Wednesday Aug 12, 2009

Netbeans Java Presentation

Small presentation(actually very small) on Netbeans and Java. Mostly covers the features, netbeans provide for Java SE. Like Profiling, Debugging..

http://blogs.sun.com/vaibhav/resource/BasicOfNetbeans_Java.pdf



Friday May 29, 2009

Welcoming JavaOne

Straightaway to JavaOne : http://java.sun.com/javaone/

Best wished to all the presenters and attendees. JavaOne going to rock :).

PS: Sorry, no technical writing in this post.

Tuesday Jan 06, 2009

Managing Java Process from Java Code

Back to Java :). Here is a small blog on how to manage Java Process from Java itself.

Long back, I had written one blog on how to list Java Process running on System by Java Code. But with the new features of JDK6, you can not only see the list but can manage the other running Java Process. This is possible using class LocalVirtualMachine. This class has a list of methods :

connectorAddress,
displayName,
getAllVirtualMachines,
getLocalVirtualMachine,
isAttachable,
isManageable,
startManagementAgent,
toString,
vmid

Here I am just showing a simple code, which will again tell you all the running Java Process.

import sun.tools.jconsole.\*;
import java.util.\*;
public class Main {

public static void main(String[] args) {
Map map = LocalVirtualMachine.getAllVirtualMachines();
Iterator iter = map.values().iterator();
LocalVirtualMachine vm = null;
while (iter.hasNext()) {
vm = (LocalVirtualMachine)iter.next();
System.out.println(vm.displayName());
}
}
}

A very very small code :). Note that this class is not in rt.jar so we need to add jconsole.jar and tools.jar in the classpath section.
So, for running we need to use :

D:/Program Files/Java/jdk1.6.0_11/bin/ControlJavaApp>../javac -cp "D:/Program Fi
les/Java/jdk1.6.0_11/lib/jconsole.jar" Main.java

D:/Program Files/Java/jdk1.6.0_11/bin/ControlJavaApp>../java -cp .;"D:/Program F
iles/Java/jdk1.6.0_11/libjconsole.jar";"D:Program Files/Java/jdk1.6.0_11/lib/t
ools.jar" Main

Or we can modify classpath in Env. Variables.

Right now, in my system it is displaying:

Main
org/netbeans/modules/javafx/preview/Main 1
That means, this code itself and Netbeans is running as a java process.

In next blog, we will try to see how to manage(not listing) other running java code from a java code. I am not able to find too much of doc from net, so things are slow :).

Monday Dec 01, 2008

A simple bad digital Clock

Here how to use Java code inside JavaFX and make a simple digital clock. Bad because i have not put the proper makeup :).

//Clock.fx

package digitalclock;

import javafx.scene.\*;
import javafx.scene.paint.\*;
import javafx.scene.text.\*;
import javafx.scene.transform.\*;
import javafx.animation.\*;
import javafx.scene.shape.\*;

// Java Legacy
import java.util.\*;

var months:String[] = ["JAN", "FEB", "MAR", "APR", "MAY", "JUN",
                "JUL", "AUG", "SEP", "OCT", "NOV", "DEC"];

public class Clock extends CustomNode {

   var radius = -20;
    // shifting the X center
    var centerX: Number = 50 ;
    // shifting the Y center
    var centerY: Number = 50 ;
    var hours:String;
    var minutes:String;
    var seconds:String;
    var date:String;
    var month:String;
    var year:String;
    var combination: String;

    // intializing the watch
    init {
        var timeline = Timeline {
            repeatCount: Timeline.INDEFINITE
            keyFrames : [
                KeyFrame {
                    time : 1s
                    action: function() {
                        actionOnTick();
                    }
                }
            ]
        }
        timeline.play();
    }
    function createCalendar() {
        var date = new Date();
        def calendar = Calendar.getInstance();
        calendar.setTime(new Date()); // fix for mobile
        calendar
    }
    // action taken on one tick
    public function actionOnTick () {
        var calendar = createCalendar();
        seconds = String.valueOf(calendar.get(Calendar.SECOND));
        if(seconds.length()!=2)  {
            seconds = "0{seconds}";
        }
        minutes = String.valueOf(calendar.get(Calendar.MINUTE));
        if(minutes.length()!=2)  {
            minutes = "0{minutes}";
        }
        hours = String.valueOf(calendar.get(Calendar.HOUR));
         if(hours.length()!=2)  {
            hours = "0{hours}";
        }
        date = String.valueOf(calendar.get(Calendar.DATE));
        if(date.length()!=2)  {
            date = "0{date}";
        }
        month = months[(calendar.get(Calendar.MONTH))];
        year = String.valueOf((calendar.get(Calendar.YEAR)));
        combination = "{hours}:{minutes}:{seconds}  {date}-{month}-{year}";
    }

