import java.awt.*; import java.awt.event.*; import java.util.ArrayList;

import javax.swing.*;

public class SimplePaint extends JPanel implements MouseListener, MouseMotionListener {

public static void main(String[] args) { JFrame window = new JFrame("Simple Paint"); SimplePaint content = new SimplePaint(); window.setContentPane(content); window.setSize(700,380); window.setLocation(100,100); window.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE ); window.setVisible(true);

}

private final static int BLACK = 0, RED = 1, GREEN = 2, BLUE = 3, CYAN = 4, MAGENTA = 5, YELLOW = 6;

private int currentColor = BLACK; private int prevX, prevY; private boolean dragging;

// *** Let's make a nested class to define a new data type that will be stored in a data structure // e.g. (not a Rectangle[] rectangles) private class Line { private int x1, x2, y1, y2; private int colorCode; public Line(int x1, int x2, int y1, int y2, int colorCode) { super(); this.x1 = x1; this.x2 = x2; this.y1 = y1; this.y2 = y2; this.colorCode = colorCode; } } private ArrayList lines = new ArrayList(); /** * Constructor for SimplePaintPanel class sets the background color to be * white and sets it to listen for mouse events on itself. */ SimplePaint() { this.setBackground(Color.WHITE); //*** Since the SimplePaint JPanel is also a Listener, register appropriately this.addMouseListener(this); this.addMouseMotionListener(this); }

public void paintComponent(Graphics g) { super.paintComponent(g);

int width = getWidth(); int height = getHeight();

int colorSpacing = (height - 56) / 7;

g.setColor(Color.GRAY); g.drawRect(0, 0, width-1, height-1); g.drawRect(1, 1, width-3, height-3); g.drawRect(2, 2, width-5, height-5); g.fillRect(width - 56, 0, 56, height); g.setColor(Color.WHITE); g.fillRect(width-53, height-53, 50, 50); g.setColor(Color.BLACK); g.drawRect(width-53, height-53, 49, 49); g.drawString("CLEAR", width-48, height-23); g.setColor(Color.BLACK); g.fillRect(width-53, 3 + 0*colorSpacing, 50, colorSpacing-3); g.setColor(Color.RED); g.fillRect(width-53, 3 + 1*colorSpacing, 50, colorSpacing-3); g.setColor(Color.GREEN); g.fillRect(width-53, 3 + 2*colorSpacing, 50, colorSpacing-3); g.setColor(Color.BLUE); g.fillRect(width-53, 3 + 3*colorSpacing, 50, colorSpacing-3); g.setColor(Color.CYAN); g.fillRect(width-53, 3 + 4*colorSpacing, 50, colorSpacing-3); g.setColor(Color.MAGENTA); g.fillRect(width-53, 3 + 5*colorSpacing, 50, colorSpacing-3); g.setColor(Color.YELLOW); g.fillRect(width-53, 3 + 6*colorSpacing, 50, colorSpacing-3); g.setColor(Color.WHITE); g.drawRect(width-55, 1 + currentColor*colorSpacing, 53, colorSpacing); g.drawRect(width-54, 2 + currentColor*colorSpacing, 51, colorSpacing-2); for (int i = 0; i < lines.size(); i++) { switch(lines.get(i).colorCode) { case BLACK: g.setColor(Color.BLACK); break; case RED: g.setColor(Color.RED); break; case GREEN: g.setColor(Color.GREEN); break; case BLUE: g.setColor(Color.BLUE); break; case CYAN: g.setColor(Color.CYAN); break; case MAGENTA: g.setColor(Color.MAGENTA); break; case YELLOW: g.setColor(Color.YELLOW); break; } g.drawLine(lines.get(i).x1, lines.get(i).y1, lines.get(i).x2, lines.get(i).y2); } } // end paintComponent()

private void changeColor(int y) { int width = getWidth(); int height = getHeight(); int colorSpacing = (height - 56) / 7; int newColor = y / colorSpacing; System.out.println("y: " + y + " colorSpacing: " + colorSpacing + " newColor: " + newColor); if (newColor < 0 || newColor > 6) return; currentColor = newColor; }

/** * This is called when the user presses the mouse anywhere in the panel. * There are three possible responses, depending on where the user clicked: * Change the current color, clear the drawing, or start drawing a curve. * (Or do nothing if user clicks on the border.) */ public void mousePressed(MouseEvent evt) { int x = evt.getX(); int y = evt.getY();

int width = getWidth(); int height = getHeight();

if (dragging == true) // Ignore mouse presses that occur return; // when user is already drawing a curve. // (This can happen if the user presses // two mouse buttons at the same time.) //***like left button is down+dragging but you click the right button if (x > width - 53) { if (y > height - 53) { // ***Clicked on "CLEAR button". } else { changeColor(y); // Clicked on the color palette. // ***update the highlighted square of color } } else if (x > 3 && x < width - 56 && y > 3 && y < height - 3) { // The user has clicked on the white drawing area. // Start drawing a curve from the point (x,y). prevX = x; prevY = y; dragging = true; }

} // end mousePressed()

/** * Called whenever the user releases the mouse button. If the user was drawing * a curve, the curve is done, so we should set dragging to false */ public void mouseReleased(MouseEvent evt) { if (dragging == false) return; // Nothing to do because the user isn't drawing. dragging = false; }

/** * Called whenever the user moves the mouse while a mouse button is held down. * If the user is drawing, draw a line segment from the previous mouse location * to the current mouse location, and set up prevX and prevY for the next call. * Note that in case the user drags outside of the drawing area, the values of * x and y are "clamped" to lie within this area. This avoids drawing on the color * palette or clear button. */ public void mouseDragged(MouseEvent evt) { if (dragging == false) return; // Nothing to do because the user isn't drawing.

int x = evt.getX(); // x-coordinate of mouse. int y = evt.getY(); // y-coordinate of mouse.

if (x < 3) // Adjust the value of x, x = 3; // to make sure it's in if (x > getWidth() - 57) // the drawing area. x = getWidth() - 57;

if (y < 3) // Adjust the value of y, y = 3; // to make sure it's in if (y > getHeight() - 4) // the drawing area. y = getHeight() - 4;

// *** update our data structure to reflect the new state as the user is dragging // Remember, NO DRAWING here!

} // end mouseDragged()

public void mouseEntered(MouseEvent evt) { } // Some empty routines. public void mouseExited(MouseEvent evt) { } // (Required by the MouseListener public void mouseClicked(MouseEvent evt) { } // and MouseMotionListener public void mouseMoved(MouseEvent evt) { } // interfaces).

} // end class SimplePaint

The goal is to have it paint and be smooth with different colors.