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Tag: netbeans

JavaFX, handling events with overlapping elements

Here is a problem I faced those days while programming with JavaFX.
When you perform a click in a JavaFX area, mouse events are called to all nodes through that position. You can see this behavior in this video.

Example 1.

Here is the code.

import javafx.application.*;
import javafx.scene.geometry.*;
import javafx.scene.geometry.Rectangle;
import javafx.scene.paint.Color;
import javafx.input.MouseEvent;

Frame {
    width: 200
    height: 200
    visible: true
    stage: Stage {
        content: [
            Rectangle {
                var color1 = Color.BLUE;
                x: 10, y: 10, width: 140, height: 90, fill: bind color1
                onMouseClicked: function( e: MouseEvent ):Void {
                    if (color1==Color.BLUE){
                        color1 = Color.GREEN;
                    } else {
                        color1 = Color.BLUE
                    }
                }
            },
            Circle {
                var color2 = Color.RED
                centerX: 100, centerY: 100, radius: 40, fill: bind color2
                onMouseClicked: function( e: MouseEvent ):Void {
                    if (color2==Color.YELLOW){
                        color2 = Color.RED;
                    } else {
                        color2 = Color.YELLOW
                    }
                }
            }
        ]
    }
}

This is the default behavior. All node are called with a mouse event. Is a expected and robust behavior but sometimes we just don’t want that. We want events called to just one node or a set of nodes.

Example 2.

Is exactly the same code but with blocksMouse: true in the circle node. When blocksMouse is true the mouse event will not be called to others node behind it.

package overlapping;

import javafx.application.*;
import javafx.scene.geometry.*;
import javafx.scene.geometry.Rectangle;
import javafx.scene.paint.Color;
import javafx.input.MouseEvent;

Frame {
    width: 200
    height: 200
    visible: true
    stage: Stage {
        content: [
            Rectangle {
                var color1 = Color.BLUE;
                x: 10, y: 10, width: 140, height: 90, fill: bind color1
                onMouseClicked: function( e: MouseEvent ):Void {
                    if (color1==Color.BLUE){
                        color1 = Color.GREEN;
                    } else {
                        color1 = Color.BLUE
                    }
                }
            },
            Circle {
                var color2 = Color.RED
                centerX: 100, centerY: 100, radius: 40, fill: bind color2
                blocksMouse: true
                onMouseClicked: function( e: MouseEvent ):Void {
                    if (color2==Color.YELLOW){
                        color2 = Color.RED;
                    } else {
                        color2 = Color.YELLOW
                    }
                }
            }
        ]
    }
}

Thanks guys on the OpenJDK user mail list and at OpenJFX Forum, specially this thread.

Event Review: JavaDay Juazeiro do Norte

Rafael Carneiro, Tarso Bersa, Rafael Ponte and me, after 8 hours of bus travel, arrived in Juazeiro do Norte to talk at the first JavaDay there.

Why Free Software?

JavaDay_Juazeiro_do_Norte_Silveira_Rafael Last touches

JavaDay Juazeiro do Norte Silveira Neto Coffee Break Gifts Silveira Rafael Ponte

  • Rafael Carneiro talked about Java Certification.
  • Tarso Bersa talked about Spring Framework for JEE applications.
  • I talked about NetBeans 6.
  • Rafael Ponte talked about JavaServer Faces.

We answered a lot of questions and gave lot of gifts. I also showed the Sun Academic Initiative, which they are already subscribed. We also showed several opportunities they can participate with CEJUG like free vouchers or a free travel for Belgium.

Some pictures we took. These ones during the bus travel. We saw a nice sunrise through beautiful landscapes.

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We playing guitar hero. :D The city have their own shopping with games, restaurant and cinema.

Guitar Hero Guitar Hero

The main atraction at Juazeiro is a statue of Padre (Priest) Cícero with 7 meters itself and more 8 meters of base. Pilgrimage to this statue takes place in his honour every November, attracting thousands of followers. The city’s economy is highly influenced by those travelers devotes.

Padim fitas

eu e o padim Padim

There’s a museum with several personal objects from Padre Cicero. People go there in order to thanks for miracles. If you got your a part of your body cured, of place there a wooden replica of that part of your body. If you got a car, you place a wooden car or a photo, and so on. There is thousands, maybe millions, of objects theres.

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You can see all photos at Carneiro’s album or in my album.