    // overriding the method create()
    public override function create(): Node {
        return Group {
            transforms: [
                Transform.translate(centerX, centerY)
            ]
            content: [

                Rectangle {
                    x: -35, y: 2\*radius/3 - 15
                    width: 120 height: 20
                    fill: Color.GRAY
                    opacity:0.4
                    strokeWidth: 2
                    stroke: Color.BLACK
                    arcHeight:10
                    arcWidth:10
                },
                Text {
                    font: Font {
                        size: 11
                        name: "Arial"
                    }
                    x: -31 , y: 2 \* radius / 3
                    content: bind combination
                },
                  ]
                }
        };
} 


//Main.fx
package digitalclock;

import javafx.stage.Stage;
import javafx.scene.Scene;
import javafx.scene.text.Text;
import javafx.scene.text.Font;

Stage {
    title: "Digital Clock"
    width: 160
    height: 100
    scene: Scene {
        content: Clock{}
    }
}

Wednesday Nov 26, 2008

Plug-in 2 - New/Old Plug-in's

With Plug-in 2(Java 6u10), a whole new experience comes into Java Plug-in. I have mentioned the new features of Plugin2 in some of my presentations of 6u10.

For detail, please visit this link : http://java.sun.com/javase/6/webnotes/6u10/plugin2/index.html

Switching between old/new plugin:

Java Control Panel - Advanced - Java Plug-in - Enable the next gen plug-in.

(Check this link : http://www.java.com/en/download/help/new_plugin.xml)

By default, it will take new plugin, but untick it for old plugin.

Wednesday Nov 19, 2008

Java Market Trend

Today I got a mail from Carl. He works in a company which provides Marketing stats. Here are some of the exciting marketing stats of Java :

1. Median Salary :


Generated By: OdinJobs - Techonology Job Search Engine

2. Jobs Trend line

Compare Market Statistics Generated By: OdinJobs - Techonology Job Search Engine

3. Salary Histogram :

Compare Market Statistics Generated By: OdinJobs - Techonology Job Search Engine


Now, see the market increase in Java Gaming.And there is a reason behind it, people start realizing that Java is fast and a suitable language for gaming. It happened for quite a long time developed used to think that Java is a slow language and not meant for game.

Compare Market Statistics Generated By: OdinJobs - Techonology Job Search Engine

Banking sector, this is quite obvious because of the market fall down, else it was little above than the last year performance.

Compare Market Statistics Generated By: OdinJobs - Techonology Job Search Engine

Defense: This is quite an interesting market. It speaks about the robustness and security of Java. Defense finds it the best language for their purpose.

Compare Market Statistics Generated By: OdinJobs - Techonology Job Search Engine

For more visit this link : Java Market Stats

Sunday Sep 21, 2008

Java - Instruction set rather than time

One guy asked a question on a Java Forum: which operation is faster - post-increment or pre-increment. I really don't feel these things make a big difference in code performance. I have written a small code to check what nanosecond API of Java is telling about it. And again I reached to a wrong benchmarking. 

class InstructionCheck {
    private int x = 0;
 
    public void countup_() {
        ++x;
    }
    public void countup() {
        x++;
    }
    public void countdown() {
        x--;
    }
    public void count2up() {
        x = x+2;
    }
    public void count2down() {
        x = x-2;
    }
    public static void main(String[] args) {
        long stime = 0;
        long etime = 0;
        InstructionCheck ic = new InstructionCheck();

        stime = System.nanoTime();
        ic.countup_();
        System.out.println(System.nanoTime() - stime);

        stime = System.nanoTime();
        ic.countup();
        System.out.println(System.nanoTime() - stime);

        stime = System.nanoTime();
        ic.countdown();
        System.out.println(System.nanoTime() - stime);

        stime = System.nanoTime();
        ic.count2up();
        System.out.println(System.nanoTime() - stime);

        stime = System.nanoTime();
        ic.count2down();        
        System.out.println(System.nanoTime() - stime);
    }
}         

And the output after several run: 

20952
5308
5587
5587
5308

Now, no doubt the first value is not correct, because of some other reason(I really don't know why) but may be some reigster setting, first time using the class or something else.

