window.
I also tried opening a second window/page using
PlatformUI.getWorkbench().getActiveWorkbenchWindow().openPage("other_perspective" , null);
But this merely changes the current window perspective but does not open a second window or tab in my browser.
Has anyone achieved a multi-tab RAP application with working selectionlisteners between the tabs?
Thanks for any help you can provide
EDIT:
THANKS a lot ralfstx, as you pointed out, I can share the listeners or anything using the shared HTTP session, so far so good. Now the next step is to be able to update a tab based on an external event.
To try my idea of refresh from another tab, I did a dummy timer that does something 2 seconds later (i.e. simulate something triggered from another tab) with:
final ServerPushSession pushSession = new ServerPushSession();
pushSession.start();
Display display = Display.getDefault();
NavigationView navigationView = ((NavigationView) window.getActivePage().findView(NavigationView.ID));
timer.schedule(new TimerTask() {
#Override
public void run() {
display.asyncExec(new Runnable() {
public void run() {
navigationView.doSomething();
}
});
}
}, 2000);
This works! The pushSession.start() forces the UI to refresh without any user interaction. So now the action doSomething() is executed on the navigationView as soon as the 2 seconds are reached.
My only remaining concern is how much load this puts on the server, but its a reasonable solution at least. I validated your answer.
EDIT2:
Just to be complete, to make sure not bump in an invalid Thread access error since we are updating a display from another display, in the doSomething() method we must execute actions using display.asyncExec:
Display display = Display.getCurrent();
public void doSomething() {
display.asyncExec(new Runnable() {
public void run() {
treeViewer.refresh();
}
});
}

With the current architecture of RAP, you can't spread workbench windows over different browser tabs. Every new browser starts a new UISession which implies another Display (see Scopes in RAP).
However, the HttpSession should be the same (unless you have cookies turned off), so you could use this as a means of communicating between different browser tabs.

Related

How to close a dialog in code?

So I'm making a eclipse plugin and I have a made my own dialog by extending the dialog class.
My dialog basically populates a treeview with data from a server. Sometimes the data cannot be populated (because the server is down) so my treeview is empty.
I have made another dialog appear reporting the error if I am unable to connect to the server.
My problem is that I would like to close the initial dialog when I press ok in the error dialog.
I have not been able to find a good way to do this.
I have tried setting setBlockOnOpen to false.
I have tried calling cancelPressed.
Neither of them have worked.
I called them in the createDialogArea function.
Any Ideas on how I could get this to work?
It is basically user cancelling dialog. you need to invoke cancelPressed() so it will be consistent handling if you have any code that depends on returnCode
if(noDataLoaded){
Display.getDefault().asyncExec(new Runnable() {
public void run() {
cancelPressed():
}
});
}
You need to do the close call after the dialog creation has finished. You can do this by using this code:
parent.getDisplay().asyncExec(new Runnable()
{
#Override
public void run()
{
close();
}
});
in your createDialogArea method. However the dialog may appear briefly. It would be better to do your check before creating the dialog.

Eclipse: Converting actions in commands for a specific view

My original RCP was started in 3.x and currently I am running it on Juno with the compatibility layer. I was looking into doing a soft migration so I have started to slowly change my practices. One of the things I am doing is to change my actions into commands.
I have a view (which is like a directory explorer) currently that adds actions to the toolbar and popup menu of the view. These actions call specific methods in the view, for example to go up one directory.
It was easy to do this by action because I just create my action in the View class itself and programmatically add them to the toolbar
IToolBarManager mgr = getViewSite().getActionBars().getToolBarManager();
mgr.add(upDirectory);
mgr.add(refresh);
mgr.add(changeRoot);
and the creation of the actions are called from the createPartControl()
upDirectory = new Action("Go up one directory") {
public void run() {
goUpOneDirectory();
}
};
where goUpOneDirectory() is a method in the view
If I want to convert this to a command, I want to be able to access this method of the view in my handler. So I tried the following,
private void createHandlers()
{
IHandlerService handlerService = (IHandlerService) getSite().getService(IHandlerService.class);
IHandler upDirHandler = new AbstractHandler() {
public Object execute(ExecutionEvent event)
throws ExecutionException {
goUpOneDirectory();
return null;
}
};
handlerService.activateHandler("updir.id", upDirHandler);
}
And createHandlers is called in the createPartControl, and the command is added via the plugin.xml to the toolbar of the view. The problem is that the moment my view is out of focus it disables the buttons in the toolbar for these commands.
I want them to remain enabled at all times. How can I do that?
I know that the isEnabled() returns true all the time so I am not sure why it happens. The activateHanlder is called once in createPartControl so I feel that it should remain active all the time.
Edit: Ok I just saw this ,
IHandlerService from the workbench part site is the part handler
service. Any handlers activated through the part handlers service will
only be active when that part is active. Any listeners added to the
part handler service will be removed when the part is disposed, and
any active handlers will be deactivated (but not disposed).
So how can I get this,
IHandlerService from the workbench is the global handler service. it
provides no special activation scoping or lifecycle.
Sorry, I should have waited a bit longer before asking, I figured it out!
I changed the,
IHandlerService handlerService = (IHandlerService) getSite().getService(IHandlerService.class);
to
IHandlerService handlerService = (IHandlerService) PlatformUI.getWorkbench().getService(IHandlerService.class);
and it worked.
I will leave the question in case it helps other people.

