How to use menu event

[Subitha Sangar]

Hi i am a basic leaner in java. Anyone please help me how can i change the colour when i choose the coloritem from menubar. May be my OOPs comcept is wrong. But i should keep 4 different programs. Please tell me how i have to use the OOP concept to keep 4 programs and do this work. My 4 programes are bellow. Advance thanks for your help.

1) PaintMain.java
================
 
import javax.swing.*;
 
public class PaintMain {

public static void main(String args[])
{
JFrame frame = new JFrame("draw"); 

PMenuBar menucontent = new PMenuBar();
frame.setJMenuBar(menucontent.createMenuBar());
 
PaintPanel toolitem = new PaintPanel();
frame.add(toolitem);
 
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 
frame.setVisible(true);
}
 
}
 
2) PMenuBar.java
==================
 
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
 
 
public class PMenuBar implements ActionListener {
 

 
JMenuItem redb = new JMenuItem("Red");
JMenuItem greenb = new JMenuItem("Green");
JMenuItem yellowb = new JMenuItem("Blue");
 
 
JMenuBar createMenuBar()
{
JMenuBar menubar = new JMenuBar();
 
JMenu filemenu = new JMenu("Color Chooser");

filemenu.add(redb);
filemenu.add(greenb);
filemenu.add(yellowb);
 
redb.addActionListener(this);
greenb.addActionListener(this);
yellowb.addActionListener(this);
 
menubar.add(filemenu);

return menubar;
}

public void actionPerformed(ActionEvent e)
{
JMenuItem menuitem = (JMenuItem)e.getSource();
if(menuitem == redb) {

}
if(menuitem == greenb) {

}
if(menuitem == yellowb) {

}
}
 
}
 
 
3) PaintPanel.java
====================
 
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
 
public class PaintPanel extends JPanel implements ActionListener {
 
private JButton linebt, ovalbt, flovalbt;
private DrawareaPanel drawareapanelb;

 
 

public PaintPanel()
{
 
 
linebt = new JButton("Line");
ovalbt = new JButton("Oval");
flovalbt = new JButton("Fill Oval");
 
JPanel pnlbt = new JPanel();
pnlbt.setBackground( Color.YELLOW );
 
 
 
pnlbt.add(linebt);
pnlbt.add(ovalbt);
pnlbt.add(flovalbt);
 
 
drawareapanelb = new DrawareaPanel();
 
 

 
setLayout(new BorderLayout());
 
add(pnlbt, BorderLayout.NORTH);
 
add(drawareapanelb, BorderLayout.CENTER);
 
linebt.addActionListener(this);
ovalbt.addActionListener(this);
flovalbt.addActionListener(this);
 
 
}
 
 
public void actionPerformed(ActionEvent event)
{
if(event.getSource() == linebt) {

drawareapanelb.findbutton("linebut");
}
 
if(event.getSource() == ovalbt) {
drawareapanelb.findbutton("ovalbut");
}
if(event.getSource() == flovalbt) {
drawareapanelb.findbutton("flovalbut");
}

}
 

 
}
 
 
4) DrawareaPanel.java
========================
 
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.util.*;
 
 
public class DrawareaPanel extends JPanel implements MouseListener, MouseMotionListener {
 
int x1, y1, x2, y2;
 
 
public String button;
public Color colour = Color.black;
 
 
public DrawareaPanel()
{
addMouseListener(this);
addMouseMotionListener(this);
}
 
 
public void mousePressed(MouseEvent e)
    {
x1 = e.getX();
y1 = e.getY();
    }
 
public void mouseDragged(MouseEvent e)
{
x2 = e.getX();
y2 = e.getY();

repaint();
}
 
 
 
    public void mouseReleased(MouseEvent e){ repaint(); }
    public void mouseClicked(MouseEvent e){}
    public void mouseEntered(MouseEvent e){}
    public void mouseExited(MouseEvent e){}
    public void mouseMoved(MouseEvent e){}
 
public void paintComponent(Graphics g)
{
super.paintComponent(g);
Graphics2D g2=(Graphics2D) g;

 
g2.setColor(colour);

if(button == "linebut"){
 g2.drawLine(x1, y1, x2 , y2);
           }
if(button == "ovalbut"){
 g2.drawOval(x1, y1, x2 - x1, y2 - y1);
           }
if(button == "flovalbut"){
g2.fillOval(x1, y1, x2 - x1, y2 - y1);
           }

