View source for FAQ How do activities get enabled?

There are two kinds of activities
#[[#1. Conventional activities|Conventional activities]]
#[[#2. Expression-enabled activities|Expression-enabled activities]]

== 1. Conventional activities ==
When a user starts a new workspace, all activities will typically be disabled.
As the user explores the application and starts to use new features, more
activities can become enabled as they are needed.  This enablement typically happens automatically when the workbench determines
that a user is starting to use features defined in a disabled activity.
The workbench defines a number of <i>trigger points</i>, UI
interactions that signal the introduction of a new activity.
For example, the Eclipse IDE workbench considers creation of
a project to be a trigger point.  When a project is created, the
workbench looks at the natures on that project and enables
any activities that have pattern bindings matching any of the
nature IDs.


You can define your own trigger points for any logical place
where new plug-in functionality will be introduced.  The trigger
point itself doesn&#146;t need to know about any particular activities; it simply needs to define an identifier that represents the new
functionality.  The identifier should be in the form either 
<tt>&lt;plugin-id&gt;/&lt;local-id&gt;</tt>
or simply <tt>&lt;local-id&gt;</tt>. Using that ID, you can
enable any matching activities as follows:
<source lang="java">
String id = ...
IWorkbench wb = PlatformUI.getWorkbench();
IWorkbenchActivitySupport as = wb.getActivitySupport();
IActivityManager am = as.getActivityManager();
IIdentifier identifier = am.getIdentifier(id);
Set activities = new HashSet(am.getEnabledActivityIds());
if (activities.addAll(identifier.getActivityIds())) {
   as.setEnabledActivityIds(activities);
}
</source>
The exact format of the ID used for your trigger point should be
well documented so that activity writers will be able to write
appropriate pattern bindings for activating their activities using
your trigger points.


Activities can also be enabled or disabled explicitly by an end
user.  Again, this is something only the advanced user will
do.  The success of activities as a mechanism for scalability
and progressive disclosure relies on carefully chosen trigger
points in the user interface for seamlessly enabling activities.

== 2. Expression-enabled activities ==
For a description of expression-enabled activities look at [[FAQ What is the purpose of activities?]].<br/>
Expression-enabled activities can, of course, only be enabled through an enablement of their expressions.

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<hr><font size=-2>This FAQ was originally published in [http://www.eclipsefaq.org Official Eclipse 3.0 FAQs]. Copyright 2004, Pearson Education, Inc. All rights reserved. This text is made available here under the terms of the [http://www.eclipse.org/legal/epl-v10.html Eclipse Public License v1.0].</font>