This is an adapted version of the answer given by Vivien Barousse with the update from Vulcan applied. In this example I use sliders to dynamically retreive the RGB values from three sliders and display that color in a rectangle. Then in method toHex() I use the values to create a color and display the respective Hex color code.
This example does not include the proper constraints for the GridBagLayout. Though the code will work, the display will look strange.
public class HexColor
{
public static void main (String[] args)
{
JSlider sRed = new JSlider(0,255,1);
JSlider sGreen = new JSlider(0,255,1);
JSlider sBlue = new JSlider(0,255,1);
JLabel hexCode = new JLabel();
JPanel myPanel = new JPanel();
GridBagLayout layout = new GridBagLayout();
JFrame frame = new JFrame();
//set frame to organize components using GridBagLayout
frame.setLayout(layout);
//create gray filled rectangle
myPanel.paintComponent();
myPanel.setBackground(Color.GRAY);
//In practice this code is replicated and applied to sGreen and sBlue.
//For the sake of brevity I only show sRed in this post.
sRed.addChangeListener(
new ChangeListener()
{
@Override
public void stateChanged(ChangeEvent e){
myPanel.setBackground(changeColor());
myPanel.repaint();
hexCode.setText(toHex());
}
}
);
//add each component to JFrame
frame.add(myPanel);
frame.add(sRed);
frame.add(sGreen);
frame.add(sBlue);
frame.add(hexCode);
} //end of main
//creates JPanel filled rectangle
protected void paintComponent(Graphics g)
{
super.paintComponent(g);
g.drawRect(360, 300, 10, 10);
g.fillRect(360, 300, 10, 10);
}
//changes the display color in JPanel
private Color changeColor()
{
int r = sRed.getValue();
int b = sBlue.getValue();
int g = sGreen.getValue();
Color c;
return c = new Color(r,g,b);
}
//Displays hex representation of displayed color
private String toHex()
{
Integer r = sRed.getValue();
Integer g = sGreen.getValue();
Integer b = sBlue.getValue();
Color hC;
hC = new Color(r,g,b);
String hex = Integer.toHexString(hC.getRGB() & 0xffffff);
while(hex.length() < 6){
hex = "0" + hex;
}
hex = "Hex Code: #" + hex;
return hex;
}
}
A huge thank you to both Vivien and Vulcan. This solution works perfectly and was super simple to implement.