I am trying to paint colored rectangles of equal width under a JSlider such that the tick marks separate colors. I am really close but cannot get it quite perfect. I have printed out a bunch of values and my issue is the slider's width is not the actual length of the sliding bar. The x position of the slider is not the starting place of the bar either. Here is my code setting my Colored Rectangles bounds in terms of the sliders position.
for(int i = 0; i < Global.emSpectrum.length; i++) //emSpectrum.length is the number of colored rectangles
{
emSpectrum.get(i).setColorRect(Global.emSpectrum[i], 13 + i * (int)((this.slider.getWidth())/Global.emSpectrum.length), //13 lines up the first color under the bar
this.slider.getY() + this.slider.getHeight()/2, (int)((this.slider.getWidth())/Global.emSpectrum.length),
(int)(Global.rectHeight * getHeight()));
}
Is there just a better way to go about this?
Thanks!
Yep, a decent solution is to use a Dictionary such as a HashTable<Integer, JLabel> and fill it with JLabels that hold ImageIcons of your color rectangles, using an Integer that corresponds with the appropriate location on the JSlider. For example, my SSCCE:
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.util.Dictionary;
import java.util.Hashtable;
import javax.swing.*;
public class SliderEg extends JPanel {
public static final Color[] COLORS = { Color.red, Color.orange,
Color.yellow, Color.green, Color.blue, Color.cyan};
private static final int BI_W = 30;
private static final int BI_H = 10;
private JSlider slider = new JSlider(0, 100, 0);
public SliderEg() {
int majorSpacing = slider.getMaximum() / (COLORS.length - 1);
Dictionary<Integer, JLabel> dictionary = new Hashtable<Integer, JLabel>();
slider.setMajorTickSpacing(majorSpacing);
slider.setPaintLabels(true);
slider.setPaintTicks(true);
slider.setSnapToTicks(true);
for (int i = 0; i < COLORS.length; i++) {
ImageIcon icon = createColorIcon(COLORS[i]);
JLabel label = new JLabel(icon);
int key = i * majorSpacing;
dictionary.put(key, label);
}
slider.setLabelTable(dictionary);
setLayout(new BorderLayout());
add(slider, BorderLayout.CENTER);
}
private ImageIcon createColorIcon(Color color) {
BufferedImage img = new BufferedImage(BI_W, BI_H,
BufferedImage.TYPE_INT_RGB);
Graphics g = img.getGraphics();
g.setColor(color);
g.fillRect(0, 0, BI_W, BI_H);
g.dispose();
return new ImageIcon(img);
}
private static void createAndShowGui() {
SliderEg mainPanel = new SliderEg();
JFrame frame = new JFrame("SliderEg");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().add(mainPanel);
frame.pack();
frame.setLocationByPlatform(true);
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGui();
}
});
}
}
Related
Hereunder is a minimal example of a bug I can't fix in a Java program.
The bug consists is that the lines are randomly shown in the JFrame: sometimes I see the board at runtime, sometimes not.
Any hint greatly appreciated.
import java.awt.Graphics;
import javax.swing.JFrame;
public class EssaiDrawLine extends JFrame{
public static void main(String[] args) {
EssaiDrawLine mafenetre = new EssaiDrawLine();
mafenetre.setVisible(true);
}
// constructeur
public EssaiDrawLine() {
setTitle("mon titre");
setSize(600, 500);
}
public void paint(Graphics g) {
super.paint(g);
for (int i = 0; i <= 8; i++) {
g.drawLine(50 * i + 10, 40, 50*i + 10, 440);
g.drawLine(10, 50 * i + 40, 410, 50 * i + 40);
}
g.drawString("Cliquer pour obtenir la prochaine solution", 20, 470);
}
}
Another option: don't draw the lines but instead create a grid of components, such as a 2-D array of JPanels held in another JPanel, one that uses GridLayout, and then give the JPanels a MouseListener so that they can respond to mouse events. For example, a simple version of this could look something like so (please read the comments in the code):
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.GridLayout;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import javax.swing.*;
#SuppressWarnings("serial") // get rid of warning
public class EssaiDrawLine3 extends JPanel {
private static final int SIDE = 8;
private static final int SQR_LENGTH = 50;
