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| <title>Writing the help action</title> |
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| |
| <h3>Writing the help action</h3> |
| |
| <p>The interface <a href="../reference/api/org/eclipse/help/ILiveHelpAction.html"><b>ILiveHelpAction</b></a> |
| is used to build an active help action.</p> |
| |
| |
| <p>It is straightforward to implement an <a href="../reference/api/org/eclipse/help/ILiveHelpAction.html"><b>ILiveHelpAction</b></a><b>.</b> |
| You must implement two methods.</p> |
| |
| |
| <ul> |
| <li><b>run()</b> - This method is called to run the live help action. |
| This method will be called by the help system from a non-UI thread, so UI |
| access must be wrapped in a <b><a href="../reference/api/org/eclipse/swt/widgets/Display.html">Display.syncExec()</a></b> |
| method. </li> |
| <li><b>setInitializationString(String)</b> - This method is called to |
| initialize your action with a String data parameter you can specify in the |
| HTML which runs the JavaScript <b>liveAction</b>. |
| If you don't need initialization data, you can just implement |
| this method to do nothing. This method is called before <b>run()</b>.</li> |
| </ul> |
| |
| |
| <p>Here is a simple implementation of a live help action that opens a message |
| dialog. We don't need any information from the JavaScript, so the |
| initialization data is ignored.</p> |
| |
| |
| <pre>package org.eclipse.platform.doc.isv.activeHelp; |
| |
| import org.eclipse.help.ILiveHelpAction; |
| import org.eclipse.jface.dialogs.MessageDialog; |
| import org.eclipse.swt.widgets.*; |
| import org.eclipse.ui.*; |
| /** |
| * Sample Active Help action. |
| */ |
| public class ActiveHelpOpenDialogAction implements ILiveHelpAction { |
| |
| public void setInitializationString(String data) { |
| // ignore the data. We do not use any javascript parameters. |
| } |
| |
| public void run() { |
| // Active help does not run on the UI thread, so we must use syncExec |
| Display.getDefault().syncExec(new Runnable() { |
| public void run() { |
| IWorkbenchWindow window = |
| PlatformUI.getWorkbench().getActiveWorkbenchWindow(); |
| if (window != null) { |
| // Bring the Workbench window to the top of other windows; |
| // On some Windows systems, it will only flash the Workbench |
| // icon on the task bar |
| Shell shell = window.getShell(); |
| shell.setMinimized(false); |
| shell.forceActive(); |
| // Open a message dialog |
| MessageDialog.openInformation( |
| window.getShell(), |
| "Hello World.", |
| "Hello World."); |
| } |
| } |
| }); |
| } |
| }</pre> |
| |
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