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I want to draw a recangle on a JPanel. Am able to draw with the following code.
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);
}
}
}
But getContentPane().add(new MyComponent()); Instead of this statement,I need to add one base panel to the frame. On the base panel I want to add the MyComponent panel.
JPanel basePanel = new JPanel();
basePanel = new MyComponent();
getContentPane().add(basePanel);
If I do like this, the rectangle is not getting visible. any idea? And also I need to change the size of the rectangle at runtime. is it possible?
690
1) for Swing JComponent you have to use paintComponent() instead of paint() method
2) your JComponent doesn't returns PreferredSize
for example
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);
}
}
Since you wanted to change the Dimensions of your Rectangle at run time, try this code for that :
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);
}
}
I had tried drawing a square and circle, dynamically varying the size at runtime....attaching the complete code ..if it helps.
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);
}
}
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