Trying to draw on a canvas with sliders

I am attempting to use jsliders to allow a user to pinpoint the origin of a circle to be drawn on a canvas. I am using a button to show and hide the circle. I am using paint on an inner jpanel so that paint will not write over components. However, the coordinates inside the jpanel are different than the coordinates for the entire frame. So, it is very difficult for me to get the coordinates of the jslider and then translate it to the jpanel to draw the circle. Is there an easy way to figure this out without a ton of guess and check? I am also using the custom layout miglayout. I have included the code for my GUI class as well as my custom JPanel I made so I could mess with the paint method.

public class CircleGUI extends JFrame implements ActionListener {
private MigLayout layout = new MigLayout();
private CustomPanel innerpanel;
private JSlider x,y;
private JColorChooser colorpick;
private JButton state;
private boolean bstate;
CircleGUI()  {
initialize();
}
private void initialize()  {
Border blackline = BorderFactory.createLineBorder(Color.black);
bstate = false;
x = new JSlider(JSlider.HORIZONTAL,650,325);
x.setPaintTicks(true);
x.setPaintLabels(true);
x.setPreferredSize(new Dimension(650,0));
y = new JSlider(JSlider.HORIZONTAL,650,325);
y.setPaintTicks(true);
y.setPaintLabels(true);
y.setInverted(true);
y.setOrientation(JSlider.VERTICAL);
y.setPreferredSize(new Dimension (0,600));
colorpick = new JColorChooser();
state = new JButton("Show");
state.addActionListener(e -> {
if(!bstate) {
int positionx = x.getValue() - 80;
int positiony = y.getValue();
Color c = colorpick.getColor();
innerpanel.setColor(c);
innerpanel.setX(positionx);
innerpanel.setY(positiony);
innerpanel.repaint();
state.setText("Hide");
bstate = true;
} else {
Color transparent = new Color(0,0,0,0);
innerpanel.setColor(transparent);
innerpanel.repaint();
state.setText("Show");
bstate = false;
}
});
JPanel outerpanel = new JPanel(layout);
innerpanel = new CustomPanel();
innerpanel.setPreferredSize(new Dimension(600,600));
innerpanel.setBorder(blackline);
outerpanel.add(x,"wrap");
outerpanel.add(y,"split 2");
outerpanel.add(innerpanel);
outerpanel.add(state,"wrap");
outerpanel.add(colorpick);
this.setSize(1000, 1000);
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
this.add(outerpanel);
}
@Override
public void actionPerformed(ActionEvent e) {
}
}
public class CustomPanel extends JPanel implements ActionListener {
private Color c;
private int x;
private int y;
public CustomPanel() {
c = null;
}
@Override
public void actionPerformed (ActionEvent e) {
}
public void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2 = (Graphics2D) g;
g2.setPaint(c);
g2.fill(new Ellipse2D.Double(x, y, 100, 100));
}
public void setColor(Color c) {
this.c = c;
}
public void setX(int x) {
this.x = x;
}
public void setY(int y) {
this.y = y;
}
}

Your problem is you are trying to make a one-to-one mapping between the value of the JSlider and the coordinate in your CustomPanel. You should use the JSlider value as a percentage, i.e. minimum value zero and maximum value 100. If you want the circle to appear in the middle of the CustomPanel so you place both JSliders in their mid-points, i.e. both at 50%. Then you calculate 50% of the corresponding dimension to get the coordinate. If the width of CustomPanel is 600, then 50% of 600 is 300 so positionx needs to be 300.

The only thing I changed in your code is the calculation of positionx and positiony.

import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.geom.Ellipse2D;

import javax.swing.BorderFactory;
import javax.swing.JButton;
import javax.swing.JColorChooser;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JSlider;
import javax.swing.border.Border;

import net.miginfocom.swing.MigLayout;

public class CircleGUI extends JFrame implements ActionListener {
    private MigLayout layout = new MigLayout();
    private CustomPanel innerpanel;
    private JSlider x,y;
    private JColorChooser colorpick;
    private JButton state;
    private boolean bstate;

    CircleGUI() {
        initialize();
    }

    private void initialize() {
        Border blackline = BorderFactory.createLineBorder(Color.black);
        bstate = false;

//        x = new JSlider(JSlider.HORIZONTAL, 650, 325);
        x = new JSlider(0, 100, 10);
        x.setPaintTicks(true);
        x.setPaintLabels(true);
        x.setPreferredSize(new Dimension(650, 0));

//        y = new JSlider(JSlider.HORIZONTAL, 650, 325);
        y = new JSlider(0, 100, 10);
        y.setPaintTicks(true);
        y.setPaintLabels(true);
        y.setInverted(true);
        y.setOrientation(JSlider.VERTICAL);
        y.setPreferredSize(new Dimension(0, 600));

        colorpick = new JColorChooser();
        state = new JButton("Show");
        state.addActionListener(e -> {
            if (!bstate) {
                int positionx = Math.round(x.getValue() / 100.0f * innerpanel.getSize().width) - 50;
                int positiony = Math.round(y.getValue() / 100.0f * innerpanel.getSize().height) - 50;
                Color c = colorpick.getColor();
                innerpanel.setColor(c);
                innerpanel.setX(positionx);
                innerpanel.setY(positiony);
                innerpanel.repaint();
                state.setText("Hide");
                bstate = true;
            }
            else {
                Color transparent = new Color(0, 0, 0, 0);
                innerpanel.setColor(transparent);
                innerpanel.repaint();
                state.setText("Show");
                bstate = false;
            }
        });
        JPanel outerpanel = new JPanel(layout);
        innerpanel = new CustomPanel();
        innerpanel.setPreferredSize(new Dimension(600, 600));
        innerpanel.setBorder(blackline);
        outerpanel.add(x, "wrap");
        outerpanel.add(y, "split 2");
        outerpanel.add(innerpanel);
        outerpanel.add(state, "wrap");
        outerpanel.add(colorpick);

        this.setSize(1000, 1000);
        this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        this.add(outerpanel);
    }

    @Override
    public void actionPerformed(ActionEvent e) {

    }

    public static void main(String[] args) {
        EventQueue.invokeLater(() -> {
            CircleGUI cg = new CircleGUI();
            cg.setVisible(true);
        });
    }
}

class CustomPanel extends JPanel implements ActionListener {
    private Color c;
    private int x;
    private int y;

    public CustomPanel() {
        c = null;
    }

    @Override
    public void actionPerformed(ActionEvent e) {

    }

    public void paintComponent(Graphics g) {
        super.paintComponent(g);
        Graphics2D g2 = (Graphics2D) g;
        g2.setPaint(c);
        g2.fill(new Ellipse2D.Double(x, y, 100, 100));
    }

    public void setColor(Color c) {
        this.c = c;
    }

    public void setX(int x) {
        this.x = x;
    }

    public void setY(int y) {
        this.y = y;
    }
}