private static final int GAP = 5;
private static final Color CLICK_COLOR = Color.RED;
private static final Color SQR_COLOR = Color.LIGHT_GRAY;
private static final String CLICK_TEXT = "Cliquer pour obtenir la prochaine solution";
// our grid of JPanel
private JPanel[][] grid = new JPanel[SIDE][SIDE];
public EssaiDrawLine3() {
// JPanel to hold the grid
// give it an 8x8 GridLayout with 1 pixel gap for lines to show
JPanel gridHolder = new JPanel(new GridLayout(SIDE, SIDE, 1, 1));
// background color that shows through as lines in gaps in grid
gridHolder.setBackground(Color.BLACK);
gridHolder.setBorder(BorderFactory.createLineBorder(Color.black));
// mouse listener to add to each JPanel cell
MyMouse myMouse = new MyMouse();
// nested for loop to create our grid of JPanels
for (int row = 0; row < grid.length; row++) {
for (int col = 0; col < grid[row].length; col++) {
// create a single cell
JPanel cellPanel = new JPanel();
// size it 50x50 pixels
cellPanel.setPreferredSize(new Dimension(SQR_LENGTH, SQR_LENGTH));
// add the mouse listener to it
cellPanel.addMouseListener(myMouse);
// give it a default background color
cellPanel.setBackground(SQR_COLOR);
// place it into the 2-D array of JPanel
grid[row][col] = cellPanel;
// place it into the grid layout-using JPanel
gridHolder.add(cellPanel);
}
}
// display text at the bottom
JLabel label = new JLabel(CLICK_TEXT, SwingConstants.CENTER);
// allow gaps around the main JPanel
setBorder(BorderFactory.createEmptyBorder(GAP, GAP, GAP, GAP));
// give the main JPanel a BorderLayout
setLayout(new BorderLayout(GAP, GAP));
add(gridHolder); // add the grid to the CENTER position
// add the JLabel to the bottom position
add(label, BorderLayout.PAGE_END);
}
private class MyMouse extends MouseAdapter {
#Override
public void mousePressed(MouseEvent e) {
// get the JPanel cell that was clicked
JComponent comp = (JComponent) e.getSource();
// get its color and change it
Color color = comp.getBackground();
if (color.equals(CLICK_COLOR)) {
comp.setBackground(SQR_COLOR);
} else {
comp.setBackground(CLICK_COLOR);
}
}
}
private static void createAndShowGui() {
EssaiDrawLine3 mainPanel = new EssaiDrawLine3();
JFrame frame = new JFrame("Essai Draw Line3");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().add(mainPanel);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(() -> createAndShowGui());
}
}
Never draw directly in the JFrame but instead within a JPanel's paintComponent method, and then display that JPanel in your JFrame. This is all well explained in the standard tutorials: : Lesson: Performing Custom Painting
import java.awt.Dimension;
import java.awt.Graphics;
import javax.swing.*;
#SuppressWarnings("serial")
public class EssaiDrawLine2 extends JPanel {
private static final int PS_WIDTH = 600;
private static final int PS_HEIGHT = 500;
public EssaiDrawLine2() {
setPreferredSize(new Dimension(PS_WIDTH, PS_HEIGHT));
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
for (int i = 0; i <= 8; i++) {
g.drawLine(50 * i + 10, 40, 50 * i + 10, 440);
g.drawLine(10, 50 * i + 40, 410, 50 * i + 40);
}
g.drawString("Cliquer pour obtenir la prochaine solution", 20, 470);
}
private static void createAndShowGui() {
EssaiDrawLine2 mainPanel = new EssaiDrawLine2();
JFrame frame = new JFrame("Essai Draw Line");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().add(mainPanel);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(() -> createAndShowGui());
}
}
Currently, I have to JComponents contained in a JPanel with a vertical box layout.
This way, I can have the first component centered, as shown below, and have the bottom component (which is quite long) below. However, since the bottom component is very long I wanted to add a slider just for that specific component. This way, the user can see all of the bottom component with the upper component remaining centered. However, my code below doesn't fix anything and the scrollbar never even works. The only information about GPComponent and GPinfinity you need to know is they override the preferredSize, minimumSize, maximumSize, and paintComponent methods (they extend JComponent).