But if we see the assemble code, it will simple say that there is(should) no difference in ++i or i++. Look at this :

public void countup_();
  Code:
   0:   aload_0
   1:   dup
   2:   getfield        #2; //Field x:I
   5:   iconst_1
   6:   iadd
   7:   putfield        #2; //Field x:I
   10:  return

public void countup();
  Code:
   0:   aload_0
   1:   dup
   2:   getfield        #2; //Field x:I
   5:   iconst_1
   6:   iadd
   7:   putfield        #2; //Field x:I
   10:  return

The complete assemble code, you can see by option javap -c FileName. My personal opinion is to check the instruction set rather checking the time by nanosecond or millisecond because some benchmarking issue can lead to a different result(which can be completely wrong, like in our case). Here we can easily see that ++i and i++ leads to same instruction and hence both will be more or less equal in performace.

Monday Sep 15, 2008

A nasty Problem - Java Code

Few days back, I got a problem in which actually I have to get the fields, constructor and method name from a java class. One can think of using reflection API and the problem is easy to solve, but that is not the case. Reflection API can only be used on class files not Java file. Than a quick idea came into mind to compile the file internally, use reflection and then delete the class file, if user don't want to see it. This is never be a tough job if I use JDK6 JavaCompiler code which is :

import java.io.IOException;

import javax.tools.JavaCompiler;
import javax.tools.ToolProvider;

public class JDK6FirstCompile {
  public static void main(String args[]) throws IOException {
    JavaCompiler compiler = ToolProvider.getSystemJavaCompiler();
    int results = compiler.run(null, null, null, "HelloWorld.java");
    System.out.println("Success: " + (results == 0));
  }
}


class HelloWorld {
  public static void main(String args[]) {
    System.out.println("Hello, World");
  }
}


But but, I was constraint to use JDK5 or less. So, this JDK6 API is not worth for me :-(. Finally, came up with a small code, which probably can do this in all the case. Hoping it will not lose any generic behavior and run in all cases.

Here is the code:

import java.io.\*;

public class CompileCheck {

public void compileClasses2() {
        try {
            String command = System.getProperty("java.home")+File.separator + ".." + File.separator+"bin"+File.separator+"javac " + "HelloWorld.java";
            System.out.println(command);
            Runtime.getRuntime().exec(command);
    } catch (Exception e) { }
    }


    public static void main(String[] args) {
 
        CompileCheck c = new CompileCheck();
        c.compileClasses2();
    }
}


In place of HelloWorld, I can surely use any path where the java file resides. And off course, I can use \*.java as well :-). Please let me know your opinion or any other method easier than this from which I can get class methods, attributes and all from a java file.

Saturday Sep 13, 2008

Last week.. a competition code !

Last week, IEC celebrates OpenSource Mela. In code war, we got a programming contest in which the problem statement is :

5 \* 4 / 2 - 5 + 2 = 7 (evaluated from left to right). So, input format is:

5 4 2 5 2 7

and output is to put into a valid expression format(all possible format). So, if its 2 2 4, then 2+2=4 and 2\*2=4 is possible. I have written some code for this, which goes here :

package problemstatement1;

import java.util.List;

public class Main {

    String input = "2 0 2";
    String output = new String();  // 5 \* 4 / 2 - 5 + 2 = 7
    int resultVal = 0;
    String operatorseq = new String();
    int result = 0;
    int totalcounter = 0;
    boolean flag = true;
 
