[Eclipse] The Eclipse RCP Command Framework

短命女 2022-09-30 00:32 164阅读 0赞

## 准备翻译 [The Eclipse RCP Command Framework][] ##

概述：

从一Eclipse 设计的一开始，就关注与扩展性。因此，几乎所有的用户界面都能被扩展。但是当Eclipse RCP出现以后，发现UI 的扩展不太好用。Eclipse 3.3 以后，推出了一套新的UI 扩展，来取代以前的扩展。

1 以前的Action Contribution 设计

通过扩展点定义的Action 都继承JFace 的IAction 接口

[IAction][] 接口, 他抽象了用户的一个动作(Action) ，使动作和特殊的小部件分离，如菜单和工具栏中的按钮:

interface IAction \{ void setText(String text); void setImageDescriptor(ImageDescriptor image); void setAccelerator(int keycode); void setEnabled(boolean enabled); void run(); // ... more setters and getters \}

请注意这个类中耦合度：文本，图像，快捷键，动作(这里指run 方法) 都耦合在一起。这里UI 和逻辑没有分离，所有Eclipse 3.3 引入command 模式，实现分离。

我们在来看看这些扩展：

**org.eclipse.ui.actionSets:** 为主菜单和主工具栏贡献UI。 Some abstraction from the implementation is possible by declaring a contributed action as retargetable. In this case parts can register local handlers via API.

**org.eclipse.ui.editorActions:** This extension point also allows contributions to the main menu and tool bar which are bound to a particular editor type.

**org.eclipse.ui.actionSetPartAssociations:** While the former extension point allows editor specific contributions to the main menu and tool bar this one provides a similar functionality for all parts including views: It controls the visibility of action sets depending whether a particular editor or part is active within the workbench window.

**org.eclipse.ui.viewActions:** Each view may have a local tool bar and pull-down menu. This is the extension point to populate them for particular view types.

**org.eclipse.ui.popupMenus:** For additions to context menus, either for specific views (viewerContribution) or for particular objects wherever they appear in the views (objectContribution).

[The Eclipse RCP Command Framework]: http://svn2.assembla.com/svn/eclipsecommands/trunk/EclipseCommands/contents/article.html
[IAction]: http://help.eclipse.org/ganymede/topic/org.eclipse.platform.doc.isv/reference/api/org/eclipse/jface/action/IAction.html