JFrame frame = new JFrame();
JPanel panel = new JPanel();
GPComponent gp = new GPComponent(n, k);
GPinfinityComponent gpi = new GPinfinityComponent(n, k);
Box box = new Box(BoxLayout.Y_AXIS);
panel.add(Box.createVerticalGlue());
panel.add(gp);
panel.add(Box.createVerticalGlue());
JScrollPane thePane = new JScrollPane(gpi, JScrollPane.VERTICAL_SCROLLBAR_NEVER,JScrollPane.HORIZONTAL_SCROLLBAR_ALWAYS);
panel.add(thePane);
frame.pack();6
frame.add(panel, BorderLayout.CENTER); // just to be clear
frame.setVisible(true);
final int FRAME_WIDTH = 600;
final int FRAME_HEIGHT = 600;
frame.setSize(FRAME_WIDTH, FRAME_HEIGHT);
frame.setTitle("GP("+n+", "+k+")");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setVisible(true);
Also: the maximumSize=minimumSize=preferredSize for both components
For the circular one the dimensions are (350, 350) and for the other the dimensions are (5000, 150).
You state:
...and for the other the dimensions are (5000, 150).
If this is the component that is supposed to show the scrollbars, the Java is telling you otherwise, that it is in fact much shorter than you suppose it to be. I wonder if you're setting size instead of preferredSize. You actually should not be setting either but rather should override getPreferredSize() and have it return a dimension appropriate for the component.
For more detailed help, consider creating and posting a minimal example program.
Edit
For example, my MCVE:
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.GridBagLayout;
import java.awt.RenderingHints;
import javax.swing.*;
#SuppressWarnings("serial")
public class PreferredSizeEg extends JPanel {
private static final int PREF_W = 800;
private static final int PREF_H = 600;
public PreferredSizeEg() {
JPanel centerPanel = new JPanel(new GridBagLayout());
centerPanel.add(new CenterImagePanel());
JScrollPane scrollpane = new JScrollPane(new LongImagePanel(),
JScrollPane.VERTICAL_SCROLLBAR_NEVER,
JScrollPane.HORIZONTAL_SCROLLBAR_ALWAYS);
setLayout(new BorderLayout());
add(centerPanel, BorderLayout.CENTER);
add(scrollpane, BorderLayout.PAGE_END);
}
#Override
public Dimension getPreferredSize() {
return new Dimension(PREF_W, PREF_H);
}
private class LongImagePanel extends JPanel {
private static final int LI_PREF_W = 5000;
private static final int LI_PREF_H = 150;
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2 = (Graphics2D) g;
g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
RenderingHints.VALUE_ANTIALIAS_ON);
int index = 0;
int spriteWidth = 50;
while ((index) * spriteWidth < getWidth()) {
Color c = index % 2 == 0 ? Color.green : Color.red;
g.setColor(c);
int x = 2 + index * spriteWidth;
int y = 2;
int width = getHeight() - 4;
int height = width;
g.fillOval(x, y, width, height);
index++;
}
}
#Override
public Dimension getPreferredSize() {
return new Dimension(LI_PREF_W, LI_PREF_H);
}
}
private class CenterImagePanel extends JPanel {
private static final int CIP_PREF_W = 200;
private static final int CIP_PREF_H = CIP_PREF_W;
public CenterImagePanel() {
setBorder(BorderFactory.createLineBorder(Color.BLACK));
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2 = (Graphics2D) g;
g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
RenderingHints.VALUE_ANTIALIAS_ON);
g.setColor(Color.green);
int x = 5;
int y = x;
int width = getWidth() - 2 * x;
int height = getHeight() - 2 * y;
g.fillOval(x, y, width, height);
}
#Override
public Dimension getPreferredSize() {
return new Dimension(CIP_PREF_W, CIP_PREF_H);
}
}
private static void createAndShowGui() {
PreferredSizeEg mainPanel = new PreferredSizeEg();
JFrame frame = new JFrame("PreferredSizeEg");
frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
frame.getContentPane().add(mainPanel);
frame.pack();
frame.setLocationByPlatform(true);
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGui();
}
});
}
}
Which displays as:
I know there have been many topics on this subject before and I have used Google extensively to figure this out, but whatever I do I cannot get two panels to display in one JFrame. I have tried many things including CardLayout but that didn't seem to work. I have a feeling this is a very easy solution..
The purpose is to see the difference between the two panels due to the random positioning.
