org.eclipse.ua.tests/data/help/performance/search/ua_help_context_dynamic.htm - platform/eclipse.platform.ua - Git at Google

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 <script type="text/javascript" src="PLUGINS_ROOT/org.eclipse.help/livehelp.js"></script>
 <title>Dynamic context help</title>
 </head>
 <body>

 <h2>Dynamic context help</h2>

 <p>
 In addition to statically associating widgets and context Ids, it is possible to
 provide this information dynamically for a more dynamic context-sensitive help
 capability. Help system uses context Ids to locate the matching
 <a href="../reference/api/org/eclipse/help/IContext.html">
 org.eclipse.help.IContext</a> object. The new Help view tracks activation of the
 workbench parts (views and editors) and checks if they adapt to
 <a href="../reference/api/org/eclipse/help/IContextProvider.html">
 org.eclipse.help.IContextProvider</a> interface. If they do, the view will use
 the context provider to locate the <code>IContext</code> object and get the
 required information from it. This object can be cached or created on the fly.</p>
 <p>
 Workbench parts that want to create the context object dynamically should adapt
 to the <code>IContextProvider.class</code> object as a key:</p>
 <blockquote>
 	<pre>public Object getAdapter(Class key) {
 	if (key.equals(IContextProvider.class)) {
 		return new MyContextProvider();
 	}
 	return super.getAdapter(key);
 }</pre>
 </blockquote>
 <p>The context provider interface requires implementation of three methods:</p>
 <blockquote>
 	<pre>public class MyContextProvider implements IContextProvider {
 	int getContextChangeMask() {
 		return NONE;
 	}
 	IContext getContext(Object target) {
 		return myContext;
 	}
 	String getSearchExpression(Object target) {
 		return null;
 	}
 }</pre>
 </blockquote>
 <p>If context change mask returns <code>NONE</code>, context object will need to
 be provided when the workbench part is activated. If <code>SELECTION</code> is
 returned, you will need to provide context object that is sensitive to the
 current selection in the part. Each time part selection provider fires a
 selection change event, the context provider will be asked to provide context
 object.</p>
 <p>Optionally, search expression for the dynamic help can be provided.
 Otherwise, a combination of the part name and perspective name will be used with
 good results in most cases.
 </p>

 <p>
 <b>Note:</b> In addition to using context providers (or alternatively), you can use
 XML annotations to <a href="ua_dynamic_filters.htm">filter</a> topics in context
 help.
 </p>

 </body>
 </html>
	<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
	<html>
	<head>
	<meta name="copyright" content="Copyright (c) IBM Corporation and others 2000, 2006. This page is made available under license. For full details see the LEGAL in the documentation book that contains this page." >
	<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
	<meta http-equiv="Content-Style-Type" content="text/css">
	<link rel="STYLESHEET" href="../book.css" charset="ISO-8859-1" type="text/css">
	<script type="text/javascript" src="PLUGINS_ROOT/org.eclipse.help/livehelp.js"></script>
	<title>Dynamic context help</title>
	</head>
	<body>

	<h2>Dynamic context help</h2>

	<p>
	In addition to statically associating widgets and context Ids, it is possible to
	provide this information dynamically for a more dynamic context-sensitive help
	capability. Help system uses context Ids to locate the matching
	<a href="../reference/api/org/eclipse/help/IContext.html">
	org.eclipse.help.IContext</a> object. The new Help view tracks activation of the
	workbench parts (views and editors) and checks if they adapt to
	<a href="../reference/api/org/eclipse/help/IContextProvider.html">
	org.eclipse.help.IContextProvider</a> interface. If they do, the view will use
	the context provider to locate the <code>IContext</code> object and get the
	required information from it. This object can be cached or created on the fly.</p>
	<p>
	Workbench parts that want to create the context object dynamically should adapt
	to the <code>IContextProvider.class</code> object as a key:</p>
	<blockquote>
	<pre>public Object getAdapter(Class key) {
	if (key.equals(IContextProvider.class)) {
	return new MyContextProvider();
	}
	return super.getAdapter(key);
	}</pre>
	</blockquote>
	<p>The context provider interface requires implementation of three methods:</p>
	<blockquote>
	<pre>public class MyContextProvider implements IContextProvider {
	int getContextChangeMask() {
	return NONE;
	}
	IContext getContext(Object target) {
	return myContext;
	}
	String getSearchExpression(Object target) {
	return null;
	}
	}</pre>
	</blockquote>
	<p>If context change mask returns <code>NONE</code>, context object will need to
	be provided when the workbench part is activated. If <code>SELECTION</code> is
	returned, you will need to provide context object that is sensitive to the
	current selection in the part. Each time part selection provider fires a
	selection change event, the context provider will be asked to provide context
	object.</p>
	<p>Optionally, search expression for the dynamic help can be provided.
	Otherwise, a combination of the part name and perspective name will be used with
	good results in most cases.
	</p>

	<p>
	<b>Note:</b> In addition to using context providers (or alternatively), you can use
	XML annotations to <a href="ua_dynamic_filters.htm">filter</a> topics in context
	help.
	</p>

	</body>
	</html>