NetBeans IDE 5.x HTML Editor Tutorial

Playing with the Sample

Although this is a very simple demo application, it is not a toy! It is a real program that supports easy editing of HTML pages, with features such as code completion, validation, and predefined HTML snippets. To start the editor, make sure Java and WebStart are enabled on your computer and click on the following link:

Launch NetBeans HTML Editor

After dealing with WebStart and seeing a splash screen, you should see the HTML editor:

Getting the Sources

So much for the end-user features. Let's now look at the code that runs this demo application. The source code is available in the NetBeans CVS repository and can be checked out or browsed online. The best way to study the source is to:

    cvs -d :pserver:anoncvs@cvs.netbeans.org:/cvs login
    cvs -d :pserver:anoncvs@cvs.netbeans.org:/cvs co contrib/sampleapps/htmleditor

Once you have the sources, open the project in NetBeans IDE 5.x. After you open the project, you will probably need to use the Project Properties dialog box to set the right location of the NetBeans IDE to make the project compilable.

The whole source consists of about 30 files, including build scripts, property files, images, which were mostly generated automatically by the NetBeans IDE 5.x plug-in module development support. Not much work needed to be done to create the HTML editor— it was not written from scratch, but heavilly reuses the existing components provided by NetBeans IDE 5.x. As a result, you get a very complex and compelling application, without writing any lines of code.

Now that you know what the end result looks like, you will assemble the HTML editor from scratch and learn how to make it optimally webstartable.

Generating the Skeleton Application

1. Using the New Project wizard (Ctrl-Shift-N), create a Module Suite Project from the template in the NetBeans Plug-in Modules category.

2. Make a few changes in the module suite's Project Properties dialog box:

   • In the Application panel, specify that this is going to be a Standalone Application. When asked whether you want to exclude NetBeans IDE modules, click Skip. The HTML editor is going to need several of the IDE's modules, while others will not be necessary. You will exclude the superfluous ones in the next step. Make sure to also add a branding name for the executable and an application title for the titlebar, as shown below:

     

   • In the Splash Screen panel, provide the application's splash screen, as shown below:

     

     If you do not have a splash screen, use this one.

   • Select the subset of modules that you need in the Libraries panel of the module suite. There, the only clusters that need to be selected are ide6 and platform6. Within the platform6 cluster, only the modules in this screenshot need to be selected, while in ide6, this screenshot and this screenshot show the required modules.

     So, the selected modules in platform6 are as follows:

     Actions APIs
     Bootstrap
     Core
     Core - Execution
     Core - UI
     Core - Windows
     Datasystems API
     Dialogs API
     Execution API
     Explorer and Property Sheet API
     Favorites
     File System API
     General Queries API
     I/O APIs
     JavaHelp Integration
     Look & Feel Customization Library
     Master Filesystem
     Module System API
     Nodes API
     Output Window
     Progress API & UI
     Settings API
     Settings Options API
     Startup
     Tab Control
     Text API
     UI Utilities API
     Utilities API
     Window System API

     And, in ide6, make sure the following are selected:

     Core - Component Palette
     Editor
     Editor Code Completion
     Editor Code Folding
     Editor Code Templates
     Editor Hints
     Editor Library
     Editor MIME Lookup
     Editor Settings
     Editor Settings Storage
     Editor Utilities
     Error Stripe API
     Error Stripe Core
     Experimental Search API
     HTML
     HTML Editor
     HTML Editor Library
     Image
     Plain Editor
     Plain Editor Library
     Project API
     Project UI API
     Tags Based Editors Library
     User Utilities

After finishing this step, the application should be able to start both as a standalone application and as a web-startable application. In the Projects window, right-click the project and choose Run to run the rich-client application or Run JNLP Application to run it as a web-startable application.

Pruning the User Interface

You can keep or reject as much of the IDE's user interface as you want. Your HTML editor probably does not need any or all of the items under the Tools menu. Similarly, maybe there are toolbars or toolbar buttons that you can do without. In this section, you prune the IDE's user interface until you are left with a subset that is useful to your rich-client application.

1. Using the New Project wizard (Ctrl-Shift-N), select the Module Project template in the NetBeans Plug-in Modules category. In the Name and Location panel, make sure that you add the module project to the module suite project that you created in the previous section.

2. In the Important Files node, expand the XML Layer node. Two subnodes are exposed:

   

   In the <this layer in context> node, the IDE shows you a merged view of all virtual files that all modules register in their layers. To exclude items, you can right-click them and choose 'Delete', as shown below:

   

   The IDE then adds tags to the plug-in module's layer.xml file which, when the plug-in module is installed, hides the items that you have deleted. For example, by right-clicking Menu Bar/Edit, you can remove menu items that are not necessary for the HTML Editor. By doing this, you generate snippets such as the following in the layer.xml file:

   <folder name="Menu">
       <folder name="Edit">
           <file name="org-netbeans-core-actions-JumpNextAction.shadow_hidden"/>
           <file name="org-netbeans-core-actions-JumpPrevAction.shadow_hidden"/>
       </folder>       
   </folder>

   The result of the above snippet is that the JumpPrevAction and JumpNextAction actions provided by another plug-in module are removed from the menu by the plug-in module that you are creating.

3. Use the approach described in the previous step to hide as many toolbars, toolbar buttons, menus, and menu items as you want.

Tweaking the Window Layout

By using the <this layer in context> node, you can not only delete existing items, but you can also change their content. For example, the HTML editor works on HTML files, so in contrast to the regular IDE, which works with Java source files and projects as well, it makes sense to show the Favorites window in the initial layout.

The definition of the window layout is also described as files in layers, all stored under the Windows2 folder. The files in the Windows2 folder are pseudo-human readable XML files defined by the Window System APIs. They are quite complex but the good news is that for purposes of the HTML editor it is not necessary to understand them fully, as shown below.

1. Right-click the Windows2 node and choose Find.

2. Search for an object named Favorites, ignoring the case.

   You will find two files:

   Windows2/Components/favorites.settings
   Windows2/Modes/explorer/favorites.wstcref
   

   The first file defines what the component is going to look like and how it gets created. As this does not need to be changed, there is no need to modify the file. The second is more interesting for your purposes, it contains the following:

   <tc-ref version="2.0">
       <module name="org.netbeans.modules.favorites/1" spec="1.1" />
       <tc-id id="favorites" />
       <state opened="false" />
   </tc-ref>

3. Even though most of the XML is cryptic, there is one line which seems promising—without reading any kind of documentation it seems likely that changing the false to true is going to make the component opened by default. And indeed, after restarting the application, the Favorites tab is opened by default.

4. In a similar way you can change the Component Palete so that it opens by default.

5. Next, since you are overriding the Core - Component Palette module and the Favorites module, you need to create runtime dependencies for these modules. Right-click the module project in the Projects window, choose Properties, and, in the Libraries panel, select the two modules that you need to override:

   

   Now open the Project Metadata file in the Important Files node. Notice that the two module dependencies have been declared as follows:

   <dependency>
     <compile-dependency/>
     <build-prerequisite/>
     <run-dependency>
     ...
     </run-dependency>
   <dependency>

   Since you have no Java classes in your project, you will generate build errors if you build the project while there are compile dependencies and build prerequisites. Prevent this problem by manually deleting the <compile-dependency> and <build-prerequisite> tags. However, since you are overriding these modules at runtime, you need to keep the <run-dependency> tags.