Change opacity of a TreeItem

I have a server and client using gwt.
In my client page i have a tree item displayed.
I want to do one of the following:
- disable the tree item when a function is called.
- made opaque the entire client page or only the tree item when a function is called.
By made opaque, i want to do the same as occur when i debug my project with eclipse and i stop and i get the following in the client page
GWT Code Server Disconnected
Most likely, you closed GWT Development Mode. Or, you might have lost network connectivity. To fix this, try restarting GWT Development Mode and REFRESH this page.
Please give me some indication on how to do it and if it is possible.
you create a handler for you function call(s) and add the style when the funciton is called. Because GWT works with javascript it changes your appearance during runtime.
item.addClickHandler(new ClickHandler() {
public void onClick(ClickEvent event) {
event.getItem().setStyleName("newStyle");
}
});
and in the css you define you style:
newStyle: {
...
your style definition
}

Using GWTs activities and places can I navigate to a previous page without using History.back()?

I am using GWTs Activities and Places pretty much as described on http://code.google.com/webtoolkit/doc/latest/DevGuideMvpActivitiesAndPlaces.html and it is all working fine.
What I would like to do is from a particular page navigate to the previous page without using History.back() as I don't want to lose the history state. (I have a page where the user performs an action, on success I want to return to the previous page and keep the history state, on the other hand if they cancel I do want to use History.back() as I do want to lose the state).
The only way I can think of to do this is to create my own Place/History tracking code that listens to Place/History change events and makes the previous Place available to me so that I can call placeController.goto(...)
Is there an easier way of doing this? Am I missing something?
The approach I took was to store the history token in code (as suggested). I extended PlaceController and used it to track Place changes on the EventBus. Now everywhere I was using PlaceController I instead use PlaceControllerExt which has a nice previous() method that takes me back to where I came from - but navigates forward and never leaves the application.
public class PlaceControllerExt extends PlaceController {
private final Place defaultPlace;
private Place previousPlace;
private Place currentPlace;
public PlaceControllerExt(EventBus eventBus, Place defaultPlace) {
super(eventBus);
this.defaultPlace = defaultPlace;
eventBus.addHandler(PlaceChangeEvent.TYPE, new PlaceChangeEvent.Handler() {
public void onPlaceChange(PlaceChangeEvent event) {
previousPlace = currentPlace;
currentPlace = event.getNewPlace();
}
});
}
/**
* Navigate back to the previous Place. If there is no previous place then
* goto to default place. If there isn't one of these then it'll go back to
* the default place as configured when the PlaceHistoryHandler was
* registered. This is better than using History#back() as that can have the
* undesired effect of leaving the web app.
*/
public void previous() {
if (previousPlace != null) {
goTo(previousPlace);
} else {
goTo(defaultPlace);
}
}
}
You have to somehow keep track of were to return, because instead of cancel the user can hit the back button, which would be the same as clicking cancel, except there is no code in your application executed, so you have no control.
Secondly if you have the history in the url, the user could navigate directly to that page and then you should know where to go to when the user click ok. Or if the user goes directly to the page, redirect the user to another page.
One approach is to store the return history token in the history token of the page you go to. When the page is finished it can go back(or technically it would be 'go forward') to that page based on the passed return token. (Although with GWT you could easily store the history token in code).

