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
}
Related
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.
Does anybody have an idea on how I can accomplish this using Wicket?
I want to display a Wicket odal window automatically when no user activity has been detected for a certain amount of time. I'm thinking of using an AjaxSelfUpdatingBehavior in some way, but I have no clear ideas actually.
Is this possible with Wicket?
Also, you can use some js library not to catch all ajax calls and to be sure, that your user is really afk (even does not touching his mouse).
For example, see this free framework and it's demo.
And (if you using this js framework) in wicket you must handle
ifvisible.idle(function(){
Wicket.Ajax.get({u: '${callbackUrl}'})// This code will work when page goes into idle status
});
You must set ${callbackUrl} from wicket code to let js know what action to proceed in java code. It is not hard to do this. Look here.
This approach is more tricky, but if you implement this, you don't have to worry about users actions at all (he can read site's info and don't click any ajax links, but suddenly he will see modal window).
Yes you can, I use this as autologout function
public class MyTimer extends AbstractAjaxTimerBehavior {
public MyTimer(int seconds) {
this(Duration.seconds(seconds));
}
#Override
protected void onTimer(AjaxRequestTarget target) {
// show your window magic
}
}
Add this to you page (add(new MyTimer(300));) and this will be called after the number of seconds you specify. Make sure to replace the timer with a new one when doing ajax calls, or reset it.
I know there are some questions out there about the GWT ScrollPanel and how it works, but allow me to explain the situation.
I'm working on a project to implement QoS on routers. I'm now at the developping stage of the project and I need to make a webinterface to add protocols such as ssh and http and give them their bandwidth.
To save memory usage and network traffic, I do not use GWT-EXT or Smart GWT. So to set the bandwidths I use a ScrollPanel with an empty SimplePanel in it (which is way too big), leaving only the scrollbar.
Now here's the problem:
I want each scrollbar for each added protocol to start at the bottom, not the top. I can get it working through the code if I manually move the scrollbar first, then any function works, like a scrollToBottom(), or a setScrollPosition(). If I want to move scrollbars through code before moving the scrollbar manually, however, I can't call a function on it.
(I would post a picture but I can't yet - new user)
Summary:
So if I add a protocol (using a button called btnAjouter), the two slidebars (One for guaranteed bandwidth and one for the maximum bandwidth) for each protocol start at the top. I want them to start at the bottom on the load of the widget.
Is there a way to do this?
Thanks in advance!
Glenn
Okay, my colleage found the solution. It's a rather dirty one, though.
The thing is, the functions only work when the element in question is attached to the DOM. I did do a check with a Window.alert() to see if it was attached, and it was. But the prolem was that the functions were called to early, for example on a buttonclick it would've worked. The creation and attachment of the elements all happens very fast, so the Javascript can't keep up, this is the solution:
Timer t1 = new Timer()
{
#Override
public void run()
{
s1.getScroll().scrollToBottom();
s2.getScroll().scrollToBottom();
}
};
t1.schedule(20);
Using a timer isn't the most clean solution around, but it works. s1 and s2 are my custom slidebars, getScroll() gets the ScrollPanel attached to it.
You can extend ScrollPanel and override the onLoad method. This method is called immediately after a widget becomes attached to the browser's document.
#Override
protected void onLoad() {
scrollToBottom();
}
Could you attach a handler to listen to the add event and inside that handler do something like this:
panel.getElement().setScrollTop(panel.getElement().getScrollHeight());
"panel" is the panel that you add your protocol to. It doesn't have to be a ScrollPanel. An HTMLPanel will work.
You can wrap this method in a command and pass it to Schedule.scheduleDeferred if it needs to be called after the browser event loop returns:
Schedule.scheduleDeferred(new Scheduler.ScheduledCommand(
public void execute() {
panel.getElement().setScrollTop(panel.getElement().getScrollHeight());
}
));
As we are facing GWT performance issues in a mobile app I peeked into Google Wave code since it is developed with GWT.
I thought that all the buttons there are widgets but if you look into generated HTML with firebug you see no onclick attribute set on clickable divs. I wonder how they achieve it having an element that issues click or mousedown events and seemingly neither being a widget nor injected with onclick attribute.
Being able to create such components would surely take me one step further to optimizing performance.
Thanks.
ps: wasnt google going to open source client code too. Have not been able to find it.
You don't have to put an onclick attribute on the HTML to make it have an onclick handler. This is a very simple example:
<div id="mydiv">Regular old div</div>
Then in script:
document.getElementById('mydiv').onclick = function() {
alert('hello!');
}
They wouldn't set the onclick property directly, it would have been set in the GWT code or via another Javascript library.
The GWT documentation shows how to create handlers within a GWT Java app:
public void anonClickHandlerExample() {
Button b = new Button("Click Me");
b.addClickHandler(new ClickHandler() {
public void onClick(ClickEvent event) {
// handle the click event
}
});
}
This will generate an HTML element and bind a click handler to it. However, in practice this has the same result as using document.getElementById('element').onclick() on an existing element in your page.
You can hook functions to the onclick event using JavaScript. Here's an example using jQuery:
$(document).ready(function(){
$("#div-id").click(function(){
/* Do something */
});
});
If you're interested in optimizing performance around this, you may need to investigate event delegation, depending on your situation.
A click event is generated for every DOM element within the Body. The event travels from the Body down to the element clicked (unless you are using Internet Explorer), hits the element clicked, and then bubbles back up. The event can be captured either through DOM element attributes, event handlers in the javascript, or attributes at any of the parent levels (the bubbling or capturing event triggers this).
I'd imagine they've just set it in a .js file.
Easily done with say jQuery with $(document).ready() for example.
im new to GWT ive been working on it since recently..
i want to know how can i go from "entry point page" ie,ImageViewer.java..
ive been suggested to create the memory by calling constructor on a perticular button
Button button = new Button("New button");
button.addClickHandler(new ClickHandler() {
public void onClick(ClickEvent event)
{
new LookupMaster(); //this is a composite
}
});
but this is not working.. i guess v can only call or get alert messages using this type..
can some one help me.
I'm not sure how to answer, since I have the feeling you're not understanding the basic concepts totally, but that's just my interpretation.
GWT is one html page that via JavaScript methods changes the content of that one page. When you want to display 'another' page you need to do this via methods that update the html dynamically. Since you are just starting with GWT, you might want to read this page on Build User Interfaces to understand the concepts and look at some examples provided with GWT.