    // converting input into easy format
 
    String[] inputtoken = input.split(" ");
    int[] numberseq = new int[inputtoken.length - 1];
    int totaloperator = numberseq.length - 1;
 
    public void isValid() {
        if (inputtoken.length < 3) {
            System.out.println("Usages ... Input Parameter should be three or more ");
            System.exit(0);
        }
    }

    public void processInput() {
        try {
        resultVal = Integer.parseInt(inputtoken[inputtoken.length - 1]);
        } catch(NumberFormatException e) {
            System.out.println("Parsing error" + "  " + e);
            System.exit(0);
        }
        for (int i = 0; i < numberseq.length; i++) {
            try {
            numberseq[i] = Integer.parseInt(inputtoken[i]);
            } catch(NumberFormatException e) {
                System.out.println("Parsing error" + "  " + e);
                System.exit(0);
              }
        }
    }

    public void showInput() {
        for (int i = 0; i < numberseq.length; i++) {
            // System.out.println(numberseq[i]);
        }
    }

    public void getPermutation() {
        GenerateOperators gen = new GenerateOperators("+-\*/", totaloperator);
        List<String> v = gen.getVariations();
        System.out.println("Possible Solutions");
        for (int i = 0; i < v.size(); i++) {
            operatorseq = v.get(i);
            manupulate();
        }
    }

    public void manupulate() {
 
        result = 0;
 
        for (int i = 0; i < operatorseq.length(); i++) {
            if (i == 0) {
                if ((operatorseq.charAt(i)) == '+') {
                    result = result + (numberseq[i] + numberseq[i + 1]);
                }
                if ((operatorseq.charAt(i)) == '-') {
                    result = result + (numberseq[i] - numberseq[i + 1]);
                }
                if ((operatorseq.charAt(i)) == '\*') {
                    result = result + (numberseq[i] \* numberseq[i + 1]);
                }
                if ((operatorseq.charAt(i)) == '/') {
                    try {
                    result = result + (numberseq[i] / numberseq[i + 1]);
                    } catch(Exception e) {
                        flag = false;
                        // don't do anything
                    }
                }
            } else {
                if ((operatorseq.charAt(i)) == '+') {
                    result = result + numberseq[i + 1];
                }
                if ((operatorseq.charAt(i)) == '-') {
                    result = result - numberseq[i + 1];
                }
                if ((operatorseq.charAt(i)) == '\*') {
                    result = result \* numberseq[i + 1];
                }
                if ((operatorseq.charAt(i)) == '/') {
                    try {
                        result = result / numberseq[i + 1];
                    } catch(Exception e) {
                        flag = false;
                        // don't do anything
                    }
                }
            }
        }
        if (result == resultVal && flag == true) {
            totalcounter++;
            System.out.println("");
            for (int i = 0; i < numberseq.length - 1; i++) {
                System.out.print(numberseq[i] + "" + operatorseq.charAt(i));
            }
            System.out.print(numberseq[numberseq.length - 1]);
            System.out.print("= " + result);
        }
     }

    public void count() {
        if(totalcounter == 0 ) {
            System.out.println("NO EXPRESSION POSSIBLE");
            System.exit(0);
        }
        else {
            System.out.println("");
            System.out.println("Total Possible Solution :" + totalcounter);
        }
    }
    public static void main(String[] args) {
        Main main = new Main();
        main.isValid();
        main.processInput();
        main.showInput();
        main.getPermutation();
        main.count();
    }
}

and one more file which is : 

package problemstatement1;

import java.util.List;
import java.util.ArrayList;

public class GenerateOperators {

   private String a;
   private int n;

   public GenerateOperators(String a, int n) {
       this.a = a;
       this.n = n;
   }

   public List<String> getVariations() {
       int l = a.length();
       int permutations = (int) Math.pow(l, n);
       char[][] storeCombination = new char[permutations][n];
       for (int x = 0; x < n; x++) {
           int temp = (int) Math.pow(l, x);
           for (int p1 = 0; p1 < permutations;) {
               for (int al = 0; al < l; al++) {
                   for (int p2 = 0; p2 < temp; p2++) {
                       storeCombination[p1][x] = a.charAt(al);
                       p1++;
                   }
               }
           }
       }

       List<String> result = new ArrayList<String>();
       for (char[] permutation : storeCombination) {
           result.add(new String(permutation));
       }
       return result;

   }

   public static void main(String[] args) {
       GenerateOperators gen = new GenerateOperators("AAAMMBR", 7);
       List<String> v = gen.getVariations();
             for (int i=0;i<v.size();i++) {
           String s1 = v.get(i);
           System.out.println(s1);
       }

   }
}

Feel free to use this code :-).



