In java Write a program that draws out a path based on the user input. The starting coordinates for the path is the middle of the DrawingPanel. Ask the user to enter an x and a y coordinate for a DrawingPanel. Your program will draw a line from the last coordinates to the current coordinates the user enters. If the user enters an x value or y value out of bounds of the DrawingPanel, then end the program.

import javax.swing.JPanel;

import javax.swing.JOptionPane;

import javax.swing.JFrame;

import javax.swing.JLabel;  

import javax.swing.JTextField;

import javax.swing.border.Border;

import java.awt.event.ActionEvent;

import java.awt.event.ActionListener;

import javax.swing.BorderFactory;

import javax.swing.JButton;

import java.awt.BorderLayout;

import java.awt.Color;

import java.awt.FlowLayout;

import java.awt.Graphics;

import java.awt.Rectangle;

public class DrawingPanel{

private static final int width = 800;

private static final int heigth = 500;

private static JFrame mainFrame;

private static JPanel mainPanel, inputPanel, drawPanel;

private static JLabel xLabel, yLabel;

private static JTextField xField, yField;

private static JButton drawButton;

public static void main(String[] args)

{

mainFrame = new JFrame("Draw Path");

mainPanel = new JPanel(new BorderLayout());

inputPanel = new JPanel(new FlowLayout(FlowLayout.CENTER));

xLabel = new JLabel("X Coordinate: ");

xField = new JTextField(5);

yLabel = new JLabel("Y Coordinate: ");

yField = new JTextField(5);

drawButton = new JButton("Draw");

inputPanel.add(xLabel);

inputPanel.add(xField);

inputPanel.add(yLabel);

inputPanel.add(yField);

inputPanel.add(drawButton);

Border border = BorderFactory.createLineBorder(Color.black);

drawPanel = new JPanel(new FlowLayout(FlowLayout.CENTER));

drawPanel.setBorder(border);

mainPanel.add(inputPanel, BorderLayout.NORTH);

mainPanel.add(drawPanel, BorderLayout.CENTER);

mainFrame.add(mainPanel);

mainFrame.setSize(PANEL_WIDTH, PANEL_HEIGHT);

mainFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

mainFrame.setLocationRelativeTo(null);

mainFrame.setResizable(false);

mainFrame.setVisible(true);

// action listener for draw button

drawButton.addActionListener(new ActionListener() {

(use the at sign here)Override

public void actionPerformed(ActionEvent e) {

if(xField.getText().equals("") || yField.getText().equals(""))

JOptionPane.showMessageDialog(null, "Please enter the x and y coordinates!");

else

{

int x2 = Integer.parseInt(xField.getText().trim());

int y2 = Integer.parseInt(yField.getText().trim());

if(x2 > WIDTH || y2 > HEIGHT)

JOptionPane.showMessageDialog(null, "x and y coordinates should be less than "

+ width + " and " + height + " respectively!");

else

drawPath(x2, y2);

}

}

});

}

public static void drawPath(int x2, int y2)

{

int x1 = (int)drawPanel.getBounds().getCenterX();

int y1 = (int)drawPanel.getBounds().getCenterY();

Graphics g = drawPanel.getGraphics();

Rectangle r = drawPanel.getBounds();

g.setColor(drawPanel.getBackground());

g.fillRect(r.x, r.y, r.width, r.height);

g.setColor(Color. blue);

g.drawLine(x1, y1, x2, y2);

}

}

Explanation:

The class DrawingPanel is a Java class that gets the user input for the coordinate of a path with predetermined heigth and width (defined in the class). The methods of the class are; getGraphics(), getBounds(), getBackground(), setColor() and fillRect(). The result is a rectangular path GUI on the screen.

answer; histogram;

so much for the extra points :