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NomNom

Member Since 02 Aug 2010
Offline Last Active Aug 15 2012 06:27 AM
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#568450 Java Mini-Paint Program

Posted by NomNom on 08 August 2010 - 07:39 PM

Okay, all you Java programmers out there! Here's my first tutorial! The last time I checked, there wasn't a Java paint program out here yet, so hopefully I'm the first. This tutorial will cover pretty much all of the code involved, so I guess this counts as a beginner tut. So, in this program that we'll be making(if you do it right), you'll be able to draw on a blank white canvas, change the colors of your brush, and clear it! Enough chat, let's do it!

Things needed before-code:
Okay, so some things that you'll need to do before the code is make an 16x16 GIF for each of the colors that we'll have, so you'll need a blue, green, magenta, black, and red GIF (create seperate GIFs. It's not that hard. Just go to Microsoft Paint[if you're using a Microsoft OS], make a 16x16 image and fill the canvas with that color). Or, you could use mine, which are attached. =D

Remember to save the GIFs as the names of the GIFs in the code, or just change the code to fit your file names.



Something else to do(I guess you don't have to, but I like to keep things organised), is to create a Paint folder and store all your code and images in it.

Now that you've done all that, we can get to the actual code =]


/* 
 * Code by NomNom /*
 */
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;


public class paint{
	public static void main(String[] args){
		Icon iconB = new ImageIcon("blue.gif");
		//the blue image icon
		Icon iconM = new ImageIcon("magenta.gif");
		//magenta image icon
		Icon iconR = new ImageIcon("red.gif");
		//red image icon
		Icon iconBl = new ImageIcon("black.gif");
		//black image icon
		Icon iconG = new ImageIcon("green.gif");
		//finally the green image icon
		//These will be the images for our colors.
		
		JFrame frame = new JFrame("Paint It");
		//Creates a frame with a title of "Paint it"
		
		Container content = frame.getContentPane();
		//Creates a new container
		content.setLayout(new BorderLayout());
		//sets the layout
		
		final PadDraw drawPad = new PadDraw();
		//creates a new padDraw, which is pretty much the paint program
		
		content.add(drawPad, BorderLayout.CENTER);
		//sets the padDraw in the center
		
		JPanel panel = new JPanel();
		//creates a JPanel
		panel.setPreferredSize(new Dimension(32, 68));
		panel.setMinimumSize(new Dimension(32, 68));
		panel.setMaximumSize(new Dimension(32, 68));
		//This sets the size of the panel
		
		JButton clearButton = new JButton("Clear");
		//creates the clear button and sets the text as "Clear"
		clearButton.addActionListener(new ActionListener(){
			public void actionPerformed(ActionEvent e){
				drawPad.clear();
			}
		});
		//this is the clear button, which clears the screen.  This pretty
		//much attaches an action listener to the button and when the
		//button is pressed it calls the clear() method
		
		JButton redButton = new JButton(iconR);
		//creates the red button and sets the icon we created for red
		redButton.addActionListener(new ActionListener(){
			public void actionPerformed(ActionEvent e){
				drawPad.red();
			}

		});
		//when pressed it will call the red() method.  So on and so on =]
		
		JButton blackButton = new JButton(iconBl);
		//same thing except this is the black button
		blackButton.addActionListener(new ActionListener(){
			public void actionPerformed(ActionEvent e){
				drawPad.black();
			}
		});
		
		JButton magentaButton = new JButton(iconM);
		//magenta button
		magentaButton.addActionListener(new ActionListener(){
			public void actionPerformed(ActionEvent e){
				drawPad.magenta();
			}
		});
		
		JButton blueButton = new JButton(iconB);
		//blue button
		blueButton.addActionListener(new ActionListener(){
			public void actionPerformed(ActionEvent e){
				drawPad.blue();
			}
		});
		
		JButton greenButton = new JButton(iconG);
		//green button
		greenButton.addActionListener(new ActionListener(){
			public void actionPerformed(ActionEvent e){
				drawPad.green();
			}
		});
		blackButton.setPreferredSize(new Dimension(16, 16));
		magentaButton.setPreferredSize(new Dimension(16, 16));
		redButton.setPreferredSize(new Dimension(16, 16));
		blueButton.setPreferredSize(new Dimension(16, 16));
		greenButton.setPreferredSize(new Dimension(16,16));
		//sets the sizes of the buttons
		
		panel.add(greenButton);
		panel.add(blueButton);
		panel.add(magentaButton);
		panel.add(blackButton);
		panel.add(redButton);
		panel.add(clearButton);
		//adds the buttons to the panel
		
		content.add(panel, BorderLayout.WEST);
		//sets the panel to the left
		
		frame.setSize(300, 300);
		//sets the size of the frame
		frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		//makes it so you can close
		frame.setVisible(true);
		//makes it so you can see it
	}
}


class PadDraw extends JComponent{
	Image image;
	//this is gonna be your image that you draw on
	Graphics2D graphics2D;
	//this is what we'll be using to draw on
	int currentX, currentY, oldX, oldY;
	//these are gonna hold our mouse coordinates

	//Now for the constructors
	public PadDraw(){
		setDoubleBuffered(false);
		addMouseListener(new MouseAdapter(){
			public void mousePressed(MouseEvent e){
				oldX = e.getX();
				oldY = e.getY();
			}
		});
		//if the mouse is pressed it sets the oldX & oldY
		//coordinates as the mouses x & y coordinates
		addMouseMotionListener(new MouseMotionAdapter(){
			public void mouseDragged(MouseEvent e){
				currentX = e.getX();
				currentY = e.getY();
				if(graphics2D != null)
				graphics2D.drawLine(oldX, oldY, currentX, currentY);
				repaint();
				oldX = currentX;
				oldY = currentY;
			}

		});
		//while the mouse is dragged it sets currentX & currentY as the mouses x and y
		//then it draws a line at the coordinates
		//it repaints it and sets oldX and oldY as currentX and currentY
	}

	public void paintComponent(Graphics g){
		if(image == null){
			image = createImage(getSize().width, getSize().height);
			graphics2D = (Graphics2D)image.getGraphics();
			graphics2D.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
			clear();

		}
		g.drawImage(image, 0, 0, null);
	}
	//this is the painting bit
	//if it has nothing on it then
	//it creates an image the size of the window
	//sets the value of Graphics as the image
	//sets the rendering
	//runs the clear() method
	//then it draws the image


	public void clear(){
		graphics2D.setPaint(Color.white);
		graphics2D.fillRect(0, 0, getSize().width, getSize().height);
		graphics2D.setPaint(Color.black);
		repaint();
	}
	//this is the clear
	//it sets the colors as white
	//then it fills the window with white
	//thin it sets the color back to black
	public void red(){
		graphics2D.setPaint(Color.red);
		repaint();
	}
	//this is the red paint
	public void black(){
		graphics2D.setPaint(Color.black);
		repaint();
	}
	//black paint
	public void magenta(){
		graphics2D.setPaint(Color.magenta);
		repaint();
	}
	//magenta paint
	public void blue(){
		graphics2D.setPaint(Color.blue);
		repaint();
	}
	//blue paint
	public void green(){
		graphics2D.setPaint(Color.green);
		repaint();
	}
	//green paint

}


//good job, you've made your paint program =]


Yeah! You've made it through. Hopefully this helped someone with something. Thanks!

-NomNom

Attached Thumbnails

  • magenta..GIF
  • red..GIF
  • green..GIF
  • blue..GIF
  • black..GIF

  • 3


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