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Add menu item to menu at runtime [message #881071]

Sun, 03 June 2012 16:46

Eclipse User

Hello,

I need to create a submenu which is filled with elements at runtime.

I didn't find any examples or any easy way to do it, so I've implemented it via a crude "iterate over menus to find the correctly named menu, and then add MMenuElements to it".

Corresponding code in the handler:

@PostConstruct
	public void init() {
		for (final String filename : Constants.recentlyUsedFilesList) {
			DynamicMenuHelper.addMenuItemToMenu(application, "recentfiles.menu", 
					filename, "bundleclass://handlers.file.RecentFilesHandler");
		}	
	}

@PreDestroy
	public void cleanup() {
		for (final String filename : Constants.recentlyUsedFilesList) {
			DynamicMenuHelper.removeMenuItemFromMenu(application, "recentfiles.menu", filename);
		}
	}

This correctly adds the MMenuElements to the menu and seemingly also removes them, but obviously the state gets saved before the @PreDestroy method is called (I mean the "runtime" folder in the Eclipse workspace), so the menu elements don't get removed and multiply each time the application starts.

Can anyone point me in the right direction to do this?

Re: Add menu item to menu at runtime [message #881081 is a reply to message #881071]

Sun, 03 June 2012 17:20

Eclipse User

Lisi Blümelhuber wrote on Sun, 03 June 2012 23:46

I need to create a submenu which is filled with elements at runtime.

Use MMenuFactory to create the elements and then add or remove them to the children of the parent menu.

//creation
MDirectMenuItem dynamicItem = MMenuFactory.INSTANCE.createDirectMenuItem();
		dynamicItem.setLabel("Testing");
//addition 
menu.getChildren().add(dynamicItem);

where menu is the parent MMenu

Re: Add menu item to menu at runtime [message #881102 is a reply to message #881081]

Sun, 03 June 2012 18:46

Eclipse User

I do exactly that, and adding works fine.

It's removing items that doesn't work - the function marked with @PreDestroy gets executed and the list (of the menu children) gets reduced as I intend, but when I start the application again, the menu items that should have been removed are still there, plus one full set of new menu items.

Only way to avoid this is to manually delete the "runtimeXYZ" folder in the Eclipse workspace.

MMenu target = (MMenu) findMenuElement(application, menuElementId);
		List<MMenuElement> elements = target.getChildren();
		List<MMenuElement> found = new ArrayList<MMenuElement>();
		for (MMenuElement element: elements) {
			if (element.getLabel() != null && element.getLabel().equals(menuItemLabel)) {
				found.add(element);
			}
		}
		target.getChildren().removeAll(found);

[Updated on: Sun, 03 June 2012 18:49] by Moderator

Re: Add menu item to menu at runtime [message #881106 is a reply to message #881102]

Sun, 03 June 2012 18:58

Eclipse User

On your run configuration -> main tab -> check 'Clear' and select 'workspace' -> apply

However it looks like when you remove the items, they don't get removed from the model and when the app runs again it loads the model which the previous launch left with the items in the model.

Re: Add menu item to menu at runtime [message #881241 is a reply to message #881106]

Mon, 04 June 2012 03:54

Eclipse User

maybe you could remove the menu items on @PersistState instead of @PreDestroy?

Re: Add menu item to menu at runtime [message #881346 is a reply to message #881241]

Mon, 04 June 2012 07:34

Eclipse User

@PersistState is a good suggestion normally, except tht could be called at an arbitrary time with execution continuing afterwards. I see it best used to synchronize the model state with our part state.

Checking or and removing the old menu on startup is likely your best option for now. Perhaps we should have a "transient" tag Or flag for model elements so tt they aren't persisted. There's been some discussion on:

https://bugs.eclipse.org/bugs/show_bug.cgi?id=378815

Brian,

Re: Add menu item to menu at runtime [message #881503 is a reply to message #881346]

Mon, 04 June 2012 13:39

Eclipse User

First of all, thanks for your input so far!

Sopot Cela wrote on Sun, 03 June 2012 18:58

On your run configuration -> main tab -> check 'Clear' and select 'workspace' -> apply

However it looks like when you remove the items, they don't get removed from the model and when the app runs again it loads the model which the previous launch left with the items in the model.

