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Posts Tagged ‘javascript’

JavaFX – YouTube

August 2, 2009 5 comments

In previous blog I gave a simple example for JavaFX – JavaScript communication. Here we will see how to utilize this feature so as to integrate YouTube with JavaFX browser deployment. YouTube provides Data and Player APIs. We can utilize them to integrate YouTube presentation layer to JavaFX.

Given below is JavaFX app which uses YouTube Data APIs to search for videos with specified tag and displays the thumbnail images. User can click on thumbnail to view the video. The video can be controlled from JavaFX using JavaScript APIs. I’m sure a good designer can provide a much better seamless integration

Click on above image to launch the applet.
Note: Require JavaSE 6 Update 10 or above.
I’m not responsible for content shown in video

I have used YouTube Search APIs. It provides output in various formats – atom, rss, json and json-in-script. I have used the default ATOM format. Even though its using ATOM format, most of required attributes are provided in custom tags as shown below. Hence even though I used AtomTask to parse the feed, I still had to parse the custom tags in onForeignEvent : function(:Event):Void method. Details of parser is available in YTDataTask.fx.


<media:group>
    <media:category label='Science &amp; Technology' scheme='.../categories.cat'>Tech</media:category>
    <media:content url='http://...app=youtube_gdata' type='application/x-shockwave-flash' yt:format='5'/>
    <media:content url='rtsp://rtsp2.youtube.com/.../video.3gp' type='video/3gpp' yt:format='1'/>
    <media:content url='rtsp://rtsp2.youtube.com/.../video.3gp' type='video/3gpp' yt:format='6'/>
    <media:credit role='uploader' scheme='urn:youtube'>terrencebarr</media:credit>
    <media:description type='plain'>Terrence Barr...</media:description>
    <media:keywords>JavaFX, JavaFX Mobile</media:keywords>
    <media:player url='http://www.youtube.com/watch?v=6LdFq8T0Uys'/>
    <media:thumbnail url='http://i.ytimg.com/.../default.jpg' height='90' width='120' time='00:04:25.500'/>
    <media:thumbnail url='http://i.ytimg.com/.../2.jpg' height='90' width='120' time='00:04:25.500'/>
    <media:thumbnail url='http://i.ytimg.com/.../1.jpg' height='90' width='120' time='00:02:12.750'/>
    <media:thumbnail url='http://i.ytimg.com/.../3.jpg' height='90' width='120' time='00:06:38.250'/>
    <media:thumbnail url='http://i.ytimg.com/.../hqdefault.jpg' height='360' width='480'/>
    <media:title type='plain'>Getting Started with JavaFX Mobile...</media:title>
    <yt:aspectRatio>widescreen</yt:aspectRatio>
    <yt:duration seconds='531'/>
    <yt:uploaded>2009-07-28T21:45:00.000Z</yt:uploaded>
    <yt:videoid>6LdFq8T0Uys</yt:videoid>
</media:group>

YouTube provides “Chromeless Player” with JavaScript API support. We can obtain the videoid using above Data APIs and pass this to player using JavaScript APIs. We can perform operations such as – load video, play, pause, stop, seek, mute/un-mute – on video. Refer to JavaScript API documentation for more information.

All these APIs are encapsulated in a file – JavaYT.js. A Java wrapper for this javascript file is provided so as to invoke these APIs from Java – JavaYTUtil.java. This in turn uses JavaScriptUtil.java as shown in previous post.

Both YouTube player and JavaFX is added to a Table so as to render them together. Please refer to JavaFXYT.html for more information.

Try it out and let me know feedback

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Categories: javafx Tags: ,

JavaFX – JavaScript Communication

July 28, 2009 9 comments

There is a tutorial on JavaFX Script – JavaScript Bridge, JavaFX Sample, Plug-In Live Connect and Carl’s blog to list a few.. But still see questions about this (JavaSE Plug-In) feature. Hence just thought about writing a blog to demonstrate this..

I think the question primarily arise because, people have tried it but it doesn’t seem to work. The feature is stable only with JavaSE 6 Update 10 and above. So if you are using older JRE (as in default settings of Mac) the feature will not work as expected.

In below example, I have two user interface. One with HTML and another in JavaFX. When I click on HTML buttons it will invoke Java API and show message box using javax.swing.JOptionPane. When I click on JavaFX buttons, it will call JavaScript method such as alert, confirm, prompt to show message box.

Click on above image to launch the applet

JavaScript methods are invoked from Java or JavaFX using netscape.javascript.JSObject. An instance of JSObject can be obtained using static method JSObject.getWindow() by passing the current applet instance as argument.

Applet instance can be obtained from JavaFX as shown below:


var applet = FX.getArgument("javafx.applet"as Applet;

Next we need to get instance of JSObject. These classes are available in plugin.jar. So we need to include explicitly plugin.jar in classpath. Instead we can also use reflection to invoke these methods. I have used reflection and created a wrapper – JavaScriptUtil. This can be instantiated by passing above applet instance.

A series of method to show message box is added both JavaScript and JavaFX as shown below.