Sunday Sep 07, 2008

Sunday work - Tracing in FX and Blog Change :-)

 I did some fine tuning in my blog page after long time :-). I have added two more link in Links section, which can be helpful in :

1. Telling which JRE's are there on your machine(blog readers) machine.

2. And second will install the latest JRE(It will start installation directly, so careful :-D)

Alright, So now again one post for JavaFX. Finally I am able to write tracing path code in JavaFX. I have seen this in lot of Physics Motions where they show motion with tracing effect. Have a look at the output :

Here the ball is moving in a cosine fashion and so the trace. Easiest way to achieve this is to write code in update method. Have a look on the code, its small:

package tracemotion;

import javafx.scene.Node;
import javafx.scene.CustomNode;
import javafx.scene.Group;
import javafx.application.Frame;
import javafx.application.Stage;
import javafx.animation.Timeline;
import javafx.animation.KeyFrame;
import javafx.scene.geometry.\*;
import javafx.scene.effect.\*;
import javafx.scene.paint.\*;

import java.lang.System;
import java.lang.Math;

var t : Number = 0.0;

Frame {
    var input : TracingBall = TracingBall {};
    stage : Stage {
        fill: Color.BLACK;
        content : bind [
            input
        ]
    }
 
    visible : true
    title : "Tracing Ball"
    width : 600
    height : 600
    closeAction : function() { java.lang.System.exit( 0 ); }
}

class TracingBall extends CustomNode {

    attribute tracingballs : Circle[];
    attribute length : Integer = 600;
    attribute timer : Timeline = Timeline {
        repeatCount: Timeline.INDEFINITE
        keyFrames :
            KeyFrame {
                time : 100ms
                action : function() {
                    update();
                    t = t+0.3;
                }
            }
    }
 public function update() : Void {
        for( i in [0..length - 30] ) {
            tracingballs[i].centerX = tracingballs[i+30].centerX;
            tracingballs[i].centerY = tracingballs[i+30].centerY;
            tracingballs[i].radius = tracingballs[i+30].radius;
            tracingballs[i].opacity=0.4;
        }
        tracingballs[length] = Circle {
           centerX : bind(100 + t \* 30), 
           centerY : (300 + Math.cos(t) \* 100), 
           radius : 30, 
           fill : bind LinearGradient {
                    proportional: true
                    stops: [
                        Stop { offset: 0.0 color: Color.RED },
                        Stop { offset: 1.0 color: Color.GAINSBORO },
                    ]
                },
           opacity : 1.0 
 
        };
 }
 public function create(): Node {
        return Group {
            content : bind[tracingballs]   
        };
 }
 init {
        for( i in [0..length] ) {
            insert Circle { fill : bind LinearGradient {
                    proportional: true
                    stops: [
                        Stop { offset: 0.0 color: Color.RED },
                        Stop { offset: 1.0 color: Color.GAINSBORO },
                    ]
                },
                } into tracingballs;
 
        }   
        timer.start();
    }        
}
Some lines in code are filling those fancy colors in ball(some lines are hard coded as well).I am a real bad guy in filling nice catchy colors(this color looks like a sun and a moon combination). Any comments/improvements are welcome !

Saturday Sep 06, 2008

Guassian Blur Example JavaFX

This is one simulation of Golden Eyes :-D(with an ugly face). I tried to make one use of Gaussian Blur which is applied in the white color of eyes. Adding this spot in the eyes gives a real simulation.

Here is the simple code :

package eyes;

import javafx.application.Frame;
import javafx.application.Stage;
import javafx.scene.geometry.Arc;
import javafx.scene.geometry.\*;
import javafx.scene.paint.Color;
import javafx.scene.paint.\*;
import javafx.scene.effect.\*;

var y: Number = 150;
Frame {
    title: "Golden Eyes"
    width: 500
    height: 500
    closeAction: function() { java.lang.System.exit( 0 ); 
    }
    visible: true

    stage: Stage {
        fill: Color.GRAY;
        content: [  
 
            Circle {
                centerX: 160, centerY: y
                radius: 23
                fill: LinearGradient {
                    startX: 0.0
                    startY: 0.0
                    endX: 1.0
                    endY: 0.0
                    proportional: true
                    stops: [
                        Stop { offset: 0.0 color: Color.GOLD },
                        Stop { offset: 1.0 color: Color.BLACK }
                    ]
                }
                opacity: 0.9
            },
 
