7. Eclipse4 RCP Application不得不掌握的概念

今天药忘吃喽~ 2022-07-18 04:19 190阅读 0赞

本文主要介绍Eclipse 4 RCP Application中的：Model Objects和Features。

## 1. Model Objects ##

在Eclipse 框架启动的时候会通过.Application.e4.xmi配置文件自动解析一些Application model Objects。 下表主要展示在Eclipse中常见的一些重要的Model Objects:

<table> 
 <thead> 
  <tr> 
   <th>Model Elements</th> 
   <th align="left">Description</th> 
  </tr> 
 </thead> 
 <tbody> 
  <tr> 
   <td>MApplication</td> 
   <td align="left">Describes the application object. All other model elements are contained in this object.</td> 
  </tr> 
  <tr> 
   <td>MAddon</td> 
   <td align="left">A self-contained component typically without user interface. It can register for events in the application life cycle and handle these events.</td> 
  </tr> 
  <tr> 
   <td>MWindow</td> 
   <td align="left">Represents a window in your application.</td> 
  </tr> 
  <tr> 
   <td>MTrimmedWindow</td> 
   <td align="left">Similar to MWindow but it allows containing toolbars for the windows (via the TrimBars model elements).</td> 
  </tr> 
  <tr> 
   <td>MPerspective</td> 
   <td align="left">Represents a different layout of parts to be shown inside the window. Should be contained in a MPerspectiveStack.</td> 
  </tr> 
  <tr> 
   <td>MPart</td> 
   <td align="left">Represents the model element part, e.g., a view or an editor.</td> 
  </tr> 
  <tr> 
   <td>MDirtyable</td> 
   <td align="left">Property of MPart which can be injected. If set to true, this property informs the Eclipse platform that this Part contains unsaved data (is dirty). In a handler you can query this property to provide a save possibility.</td> 
  </tr> 
  <tr> 
   <td>MPartDescriptor</td> 
   <td align="left">MPartDescriptor is a template for new parts. A new part based on this part descriptor can be created and shown via the Eclipse framework.</td> 
  </tr> 
  <tr> 
   <td>Snippets</td> 
   <td align="left">Snippets can be used to pre-configure model parts which you want to create via your program. You can use the Eclipse framework to clone such a application model at runtime.</td> 
  </tr> 
 </tbody> 
</table>

## 2. feature projects 和feature ##

使用eclipse 的创建feature project 和创建一个plugin project是一样的。一个feature project包含 features。一个 feature可以描述一系列的plugins 和 feature ，通常是将一系列相关的组件组合到一个feature中当做是一个逻辑单元。当然Feature和plug-in 一样，也有名称name，版本号version number，通常在license中指定这些信息。  
如下为一个简单的feature.xml文件：

<?xml version="1.0" encoding="UTF-8"?>
    <feature 
        id="com.vogella.eclipse.featuretest.feature" 
        label="Feature" version="1.0.0.qualifier" 
        provider-name="vogella GmbH">
    
        <description url="http://www.example.com/description">
              [Enter Feature Description here.] 
        </description> 
    
        <license url="http://www.example.com/license">
            [Enter License Description here.] 
        </license> 
    <plugin 
        id="com.vogella.eclipse.featuretest.feature" 
        install-size="0" 
        version="0.0.0" 
        unpack="false"/> 
    </feature>

### 2.1 创建Feature Project ###

File –> New –>Other –>Plug-in Development –> Feature Project

### 2.2 编辑Feature信息 ###

*  information tab：可以让你给这个feature添加 desciption 和 copyright .
 *  plug-in tab ：允许将plug-in 添加到当前feaure；
 *  include Feature Tab： 可以将别的feature包含到该feature中；
 *  Dependencied tab： 可以定义其他feature，哪个必须使用当前feature;
 *  build tab：用于构建过程，包含feature.xml。

### 2.3 feature， plug-in 和Product ###

一个产品，可以是依赖于plugin或者feature的，这些设置可以通过product的Overview tab进行配置。  
在product的编辑器界面的contents tab指定该产品由那些plugin或者feature组成的。

一个product不会自动执行依赖关系，若你将一个feature添加进产品，同时也想将其依赖添加进来，就可以点击required 按钮，进行添加。

### 2.4 使用Feature的优点 ###

*  Feature将plugin分组，组成的逻辑单元，更容易掌控一系列的plugin组件。取代了添加一个个独立的plugin到product configure 文件中，使用feature对他们进行分组;
 *  feature可以使用eclipse update manager , build progress 来选择最终eclipse产品。feature可以作为一个基础定义一个启动配置。

eclipse提供了几种预定义的features， 比如，给Eclipse RCP application 定义的 org.eclipse.e4.rcp