1º Java Day em Juazeiro do Norte

Esse fim de semana o CEJUG vai colocar o pé na estrada e partir rumo a Juazeiro do Norte para realizar, no dia 31 de Maio, um JavaDay, ciclo de palestras sobre tecnologia Java.

Essa é a grade de palestras:

Horário Palestra Palestrante
08:30 Certificação Java. A palestra tem o intuito de apresentar as Certificações da Tecnologia Java, os programas de estudos para obtenção destas certificações, como o mercado de trabalho local avalia os profissionais certificados e as estatísticas referentes a remuneração dos profissionais certificados. Rafael Carneiro é JUG Leader do CEJUG (Ceará Java Users Group) e também coordenador do
PortalJava. Trabalha na IVIA, gosta de ler diversos blogs sobre Java e possui algumas certificações da Sun.
Mantém um blog sobre desenvolvimento de software no endereço www.rafaelcarneiro.org.
09:30 Utilizando o Spring Framework em Aplicações JEE. Desenvolver aplicações na plataforma JEE pode tornar-se difícil dependendo das tecnologias escolhidas. Esta palestra tem o objetivo de mostrar como o Spring Framework pode simplificar o desenvolvimento de software nessa plataforma, mantendo a solução leve e com serviços avançados, tais como gerenciamento de transações, acesso remoto a Web-Services ou RMI, e transparência no uso de AOP. Tarso Bessa é um entusiasta Java e atua no desenvolvimento na plataforma há 5 anos. Possui foco em tecnologias Web e gosta de ler bastante sobre novas tecnologias, tendências de mercado e computação distribuída. Atualmente trabalha na IVIA como Arquiteto Java, é formado em Informática pela UNIFOR e possui
algumas certificações da Sun, entre elas a SCEA.
10:30 Conhecendo o NetBeans 6. O NetBeans é uma plataforma de desenvolvimento gratuita, livre, multiplataforma e multilinguagem. A palestra apresenta os recursos básicos do NetBeans 6, focando a facilidade de seu aprendizado, seus recursos de produtividade e usabilidade, além da inclusão de linguagens como Ruby, JavaScript e PHP. Silveira Neto é estudante de Computação na Universidade Federal do Ceará, Embaixador de
Campus da Sun Microsystems, participa do grupo de pesquisa ParGO (Paralelismo, Grafos e Otimização combinatória) e é membro do CEJUG (Ceará Java Users Group). Tem como hobbies os blogs (silveiraento.net e eupodiatamatando.com), o desenho e o desenvolvimento de Softwares Livres.
11:30 JavaServer Faces, desenvolvendo aplicações web com produtividade. JSF é um framework que auxilia o desenvolvimento de sistemas para a Web, fornecendo recursos avançados e dinâmicos. A palestra aborda os principais conceitos da tecnologia, como ciclo de vida, características, mercado de trabalho e integração com outros frameworks do mercado. Rafael Ponte atua com desenvolvimento de software há mais de 3 anos, atualmente é analista
pogramador na IVIA, com foco no desenvolvimento de aplicações web, entusiasta Java, JSF e Domain Driven
Design, moderador da lista de discussão JavaServer Faces International Group e sócio fundador da empresa
de consultoria Triadworks. Mantém um blog no endereço www.rponte.com.br.

Vai acontecer na Faculdade de Juazeiro do Norte (Rua São Francisco 1224 A São Miguel, Juazeiro do Norte, Ceará), no dia 31 de Maio a partir das 8:30. Além das palestras também vão haver sorteios de vários brindes.

O evento é uma promoção do CEJUG e da Coordenação do Curso de Sistemas de Informação da Faculdade de Juazeiro do Norte.

Java key listening example

This post continues a serie of posts I’m writing about 2D game development in Java.
A simple example of an JPanel that implements KeyListener (and a little trick) to handle KeyEvents to move a white square.

Java KeyListening Example

import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import javax.swing.JPanel;
import javax.swing.JTextField;

public class KeyPanel extends JPanel implements KeyListener{
    private int x=50,y=50;
    public KeyPanel() {
        JTextField textfield = new JTextField();
        textfield.addKeyListener(this);
        add(textfield);
        textfield.setPreferredSize(new Dimension(0,0));
    }

    public void keyTyped(KeyEvent e) {}

    public void keyReleased(KeyEvent e) {}

    public void keyPressed(KeyEvent e) {
        if (e.getKeyCode() == KeyEvent.VK_LEFT)
            x-=5;
        if (e.getKeyCode() == KeyEvent.VK_RIGHT)
            x+=5;
        if (e.getKeyCode() == KeyEvent.VK_DOWN)
            y+=5;
        if (e.getKeyCode() == KeyEvent.VK_UP)
            y-=5;
        this.repaint();
    }

    @Override
    public void paintComponent(Graphics g) {
        super.paintComponent(g);
        g.setColor(Color.black);
        g.fillRect(0, 0, 500, 500);
        g.setColor(Color.white);
        g.fillRect(x, y, 50, 50);
    }
}

Download the complete NetBeans source project files: KeyTest.tar.bz2.