Here are some of the java files (only pertinent code - there is also a Snowman.java but it just provides the drawing for the snowmen similar to ghost.java):
Ghost.java
import java.awt.*;
public class Ghost
{
private int x, y;
private String name;
private boolean happy;
private Color color;
public Ghost (Color shade, int upperX, int upperY, String a, boolean b)
{
color = shade;
x = upperX;
y = upperY;
name = a;
happy = b;
}
public void draw (Graphics page)
{
page.setColor(color);
page.fillOval (x, y, 50, 125);
page.fillRect (x+1, y+60, 49, 75); // body of ghost
page.setColor(Color.black);
page.fillOval (x+12, y+10, 8, 8);
page.fillOval (x+32, y+10, 8, 8); // eyes
page.setColor(Color.white);
page.drawString(name, x+8, y-5); // name
page.setColor(Color.black);
if (happy == true)
page.fillArc (x+10, y+30, 33, 10, 180, 180);
else
page.fillArc (x+10, y+30, 33, 10, 0, 180); // smile/frown
}
public void setColor (Color shade)
{
color = shade;
}
public void setX (int upperX)
{
x = upperX;
}
public void setY (int upperY)
{
y = upperY;
}
HalloweenPanel.java :
import javax.swing.*;
import java.awt.*;
import java.util.Random;
public class HalloweenPanel extends JPanel
{
private Ghost ghost1, ghost2, ghost3;
private Snowman snowman1, snowman2;
public HalloweenPanel()
{
setBackground (Color.black);
Random rand = new Random();
int randomX = rand.nextInt(700)+50;
int randomY = rand.nextInt(400)+50;
boolean randomHappy = (Math.random() < 0.5);
boolean randomHappy2 = (Math.random() < 0.5);
ghost1 = new Ghost (Color.white, randomX, randomY, "Scary", randomHappy2);
ghost2 = new Ghost (Color.blue, randomX, 100, "Happy", true);
ghost3 = new Ghost (Color.yellow, 300, randomY, "Scared", randomHappy);
snowman1 = new Snowman (500, 50);
snowman2 = new Snowman (750, 100);
}
public void paintComponent (Graphics page)
{
Random rand = new Random();
int randomX2 = rand.nextInt(900);
int randomY2 = rand.nextInt(500);
super.paintComponent(page);
ghost2.setX(randomX2);
ghost3.setY(randomY2);
ghost1.draw(page);
ghost2.draw(page);
ghost3.draw(page);
snowman1.draw(page);
snowman2.draw(page);
}
}
HalloweenDriver.java:
import javax.swing.*;
import java.awt.*;
public class HalloweenDriver
{
public static void main (String[] args)
{
JFrame frame = new JFrame ("Halloween - Winter is Coming..");
frame.setDefaultCloseOperation (JFrame.EXIT_ON_CLOSE);
JPanel mainPanel = new JPanel();
HalloweenPanel panel = new HalloweenPanel();
HalloweenPanel panel2 = new HalloweenPanel();
mainPanel.setLayout(new GridLayout(1,0));
mainPanel.add(panel);
mainPanel.add(panel2);
frame.add(mainPanel);
frame.pack();
frame.setVisible(true);
}
}
frame.getContentPane().add(panel);
frame.getContentPane().add(panel2);
You are trying to add two panels to the CENTER of a BorderLayout. This can't be done.
Try:
frame.getContentPane().add(panel, BorderLayout.CENTER);
frame.getContentPane().add(panel2, BorderLayout.SOUTH);
to see the difference.
If this isn't what you want then try another layout manager. Read the Swing tutorial on Layout Managers.
Or, if you are trying to stack the two panels on top of one another (on the Z axis) then try the OverlayLayout. This is not covered in the tutorial so you will need to look at the API. You will also need to make the "top" panel non-opaque() so it doesn't paint over top of the bottom panel.
There is a window in which I want to place a button, and then paint the whole area beneath it. In other words, button should cover a piece of painting.
