java and graphics........ughhhhhh

x in the city

i got a wee program here, and i want to change the size of the line on the jpanel by using the jbuttons jb1-jb4

what code do i put into the action performed area, and i need implements action listener in the main class as well after mouse listener ??????

thanks guys......and gals.


+++++++++++++++++++++++++++++++++++++++++++++++++++++++



package drawframe;

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import javax.swing.JButton;

public class MyCanvas extends Canvas implements MouseListener {
int fromX=0, fromY=0, toX=0, toY=0;

public MyCanvas() {

this.addMouseListener(this);
this.setSize(256,256);
toX= 150;
toY= 200;
}

public void mouseClicked(MouseEvent e)
{
System.out.println("x pos: " + e.getX() + " y pos: " + e.getY());
this.setBackground(new Color(0, e.getX(), e.getY()));
}
public void mouseEntered(MouseEvent e)
{
//this.setBackground(new Color(255, 0, 0));
}
public void mouseExited(MouseEvent e)
{
this.setBackground(new Color(255, 255, 255));
}

public void mousePressed(MouseEvent e)
{
fromX= e.getX();
fromY = e.getY();
}

public void mouseReleased(MouseEvent e)
{
toX= e.getX();
toY = e.getY();
this.repaint();
}

public void mouseDragged(MouseEvent e){
toX= e.getX();
toY = e.getY();
this.repaint();
}

public void mouseMoved(MouseEvent e){
fromX= e.getX();
fromY = e.getY();
}

public void paint(Graphics g){
Graphics2D g2d = (Graphics2D)g;
g2d.setColor(new Color(244,0,0));
// g.fillRect(10,10,60,60);
// g.drawRect(1,1,100,100);
g2d.setStroke(new BasicStroke(10));
// Graphics2D g2d =
g2d.drawLine(fromX,fromY,toX,toY);
}
public void actionPerformed(ActionEvent e) {

if (e.getSource()==Size1);


???????????????????????????



}


}



++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

package drawframe;//class directory

//Imports = includes
import javax.swing.*;
import java.awt.*;
import javax.swing.JButton;

public class DrawFrame{
JFrame f1;
JPanel jp1;
JPanel jp2;
JButton jb1,jb2,jb3,jb4;


public DrawFrame(){
f1 = new JFrame();
jp1 = new JPanel();
jp2 = new JPanel();

JButton jb1 = new JButton();
jb1.setText("Size 1");
jb1.setBackground(Color.green);
JButton jb2 = new JButton();
jb2.setText("Size 2");
jb2.setBackground(Color.yellow);

JButton jb3 = new JButton();
jb3.setText("Size 3");
jb3.setBackground(Color.orange);
JButton jb4 = new JButton();
jb4.setText("Size 4");
jb4.setBackground(Color.pink);


jp1.setBackground(Color.black);
jp2.setBackground(Color.white);
jp1.setPreferredSize(new Dimension(200,300));
jp2.setPreferredSize(new Dimension(80,30));
jp1.setLayout(new FlowLayout());
jp1.add(jb1);
jp1.add(jb2);
jp1.add(jb3);
jp1.add(jb4);
jp1.add(jp2);

Container c = f1.getContentPane();
c.setLayout(new FlowLayout());

MyCanvas myCanvas = new MyCanvas ();
c.add(jp1);
c.add(myCanvas);
f1.pack();
f1.setVisible(true);
}

public static void main (String args[]){
DrawFrame drawFrame = new DrawFrame();
}

}

Dr Pepper

Please use tabs to indent methods and if/for/while blocks, etc.

It's very hard to tell what's going on otherwise and takes a lot longer to figure out (hence, don't know what "line" you're talking about). As for adding implemented interfaces you can just separate them with a comma:

public class MyCanvas extends Canvas implements MouseListener, ActionListener

Hope that helps!

boo-boo

if you had indentation in your code already and it was stripped out when posting to boards you could try prefixing the code segment with <pre> and adding </pre> to the end to preserve indenation

x in the city

thanks guys,

the line of code i need altered is between the ??????? bit.

(the actionlistener section, which needs to be added)
all that happens when u run it, is you get a frame with 4 buttons and u can draw a line in a jpanel and i want to alter the size (width) of the line being drawn by using the buttons.......jbuton 1 = size 1 jbutton2 = size 2, etc........

Dr Pepper

Howdy,

I have added a wee bit to the classes as shown below and it seems to work..
I put the ActionListener into the DrawFrame class and it calls a drawLine1 method in myCanvas (I only did it for button 1.. you can fill in the rest yourself!). I added some (hopefully) helpful comments also.

I also took out the package declaration at the start. I never learned to use packages like that so I don't know how that works!!

You in college? Where?

Good Luck..

<PRE>

//package drawframe;//class directory

//Imports = includes
import javax.swing.*;
import java.awt.*;
import javax.swing.JButton;
import java.awt.event.*;

public class DrawFrame implements ActionListener
{
JFrame f1;
JPanel jp1;
JPanel jp2;
JButton jb1,jb2,jb3,jb4;
MyCanvas myCanvas;

public DrawFrame()
{
f1 = new JFrame();
jp1 = new JPanel();
jp2 = new JPanel();

