/** * This program shows six slider bars that the user can manipulate * to set the red, green, blue, hue, brightness, and saturation components * of a color. A color patch shows the selected color, and there are * six labels that show the numerical values of all the components. * RGB components are specified as integers in the range 0 to 255. * HSB components are specified as float values in the range 0.0F to 1.0F. * @author David J. Eck */ import java.awt.*; import javax.swing.*; import javax.swing.event.*; public class SimpleColorChooser extends JPanel implements ChangeListener { /** * A main routine enables this class to be run as a program. The main * routine just creates a window whose content pane is a panel of * type SimpleColorChooser. */ public static void main(String[] args) { JFrame window = new JFrame("Simple Color Chooser"); window.setContentPane( new SimpleColorChooser() ); window.pack(); window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); window.setResizable(false); Dimension screensize = Toolkit.getDefaultToolkit().getScreenSize(); window.setLocation( (screensize.width - window.getWidth()) / 2, (screensize.height - window.getHeight()) / 2); window.setVisible(true); } // ----------------------------------------------------------------------- private float[] hsb = new float[3]; // For holding HSB color components. private int r = 255, g = 0, b = 0; // The RGB color components. private JSlider hueSlider, brightnessSlider, saturationSlider, // Slider bars. redSlider, greenSlider, blueSlider; private JLabel hueLabel, brightnessLabel, saturationLabel, // Display component values. redLabel, greenLabel, blueLabel; private JPanel colorCanvas; // Color patch for displaying the color. /** * Sets up the panel's content, layout, and event listening. */ public SimpleColorChooser() { Color.RGBtoHSB(r,g,b,hsb); // Get HSB equivalent of RGB color /* Create JSliders with possible values from 0 to 255. */ hueSlider = new JSlider(0,255,(int)(255*hsb[0])); saturationSlider = new JSlider(0,255,(int)(255*hsb[1])); brightnessSlider = new JSlider(0,255,(int)(255*hsb[2])); redSlider = new JSlider(0,255,255); greenSlider = new JSlider(0,255,0); blueSlider = new JSlider(0,255,0); /* Create Labels showing current RGB and HSB values. */ hueLabel = new JLabel(String.format(" Hue = %1.5f", hsb[0])); saturationLabel = new JLabel(String.format(" Saturation = %1.5f", hsb[1])); brightnessLabel = new JLabel(String.format(" Brightness = %1.5f", hsb[2])); redLabel = new JLabel(" Red = " + r); greenLabel = new JLabel(" Green = " + g); blueLabel = new JLabel(" Blue = " + b); /* Set background colors for JLabels, and make them opaque so they don't inherit the gray background of the panel. */ hueLabel.setBackground(Color.WHITE); saturationLabel.setBackground(Color.WHITE); brightnessLabel.setBackground(Color.WHITE); redLabel.setBackground(Color.WHITE); greenLabel.setBackground(Color.WHITE); blueLabel.setBackground(Color.WHITE); hueLabel.setOpaque(true); saturationLabel.setOpaque(true); brightnessLabel.setOpaque(true); redLabel.setOpaque(true); greenLabel.setOpaque(true); blueLabel.setOpaque(true); /* Set the panel to listen for changes to the slicer' values */ hueSlider.addChangeListener(this); saturationSlider.addChangeListener(this); brightnessSlider.addChangeListener(this); redSlider.addChangeListener(this); greenSlider.addChangeListener(this); blueSlider.addChangeListener(this); /* Create a canvas whose background color will always be set to the currently selected color. */ colorCanvas = new JPanel(); colorCanvas.setBackground(Color.RED); colorCanvas.setPreferredSize(new Dimension(200,200)); /* Set up the GUI */ setLayout(new GridLayout(1,3,3,3)); setBackground(Color.DARK_GRAY); setBorder(BorderFactory.createLineBorder(Color.DARK_GRAY, 2)); JPanel sliders = new JPanel(); JPanel labels = new JPanel(); add(sliders); add(labels); add(colorCanvas); /* Add the Sliders and the Labels to their respective panels. */ sliders.setLayout(new GridLayout(6,1,2,2)); sliders.setBorder(BorderFactory.createEmptyBorder(0,5,0,5)); sliders.add(redSlider); sliders.add(greenSlider); sliders.add(blueSlider); sliders.add(hueSlider); sliders.add(saturationSlider); sliders.add(brightnessSlider); labels.setLayout(new GridLayout(6,1,2,2)); labels.setBackground(Color.DARK_GRAY); labels.add(redLabel); labels.add(greenLabel); labels.add(blueLabel); labels.add(hueLabel); labels.add(saturationLabel); labels.add(brightnessLabel); } // end constructor /** * This is called when the user has changed the values on * one of the sliders. All the sliders and labels * and the color patch are reset to correspond to the new color. */ public void stateChanged(ChangeEvent evt) { JSlider source = (JSlider)evt.getSource(); if ( ! source.getValueIsAdjusting() ) { // Ignore change events that are not produced by the user // adjusting the slider; such events are generated when the // change is made programmatically. return; } int r1, g1, b1; r1 = redSlider.getValue(); g1 = greenSlider.getValue(); b1 = blueSlider.getValue(); if (r != r1 || g != g1 || b != b1) { // One of the RGB components has changed. r = r1; g = g1; b = b1; Color.RGBtoHSB(r,g,b,hsb); hueSlider.setValue((int)(255*hsb[0])); saturationSlider.setValue((int)(255*hsb[1])); brightnessSlider.setValue((int)(255*hsb[2])); } else { // One of the HSB components has changed. hsb[0] = hueSlider.getValue()/255.0F; hsb[1] = saturationSlider.getValue()/255.0F; hsb[2] = brightnessSlider.getValue()/255.0F; int rgb = Color.HSBtoRGB(hsb[0],hsb[1],hsb[2]); r = (rgb >> 16) & 0xFF; g = (rgb >> 8) & 0xFF; b = rgb & 0xFF; redSlider.setValue(r); greenSlider.setValue(g); blueSlider.setValue(b); } redLabel.setText(" Red = " + r); greenLabel.setText(" Green = " + g); blueLabel.setText(" Blue = " + b); hueLabel.setText(String.format(" Hue = %1.5f", hsb[0])); saturationLabel.setText(String.format(" Saturation = %1.5f", hsb[1])); brightnessLabel.setText(String.format(" Brightness = %1.5f", hsb[2])); colorCanvas.setBackground(new Color(r,g,b)); colorCanvas.repaint(); // Tell the system to redraw the canvas in its new color. } // end stateChanged } // end class SimpleColorChooser