import java.awt.*;
import javax.swing.*;
class Window
{
private JFrame frame;
private JButton launchButton;
private JPanel pnllaunchButton;
private JPanel paintingPanel;
//width and height of client area
private Rectangle dim;
//w,h - width and height of the whole window
public Window(String title,int w,int h)
{
frame = new JFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLocation(0,0);
frame.setMinimumSize( new Dimension(110,110));
frame.setSize(w, h);
frame.setVisible(true);
frame.setTitle(title);
frame.setResizable(false);
addLaunchButton();
}
private void addLaunchButton()
{
pnllaunchButton = new JPanel();
launchButton = new JButton("Plot!");
dim = new Rectangle();
frame.getContentPane().getBounds(dim);
pnllaunchButton.setBounds(dim.width-100,dim.height-25,100,25);
launchButton.setBounds(dim.width-100,dim.height-25,100,25);
pnllaunchButton.setLayout(null);
pnllaunchButton.add(launchButton);
frame.getContentPane().add(pnllaunchButton);
frame.getContentPane().setComponentZOrder(pnllaunchButton, new Integer(2));
}
public void drawCoordinateSystem()
{
paintingPanel = new JPanel();
paintingPanel.add(new CoordinateSystem());
frame.getContentPane().add(paintingPanel);
frame.getContentPane().setComponentZOrder(paintingPanel,new Integer(3));
}
}
class CoordinateSystem extends JPanel
{
#Override
public void paintComponent(Graphics g)
{
super.paintComponent(g);
Dimension size = this.getSize();
g.setColor(Color.BLACK);
g.drawLine(0,size.height/2,size.width, size.height/2);
g.drawLine(size.width/2, 0, size.width/2, size.height);
}
}
public class GC {
public static void main(String[] args)
{
Window h = new Window("GC",800,600);
h.drawCoordinateSystem();
}
}
This code doesn't fulfill the specification. Program creates an empty window and outputs:
run:
Exception in thread "main" java.lang.IllegalArgumentException: illegal component position
at java.awt.Container.checkAdding(Container.java:504)
at java.awt.Container.setComponentZOrder(Container.java:759)
at Window.addLaunchButton(Window.java:46)
at Window.<init>(Window.java:26)
at GC.main(GC.java:10)
Could you point out my mistake? setComponentZOrder() method doesn't seem to be described precisely in javadoc.
Rename your class. The Window class is already part of the standard core Java libraries, and your class name could cause present or future problems.
Don't us null layouts and setBounds(...). This is bad, bad, bad, and will make it very difficult to maintain or upgrade your application. Instead, learn about and use the layout managers.
Consider making a JLabel the contentPane, make it opaque, give it a layout and an ImageIcon and add your components to it.
The ImageIcon can hold a BufferedImage with a grid.
For example:
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.FlowLayout;
import java.awt.GradientPaint;
import java.awt.Graphics2D;
import java.awt.image.BufferedImage;
import javax.swing.*;
public class MyWindow {
private static final int PREF_W = 800;
private static final int PREF_H = 600;
private static final Color COLOR0 = Color.red;
private static final Color COLOR1 = Color.blue;
private static final float COLOR_REPEAT_DIST = 30f;
private JLabel backGroundLabel = new JLabel();
public MyWindow() {
backGroundLabel.setOpaque(true);
backGroundLabel.setLayout(new BorderLayout());
int eb = 15;
BufferedImage bkgrndImg = createBkgrndImage();
ImageIcon icon = new ImageIcon(bkgrndImg);
backGroundLabel.setIcon(icon);
JPanel bottomPanel = new JPanel();
bottomPanel.setLayout(new FlowLayout(SwingConstants.RIGHT, eb, eb));
bottomPanel.setOpaque(false);
bottomPanel.add(new JButton("Plot"));
backGroundLabel.add(bottomPanel, BorderLayout.PAGE_END);
}
private BufferedImage createBkgrndImage() {
BufferedImage img = new BufferedImage(PREF_W, PREF_H, BufferedImage.TYPE_INT_ARGB);
Graphics2D g2 = img.createGraphics();
g2.setPaint(new GradientPaint(0f, 0f, COLOR0, COLOR_REPEAT_DIST, COLOR_REPEAT_DIST, COLOR1, true));
g2.fillRect(0, 0, PREF_W, PREF_H);
g2.dispose();
return img;
}
public JComponent getMainPane() {
return backGroundLabel;
}
private static void createAndShowGui() {
MyWindow mainPanel = new MyWindow();
JFrame frame = new JFrame("MyWindow");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().add(mainPanel.getMainPane());
frame.pack();
frame.setLocationByPlatform(true);
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGui();
}
});
}
}
Which looks like so:
Pass an int instead of an Integer to the setComponentZOrder method.