            Circle {
                centerX: 160, centerY: y
                radius: 10
                fill: Color.BLACK
            },
            Circle {
                centerX: 166, centerY: y - 5
                radius: 5
                fill: Color.WHITE;
                effect : GaussianBlur {
                    radius: 6
                }
            },
            Circle {
                centerX: 250, centerY: y
                radius: 23
                fill: LinearGradient {
                    startX: 0.0
                    startY: 0.0
                    endX: 1.0
                    endY: 0.0
                    proportional: true
                    stops: [
                        Stop { offset: 0.0 color: Color.BLACK },
                        Stop { offset: 1.0 color: Color.GOLD }
                    ]
                }
                opacity: 0.2
            },
 
 
            Circle {
                centerX: 250, centerY: y
                radius: 10
                fill: Color.BLACK
            },
            Circle {
                centerX: 244, centerY: y - 5
                radius: 5
                fill: Color.WHITE;
                effect : GaussianBlur {
                    radius: 6
                }
            },
            Circle {
                centerX: 200, centerY: 180
                radius: 100
                fill: Color.SIENNA
                opacity: 0.1
 
            },
            Polyline { 
             stroke:Color.BLACK
                points: [
                    200,160, 
                    220.0,220.0,
                    180.0,220.0
                ]
            },
            Path {
               fill: LinearGradient {
                    startX: 0.0
                    startY: 0.0
                    endX: 1.0
                    endY: 0.0
                    proportional: true
                    stops: [
                        Stop { offset: 0.0 color: Color.BLACK },
                        Stop { offset: 1.0 color: Color.RED }
                    ]
                }
                elements: [
                    MoveTo { x: 160 y: 240 },
                    ArcTo { x: 250 y: 240 radiusX: 100 radiusY: 100},
 
                ]
            },
 
       ]
    }
}

Thursday Aug 28, 2008

Next BOJUG meet

We are welcoming all the Java Engineers in Bangalore to join BOJUG. Its Bangalore Open Java Users Group. Before going into the schedule of this time meet, we motivate you to join the BOJUG group at: http://bojug.wikispaces.com/ and http://bojug.dev.java.net. Now, here are the talks of the week: 

The next Bangalore Open Java Users Group (BOJUG) (http://bojug.dev.java.net)  meet has been planned for Saturday August 30, 2008,Time: 11.30 AM .

Venue:

Thoughtworks Bangalore

Tower C, Corporate Block, Diamond District, Airport Road
Landmarks: The first set of buildings after the Indiranagar flyover,
opp to the TJIF restaurant.

Google Maps Location: http://maps.google.com/maps?f=q&hl=en&geocode=&q=thoughtworks,+bangalore&ie=UTF8&filter=0&ll=12.996864,77.651196&spn=0.075603,0.154495&z=13

Time: 11.30 AM
Session Details:

1. Java FX..Its just the beginning-Vaibhav Choudhary

JavaFX Preview SDK
NetBeans Compatibilty
Demo, Demo, Demo, Demo .. and only Demo. How to make timeline, reflection, constraint,easing, shapes, animation, Java AWT/Swing.
Last we will try to see how to use it in applet or any type of web code.

2. Beans Binding and Beans Validation- Sathish Kumar

Short discussion on the above topics

3. Tomcat Internals - Sriram Narayanan

In this talk, Sriram will cover in brief various Tomcat configuration issues (server.xml, how to avoid having to deploy during development
time, etc). He'll next cover interesting topics such as developing custom Tomcat components, and how the component assembly mechanism
works.

Monday Aug 18, 2008

Button Tabs with effects in JavaFX !

