/***********************************************************
* Tejal Desai									           *
* November 13, 2000     						           *
* CIS 525.001									           *
* Presented To: Dr. Bruce Maxim     			           *
* Assignment #3 - Java Applet 					           *
* This program is a java applet that is used to help tutor *
* people on their shapes and colors. It presents the user  *
* with 6 different shapes & 6 different colors and a panel *
* where the user selects his shape and color and the       *
* appropriate object is drawn on the panel wherever the    *
* user clicks. It refreshes after each drawing so the user *
* can try and imagine what will be drawn and then check    *
* his answer by clicking on the drawing area.              *
***********************************************************/

//import the specific libraries needed for this program
//specifically swing for applet components and the abstract
//widowing toolkit to make GUIs cross different platforms
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

//class definition line derived from the JApplet
public class LittleTutor extends JApplet {
 //variable declarations
 private JButton choices[];
 //shape names in an array format
 private String names[] = {"Square", "Circle", "Triange", "Rectangle","Oval", "Polygon"};
 //use Panels to separate the applet window
 private JPanel buttonPanel;
 private DrawPanel drawingArea;
 private JPanel radioPanel;
 //color names
 private JRadioButton red, blue, green, yellow, orange, magenta;
 private ButtonGroup ColorsGroup;
 private int width = 300, height =200;



 public void init() //predefined applet method
  {
	//create new panel where shapes will be displayed
	drawingArea = new DrawPanel(width, height);

	//create buttons for all the different shapes and use
	//the names from the array given above
	choices = new JButton[names.length];
	buttonPanel = new JPanel();
	//format the buttons in its own panel
	buttonPanel.setLayout(new GridLayout(2, choices.length));
	ButtonHandler handler = new ButtonHandler();
	//add the button names and place them on the panel
	//add a buttonhandler to listen when the buttons are pressed
    for (int i=0; i<choices.length; i++) {
		 choices[i] = new JButton(names[i]);
		 buttonPanel.add(choices[i]);
		 choices[i].addActionListener(handler);
		 }

    //create a new panel for the radio buttons
    radioPanel = new JPanel();

    //create new radio buttons for each color
    red = new JRadioButton("Red", true);
    blue = new JRadioButton("Blue", false);
    green = new JRadioButton("Green", false);
    yellow = new JRadioButton("Yellow", false);
    orange = new JRadioButton("Orange", false);
    magenta = new JRadioButton("Magenta", false);

    //display the radiobuttons on the panel
    radioPanel.add(red);
    radioPanel.add(blue);
    radioPanel.add(green);
    radioPanel.add(yellow);
    radioPanel.add(orange);
    radioPanel.add(magenta);

    //create a handler for the radiobuttons
    //and listen to all of them when clicked
    RadioButtonHandler radioHandler = new RadioButtonHandler();
    red.addItemListener(radioHandler);
    blue.addItemListener(radioHandler);
    green.addItemListener(radioHandler);
    yellow.addItemListener(radioHandler);
    orange.addItemListener(radioHandler);
    magenta.addItemListener(radioHandler);

    //create a radio button group to add all the colors
    //so that only one color can be chosen at a time
    ColorsGroup = new ButtonGroup();
    //add the colors to the new group
    ColorsGroup.add(red);
    ColorsGroup.add(blue);
    ColorsGroup.add(green);
    ColorsGroup.add(yellow);
    ColorsGroup.add(orange);
    ColorsGroup.add(magenta);

    //add a mouse listener so x and y coordinates
    //can be determined and the program knows where
    //to draw the shape.
    addMouseListener(new MouseClickHandler());

    //add the three panels to the container so
    //they are visible
    Container c = getContentPane();
    c.add(buttonPanel, BorderLayout.SOUTH);
    c.add(drawingArea, BorderLayout.CENTER);
    c.add(radioPanel, BorderLayout.NORTH);
   } //end init function


/*The following class definition is used whenever a button
is clicked.  Specifically, it finds which button was clicked
and then calls on a function, setCurrentChoice(),and passes
a parameter which tells the index of which button was clicked*/
private class ButtonHandler implements ActionListener {
	   public void actionPerformed (ActionEvent e)
	      {
		   for (int i=0; i<choices.length; i++)
		    if (e.getSource() == choices[i]) {
				drawingArea.setCurrentChoice(i);
				break;
			    } //end if
	       } //end function
	    } //end class definition

