流程设计器开发八(新建向导部分)

 

       这一节主要介绍如何通过新建向导，来新建我们扩展的文件(.workflow),要在新建增加内容，必须扩展org.eclipse.ui.newWizards，因此我们要修改plugin.xml文件，增加内容如下：

<extension

         point="org.eclipse.ui.newWizards">

      <category

            id="com.example.workflow"

            name="Workflow"/>    

      <wizard

            category="com.example.workflow"

            class="com.example.workflow.wizard.FileNewWizard"

            icon="src/com/example/workflow/icons/file.gif"

            id="com.example.workflow.filewizard"

            name="Workflow文件 "

            />

   </extension>

我们首先定义了一个组，组名是Workflow，组标识是com.example.workflow，组类似于文件夹的性质，然后定义了一个向导，各个属性的含义如下：

category属性指定组标识

class属性向导对应的类

icon属性指定向导显示的图标

id属性指定向导的标识，应该唯一

name属性指定向导显示的名称

接下来我们定义向导类，由于向导中包含一个或者多个向导页，根据实际情况而定，所以我们还要定义向导页，代码如下：

向导类

package com.example.workflow.wizard;

 

import org.eclipse.jface.viewers.IStructuredSelection;

import org.eclipse.jface.wizard.Wizard;

import org.eclipse.ui.INewWizard;

import org.eclipse.ui.IWorkbench;

 

/**

 * Create new new .workflow-file.

 * Those files can be used with the WorkflowProcessEditor (see plugin.xml).

 */

public class FileNewWizard extends Wizard implements INewWizard{     

       //定义一个向导页

       private FileCreationPage page1;                  

//给向导加上向导页

       public void addPages() {             

              addPage(page1);

       }

//在向导上点完成时，调用向导页的finish()方法。

       public boolean performFinish() {

              return page1.finish();

       }

//向导初始化的时候，设置向导的标题，新建向导页

       public void init(IWorkbench workbench, IStructuredSelection selection) {

              setWindowTitle("Create Workflow File");

              page1 = new FileCreationPage(workbench, selection);             

       }

 

}

 

向导页类

package com.example.workflow.wizard;

 

import java.io.ByteArrayInputStream;

import java.io.ByteArrayOutputStream;

import java.io.IOException;

import java.io.InputStream;

import java.io.ObjectOutputStream;

 

 

import org.eclipse.core.resources.IFile;

import org.eclipse.jface.viewers.IStructuredSelection;

import org.eclipse.swt.widgets.Composite;

import org.eclipse.ui.IWorkbench;

import org.eclipse.ui.IWorkbenchPage;

import org.eclipse.ui.PartInitException;

import org.eclipse.ui.dialogs.WizardNewFileCreationPage;

import org.eclipse.ui.ide.IDE;

 

import com.example.workflow.model.WorkflowProcess;

 

public class FileCreationPage extends WizardNewFileCreationPage{

       //定义缺省的文件扩展名

       private static final String DEFAULT_EXTENSION = ".workflow";

       private final IWorkbench workbench;

       private static int fileCount = 1;

 

       /**

        * Create a new wizard page instance.

        * @param workbench the current workbench

        * @param selection the current object selection

        * @see ShapesCreationWizard#init(IWorkbench, IStructuredSelection)

        */

       public FileCreationPage(IWorkbench workbench, IStructuredSelection selection) {

              super("workflowCreationPage1", selection);

              this.workbench = workbench;            

//设置向导页的标题和描述

              setTitle("Create a new " + DEFAULT_EXTENSION + " file");

              setDescription("Create a new " + DEFAULT_EXTENSION + " file");

       }

      

      

      

       public void createControl(Composite parent) {

              super.createControl(parent);

//设置向导页中的文件名

              setFileName("workflowExample" + fileCount + DEFAULT_EXTENSION);

//设置向导的完成按钮是否可用

              setPageComplete(validatePage());

       }

      

       /**

    *判断文件的扩展名是否为workflow

        * Return true, if the file name entered in this page is valid.

        */

       private boolean validateFilename() {

              if (getFileName() != null && getFileName().endsWith(DEFAULT_EXTENSION)) {

                     return true;

              }

              setErrorMessage("The 'file' name must end with " + DEFAULT_EXTENSION);

              return false;

       }

 

       /* (non-Javadoc)

        * @see org.eclipse.ui.dialogs.WizardNewFileCreationPage#validatePage()

        */

       protected boolean validatePage() {       

              return super.validatePage()&& validateFilename();

       }

      

       /** Return a new WorkflowProcess instance. */

       private Object createDefaultContent(){

              return new WorkflowProcess();

       }

 

       /* 得到文件的初始内容

        * @see org.eclipse.ui.dialogs.WizardNewFileCreationPage#getInitialContents()

        */

       protected InputStream getInitialContents() {

              ByteArrayInputStream bais = null;

              try {

                     ByteArrayOutputStream baos = new ByteArrayOutputStream();

                     ObjectOutputStream oos = new ObjectOutputStream(baos);

                     oos.writeObject(createDefaultContent()); // argument must be Serializable

                     oos.flush();

                     oos.close();

                     bais = new ByteArrayInputStream(baos.toByteArray());

              } catch (IOException ioe) {

                     ioe.printStackTrace();

              }

              return bais;

       }

 

 

       /**

        * This method will be invoked, when the "Finish" button is pressed.

        * @see FileCreationWizard#performFinish()

        */

       boolean finish(){

              //create a new file, result != null if successful

              IFile newFile = createNewFile();

              fileCount++;

             

              //在编辑器中打开新建的文件

              IWorkbenchPage page = workbench.getActiveWorkbenchWindow().getActivePage();

              if (newFile != null && page != null) {

                     try {

                            IDE.openEditor(page, newFile, true);

                     } catch (PartInitException e) {

                            e.printStackTrace();

                            return false;

                     }

              }

              return true;

       }

 

}

同时在插件依赖项中增加 org.eclipse.core.resources

这样运行程序，效果如图