Simple Java Tileset Example

Tilesets are a common technique in game development to create all kinds of tile-based games (from strategy to RPG games).

Here’s a example of simple 2D isometric square tilesets. I decided to use 32×32 pixels tiles and store 10 tiles per row in a single image:

I created a class called public class JGameCanvas that extends from JPanel from swing:

package game;

import java.awt.Color;
import java.awt.Graphics;
import java.awt.Image;
import java.awt.Toolkit;
import javax.swing.JPanel;

enum Tile {
GRASS, GRASS_STONE, GRASS_BAGS, T3, T4, T5, T6, T7, T8, T9,
TREE, TREE_CHOMP, TREE_DEAD, T13, T14, T15, T16, T17, T18, T19,
ROAD_H, ROAD_V, ROAD_HV_DOWN, ROAD_HV_UP, ROAD_VH_RIGHT, ROAD_VH_LEFT, ROAD_CROSS, T27, T28, T29,
WALL, WALL_POSTER, WALL_END_RIGHT, WALL_END_LEFT, T34, T35, T36, T37, T38, T39,
T40, T41, T42, T43, T44, T45, T46, T47, T48, T49,
NEWS, T51,      RES_1, RES_2, BUSS_1, BUSS_2, HOSP_1, HOSP_2, MARK_1, MARK_2,
PIZZ_1, PIZZ_2, RES_3, RES_4, BUSS_3, BUSS_4, HOSP_3, HOSP_4, MARK_3, MARK_4,
PIZZ_3, PIZZ_4, RES_5, RES_6, BUSS_5, BUSS_6, HOSP_5, HOSP_6, MARK_5, MARK_6
}

public class JGameCanvas extends JPanel{
    private static final int tW = 32; // tile width
    private static final int tH = 32; // tile height
    private static final Tile map[][] =
    {{Tile.TREE,Tile.TREE, Tile.TREE, Tile.ROAD_V, Tile.GRASS, Tile.TREE, Tile.TREE_DEAD, Tile.GRASS_STONE, Tile.TREE, Tile.TREE},
     {Tile.WALL, Tile.WALL_POSTER, Tile.WALL_END_RIGHT , Tile.ROAD_V, Tile.WALL_END_LEFT, Tile.WALL, Tile.WALL_END_RIGHT, Tile.TREE_CHOMP, Tile.GRASS_STONE, Tile.GRASS_STONE},
     {Tile.GRASS,Tile.GRASS, Tile.GRASS_STONE, Tile.ROAD_V, Tile.GRASS, Tile.GRASS, Tile.GRASS, Tile.GRASS, Tile.GRASS, Tile.GRASS},
     {Tile.PIZZ_1,Tile.PIZZ_2, Tile.GRASS, Tile.ROAD_V, Tile.GRASS, Tile.GRASS, Tile.GRASS, Tile.GRASS, Tile.GRASS, Tile.GRASS},
     {Tile.PIZZ_3,Tile.PIZZ_4, Tile.GRASS, Tile.ROAD_V, Tile.GRASS, Tile.GRASS, Tile.MARK_1, Tile.MARK_2, Tile.HOSP_1, Tile.HOSP_2},
     {Tile.ROAD_H,Tile.ROAD_H, Tile.ROAD_H, Tile.ROAD_VH_LEFT, Tile.TREE, Tile.TREE_DEAD, Tile.MARK_3, Tile.MARK_4, Tile.HOSP_3, Tile.HOSP_4},
     {Tile.GRASS,Tile.BUSS_1, Tile.BUSS_2, Tile.ROAD_V, Tile.TREE, Tile.NEWS, Tile.MARK_5, Tile.MARK_6, Tile.HOSP_5, Tile.HOSP_6},
     {Tile.GRASS,Tile.BUSS_3, Tile.BUSS_4, Tile.ROAD_VH_RIGHT, Tile.ROAD_H, Tile.ROAD_H, Tile.ROAD_H, Tile.ROAD_H, Tile.ROAD_H, Tile.ROAD_H},
     {Tile.GRASS,Tile.BUSS_5, Tile.BUSS_6, Tile.ROAD_V, Tile.GRASS, Tile.GRASS, Tile.GRASS, Tile.GRASS, Tile.GRASS, Tile.GRASS},
     {Tile.GRASS,Tile.GRASS, Tile.GRASS, Tile.ROAD_V, Tile.GRASS, Tile.GRASS, Tile.GRASS, Tile.GRASS, Tile.GRASS, Tile.GRASS}
    };