 
} 
 
public void findbutton(String a)
{
button = a;

}
 
public void findcolour(Color b)
{
colour = b;
}
 
}

EDIT by mw: Added Code Tags to original poster's indentation.
[ January 16, 2006: Message edited by: marc weber ]

[Gregg Bolinger]

Moving to the Swing forum.

[Michael Dunn]

it's just a matter of adding the colors to PMenuBar, then a method to
return the selected color (note I changed the class to extend JMenuBar),
then adding some refences between the classes, so that when paintComponent()
is called, it gets the selected color from the menu bar

(for simplicity (mine) I combined all the classes into one jave file)

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.util.*;
class PaintMain {
  public static void main(String args[])
  {
    JFrame frame = new JFrame("draw");
    PMenuBar menucontent = new PMenuBar();
    frame.setJMenuBar(menucontent);
    PaintPanel toolitem = new PaintPanel(menucontent);
    frame.getContentPane().add(toolitem);
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.setLocation(400,300);
    frame.setSize(300,200);
    frame.setVisible(true);
  }
}
class PMenuBar extends JMenuBar implements ActionListener
{
  Color[] colors = {Color.RED,Color.GREEN,Color.BLUE,Color.BLACK};
  int colorSelection = 3;
 
  JMenuItem redb = new JMenuItem("Red");
  JMenuItem greenb = new JMenuItem("Green");
  JMenuItem yellowb = new JMenuItem("Blue");
  public PMenuBar()
  {
    createMenuBar();
  }
  public Color getColor()
  {
    return colors[colorSelection];
  }
  void createMenuBar()
  {
 
    JMenu filemenu = new JMenu("Color Chooser");
    filemenu.add(redb);
    filemenu.add(greenb);
    filemenu.add(yellowb);
    redb.addActionListener(this);
    greenb.addActionListener(this);
    yellowb.addActionListener(this);
    add(filemenu);
  }
  public void actionPerformed(ActionEvent e)
  {
    JMenuItem menuitem = (JMenuItem)e.getSource();
    if(menuitem == redb) {
     colorSelection = 0;
    }
    else if(menuitem == greenb) {
      colorSelection = 1;
    }
    else if(menuitem == yellowb) {
      colorSelection = 2;
    }
    else colorSelection = 3;
  }
}
class PaintPanel extends JPanel implements ActionListener
{
  private JButton linebt, ovalbt, flovalbt;
  private DrawareaPanel drawareapanelb;
  public PaintPanel(PMenuBar p)
  {
    linebt = new JButton("Line");
    ovalbt = new JButton("Oval");
    flovalbt = new JButton("Fill Oval");
    JPanel pnlbt = new JPanel();
    pnlbt.setBackground( Color.YELLOW );
    pnlbt.add(linebt);
    pnlbt.add(ovalbt);
    pnlbt.add(flovalbt);
    drawareapanelb = new DrawareaPanel(p);
    setLayout(new BorderLayout());
    add(pnlbt, BorderLayout.NORTH);
    add(drawareapanelb, BorderLayout.CENTER);
    linebt.addActionListener(this);
    ovalbt.addActionListener(this);
    flovalbt.addActionListener(this);
  }
  public void actionPerformed(ActionEvent event)
  {
    if(event.getSource() == linebt) {
      drawareapanelb.findbutton("linebut");
    }
 