Clearing the workspace works, but my impression is exactly what you wrote in your last sentence - the model stays the same, and that's unacceptable for the release application.

Christoph Keimel wrote on Mon, 04 June 2012 03:54

maybe you could remove the menu items on @PersistState instead of @PreDestroy?

I tried that, but the method then does not get called at exiting the application.

Brian de Alwis wrote on Mon, 04 June 2012 07:34

... Checking or and removing the old menu on startup is likely your best option for now.

Do you mean the menu where I want to put the dynamically generated menu items into or the menu items?
When I simply remove the menu items from the menu

target.getChildren().clear();

, on first click on one of the menu items I get a fat stacktrace with no functions of my own involved - after that, the menu items in the menu are unlabeled and throw further exceptions or do nothing when being clicked.

java.lang.NullPointerException
	at org.eclipse.e4.ui.workbench.renderers.swt.DirectContributionItem.getExecutionContext(DirectContributionItem.java:476)
	at org.eclipse.e4.ui.workbench.renderers.swt.DirectContributionItem.executeItem(DirectContributionItem.java:450)
	at org.eclipse.e4.ui.workbench.renderers.swt.DirectContributionItem.handleWidgetSelection(DirectContributionItem.java:360)
	at org.eclipse.e4.ui.workbench.renderers.swt.DirectContributionItem.access$1(DirectContributionItem.java:344)
	at org.eclipse.e4.ui.workbench.renderers.swt.DirectContributionItem$2.handleEvent(DirectContributionItem.java:301)
	at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:84)
	at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1053)
	at org.eclipse.swt.widgets.Display.runDeferredEvents(Display.java:4169)
	at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3758)
	at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine$9.run(PartRenderingEngine.java:1021)
	at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:332)
	at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.run(PartRenderingEngine.java:915)
	at org.eclipse.e4.ui.internal.workbench.E4Workbench.createAndRunUI(E4Workbench.java:86)
	at org.eclipse.e4.ui.internal.workbench.swt.E4Application.start(E4Application.java:150)
	at org.eclipse.equinox.internal.app.EclipseAppHandle.run(EclipseAppHandle.java:196)
	at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.runApplication(EclipseAppLauncher.java:110)
	at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.start(EclipseAppLauncher.java:79)
	at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:353)
	at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:180)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
	at java.lang.reflect.Method.invoke(Unknown Source)
	at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:629)
	at org.eclipse.equinox.launcher.Main.basicRun(Main.java:584)
	at org.eclipse.equinox.launcher.Main.run(Main.java:1438)
	at org.eclipse.equinox.launcher.Main.main(Main.java:1414)

I really thought that implementing a "recent files" menu would be a very simple feature to implement - maybe I'm overlooking something terribly obvious (this framework is new to me)?

Re: Add menu item to menu at runtime [message #881513 is a reply to message #881503]

Mon, 04 June 2012 14:17

Eclipse User

Lisi, if you could post a zip attachment with a small sample project showing this situation we would be happy to help out.

Re: Add menu item to menu at runtime [message #881546 is a reply to message #881513]

Mon, 04 June 2012 16:07

Eclipse User

That would of course be great - the example is as small as it gets Smile

.

There is some unnecessary recursion in the RecentFilesHandler.init() (pointing to itself), but creating another handler class doesn't change the relevant behavior.

Attachment: menudemo.zip
(Size: 10.70KB, Downloaded 498 times)

Re: Add menu item to menu at runtime [message #881573 is a reply to message #881546]

Mon, 04 June 2012 17:23

Eclipse User

Try adding

((EObject)application).eResource().save(null);

as the last line of the predestroy method after

DynamicMenuHelper.clearMenu(application, "menudemo.recentfiles.menu");

Re: Add menu item to menu at runtime [message #881879 is a reply to message #881573]

Tue, 05 June 2012 08:15

Eclipse User

Working perfectly in both the sample project and the real one.

Thank you for your time and effort!

Re: Add menu item to menu at runtime [message #985880 is a reply to message #881879]

Fri, 16 November 2012 09:43

Eclipse User

Hi,

thank you for solution above, it was very helpful. However, I have problem with finding which element of the Menu was clicked in execute method of handler. I would be grateful for any hint.

[EDIT] Solution is of course commands parameter..

[Updated on: Fri, 16 November 2012 12:20] by Moderator

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