trapecio - dibujar una elipse en java

Dibujo de rectángulo en un JPanel

Question

Quiero hacer un recanke en un JPanel. Puedo dibujar con el siguiente código.

public class DrawingColor extends JFrame
{
public static void main(String[] args)
{
DrawingColor d = new DrawingColor();
}
public DrawingColor()
{
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
getContentPane().add(new MyComponent());
setSize(400,400);
setVisible(true);
}
public class MyComponent extends JComponent
{
@Override
public void paint(Graphics g)
{
int height = 200;
int width = 120;
g.setColor(Color.red);
g.drawRect(10, 10, height, width);
g.setColor(Color.gray);
g.fillRect(11, 11, height, width);
g.setColor(Color.red);
g.drawOval(250, 20, height, width);
g.setColor(Color.magenta);
g.fillOval(249, 19, height, width);
}
}
}

Pero getContentPane (). Add (new MyComponent ()); En lugar de esta afirmación, necesito agregar un panel base al marco. En el panel base quiero agregar el panel MyComponent.

 JPanel basePanel = new JPanel();
basePanel = new MyComponent();
getContentPane().add(basePanel);

Si me gusta esto, el rectángulo no se está haciendo visible. ¿alguna idea? Y también necesito cambiar el tamaño del rectángulo en tiempo de ejecución. ¿Es posible?

Answer 1

1) para Swing JComponent tienes que usar el paintComponent() vez del método paint()

2) su JComponent no devuelve PreferredSize

por ejemplo

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.event.ComponentEvent;
import javax.swing.JComponent;
import javax.swing.JFrame;
public class CustomComponent extends JFrame {
private static final long serialVersionUID = 1L;
public CustomComponent() {
setTitle("Custom Component Graphics2D");
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
public void display() {
CustomComponents cc = new CustomComponents();
/*cc.addComponentListener(new java.awt.event.ComponentAdapter() {
@Override
public void componentResized(ComponentEvent event) {
setSize(Math.min(getPreferredSize().width, getWidth()),
Math.min(getPreferredSize().height, getHeight()));
}
});*/
add(cc, BorderLayout.CENTER);
CustomComponents cc1 = new CustomComponents();
add(cc1, BorderLayout.EAST);
pack();
// enforces the minimum size of both frame and component
setMinimumSize(getSize());
//setMaximumSize(getMaximumSize());
setVisible(true);
}
public static void main(String[] args) {
CustomComponent main = new CustomComponent();
main.display();
}
}
class CustomComponents extends JComponent {
private static final long serialVersionUID = 1L;
@Override
public Dimension getMinimumSize() {
return new Dimension(100, 100);
}
@Override
public Dimension getPreferredSize() {
return new Dimension(400, 300);
}
@Override
public Dimension getMaximumSize() {
return new Dimension(800, 600);
}
@Override
public void paintComponent(Graphics g) {
int margin = 10;
Dimension dim = getSize();
super.paintComponent(g);
g.setColor(Color.red);
g.fillRect(margin, margin, dim.width - margin * 2, dim.height - margin * 2);
}
}

Answer 2

Intenté dibujar un cuadrado y un círculo, variando dinámicamente el tamaño en tiempo de ejecución ... adjuntando el código completo ... si ayuda.

