Reflections
Elliptical Gradient Button in JavaFX
In JavaFX, we can make our own fancy buttons. Here in this blog, I tried to write an elliptical button. Have a look.
Here is the code :
package ellipticalbutton;
import javafx.scene.effect.*;
import javafx.scene.Group;
import javafx.scene.input.MouseEvent;
import javafx.scene.paint.*;
import javafx.scene.Scene;
import javafx.scene.shape.*;
import javafx.scene.text.*;
import javafx.stage.*;
var x=70;
var y=40;
var el:Ellipse = Ellipse {
centerX: 120
centerY: 100
radiusX: bind x
radiusY: bind y
effect: DropShadow {
offsetY: 3
color: Color.color(0.3, 0.3, 0.3)
spread:0.4
}//end effect
effect:GaussianBlur{
}
fill:RadialGradient{
centerX:0
centerY:0
radius:25
proportional:false
cycleMethod:CycleMethod.REPEAT
stops:[
Stop {
offset: 0.0
color: Color.ANTIQUEWHITE },
Stop {
offset: 0.3
color: Color.GREEN },
Stop {
offset: 0.8
color: Color.ANTIQUEWHITE }
]
}//end fill
onMousePressed: function( e: MouseEvent ):Void {
x = x - 2;
y = y - 2;
}
onMouseReleased: function( e: MouseEvent ):Void {
x = x + 2;
y = y + 2;
}
}//end ellipse
var t = Text {
font: Font {
size: 20
name:"Verdana"
}
x: 90
y: 100
content: "Press"
fill:Color.DARKGREEN
effect:DropShadow{
offsetX:10
offsetY:10
color:Color.DARKGRAY
}
}//end Text
Stage {
title: "Elliptical Button"
//style:StageStyle.UNDECORATED
width: 240
height: 320
scene: Scene {
fill:Color.LIGHTGREY
content: [Group{
content:[
el,
t
]
}
]
}
}
Posted at 09:58AM Jan 27, 2009 by vikram in Sun | Comments[7]
Sun Tech Days 2008:An insider review.
SUN tech days 08 in hyderabad was fantastic.
A lot of engineers attended and this I guess was one of the largest gathering of Developers in India in 2008.
This was a great platform for Sun to showcase its technology in India which has a large IT base.
Although the center point of focus was java and netbeans, there were also another interesting sessions.
Sessions on the new sun studio, presenters from Intel and AMD were a hit.
The demo booths were always crowded and attractive sessions were buzzing with people.
Around this time SUN had acquired MySQl and that keynote by David Axmark was fanstastic involving a lot of passion.
But there were certain things that were striking otherwise as well.
A lot of in-session advertisement hurts and takes the focus out of technology to Sun marketing.
I am not saying this was not required, but overdoing it or bringing it into the very dynamics of technology is not welcome.
And as for the other keynotes, they were too long and doing overtime.
Another thing was that Sun kept focus on software side, while it's and irony of sorts that Sun makes money more from Systems than from Software alone.
Hardware demonstrations and session need to be added as well. A simple sun machine power needs to be brought out especially in a country like India, where the market is highly price sensitive but huge.
Technology like Sun ray and desktops like the Ultra 24 boxes should also be added to the set of demonstrations.
As for my own liking, the food was best. It is heartning to see that Sun does excellent managing a conference of this stature.
Kudos to those who made the last year a success. Keep the good work going.
Posted at 02:40PM Jan 20, 2009 by vikram in Sun | Comments[11]
Writing Java Script in Java.
A small code that can call JS code from within Java.
This feature is part of the jdk6 version.
01 import javax.script.*;
02 import java.util.*;
03
04 class Sample
05 {
06 public static void main(String[] args)
07 {
08
09 ScriptEngineManager manager= new ScriptEngineManager();
10 List<ScriptEngineFactory> factories= manager.getEngineFactories();
11
12 for (ScriptEngineFactory factory: factories) {
13
14 String name = factory.getEngineName();
15 String version = factory.getEngineVersion();
16 String language = factory.getLanguageName();
17
18 System.out.println(name+"("+version+"): "+language);
19
20 for(String n: factory.getNames())
21 System.out.println(n);
22 }
23
24 // JavaScript code in a String
25 String script = "function hello(name) { print('Hello, ' + name); }";
26
27
28 ScriptEngine engine = manager.getEngineByName("JavaScript");
29
30 try
31 {
32 // evaluate JavaScript code from String
33 engine.eval("print('Hello, World')");
34 engine.eval(script);
35 Invocable inv = (Invocable) engine;
36 inv.invokeFunction("hello", "THE");
37
38 }
39 catch (ScriptException e)
40 {
41 e.printStackTrace();
42 }
43 catch (NoSuchMethodException ee){
44 ee.printStackTrace();
45 }
46
47
48 }
49 }
Posted at 12:22PM Jan 20, 2009 by vikram in Sun | Comments[17]
SUN tech days 2009 is here
Sun tech days 2009 is happening and registrations are open.