It looks good, so I decided to put before the completion of work. I was trying to simulate some fancy effects on button, so that I can embed it somewhere in some site. Here what is the class for Button:

public class Button extends CustomNode {

    public attribute x: Number;
    public attribute y: Number;
    public attribute text: Text;
    public attribute rectangle: Rectangle;
    public attribute content: String;
 
    public function create(): Node {

Now, the buttons will look like: 

 If you move the focus on any of the button, it will shine like this :

 or like this :

This simple 2 line animation is achieved by playing with the opacity code. Though I am not able to fit my text inside the button which currently I am trying to bind out. But simple flashy buttons are easy to achieve. Here is the code:

package flashybutton;

import javafx.scene.CustomNode;
import javafx.scene.Group;
import javafx.scene.Node;
import javafx.scene.text.\*;
import javafx.scene.geometry.\*;
import javafx.scene.paint.Color;
import javafx.application.Frame;
import javafx.application.Stage;
import javafx.ext.swing.TextField;
import javafx.scene.Font;
import javafx.scene.FontStyle;
import javafx.scene.paint.\*;
import javafx.input.MouseEvent;


var x: Number = 100;
var y: Number = 100;
var color: Color;
var buttons:Button[]; 
var text: Text;
var content: String;
var width: Number = 100;
var height: Number = 40;
var arcWidth:Number = 10;
var arcHeight: Number = 10;
var opacity: Number = 0.6;

for( i in [1..5] ) {
    insert Button {
        x:100 + 100 \* i,
        y:100,
        content: "HelloWorld" + i,
        opacity: 0.6
    } into buttons;
}     
Frame {
    title: "MyApplication"
    width: 1000
    height: 200
    closeAction: function() { java.lang.System.exit( 0 ); 
    }
    visible: true

    stage: Stage {
        fill: Color.BLACK
        content: [ 
            buttons
        ]
    }
}

public class Button extends CustomNode {

    public attribute x: Number;
    public attribute y: Number;
    public attribute text: Text;
    public attribute rectangle: Rectangle;
    public attribute content: String;
 
    public function create(): Node {
        return Group {
            content: [
                Rectangle {    
                    x : bind x,
                    y : bind y, 
                    fill: LinearGradient {
                        startX: 0.0
                        startY: 0.0
                        endX: 1.0
                        endY: 0.0
                        proportional: true
                        stops: [
                 //   Stop { offset: 0.0 color: Color.BLACK },
                            Stop { offset: 0.0 color: Color.BLACK },
                            Stop { offset: 0.5 color: Color.GOLD },
                            Stop { offset: 1.0 color: Color.BLACK }
                        ]
                    },
                    width: 100
                    height: 40
                    arcWidth: 10
                    arcHeight: 10
                    opacity: bind opacity
                    onMouseMoved: function( e: MouseEvent ):Void {
                        opacity = 1.0;
                    }
                    onMouseExited: function( e: MouseEvent ):Void {
                        opacity = 0.6;
                    }
                },
                Text {
                    x: bind x + 10,
                    y: bind y + height / 2 + arcHeight / 2;
                    content: bind content
 
 
                }
            ]
        }
    }
}

Motion of Ball Under Gravity - JavaFX

As written in the last blog, now we can use those MotionBall into giving some kind of motion. Here I have tried to give a simple motion of ball under gravity. After every hit there is an energy dissipation and the ball will slow down at end. The colors of balls, initial positions and radius are all random but under a constraint. 

Now, the motion of the balls should get called in timeline. Like this:

 var timeline = Timeline {
    repeatCount: Timeline.INDEFINITE
    keyFrames : [
        KeyFrame {
            time : 16ms
            action: function():Void {
                for(ball in balls) {
                    ball.motion();
                }
            }
        }
    ]
}

Here is the final code. I tried to write the value as generic as possible but pardon me if there is some hardcoded value written somewhere :

import javafx.scene.CustomNode;
import javafx.scene.Group;
import javafx.scene.Node;
import javafx.scene.geometry.\*;
import javafx.animation.Timeline;
import javafx.animation.KeyFrame;
import javafx.scene.paint.\*;
import javafx.application.Frame;
import javafx.application.Stage;
import javafx.scene.effect.\*; 

