FAQ What is the difference between perspectives and activities? - Revision history http://wiki.eclipse.org/index.php?title=FAQ_What_is_the_difference_between_perspectives_and_activities%3F&action=history Revision history for this page on the wiki en MediaWiki 1.23.2 Thu, 25 Dec 2014 04:10:41 GMT Claffra at 20:27, 14 March 2006 http://wiki.eclipse.org/index.php?title=FAQ_What_is_the_difference_between_perspectives_and_activities%3F&diff=3186&oldid=prev http://wiki.eclipse.org/index.php?title=FAQ_What_is_the_difference_between_perspectives_and_activities%3F&diff=3186&oldid=prev <p></p> <p><b>New page</b></p><div>''<br /> <br /> <br /> <br /> <br /> <br /> At first glance, perspectives and activities are very similar. Both<br /> modify the appearance of the workbench, adding and removing menus<br /> and toolbar buttons, depending on a course-grained user task. When <br /> trying to figure out how to carve up a large product into usable<br /> pieces, it is sometimes difficult to figure out when to use activities,<br /> perspectives, or both. Apart from the prosaic difference that perspectives<br /> were an Eclipse 1.0 invention and activities are new in Eclipse 3.0, a number of other subtle differences exist.<br /> <br /> <br /> The most obvious difference between activities and perspectives is<br /> that activities are not intended to alter the layout of views and editors<br /> that are currently open. Activities change the menus and toolbars but<br /> don&amp;#146;t make real estate changes that can cause the user to lose context.<br /> Perspectives have a dual role of dictating screen layout and<br /> altering the menus and toolbars. This connection is<br /> often not obvious to users, and they are often confused about<br /> why a certain menu or keyboard shortcut appears in one place<br /> but not another. <br /> <br /> <br /> Second, activities are intended to be largely implicit. Whereas perspectives<br /> are explicitly visible and controlled entirely by the user, activities<br /> are not directly user controlled. Essentially, activities try to have<br /> some smarts about when they are needed and activate and<br /> deactivate accordingly, depending on what the user is doing. Although <br /> perspectives do this to a certain extent, such as switching to the<br /> Debug perspective automatically when an application is launched<br /> in debug mode, automatically changing<br /> the user interface layout is a general user interface no-no. Because <br /> activities are not tied to a particular screen layout, they can change<br /> automatically without causing the user to lose context.<br /> <br /> <br /> Finally, perspectives<br /> are partially defined programmatically, whereas activities are defined entirely <br /> declaratively. The importance of this difference is that activities are not<br /> intended to be defined by programmers who are working on individual<br /> plug-ins. Because the designer of a single plug-in cannot envision the<br /> emergent behavior of a system built of hundreds of plug-ins&amp;#151;or at <br /> least not without violating the modular principles of the plug-in<br /> architecture&amp;#151;he or she has no way of knowing what set of activities<br /> might be appropriate. Activities are a form of meta-glue that regulate<br /> how plug-ins interact and so must be defined at a higher level. Typically,<br /> activities will be created by a system configurer or <br /> human-computer interaction (HCI) expert<br /> who has a better picture of the total functionality of the product.<br /> <br /> &lt;hr&gt;&lt;font size=-2&gt;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].&lt;/font&gt;</div> Tue, 14 Mar 2006 20:27:59 GMT Claffra http://wiki.eclipse.org/Talk:FAQ_What_is_the_difference_between_perspectives_and_activities%3F