[news.eclipse.platform.rcp] Re: Enable/disable visible/not visible Menus

[Nick Edgar <nick_edgar@xxxxxxxxxxxxxxxxxxxxxxxxxxx>]

Using actionSetPartAssociations is the way to go if you want action set 
visibility to depend on whether your view is active.  The view needs to 
be -active- however, not just -open- in the perspective.  (Note that for 
editors, though, it suffices for the editor to be top-most, not 
necessarily active.  This is done for menu stability when switching back 
and forth between the editor and supporting views.)
A good way to see this effect is to open the Package Explorer view when 
in the Resource perspective, and switch between it and the Navigator view.
You can see which action sets get turned on via Window > Customize 
Perspective > Commands tab.

You can also associate the action set with the perspective (either in 
the perspective factory, or via the perspectiveExtensions extension 
point).  For example, some of the action sets associated with the 
Package Explorer are always on in the Java perspective.

But if there are other criteria for when the action set should be 
visible (and I'm not talking about enablement of individual items here), 
then that is not currently well-supported in the workbench, though you 
can programmatically hide/show action sets via 
IWorkbenchPage.hide/showActionSet(id).

For enablement of the actions, rather than registering them in some 
global map and then walking the map when your model state changes, I 
would have each action register itself with your model, and listen for 
the appropriate changes, updating its own enablement when conditions change.

I'm sure this doesn't answer all your questions, but hopefully this is a 
start to narrowing them down.

Nick

Nigel Pickard wrote:
> Well, I've had a painful time working out how to make visible/not 
> visible and enable/disable menus supplied to the workbench by a plugin 
> given certain conditions.  I'm posting this in the hope it might save 
> someone some time when attempting to do the same -and for others to 
> hopefully correct me if I've gone astray (if you read to the end of this 
> post, you will *know* I have).  Unfortunately searching the newsgroup 
> does reveal some posts requesting similar help, but they are not 
> answered or I've found some of the replies do not seem to work.
>
>
> Background:
> -----------
> I have a plugin ("testplugin").  In my actionset ("testactionset") I 
> have a view ("testview") and a menu ("testmenu") and an action related 
> to the menu ("testaction").  When "testview" comes up, I want the 
> "testmenu" to be visible on the workbench menu (similar to if you select 
> the java perspective or cvs perspective in Eclipse, you get some new 
> menu options unique to that perspective or view).  Likewise if 
> "testview" is closed, I want the "testmenu" menu to disappear.
>
> Additionally, I want to sometimes disable or enable the "testmenu" 
> option based on some other logic -e.g. another menu option was pressed 
> or a logical condition was met meaning my "testmenu" is disabled.
>
>
> Assumptions
> -----------
> You've added the necessary menus and related actions already.  You have 
> know the relationship between actionsets, actions, menus, etc.
>
>
> The Role of the Plugin.xml
> --------------------------
> Editing the plugin.xml will allow you to add (i.e. configure) the menu 
> and action items and set the initial states of the menus. From reading 
> the documentation, enablements seemed the way to go!
> HOWEVER: enablements are mostly(see caveat below this paragraph) a "one 
> time" deal of being read and initializing the menus.  This is contrary 
> to the help documentation (see http://help.eclipse.org/help31/index.jsp, 
> Platform Plug-in Developer Guide, Programmers Guide, Advanced Workbench 
> Concepts, Boolean expressions and action filters) which can be 
> (easily!!) read so that you might think an enablement condition may be 
> set to govern visibility and enablement as the application is used.
>
> Caveat here: I did not test using selection criteria, but I did try this 
> using an enablement with a systemProperty, pluginState and objectState 
> (yes, I did implement the IActionFilter interface in my action class 
> there!) and indeed confirmed these values had changed by logging. 
> I'm sure there are some Eclipse developers out there who are shaking 
> their heads and saying "But of course...!".  Let me just say, I didn't 
> find it to be obviously stated!  A simple sentence in the help about 
> this could have saved me alot of time.  Here is a post that made me 
> first realize this:
>
> http://dev.eclipse.org/newslists/news.eclipse.platform.rcp/msg05661.html
>
> (Many thanks to Nick Edgar on this).
>
>
> Making a Menu Visible or Not Visible Depending on Which View is Open
> --------------------------------------------------------------------
> Initially I wanted to make my "testmenu" menu visibility associated with 
> a perspective, but in the end I associated the menu visibility to my 
> "testview" view (and of course you can add other dependent views as well 
> to effectively build up a perspective anyway).  I associated a view to 
> menu visibility by doing the following:
>
> i. in the plugin.xml for my "testplugin", add a 
> actionSetPartAssociations extension.
> ii. Add a new actionSetPartAssociation to this.  Set the target id to 
> appopriate actionset (e.g. "testactionset").
> iii. Add a new part to the setpartassociation, and set the id to the 
> view id we wish to relate the menu and action to (e.g. "testview").
>
> This will mean that whenever the "testview" is open, the menu "testmenu" 
> related to the action "testaction" is visible, and likewise is not 
> visible when the "testview" is closed.
>
> Here is a snippet of my plugin.xml file for this (testview definition 
> excluded for brevity):
>
> <!-- defining the actionset with action and menu -->
> <extension point="org.eclipse.ui.actionSets">
>  <actionSet label="testactionset" id="testactionset">
>    <action label="testaction option" class="my.code.Testaction"       
> style="push" menubarPath="file/additions" id="testaction">
>    </action>
>    <menu label="testmenu option" path="additions" id="testmenu"/>
>  </actionSet>
> </extension>
>
> <!-- defining the part association -->
> <extension point="org.eclipse.ui.actionSetPartAssociations">
>  <actionSetPartAssociation targetID="testactionset">
>    <part id="testview"/>
>  </actionSetPartAssociation>
> </extension>
>
>
> Making a Menu Enabled or Disabled Depending on a Programmatical Condition
> -------------------------------------------------------------------------
> This was pretty easy, though I think I'm not doing it the easy way -I 
> just couldn't find the appropriate method to interrogate the workbench 
> contents to obtain all the Action ids (if anyone reads this far, I'm 
> open to suggestions and an example on this one). I'm still working on 
> this -at the moment I am populating a Map of Action ids and IAction 
> objects when the IWorkbenchWindowActionDelegate class's run(IAction 
> action) method is invoked..... the IAction is added to the Map if it 
> does not already exist.... ugh, not the way to do it I know!  Anyway, 
> once I have references to the IAction objects, I can then easily enable 
> or disable them programmatically based on a condition.
>
> Please feel free to correct/help/add to this.