/* You had JButton JButton jb1 = new JButton() here..
This creates a new JButton object which only exists in this constructor (method)
Better to declare the buttons above so they can be used
throughout the class (i.e. in actionPerformed also) */
jb1 = new JButton();
jb1.setText("Size 1");
jb1.addActionListener(this);
jb1.setBackground(Color.green);

jb2 = new JButton();
jb2.setText("Size 2");
jb2.setBackground(Color.yellow);

jb3 = new JButton();
jb3.setText("Size 3");
jb3.setBackground(Color.orange);

jb4 = new JButton();
jb4.setText("Size 4");
jb4.setBackground(Color.pink);


jp1.setBackground(Color.black);
jp2.setBackground(Color.white);
jp1.setPreferredSize(new Dimension(200,300));
jp2.setPreferredSize(new Dimension(80,30));
jp1.setLayout(new FlowLayout());
jp1.add(jb1);
jp1.add(jb2);
jp1.add(jb3);
jp1.add(jb4);
jp1.add(jp2);

Container c = f1.getContentPane();
c.setLayout(new FlowLayout());

myCanvas = new MyCanvas();
c.add(jp1);
c.add(myCanvas);
f1.pack();
f1.setVisible(true);
}

/* I added the actionPerformed to this class since the buttons exist here.
This simply calls a method in myCanvas and draws a line from that method.
I'm sure there's a way to call myCanvas -> actionPerformed with buttons in this class
but I don't know it!!! */
public void actionPerformed( ActionEvent e )
{
if( e.getSource() == jb1 )
{
myCanvas.drawLine1();
}
}

public static void main (String args[])
{
DrawFrame drawFrame = new DrawFrame();
}

}

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

//package drawframe;

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import javax.swing.JButton;

public class MyCanvas extends Canvas implements MouseListener
{
int fromX=0, fromY=0, toX=0, toY=0;

public MyCanvas()
{
this.addMouseListener(this);
this.setSize(256,256);
toX= 150;
toY= 200;
}

public void mouseClicked(MouseEvent e)
{
System.out.println("x pos: " + e.getX() + " y pos: " + e.getY());
this.setBackground(new Color(0, e.getX(), e.getY()));
}
public void mouseEntered(MouseEvent e)
{
//this.setBackground(new Color(255, 0, 0));
}
public void mouseExited(MouseEvent e)
{
this.setBackground(new Color(255, 255, 255));
}

public void mousePressed(MouseEvent e)
{
fromX= e.getX();
fromY = e.getY();
}

public void mouseReleased(MouseEvent e)
{
toX= e.getX();
toY = e.getY();
this.repaint();
}

public void mouseDragged(MouseEvent e)
{
toX= e.getX();
toY = e.getY();
this.repaint();
}

public void mouseMoved(MouseEvent e)
{
fromX= e.getX();
fromY = e.getY();
}

public void paint(Graphics g)
{
Graphics2D g2d = (Graphics2D)g;
g2d.setColor(new Color(244,0,0));
g2d.setStroke(new BasicStroke(10));
g2d.drawLine(fromX,fromY,toX,toY);
}

/* This method is called from DrawFrame when button 1 is pressed */
public void drawLine1()
{
fromX = 10;
fromY = 10;
toX = 100;
toY = 10;
this.repaint();
}
}

</PRE>

x in the city

i going to a renowed institution in the west of ireland.........no not that type of institution ^^

im only starting off with java, you seem rather prolific.

i will have a gander with all this later and get back to you.
cheers dude


<><

Hobbes

Please use the [ C O D E ] tag.. eg.

this is code
   which is
      indented

Dr Pepper

Thanks Hobbes, was wondering how you do that!

vorbis

just a word about action listeners. If you don't want to declare all the buttons at the top of the class, use actioncommands instead.
e.g. instead of
button1.addActionListener(this);
use
button1.setActionCommand("copy");

then in actionPerformed you can just get the action command
e.g.
public void actionPerformed(ActionEvent e)
if (e.getActionCommand().equals("copy")
{
...
}

I find it a bit easier. It also means that two buttons can use the same code.

Dr Pepper

Yeh, good point! Forgot about that trick..

x in the city

____________


hi guys

still trying to get the buttons to change the width of the line thats drawn on the canvas,

this code should work, but i get loads of errors, do i have to set up a setlinesize class or something for this to work?

??

thanks ^^




public void actionPerformed( ActionEvent e ){



if (ae.getSource() == jb1 ){
System.out.println("button1 pushed");
MyCanvas.setLineSize(2);

}else
if (ae.getSource() == jb2 ){
System.out.println("button2 pushed");
MyCanvas.setLineSize(4);
}else
if (ae.getSource() == jb3 ){
System.out.println("button3 pushed");
MyCanvas.setLineSize(7);
}else
if (ae.getSource() == jb4 ){
System.out.println("button4 pushed");
MyCanvas.setLineSize(10);
}

}











___________

Dr Pepper

Originally posted by x in the city
____________

public void actionPerformed( ActionEvent e ){

if (ae.getSource() == jb1 ){
System.out.println("button1 pushed");
MyCanvas.setLineSize(2);

}else
if (ae.getSource() == jb2 ){
System.out.println("button2 pushed");
MyCanvas.setLineSize(4);
}else
if (ae.getSource() == jb3 ){
System.out.println("button3 pushed");
MyCanvas.setLineSize(7);
}else
if (ae.getSource() == jb4 ){
System.out.println("button4 pushed");
MyCanvas.setLineSize(10);
}

}

___________

Hi 'x in the city',

You have declared an attribute of type ActionEvent called 'e' as a parameter in the method above but you seem to refer to 'ae' in the body of the method. I pretty sure this should be 'e.getSource()' or 'ae', just make sure they're both the same.

Also setLineSize() should be a method in myCanvas, not a separate class. Givus a shout if you need any help making this method or calling it or if you need any more clarification!

Good luck,
B

x in the city

hi dude

thanks for your help, i got it sussed out now, but will be back to you again no doubt.....

ciao!

Eza