import java.awt.Color;
import java.awt.Container;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.awt.geom.Ellipse2D;
import java.awt.geom.Rectangle2D;
import javax.swing.*;
import java.*;
import java.awt.Canvas;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;
class DisplayCanvas extends Canvas
{
static boolean clip = false;
static boolean clipfurther = false;
static boolean isReset = false, isSlider = false;
int w, h;
static int wi = 300, hi = 300;
public DisplayCanvas()
{
//setSize(300, 300);
setBounds(20, 40, 300, 300);
setBackground(Color.white);
}
public void paint(Graphics g)
{
Graphics2D g2=(Graphics2D) g;
w = getSize().width;
h = getSize().height;
if(clip)
{
// Ellipse2D e = new Ellipse2D.Float(w/4.0f,h/4.0f,w/2.0f,h/2.0f);
Rectangle2D r = null;
if(isSlider)
{
r = new Rectangle2D.Float((w)/(4.0f), (h)/(4.0f), wi/2.0f, hi/2.0f);
// isSlider=false;
}
else
r = new Rectangle2D.Float(w/4.0f, h/4.0f, wi/2.0f, hi/2.0f);
//g2.setClip(e);
System.out.println("Width : "+ wi +" Height : "+ hi);
g2.setClip(r);
System.out.println(g2.getClipBounds());
if(shape.selectedcolor == "red")
{
g2.setColor(Color.red);
}
else if(shape.selectedcolor == "blue")
{
g2.setColor(Color.BLUE);
}
else if(shape.selectedcolor == "yellow")
{
g2.setColor(Color.yellow);
}
//g2.setColor(Color.RED);
g2.fillRect(0, 0, w, h);
}
else if(clipfurther)
{
//Rectangle r = new Rectangle(w/4, h/4, w/4, h/4);
Ellipse2D r = new Ellipse2D.Float(w/4.0f, h/4.0f, wi/2.0f, hi/2.0f);
g2.clip(r);
//g2.setColor(Color.green);
//g2.setColor(Color.getColor(shape.selectedcolor));
if(shape.selectedcolor == "red")
{
g2.setColor(Color.red);
}
else if(shape.selectedcolor == "blue")
{
g2.setColor(Color.BLUE);
}
else if(shape.selectedcolor == "yellow")
{
g2.setColor(Color.yellow);
}
g2.fillRect(0, 0, w, h);
}
}
}
class RadioListener implements ActionListener
{
public void actionPerformed(ActionEvent e)
{
if(e.getSource() == shape.circle)
{
shape.selectedcolor = shape.selectedcolor_reset;
System.out.println("Inside circle "+ shape.selectedcolor_reset);
System.out.println("2222222222");
DisplayCanvas.clip = true;
DisplayCanvas.clipfurther = false;
shape.canvas.repaint();
}
if (e.getSource() == shape.square)
{
shape.selectedcolor = shape.selectedcolor_reset;
System.out.println("333333333333333");
DisplayCanvas.clip = false;
DisplayCanvas.clipfurther = true;
shape.canvas.repaint();
}
}
}
class shape extends JFrame implements ActionListener
{
static String fname;
static JPanel panel, draw;
static Container contentpane, draw_pane;
static JFrame frame;
static JLayeredPane layer, draw_layer;
static JTextField user;
static JButton reset, cancel;
static JLabel file1, file2;
static JTextField text1;
static JRadioButton circle, square;
static JInternalFrame iframe, errmessage;
static JComboBox colors;
static JEditorPane sqc;
static JScrollPane scroller;
static JSlider slider;
String colors_array[]={"...", "red", "blue", "yellow"};
static DisplayCanvas canvas;
static String selectedcolor, selectedcolor_reset;
shape()
{
canvas=new DisplayCanvas();
panel= new JPanel();
panel.setBounds(20,20,250,140);
//panel.setLayout(new FlowLayout(10, 10, 10));
panel.setLayout(null);
contentpane = getContentPane();
contentpane.add(canvas);
//draw_pane=getContentPane();
layer = new JLayeredPane();
layer.setBounds(50,245,300,205);
layer.setForeground(Color.blue);
draw_layer = new JLayeredPane();
draw_layer.setBounds(200, 200, 80, 30);
draw_layer.setForeground(Color.BLACK);
draw = new JPanel();
draw.setBounds(20, 20, 250, 300);
draw.setLayout(null);
reset = new JButton("RESET");
reset.setBounds(360, 60, 100, 25);
circle = new JRadioButton("Square");
circle.setBounds(400, 100, 100, 40);
circle.setActionCommand("encryption");
square = new JRadioButton("Circle");
square.setBounds(330,100, 60, 40);
square.setActionCommand("decryption");
colors = new JComboBox(colors_array);
colors.setBounds(405, 140, 80, 30);
colors.setVisible(true);
file1 = new JLabel(" Select Color :");
file1.setBounds(320, 130, 150, 50);
//defining the Button Group for the Radio Buttons
ButtonGroup group = new ButtonGroup();
group.add(circle);
group.add(square);
cancel = new JButton("Exit");
cancel.setBounds(365, 250, 85, 25);
file2 = new JLabel("SIZE :");
file2.setBounds(336, 180, 150, 50);
setslider(0, 100, 100, 25, 5);
slider.setBounds(386, 190, 100, 50);
slider.setVisible(true);
panel.add(file2);
panel.add(layer);
panel.add(circle);
panel.add(square);
panel.add(colors);
panel.add(slider);
panel.add(file1);
panel.add(reset);
panel.add(cancel);
//panel.add(new CircleDraw());
//draw.add(draw_layer);
// draw_pane.add(draw);
contentpane.add(panel);
// contentpane.add(draw);
// contentpane.add(scroller);
RadioListener radio = new RadioListener();
circle.addActionListener(radio);
square.addActionListener(radio);
reset.addActionListener(this);
cancel.addActionListener(this);
colors.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent ae)
{
JComboBox cb = (JComboBox)ae.getSource();
selectedcolor = (String)cb.getSelectedItem();
System.out.println(selectedcolor);
selectedcolor_reset = selectedcolor;
System.out.println("SELECTED "+ cb.getSelectedIndex());
canvas.repaint();
}
});
addWindowListener(new WindowAdapter()
{
public void windowClosing(WindowEvent e)
{
System.exit(0);
}
});
}
public void actionPerformed(ActionEvent e)
{
if(e.getSource()== cancel)
{
System.exit(0);
}
if (e.getSource() == reset)
{
System.out.println("111111111");
DisplayCanvas.clip = true;
DisplayCanvas.clipfurther = false;
DisplayCanvas.isReset = true;
shape.selectedcolor = "...";
System.out.println(" PREVIOUS " + selectedcolor_reset);
DisplayCanvas.hi = DisplayCanvas.wi = 300;
canvas.repaint();
}
}
public class SliderListener implements ChangeListener
{
public SliderListener()
{
}
public void stateChanged(ChangeEvent e)
{
JSlider slider = (JSlider)e.getSource();
System.out.println(slider.getValue());
DisplayCanvas.wi = slider.getValue() * 3;
DisplayCanvas.hi = DisplayCanvas.wi;
DisplayCanvas.isSlider = true;
canvas.repaint();
}
}
public void setslider(int min,int max,int init,int mjrtk,int mintk)
{
slider = new JSlider(JSlider.HORIZONTAL, min, max, init);
slider.setPaintTicks(true);
slider.setMajorTickSpacing(mjrtk);
slider.setMinorTickSpacing(mintk);
slider.setPaintLabels(true);
slider.addChangeListener((ChangeListener) new SliderListener());
}
}
public class display
{
static JFrame frame;
/**
* @param args the command line arguments
*/
public static void main(String[] args)
{
// TODO code application logic here
frame=new shape();
frame.setBounds(380, 200, 500, 400);
frame.setTitle("SHAPE AND COLOR");
frame.setVisible(true);
}
}