    private Image tileset;

    public JGameCanvas() {
        tileset = Toolkit.getDefaultToolkit().getImage(this.getClass().getResource("resources/tileset.png"));
    }

    @Override
    protected void paintComponent(Graphics g) {
        g.setColor(Color.black);
        g.fillRect(0, 0, getWidth(), getHeight());

        for(int i=0;i<10;i++)
            for(int j=0;j<10;j++)
                drawTile(g, map[j][i], i*tW,j*tH);
    }

    protected void drawTile(Graphics g, Tile t, int x, int y){
        // map Tile from the tileset
        int mx = t.ordinal()%10;
        int my = t.ordinal()/10;
        g.drawImage(tileset, x, y, x+tW, y+tH,
                mx*tW, my*tH,  mx*tW+tW, my*tH+tH, this);
    }
}

Program running:

Those graphics I created for the game Batalhão and are under Creative Commons Attribution Share Alike 3.0 license. The source code is under GPL license, download the NetBeans project with sources: tileset.tar.bz2.

NetBeans Day Fortaleza with Gregg Sporar

Gregg Sporar and CEJUG

Those days Gregg Sporar, NetBeans enthusiast working at Sun Microsystems was here in Brazil and went to our city Fortaleza to speak in our NetBeans Day Fortaleza. We had only a couple of days to prepare everything but is always good work under such pressure. :-)

Me at the airport

Me and my friend (Cassiano Carvalho) could toke care of him. First we got Gregg at our international airport, Pinto Martins from a flight from Recife. After that we went to a typical food dinner at Coco Bambu where’s Gregg could taste our tapioca and figure why our local JUG (CEJUG) event is called Tapioca with Coffee.

Gregg tasting Tapioca

After that we went to the hotel but we did not have realized that that day was the birthday of our city Fortaleza and the birthday party was a public concert at beach of one of most famous artist in Brazil, Roberto Carlos.

Roberto Carlos in the early years
Roberto Carlos in the early years… :P

For those who are not Brazilians, To have an idea what Roberto Carlos is, just imagine (in a smaller proportion of course) some kind of Brazilian Elvis Presley. When we quited the restaurant the show was just finished, we had a huge crowd walking back for everywhere, streets blocked, mess and traffic extremely slow. We spend about two hour on this. We decided to park the car, get Gregg’s luggage and go walking the hotel. Luckily the rain don’t caught us.

Rainy Day

In the morning was raining cats and dogs at Fortaleza, what is very uncommon.

Gregg cheking out

I picked Gregg at the hotel to the campus so we can meet the NPD (acronym in Portuguese for Data Processing Core) building, the Internet backbone of the entire state and where some projects are using NetBeans. Gregg also met our CS department, our labs and our cluster.

While that we prepared the auditorium and some last details, test microphones and projector.

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People started to get and we got their names and mails for event certifications. I opened the event talking about NetBeans, CEJUG projects and opportunities for the students.

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People from TV Software Livre (Free Software Television) was there too to record and transmit the event.

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The first Gregg’s talk was about NetBeans and some new features from the last version of NetBeans and some new features for the version 6.1.

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The second was about Memory Leaks in Java and a method for detecting those. Very interesting.

Gregg Sporar

NetBeans Day Fortaleza

NetBeans Day Fortaleza

NetBeans Day NetBeans Day Fortaleza

Gregg Sporar

After Gregg quited to fly to Brasilia I did a presentation on NetBeans 6 and 6.1 Beta news features. You can download Gregg’s slides here and here, my slides here.The recorded video is hosted at Google Video. You can see more photos in this album:

Gregg Sporar

Gregg, thank you very much and hope you liked your quick visit to Fortaleza. ;) Thanks also CEJUG and all guys that made this event possible.