Best Practices GWT Event Handling

I have a question regarding the event handling on client side in GWT.
In our application we have a quite complex structure of different modules and pages which are communicating via the gwt eventbus on client side. Now the amount of events is growing to fast for my opinion. E.g. I am opening a popup I need:
An event for opening the popup
An event for asking some data within the client
An event for getting back the data and fill in the dialog
An event for closing the popup
An event for handling the save Button
Am I thinking a little bit to complicated or missing something in the EventBus implementation? I just wanted to have some feedback out of the community as you are facing the same issues.
For what it's worth, I have lots of events and more growing. And yes, I wonder if I can do with less, but when I skip an event and link elements directly, I regret it.
Here's an example that I just fixed up yesterday. I have a DataGrid widget. I also support re-ordering of columns, hiding of columns, re-sizing columns, and coloring columns with a popup dialog. You click on a configure button, and a popup with the columns listed shows, and the user can click checkboxes to show or hide columns, click on a Move Up / Move Down button to re-order columns, and so on. Hit Apply on the popup and the popup disappears and the DataGrid re-configures.
Except that it didn't. You'd click on Apply and the popup would just sit there, the user would wonder what was going on, the DataGrid would re-configure underneath, and then the popup would go away. We're only talking a short amount of time -- maybe a second or a bit more -- but it was so so noticeable. Why was it happening? Because I got lazy and tied the popup directly to the configure button, and the Apply button directly to the DataGrid. You'd hit Apply, for example, and the call would be made to the DataGrid with the new configuration information. Only when the call returned would the popup would be torn down.
I knew it was bad when I did it, but I was being lazy. So I took the 20 minutes I needed to write up two messages and associated handlers in my mediator singleton. One message is issued by the DataGrid to start the configuration dialog, and one is issued by the popup to configure the DataGrid. Now the widgets are de-coupled, and the performance is much snappier. There is no sense of "stickiness".
Now to your example, can you not combine (1) and (2)? And also (3), (4), and (5)? When the user clicks the configure button on my app, the event carries with it the current configuration information (including a reference to the DataGrid that originated the request). You can call this information the "payload". When the user clicks the Apply button on the popup, the event payload includes all the new configuration information (including a reference to that original target DataGrid) that the event handler feeds to the target DataGrid when the event is handled. Two events -- one to kick off the configuration and one to apply the end result.
Yes there are a plethora of events in any app that does something interesting, but events can carry a lot of information, so I would look at whether your event organization is too fractured.
As a extra bit, here is the code I use. I shamelessly copied elements of this pattern from one of Google's examples.
The user can ask for help using a menu item:
#UiField
MenuItem help;
help.setCommand(new Command() {
#Override
public void execute() {
BagOfState.getInstance().getCommonEventBus().fireEvent(new MenuHelpEvent());
}
});
For the event (in this case, the event fired when the user clicks on the Help menu item):
public class MenuHelpEvent extends GwtEvent<MenuHelpEvent.Handler> {
private static final Type<Handler> TYPE = new Type<Handler>();
public interface Handler extends EventHandler {
void doMenuHelp();
}
#Override
public GwtEvent.Type<Handler> getAssociatedType() {
return TYPE;
}
#Override
protected void dispatch(Handler handler) {
handler.doMenuHelp();
}
public static HandlerRegistration register(EventBus eventBus, Handler handler) {
return eventBus.addHandler(TYPE, handler);
}
}
I have a singleton called Mediator in which ALL events are registered:
MenuHelpEvent.register(BagOfState.getInstance().getCommonEventBus(),
new MenuHelpEvent.Handler() {
#Override
public void doMenuHelp() {
new MenuHelp().execute();
}
});
Every event is mated with a Command object to do the work:
public class MenuHelp implements Command {
#Override
public void execute() {
new InfoMessage(BagOfState.APP_MSG.unimplementedFeatureCaption())
.setTextAndCenter(BagOfState.APP_MSG.unimplementedFeature());
}
}
Everything is decoupled. The menu widget is bound to a command that executes and then completes. The command fires the event on the bus then completes. The event fires off the execution of a Command and the completes. The Command shows the popup help panel (in this case, an "unimplemented" message to the user -- yeah, I'll get to it soon). Every interaction with a user's input is handled extremely quickly and resolves. It can kick off a series of events to perform a long action, but never tying up the GUI to do so. And of course, since the elements are decoupled, I can call the same elements in other places (for instance, call the help Command through a button push as well as a menu item).