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Moxieapps file uploader for GWT adding multiple upload buttons

The GWT web app I'm building has a page where users can upload CSV files. The upload code uses the Moxieapps GWT Uploader, which mostly works great.
However, I've discovered a strange scenario, where navigating away from the page and back to it adds the upload button again. So the third time I visit the page, the upload section will look like this:
And the relevant part of the generated HTML viewed in an inspector shows that both the input and the div containing the "button" get added over and over (though there is only ever one dropzone):
I've gone over my code many times to see whether I was doing something that could be causing this, but haven't found anything. You don't actually manually add the button or the input; this is done automatically by the framework. The fileUploader gets initialised only once (this being GWT client code, I've debugged using the inspector as well as logging statements to the console to confirm this):
fileUploader.setButtonDisabled(true).setFileTypes("*.csv")
.setUploadURL(getBaseUrl() + "/fileUpload.upload")
.setButtonText("<span class=\"buttonText\">Select CSV file to upload</span>")
.setFileSizeLimit(FILE_SIZE_LIMIT)
.setButtonCursor(CustomUploader.Cursor.HAND)
.setButtonAction(CustomUploader.ButtonAction.SELECT_FILE)
.setUploadProgressHandler(new UploadProgressHandler() {...})
.setUploadSuccessHandler(...)
// etc. with other handlers
The method setButtonText() is called from a couple of other places, and the text changes as it should, but only on the last button (if there are several). Otherwise, there's nothing in my code that could possibly be adding the button as far as I can tell.
Has anyone else encountered this issue? Is there some property I need to set to prevent this? Could it be a bug in the moxieapps code?

After writing out my question, and adding "Could it be a bug in the moxieapps code?" at the end, I followed up on that suspicion, and it turns out that it is indeed a bug in the org.moxieapps.gwt.uploader.client.Uploader class.
The input and the "select file" button are added in the onLoad() method of that class without a check whether they may have been added already.
It looks like there hasn't been any active development on this framework for some time, so I thought it was time for a custom override version. I've tested this and it works:
package yourpackagename.client.override;
import java.util.Iterator;
import org.moxieapps.gwt.uploader.client.Uploader;
import com.google.gwt.user.client.ui.FileUpload;
import com.google.gwt.user.client.ui.Widget;
import com.google.gwt.user.client.ui.WidgetCollection;
/**
* The sole reason this class exists is to fix a bug in the moxieapps uploader
* (org.moxieapps.gwt.uploader-1.1.0.jar) where it adds a new upload input and
* button each time its <code>onLoad()</code> method is called, i.e. every time
* you navigate away from the page and then back to it.
*/
public class CustomUploader extends Uploader {
#Override
protected void onLoad() {
boolean hasFileUploadAlready = false;
WidgetCollection children = getChildren();
for (Iterator<Widget> iterator = children.iterator(); iterator.hasNext();) {
Widget eachWidget = iterator.next();
if (eachWidget instanceof FileUpload) {
hasFileUploadAlready = true;
}
}
// Only call the super method if there isn't already a file upload input and button
if (!hasFileUploadAlready) {
super.onLoad();
}
}
}
Instead of referencing the org.moxieapps.gwt.uploader.client.Uploader, I've changed the references to point to my custom uploader class, which will now check for an existing FileUpload child widget, and simply skip the original onLoad() code if it finds such a widget.
Might be a bit of a crowbar approach, but it works (and in my case, changing the maven-managed JAR file is not very practical). Hopefully, this will be useful to anyone else coming across this problem.

Set Canvas to Eclipse View?

I've created an (empty until now) View in my Eclipse Plugin. I'm also using Eclipse Cloudio. This library provides the following object (description taken from the linked site):
A TagCloud is a special org.eclipse.swt.widgets.Canvas, dedicated to display a tag cloud.
Basically it's an image showing a WordCloud. Now there are snippets on the site on how to show such TagClouds in a shell / popup.
But I'd like to show them in a view (this function is supposed to be used often and I think it's bad style to spam popup-windows).
What I do not know tho is how to set this TagCloud (which is a Canvas) to the View / make the View display the Canvas. Maybe someone can help me with this?
Edit:
gregs Answer works like a charm! It just needs another setWords() function which is called from where-ever which contains .setWords to set the words when neccessary.