    if(event.getSource() == ovalbt) {
      drawareapanelb.findbutton("ovalbut");
    }
    if(event.getSource() == flovalbt) {
      drawareapanelb.findbutton("flovalbut");
    }
  }
}
class DrawareaPanel extends JPanel implements MouseListener, MouseMotionListener
{
  int x1, y1, x2, y2;
  public String button;
  public Color colour = Color.black;
  PMenuBar pmb;
  public DrawareaPanel(PMenuBar p)
  {
    pmb = p;
    addMouseListener(this);
    addMouseMotionListener(this);
  }
  public void mousePressed(MouseEvent e)
      {
    x1 = e.getX();
    y1 = e.getY();
      }
 
  public void mouseDragged(MouseEvent e)
  {
    x2 = e.getX();
    y2 = e.getY();
 
    repaint();
  }
    public void mouseReleased(MouseEvent e){ repaint(); }
    public void mouseClicked(MouseEvent e){}
    public void mouseEntered(MouseEvent e){}
    public void mouseExited(MouseEvent e){}
    public void mouseMoved(MouseEvent e){}
 
  public void paintComponent(Graphics g)
  {
    super.paintComponent(g);
    Graphics2D g2=(Graphics2D) g;
    //g2.setColor(colour);
    g2.setColor(pmb.getColor());
    if(button == "linebut"){
     g2.drawLine(x1, y1, x2 , y2);
            }
    if(button == "ovalbut"){
     g2.drawOval(x1, y1, x2 - x1, y2 - y1);
            }
    if(button == "flovalbut"){
    g2.fillOval(x1, y1, x2 - x1, y2 - y1);
            }
  }
  public void findbutton(String a)
  {
    button = a;
  }
  public void findcolour(Color b)
  {
    colour = b;
  }
}

[Subitha Sangar]

Thanks for your help. If i have another menu item call "save" and i have one class savefile() in DrawareaPanel then how can i call savefile() from PMenuBar. Please give me an idea. Thanks in advance. My programes are below.

 
1) PaintMain.java
==================
 
import javax.swing.*;
 
public class PaintMain {

public static void main(String args[])
{
JFrame frame = new JFrame("draw"); 

PMenuBar menucontent = new PMenuBar();
frame.setJMenuBar(menucontent.createMenuBar());
 
PaintPanel toolitem = new PaintPanel();
frame.add(toolitem);
 
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 
frame.setVisible(true);
}
 
}
 

2) PMenuBar.java
==================
 
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
 

public class PMenuBar implements ActionListener {
 

 
JMenuItem save = new JMenuItem("Save");

JMenuBar createMenuBar()
{
JMenuBar menubar = new JMenuBar();
 
JMenu filemenu = new JMenu("File");

filemenu.add(Save);

 
save.addActionListener(this);

menubar.add(filemenu);

return menubar;
}

public void actionPerformed(ActionEvent e)
{
JMenuItem menuitem = (JMenuItem)e.getSource();
if(menuitem == save) {
// here i want to call savefile() in DrawareaPanel
}

}
 
}
 

 
3) PaintPanel.java
====================
 
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
 
public class PaintPanel extends JPanel implements ActionListener {
 
private JButton linebt, ovalbt, flovalbt;
private DrawareaPanel drawareapanelb;

public PaintPanel()
{
 

linebt = new JButton("Line");
ovalbt = new JButton("Oval");
flovalbt = new JButton("Fill Oval");
 
JPanel pnlbt = new JPanel();
pnlbt.setBackground( Color.YELLOW );
 

 
pnlbt.add(linebt);
pnlbt.add(ovalbt);
pnlbt.add(flovalbt);
 

drawareapanelb = new DrawareaPanel();
 


 
setLayout(new BorderLayout());
 
add(pnlbt, BorderLayout.NORTH);
 
add(drawareapanelb, BorderLayout.CENTER);
 
linebt.addActionListener(this);
ovalbt.addActionListener(this);
flovalbt.addActionListener(this);
 

}
 

public void actionPerformed(ActionEvent event)
{
if(event.getSource() == linebt) {

drawareapanelb.findbutton("linebut");
}
 
if(event.getSource() == ovalbt) {
drawareapanelb.findbutton("ovalbut");
}
if(event.getSource() == flovalbt) {
drawareapanelb.findbutton("flovalbut");
}