private void addLaunchButton()
{
pnllaunchButton = new JPanel();
launchButton = new JButton("Plot!");
dim = new Rectangle();
frame.getContentPane().getBounds(dim);
pnllaunchButton.setBounds(dim.width-100,dim.height-25,100,25);
launchButton.setBounds(dim.width-100,dim.height-25,100,25);
pnllaunchButton.setLayout(null);
pnllaunchButton.add(launchButton);
frame.getContentPane().add(pnllaunchButton);
frame.getContentPane().setComponentZOrder(pnllaunchButton, 2);
}
Any other errors aside, I need a way of converting my Color grayScale into an int. When I plug in the Color, I get an error. setRGB method takes an x, a y, and an rgb int as parameters. How do I change my Color into an int?
import java.awt.*;
import java.awt.event.*;
import java.util.*;
import java.io.*;
import javax.swing.*;
import java.awt.image.*;
import javax.imageio.ImageIO;
public class Picture{
Container content;
BufferedImage image, image2;
public Picture(String filename) {
File f = new File(filename);
//assume file is the image file
try {
image = ImageIO.read(f);
}
catch (IOException e) {
System.out.println("Invalid image file: " + filename);
System.exit(0);
}
}
public void show() {
final int width = image.getWidth();
final int height = image.getHeight();
JFrame frame = new JFrame("Edit Picture");
//set frame title, set it visible, etc
content = frame.getContentPane();
content.setPreferredSize(new Dimension(width, height));
frame.pack();
frame.setResizable(false);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
//add a menubar on the frame with a single option: saving the image
JMenuBar menuBar = new JMenuBar();
frame.setJMenuBar(menuBar);
JMenu fileMenu = new JMenu("File");
menuBar.add(fileMenu);
JMenuItem saveAction = new JMenuItem("Save");
fileMenu.add(saveAction);
JMenuItem grayScale = new JMenuItem("Grayscale");
fileMenu.add(grayScale);
grayScale.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
grayscale(width, height);
}
});
//add the image to the frame
ImageIcon icon = new ImageIcon(image);
frame.setContentPane(new JLabel(icon));
//paint the frame
frame.setVisible(true);
frame.repaint();
}
public void grayscale(int width, int height) {
for (int i = 0; i < width; i++) {
for (int j = 0; j < height; j++) {
Color color = new Color(image.getRGB(i, j));
int red = color.getRed();
int green = color.getGreen();
int blue = color.getBlue();
int rGray = red*(1/3);
int gGray = green*(2/3);
int bGray = blue*(1/10);
Color grayScale = new Color(rGray, gGray, bGray);
image.setRGB(i,j, grayScale);
}
}
show();
}
public static void main(String[] args) {
Picture p = new Picture(args[0]);
p.show();
}
}
As per comment by trashgod.
import java.awt.*;
import java.awt.event.*;
import java.util.*;
import java.io.*;
import javax.swing.*;
import java.awt.image.*;
public class Picture{
Container content;
BufferedImage image;
BufferedImage image2;
public Picture(BufferedImage image) {
this.image = image;
grayscale();
}
public void show() {
JFrame frame = new JFrame("Edit Picture");
//set frame title, set it visible, etc
content = frame.getContentPane();
frame.setResizable(false);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
//add the image to the frame
ImageIcon icon = new ImageIcon(image2);
frame.setContentPane(new JLabel(icon));
frame.pack();
//paint the frame
frame.setVisible(true);
}
public void grayscale() {
// create a grayscale image the same size
image2 = new BufferedImage(
image.getWidth(),
image.getHeight(),
BufferedImage.TYPE_BYTE_GRAY);
// convert the original colored image to grayscale
ColorConvertOp op = new ColorConvertOp(
image.getColorModel().getColorSpace(),
image2.getColorModel().getColorSpace(),null);
op.filter(image,image2);
show();
}
public static void main(String[] args) {
int size = 120;
int pad = 10;
BufferedImage bi = new BufferedImage(
size,
size,
BufferedImage.TYPE_INT_RGB);
Graphics g = bi.createGraphics();
g.setColor(Color.WHITE);
g.fillRect(0,0,size,size);
g.setColor(Color.YELLOW);
g.fillOval(pad,pad,size-(2*pad),size-(2*pad));
g.dispose();
Picture p = new Picture(bi);
p.show();
}
}
image.setRGB(i, j, grayScale.getRGB());
Take a look at what values (1/3), (2/3), and (1/10) actually have, then note that you are multiplying your red, green, and blue values by those numbers.
The color is an Object. An rgb is an int. Use colorName.getRGB() to get the integer RGB value of that color.