You just need to add the control to the view in the view createPartControl. At the simplest that would be:
#Override
public void createPartControl(final Composite parent)
{
TagCloud cloud = new TagCloud(parent, SWT.NONE);
... set up the cloud as in the example
}

How enable or disable correctly an Action

i have a little problem when i try to disable an Action of my Netbeans platform project. When the app starts, some Actions must be disabled, and i do that with this method:
CallableSystemAction.get(BuildProjectAction.class).setEnabled(FLAG);
It works, because the BuildProjectAction is disabled, but the corresponding items of the MenuBar and the Toolbar remains enabled until i click on one of it.
Only later that i have clicked on it, the comportament start to work correctly.
First question: Why?
If i want disable an Action, it's obvious that i want disable also the relative Icon in the Menu and in the Toolbar, so it must be automatic when i call Action.setEnabled(false).
It doesn't have sense that the Icons are not refreshed if i don't click on they.
Same problem if i try to use .getToolbarPresenter().setEnabled(false); and .getMenuPresenter().setEnabled(false);
For start the application with the icons disabled, I have tried to set the lazy attribute to FALSE and declare the image programmatically with the method setIcon(new ImageIcon(image)); that sets the same image for Menu and Toolbar.
And it works; there is only another problem: Menu and Toolbar have icons of different size (16x16 and 24x24).
It doesn't have sense that the if i set the icon with the #ActionRegistration(iconBase = "image.png") the correct icon is automatically selected, but if i use the method .setIcon(), it doesn't.
I have read some articles about Action, CookieAction, Lookup, but the only thing that i want is disable the graphic elements in the same moment when i disable the Action.
Second question: How i can do that?
This is an example of my Action.
#ActionID(
category = "Run",
id = "BuildProjectAction")
#ActionRegistration(
lazy = true,
iconBase = "images/icons/compile.png",
displayName = "#CTL_BuildProjectAction")
#ActionReferences({
#ActionReference(
path = "Menu/Run",
position = 3),
#ActionReference(path = "Toolbars/Run",
position = 3),
#ActionReference(
path = "Shortcuts",
name = "D-B")
})
#Messages("CTL_BuildProjectAction=Build Project")
public final class BuildProjectAction extends CallableSystemAction {
#Override
public void actionPerformed(ActionEvent e) {...}
#Override
public void performAction() {}
#Override
public String getName() {
return Bundle.CTL_BuildProjectAction();
}
#Override
public HelpCtx getHelpCtx() {
return HelpCtx.DEFAULT_HELP;
}
Thanks

The easiest way to create an action that is disabled at startup is to use the platform’s New Action Wizard to create your action, and to create one that depends on a "context" -- this is, on finding a specific object in the global lookup. If no object is available in the lookup, as at startup, then the action will be disabled.
The menu and toolbar graphic elements are bundled together with your action via the annotations. This means that enabled/disabled state of your context-aware action will automatically affect the icons in the menu and toolbar as well.
This article by Geertjan Wielenga has a walkthrough on creating a context-aware action:
http://netbeans.dzone.com/how-to-make-context-sensitive-actions
When you want to enable your action, you will add the object on which the action depends into the global lookup, which will cause the action (and its graphic elements) to be enabled.
This entry in the platform’s Developer FAQ has some examples of how to add an object to the global context:
http://wiki.netbeans.org/DevFaqAddGlobalContext
If you need to create an action that depends on a more complex set of conditions there is some discussion, as well as a code sample illustrating how to do this, in this platform developer list thread:
http://forums.netbeans.org/ptopic55295.html
The grayed-out versions of the icons that are shown when your action is disabled are created automatically by the platform. You only have to provide the "normal" non-grayed-out images.
As for the icons of different sizes, it’s a matter of filename convention. If your annotation declares the icon with #ActionRegistration(iconBase = "image.png”), then you will provide a 16x16 image called “image.png” and a 24x24 version called “image24.png”. The platform will find and use the appropriate size in the menu and toolbar.