/*The following class definition is used whenever a radio button
is chosen.  Specifically, it finds which button was selected
and then calls on a function, setCurrentColor(), and passes a
pre-defined parameter based on which button was clicked.
Specifically, red=5, blue=10, green=15, yellow=20, orange=25, and
magenta=30.  These values were chosen by the programmer and have
no inherent language connotations.*/
private class RadioButtonHandler implements ItemListener
 	{
		public void itemStateChanged(ItemEvent e)
		 {
		  if(e.getSource() == red)
		    drawingArea.setCurrentColor(5);
		  else if(e.getSource() == blue)
		    drawingArea.setCurrentColor(10);
		  else if (e.getSource() == green)
		    drawingArea.setCurrentColor(15);
		  else if (e.getSource() == yellow)
		    drawingArea.setCurrentColor(20);
		  else if (e.getSource() == orange)
		    drawingArea.setCurrentColor(25);
		  else if (e.getSource() == magenta)
		    drawingArea.setCurrentColor(30);
	     }//end function
	}//end class definition

/*The following class definition is used whenever a mouse
click occurs in the drawing area.  Specifically, the x and
y coordinates of the click are found and sent as parameters
to the setCurrentCoords function.  This is used to find out
where to draw the shapes.*/
private class MouseClickHandler extends MouseAdapter
    {
		public void mouseClicked(MouseEvent e)
		 {
		  int x= e.getX();
		  int y= e.getY();
		  drawingArea.setCurrentCoords(x,y);
	 	 }//end function
 	 }//end class definition

}//end LittleTutor class definition


//define new class which extends JPanel, an already
//pre-defined class
class DrawPanel extends JPanel {
	//set variables
	private int currentChoice = -1;
	private int currentColor = 5;
	private int xcord=0, ycord=0;
	private int width = 100, height = 100;

	/*function called when the drawing panel is initialized from the
	*init function.  Sets the width and height of the panel.*/
	public DrawPanel(int w, int h)
	    {
		width = (w>=0 ? w : 100);
		height = (h>=0 ? h : 100);
        } //end function definition

    /*The paintComponent function is used everytime the shape needs to be
    drawn.  In other words, every time repaint() is called the drawingPanel
    is cleared and the new shapes are drawn. It uses a graphic object, g.*/
    public void paintComponent (Graphics g)
    {
		super.paintComponent(g);
		    //Switch statement to determine what color to set
		    //the graphic object will be -- cases determined from
		    //the pre-determined values chosen by programmer.  See
		    //RadioButtonHandler class comments for more details.
            switch(currentColor){
				case 5:
				  g.setColor(Color.red);
				  break;
				case 10:
				  g.setColor(Color.blue);
				  break;
				case 15:
				  g.setColor(Color.green);
				  break;
				case 20:
				  g.setColor(Color.yellow);
				  break;
				case 25:
				  g.setColor(Color.orange);
				  break;
				case 30:
				  g.setColor(Color.magenta);
				  break;
		      } //end switch statement

			//Switch statement based on which button was pressed
			//and determines which shape will be drawn on the panel
			//The xcord and ycord variables are used here to determine
			//where to draw the chosen shape.
			switch(currentChoice) {
				case 0:
				 g.fillRect(xcord-25, ycord-25, 100, 100);
				 break;
				case 1:
				 g.fillOval(xcord-25, ycord-25,100,100);
				 break;
				case 2:
				 Polygon ftriangle = new Polygon();
				 ftriangle.addPoint(xcord-25,ycord-25);
				 ftriangle.addPoint(xcord + 75,ycord);
				 ftriangle.addPoint(xcord + 25,ycord + 62);
				 g.fillPolygon(ftriangle);
				 break;
				case 3:
				 g.fillRect(xcord-25, ycord-25,100,50);
				 break;
				case 4:
			     g.fillOval(xcord-25, ycord-25,55,105);
			     break;
			    case 5:
			     Polygon poly = new Polygon();
			     poly.addPoint(xcord,ycord);
				 poly.addPoint(xcord+55,ycord+25);
				 poly.addPoint(xcord+80,ycord);
				 poly.addPoint(xcord+65,ycord-60);
				 poly.addPoint(xcord+15,ycord-60);
				 g.fillPolygon(poly);
				 break;
	            }//end switch
        }//end paintComponent function

   /*NOTE: All of the following functions are called in handlers defined
    above...ie, radionbuttonhandler, buttonhandler, and mouseclickhandler*/

   //sets the currentChoice variable based on which button was clicked
   public void setCurrentChoice(int c)
      {
	  currentChoice = c;
      }

   //sets the currentColor variable based on which radio button was selected
   public void setCurrentColor(int c)
      {
	  currentColor = c;
      }

  //sets the x and y coordinates based on where the mouse was cliced
   public void setCurrentCoords(int x, int y)
      {
      xcord=x;
	  ycord=y;
	  repaint(); //once the user clicks, call repaint to draw the shape
      }
} //end class DrawPanel