JavaScript:


function show_alert() {
    alert("JS: I am an alert box!");
}

JavaFX:


public function showAlert() : Void {
    JOptionPane.showMessageDialog(null, "FX: I am an alert box!");
}

I have prefixed the message with “FX” and “JS” so as to identify the origin of message box.

Invoke JavaFX method from JavaScript:


var applet = document.getElementById('JavaFXJavaScript');
// Invoke JavaFX method from JavaScript
applet.script.showAlert();

The applet element is obtained using its id


<script>
    javafx(
       {
           codebase: "dist",
           archive: "JavaFXJavaScript.jar",
           draggable: true,
           width: 250,
           height: 120,
           code: "javafxjavascript.Main",
           name: "JavaFXJavaScript",
           id: 'JavaFXJavaScript'
       }
    );
</script>

Invoke JavaScript method from JavaFX:


var jsObject = netscape.javascript.JSObject.getWindow(applet);
jsObject.call("show_alert"[]);

Since we have wrapped all JSObject methods in JavaScriptUtil we may invoke JavaScript method as shown below.


var applet: Applet = FX.getArgument("javafx.applet"as Applet;
var jsObject = new JavaScriptUtil(applet);
jsObject.call("show_alert"[]);

Please refer to JavaFXJavaScript.html and Main.fx for more details.

Java Plug-In LiveConnect API Documentation:

Try it out and let me know feedback

var dzone_style = ‘2’;

Categories: javafx Tags:

JavaFX – News Widget

March 4, 2009 7 comments

This is an attempt to answer several queries in one go. Lets see if it helps..

  1. Can I embed JavaFX in JSP, ASP, PHP, JSF,…
    (Endless several other web technologies)?
  2. Can JavaFX dynamically interact with html page via JavaScript?
  3. Is it feasible to implement JavaFX JavaScript communication?
  4. Can JavaFX retrieve data from external services/resources?

Answer is YES! to all of above. Lets try to prove that..

We have a JavaFX Sample – RSS-Viewer which we will try to customize and integrate it into this blog. RSS-Viewer can retrieve data from various RSS feeds. It will parse the feed using JavaFX parser and render the HTML data in browser.

By default the application loads the feed from Yahoo! news. We will customize it so as to load the feed from Google News. The application accepts an argument rss_url which can be used to specify the RSS feed.

Now how will we incorporate this widget into this blog? We need to create a <div> in HTML which will act as placeholder for embedding the HTML data from JavaFX. We will update the content of this <div> using JavaScript.


<div id="ChannelData" style="text-align: center;"></div>

Now we will write a JavaScript method which will update the data from JavaFX.


function updateChannelData(channelData) {
    document.getElementById("ChannelData").innerHTML = channelData;
}

JavaFX will invoke updateChannelData( <data> ) with data from RSS feed and update the content.
Now we need to include the JavaFX Widget. For this we need to include the JavaScript dtfx.js and call javafx function passing the application attributes as shown below.


<script src="http://dl.javafx.com/1.2/dtfx.js&#34;></script>

<table width="40%" border="1" cellpadding="10" cellspacing="0">
  <tbody>
    <tr>
      <td align="center">

        <script>

          javafx(
            {
              archive: "http://javafx.com/samples/RSSViewer/webstart/RSSViewer.jar,&#34;,
              width: 610,
              height: 62,
              code: "rssviewer.Main",
              name: "RSSViewer"
            
              isApplet: "true"
              js_mode: "true"
              rss_url: "http://news.google.com/news?pz=1&ned=us&hl=en&topic=w&output=rss&#34;
            
          );
          
          function updateChannelData(channelData) {
            document.getElementById("ChannelData").innerHTML = channelData;
          }
          
        </script>
        
        <div id="ChannelData" style="text-align: center;"></div>
        
      </td>
    </tr>
  </tbody>
</table>

After embedding above code in your html you must be able to load and view Google News.

Now we have incorporated an existing widget into html page. It also uses JavaFX JavaScript interaction and loads the data from external service – Google News.

Refer to
LiveConnect Support in the Java™ Plug-In Technology
for more information on Java JavaScript communication.

But did I prove the first point – Can I embed JavaFX in JSP, ASP, PHP, JSF,…??. May be not? Please try to follow above steps and try to incorporate this widget into your page and let me know how things go. You must be able to provide any well formatted RSS feed as rss_url.

For standalone mode

function updateChannelData(channelData) {
document.getElementById(“ChannelData”).innerHTML = channelData;
}
javafx(
{
archive: “http://javafx.com/samples/RSSViewer/webstart/RSSViewer.jar,&#8221;,
width: 610,
height: 62,
code: “rssviewer.Main”,
name: “appl”
} , {
isApplet: “true”,
js_mode: “true”,
rss_url: “http://news.google.com/news?pz=1&ned=us&hl=en&topic=w&output=rss&#8221;
}
);

var dzone_url = “http://blogs.sun.com/rakeshmenonp/entry/javafx_news_widget&#8221;;
var dzone_style = ‘2’;

digg_skin = ‘compact’;
digg_window = ‘new’;

Categories: javafx Tags: , , , ,