Custom message when closing a part in Eclipse RCP 4

we have the following problem:
In our Eclipse RCP 4 application there are multiple parts and the parts are closable. When the user is closing a part there should be a custom pop-up (depending on some internal part state) which is asking the user if he really wants to close the part or not.
It seems to be not that easy to implement in Eclipse RCP 4 or we have just totally overseen something.
I'll just give you a short brieifing about the things we tried:
Use dirtable with a #persist method in the part. Though the problem is, we don't want this standard eclipse save dialog. So is there a way to override this?
public int promptToSaveOnClose(): This seemed to be promising but not for Eclipse 4 or is there a way to integrate it that way? Compare: http://e-rcp.blogspot.de/2007/09/prevent-that-rcp-editor-is-closed.html
Our last try was to integrate a custom part listener, simple example shown in the following:
partService.addPartListener(new IPartListener() {
public void partVisible(MPart part) {
}
public void partHidden(MPart part) {
partService.showPart(part, PartState.ACTIVATE);
}
public void partDeactivated(MPart part) {
}
public void partBroughtToTop(MPart part) {
}
public void partActivated(MPart part) {
}
});
The problem with this was we are running into a continuous loop. Something similar is posted over here in the last comment: Detect tab close in Eclipse editor
So I could write some more about this problem, but I think that's enough for the moment. If you need some more input just give me a hint.
Thanks for helping.

The save prompt is generated by the ISaveHandler registered in the context of the MWindow containing the MPart. You can write your own ISaveHandler and set it in the window context to replace the default.
You might also want to look at the IWindowCloseHandler also in the window context.

Thanks greg, this has helped and I was able to achieve changing the pop-up when the user closes a part. Here's a short description of what I've done:
Use the MDirtyable for marking the part as dirty whenever it's needed.
Create a custom save handler which implements ISaveHandler (when a part got closed the save method is called). Add the additional logic to this handler (e.g. a custom message dialog)
Register this handler at application start-up (I just chose a method which is called at the start-up):
#Inject
private MWindow window;
...
ISaveHandler saveHandler = new CustomSaveHandler(shell);
window.getContext().set(ISaveHandler.class, saveHandler);
Note that the registration via a model processor was sadly not that easy because the model processor is called too early. (Take a look at: http://www.eclipse.org/forums/index.php/t/369989/)
The IWindowCloseHandler is just needed when the complete window is closed, though this was not an requirement for us :).

SWT, Maintain default tab ordering when adding Key Listner

I've been creating a custom TabFolder extension that adds a key listener to allow quick tab switching using an ALT + # hotkey.
By adding the KeyAdapter to my TabFolder, the event handler works properly only when you have a tab header selected (in which case the ALT + ARROW_LEFT/ARROW_RIGHT also work.). I need this hot key to be active when any Widget with-in the TabFolder is active; however, it shouldn't be active if the selection is in a different tab folder or widget outside of a tab folder.
In an attempt to solve this, I wrote a simple recursive function to apply the key listener to all of the children of the tab folder:
public void applyQuickSwitchKeyBindings() {
removeKeyListener(ka);
addKeyListener(ka);
for(Control c: getChildren())
applyQuickSwitchKeyBindingsToChildren(c);
}
private void applyQuickSwitchKeyBindingsToChildren(Control c) {
if(c==null) return;
if(c instanceof Composite) {
Control[] controls = ((Composite)c).getChildren();
for(Control c2: controls)
applyQuickSwitchKeyBindingsToChildren(c2);
if(controls.length < 1) {
c.removeKeyListener(ka);
c.addKeyListener(ka);
}
}
}
Then i call the applyQuickSwitchKeyBindings() after I add the controls to each TabItem in the tab group.
The good news was that the quick switch hot key (ALT + #) worked great!
The bad news was that the original TAB ordering based on z-index is now gone. When you hit the SWT.TAB key you lose focus on your current text box and don't gain focus on anything else...
Questions:
1.) Can each control only have one KeyListener?
2.) Why is the original TAB traversal not working anymore?
Thanks in advance!

to 1) I'm pretty sure that more than one KeyListener is allowed.
to 2) I'm not sure, that depends on what you're doing in your KeyAdapter. Maybe you can post that too?
I just the tab order is broken somehow, you can reset ( or change ) it with a call to setTabList( Control[] ).
setTablList( new Control[] {
control1,
control2,
control3,
....
} );

So after more time learning and developing with SWT i've discovered my problem. When you add a listener it is applied to the widget/control you call the addXXXListener function on. So if that control is not active the listeners will not be fired.
The solution seems to be SWT's global Filter mechanism which allows you to add global application(Display) scope listeners.
Display.getCurrent().addFilter(SWT.keyPress, new KeyPressListener());
Pardon the incorrectness of this line, but if you google it you'll see what i mean.
I have also read to use this sparingly.