Answer 3

Como quería cambiar las dimensiones de su rectángulo en tiempo de ejecución, intente con este código para eso:

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class RectangleTest extends JFrame {
private int x;
private int y;
private static JButton buttonFullSize;
private static JButton buttonHalfSize;
public RectangleTest() {
x = 0;
y = 0;
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
final JPanel basePanel = new JPanel();
basePanel.setLayout(new BorderLayout());
final MyComponent component = new MyComponent(400, 400);
component.setOriginAndSize(0, 0, 100, 100);
buttonFullSize = new JButton("DRAW FULL SIZE");
buttonFullSize.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent ae) {
component.setOriginAndSize(x++, y++,
(basePanel.getHeight() / 4), (basePanel.getWidth() / 4));
}
});
buttonHalfSize = new JButton("DRAW HALF SIZE");
buttonHalfSize.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent ae) {
component.setOriginAndSize(x++, y++,
(basePanel.getHeight() / 8), (basePanel.getWidth() / 8));
}
});
basePanel.add(buttonHalfSize, BorderLayout.PAGE_START);
basePanel.add(component, BorderLayout.CENTER);
basePanel.add(buttonFullSize, BorderLayout.PAGE_END);
setContentPane(basePanel);
pack();
setVisible(true);
}
public static void main(String... args) {
SwingUtilities.invokeLater(new Runnable() {
@Override
public void run() {
new RectangleTest();
}
});
}
}
class MyComponent extends JComponent {
private int x;
private int y;
private int width;
private int height;
private int compWidth;
private int compHeight;
MyComponent(int w, int h) {
this.compWidth = w;
this.compHeight = h;
}
public void setOriginAndSize(int x, int y, int w, int h) {
this.x = x;
this.y = y;
this.width = w;
this.height = h;
repaint();
}
@Override
public Dimension getPreferredSize() {
return (new Dimension(compWidth, compHeight));
}
@Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
g.setColor(getBackground());
g.fillRect(x, y, width, height);
g.setColor(Color.RED);
g.drawOval(x, y, width, height);
g.setColor(Color.MAGENTA);
g.fillOval(x, y, width, height);
}
}