Posted at 01:40PM Jan 16, 2009 by vikram in Sun | Comments[4]
Getting PermGen information using jmap
The permanent generation is the area of heap that holds all the reflective data of the virtual machine
itself, such as class and method objects.
Configuring the size of the permanent generation can be important for applications that dynamically
generate and load a very large number of classes. If an application loads “too many” classes then it is possible it will abort with an OutOfMemoryError.
The specific error will look like :
“Exception in thread XXXX java.lang.OutOfMemoryError: PermGen space”
In 1 terminal start an application.
I am just using the jfc Notepad application here, since it is pretty passive and doesn't interfere with the screen while I am trying to write this.
bash-3.00$ ./java -jar ../demo/jfc/Notepad/Notepad.jar
Get the pid in this case 2239
bash-3.00$ ./jps
3131 Jps
2239 Notepad.jar
22305
10792 Main
Now in another terminal try running this
bash-3.00$ ./jmap -permstat 2239
Attaching to process ID 2239, please wait...
Debugger attached successfully.
Server compiler detected.
JVM version is 14.0-b10
finding class loader instances ..Finding object size using Printezis bits and skipping over...
Finding object size using Printezis bits and skipping over...
Finding object size using Printezis bits and skipping over...
done.
computing per loader stat ..done.
please wait.. computing liveness.....done.
class_loader classes bytes parent_loader alive? type<bootstrap> 1596 7131080 null live <internal>
0xe6e91088 1 1152 null dead sun/reflect/DelegatingClassLoader@0xb7847 8d0
0xe65142c8 6 17968 0xe6424958 dead sun/reflect/misc/MethodUtil@0xb7d67248
0xe6426528 0 0 0xe6424958 live java/util/ResourceBundle$RBClassLoader@0x b796ec78
0xe6e8a128 1 1152 null dead sun/reflect/DelegatingClassLoader@0xb7847 8d0
0xe656d8a0 1 1184 0xe65142c8 dead sun/reflect/DelegatingClassLoader@0xb7847 8d0
0xe693cd20 1 1792 null dead sun/reflect/DelegatingClassLoader@0xb7847 8d0
0xe641e710 1 8080 null live sun/misc/Launcher$ExtClassLoader@0xb79214 78
0xe6e8ee40 1 1152 null dead sun/reflect/DelegatingClassLoader@0xb7847 8d0
0xe6555668 1 1752 null dead sun/reflect/DelegatingClassLoader@0xb7847 8d0
0xe6e8cd78 1 1768 null dead sun/reflect/DelegatingClassLoader@0xb7847 8d0
0xe6424958 87 810144 0xe641e710 live sun/misc/Launcher$AppClassLoader@0xb7964f d0total = 12 1697 7977224 N/A alive=4, dead=8 N/A
Typically, we get the output in this form.
For each class loader object, the following details are printed:
1. The address of the class loader object – at the snapshot when the utility was run.
2. The number of classes loaded (defined by this loader with the method(java.lang.ClassLoader.defineClass).
3. The approximate number of bytes consumed by meta-data for all classes loaded by this class loader.
4. The address of the parent class loader (if any).
5. A “live” or “dead” indication – indicates whether the loader object will be garbage collected in the future.
6. The class name of this class loader.
Posted at 01:19PM Jan 16, 2009 by vikram in General | Comments[0]
Garbage First: 3 Differences between CMS and G1
Garbage first is a new experimental collector introduced in the hotspot VM.
It is experimental since,it is not yet fully supported and still had some bugs which are being fixed.
CMS has been the defacto garbage collector for many for quite some time now.
Here's 3 main reasons why G1 is a bit better than CMS
1. Compacting
CMS in old generation does not undergo any compaction. During a full GC, CMS marks and sweeps (deletes) the objects that are not alive in the old generation. However, it does not collect all the objects towards one end of the heap. This results in fragmentation over time, following which the vm falls back to the serial gc to do a compaction. this is definitely a time consuming and long pause activity.
In G1, since the heap is organized into regions, there is no fragmentation and even if there is for a short period of time, it is limited to particular set of regions. The entire old generation is not affected.
2. Ease of use.
G1 has a lot less number of switches as compared to CMS, tuning your applications VM is simpler.
G1 is already present in jdk7 as of now and one can try it.
to use G1, these 2 switched need to be passed.
-XX:+UnlockExperimentalVMOptions -XX:+UseG1GC
3. Predictable.
An inherent problem with CMS is that, it has a quite long pauses when it goes for a full GC.
The primary reason for this is that it has to scan the entire heap searching for live objects.
With the regions in G1, this scanning can be limited to a particular set of regions and hence the pause times can be made more predictable.
Posted at 02:15PM Jan 08, 2009 by vikram in Sun | Comments[2]