// Java Legacy
import java.lang.Math;
import java.util.Random;
import java.lang.System;


var balls:GravityBall[];
var gravity:Number= 0.1;
var width:Number = 1200;
var height:Number= 500;
var dampFactor: Number = 0.9;
 
var timeline = Timeline {
    repeatCount: Timeline.INDEFINITE
    keyFrames : [
        KeyFrame {
            time : 16ms
            action: function():Void {
                for(ball in balls) {
                    ball.motion();
                }
            }
        }
    ]
}

var rnd : Random = new Random();

for( i in [1..5] ) {
    insert GravityBall {
        x : rnd.nextInt( 100 ), y :  rnd.nextInt( 300 ), radius : rnd.nextInt( 10 ) + 20
        color : Color.rgb(rnd.nextInt(255),rnd.nextInt(255),rnd.nextInt(255))
        , opacity : 0.9
    } into balls;
}    


var rect = Rectangle {
    x: 0, y: 500
    width: 1200, height: 10
    fill: LinearGradient {
        startX: 0.0
        startY: 0.0
        endX: 1.0
        endY: 0.0
        proportional: true
        stops: [
            Stop { offset: 0.0 color: Color.TRANSPARENT },
            Stop { offset: 1.0 color: Color.WHITESMOKE }
        ]

    }
}
Frame
{
 
    title: "MyApplication"
    width: 1200
    height: 732
    closeAction: function() { java.lang.System.exit( 0 ); 
    }
    visible: true

    stage: Stage {
        fill : Color.BLACK
        content: [
            balls,
            rect
        ]
    }
}

timeline.start();

public class GravityBall extends CustomNode {

    public attribute x : Number;
    public attribute y : Number;
    public attribute radius : Number;
    public attribute color : Color;
    public attribute velocity : Number;
 
    public function motion(): Void {
        velocity += gravity;
        x += 1;
        y += velocity;
 
        if(x + radius > width ) {
            x = width - radius; //for ending at the boundary
        }
        if( y + radius > height ) {
            y = height - radius;
            velocity \*= -dampFactor;
        }
    }
 
    public function create(): Node {
        return Circle {
            centerX : bind x, centerY : bind y, radius : bind radius
            fill: bind color
 
        };
 
    }
} 

This is small output view :


Friday Aug 15, 2008

Insertion trigger in JavaFX

This weekend I have written some physics equation in JavaFX like motion under gravity and collision motion. In all  complex code, we have to write a class of MotionBall, which consist attribute like X position, Y position, Velocity, Mass and Color of Ball like:

public class MotionBall extends CustomNode {

    public attribute x: Number;
    public attribute y: Number;
    public attribute velocityX: Number;
    public attribute velocityY: Number;
    public attribute mass: Number;
    public attribute radius: Number;
    public attribute color: Color;
 
    public function create(): Node {
        return Circle {
            centerX : bind x, centerY : bind y, radius : bind radius
            fill : bind color
 
        };
    }
} 

After this, the important part is to fill these data outside the class. Say, I want to make 5 instance of MotionBall. And I want to give Center X, Center Y, radius and color. Here in this code, I want to put the Balls at the random position with random radius with random color :-). Here goes the insertion trigger in JavaFX:

package insertion;

import javafx.application.Frame;
import javafx.application.Stage;
import javafx.scene.CustomNode;
import javafx.scene.Group;
import javafx.scene.Node;
import javafx.scene.geometry.Circle;
import javafx.scene.paint.Color;
import java.util.Random;


var radius: Number;
var balls: MotionBall[];

var rnd : Random = new Random();

 for( i in [1..5] ) {
                insert MotionBall {
                    x : rnd.nextInt( 170), y :  rnd.nextInt( 170 ), radius : rnd.nextInt( 10 ) + 20
                    color : Color.rgb(rnd.nextInt(255),rnd.nextInt(255),rnd.nextInt(255))
                    , opacity : 0.9
                    } into balls;
                }    
Frame {
    title: "Insertion Example"
    width: 250
    height: 250
    closeAction: function() { java.lang.System.exit( 0 ); 
    }
    visible: true

    stage: Stage {
        fill: Color.BLACK
        content: 
            bind balls
 
    }
}
 
public class MotionBall extends CustomNode {

    public attribute x: Number;
    public attribute y: Number;
    public attribute velocityX: Number;
    public attribute velocityY: Number;
    public attribute mass: Number;
    public attribute radius: Number;
    public attribute color: Color;
 
    public function create(): Node {
        return Circle {
            centerX : bind x, centerY : bind y, radius : bind radius
            fill : bind color
 
        };
    }
}

This is how output looks like : jar file.

I have written some attribute for further use, so please ignore the use.


About

Vaibhav Hi, I am Vaibhav Choudhary working in Oracle with JDK team. This blog is all about simple concept of Java, JVM and JavaFX.

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