}
 
}
 

4) DrawareaPanel.java
========================
 
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.util.*;
 

public class DrawareaPanel extends JPanel implements MouseListener, MouseMotionListener {
 
int x1, y1, x2, y2;
 

public String button;
public Color colour = Color.black;
 

public DrawareaPanel()
{
addMouseListener(this);
addMouseMotionListener(this);
}
 
        public void savefile()
        {
              // my save file codes are here
        }
 

public void mousePressed(MouseEvent e)
    {
x1 = e.getX();
y1 = e.getY();
    }
 
public void mouseDragged(MouseEvent e)
{
x2 = e.getX();
y2 = e.getY();

repaint();
}
 

 
    public void mouseReleased(MouseEvent e){ repaint(); }
    public void mouseClicked(MouseEvent e){}
    public void mouseEntered(MouseEvent e){}
    public void mouseExited(MouseEvent e){}
    public void mouseMoved(MouseEvent e){}
 
public void paintComponent(Graphics g)
{
super.paintComponent(g);
Graphics2D g2=(Graphics2D) g;

 
g2.setColor(colour);

if(button == "linebut"){
 g2.drawLine(x1, y1, x2 , y2);
           }
if(button == "ovalbut"){
 g2.drawOval(x1, y1, x2 - x1, y2 - y1);
           }
if(button == "flovalbut"){
g2.fillOval(x1, y1, x2 - x1, y2 - y1);
           }

 
} 
 
public void findbutton(String a)
{
button = a;

}
 
public void findcolour(Color b)
{
colour = b;
}
 
}

[Michael Dunn]

what is to be saved?

how are you getting the file path/name to save to?

[Subitha Sangar]

I am going to save the drawing into an arraylist and save that arraylist as a file. my coding under savefile() is bellow. when i use the button from paintpanel it is working fine and i can able to save it... but i should use the menu and get the event from menu. i donno how to get the menu even from PMenuBar.java. Please give me an idea how can i call this save method from PMenuBar. my savefile() in DrawareaPanel is bellow.

public void savefile()
{
JFileChooser filecho = new JFileChooser(".");
filecho.setDialogTitle("Save File As");
int action = fichooser.showSaveDialog(this);

if (action != JFileChooser.APPROVE_OPTION) {
// When canceled.
return;
}


File file = filecho.getSelectedFile();

if (file.exists()) {
action = JOptionPane.showConfirmDialog(this,"File exists, overwrite the file?");
if (action != JOptionPane.YES_OPTION)
return;
}


try {
ObjectOutputStream out =
new ObjectOutputStream(new FileOutputStream(file));
//out.writeObject(getBackground());
out.writeObject(arrayline);
out.close();
}
catch (IOException e) {
JOptionPane.showMessageDialog(this,
"Error :\t" + e.getMessage());
}
}

[Michael Dunn]

this might be one way to approach the problem.

instead of passing a reference of PMenuBar to the drawingPanel,
reverse this so you now pass a reference of the drawingPanel to PMenuBar.
(PMenuBar is now approaching the stage where it's re-usability is suspect,
so perhaps working with a standard JMenuBar, as part of the main gui's code,
might be worth considering).

For the moment, working with PMenuBar, you now have a reference to the
drawingPanel, so, first up, you have put the colorSelection variable in the
drawingPanel and 'set' the number whenever the color items are clicked in the menu
(instead of 'getting' the number from PMenuBar).

next, I would have menuItems of 'Save' and 'Save As', with the JFileChooser
attached to 'Save As' (you may want to disable 'Save' until a fileName is set)

include in the method signature of drawingPanel's save(), the file name to save as
public void save(File fileName)
{
//save the data to 'fileName'
}

so, when save (or save as) is clicked, PMenuBar calls drawingPanel's save
method, passing it an argument of the filename.

[Subitha Sangar]

Hi, Michael Dunn. Thank you so much for your help. i did the same way and it is working fine.