// File:   gui-lowlevel/mouse/mousedemo/MouseTest.java
// Purpose: Demonstrate mouse listeners.
//         Written as both applet and main program.
//         Shows two ways to handle mouse listeners:
//         (1) Handled in the graphics component subclass itself.  It's common
//             for a graphics component to handle its own mouse events.
//             The moved and dragged events are handled there.
//         (2) Handled by the "owner" of the component.  This is done here
//             for the 5 MouseListener events.
// Author: Fred Swartz - 2006-10-03 - Placed in public domain.

package mousedemo;

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

//////////////////////////////////////////////////////////////// class MouseTest
public class MouseTest extends JApplet implements MouseListener{
    JTextArea              _loggingTA = new JTextArea(10, 40);
    MouseGraphicsComponent _display   = new MouseGraphicsComponent();
    
    //============================================================== constructor
    public MouseTest() {
        JButton clearBtn = new JButton("Clear");
        JLabel  commentsLbl = new JLabel("Experiment with combinations of " +
                "mouse buttons and modifier keys.");
        
        //... Add listeners.
        _display.addMouseListener(this);
        clearBtn.addActionListener(new ClearAction());
        
        //... Do layout.
        JPanel topPanel = new JPanel(new FlowLayout(FlowLayout.LEFT));
        topPanel.add(clearBtn);
        topPanel.add(commentsLbl);
        
        JPanel content = new JPanel();
        content.setLayout(new BorderLayout(5, 5));
        content.add(topPanel, BorderLayout.NORTH);
        content.add(_display, BorderLayout.WEST);
        content.add(new JScrollPane(_loggingTA), BorderLayout.CENTER);
        
        this.setContentPane(content);
    }
    
    //============================================================== method main
    public static void main(String[] args) {
        JFrame window = new JFrame("Mouse Demo");
        window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        window.setContentPane(new MouseTest());
        window.pack();                        // Do the layout.
        window.setLocationRelativeTo(null);   // Center it.
        window.setVisible(true);
    }
    
    //========================================================== mouse listeners
    // I've violated the normal formatting rules because these all belong
    // together and all do the same thing.  Normally, some of them would do
    // something, and others would just ignore the event (no statements
    // in the method body).
    //
    // For ActionEvents, it's a very bad idea to have the outer class
    // implement ActionListener because typically there are many things that
    // might cause these events: buttons, menu items, radio buttons, checkboxes,
    // etc, so there would need to be lots of separate listeners. 
    //
    // Mouse events are different.  First, they are usually handled
    // within a component which listens to its own events, as in the
    // other class here.  Handling them outside the component, as in this class,
    // is unusual, and it's unlikely that more than one component's mouse 
    // events would be handled outside.  If there was a need to separate the
    // mouse events from several components, it would be easy to just put the
    // listeners in an inner class that implements MouseListener.  
    // That might, or might not, be a cleaner way to organize the code.
    public void mouseClicked(MouseEvent e) { log(e); }
    public void mouseEntered(MouseEvent e) { log(e); }
    public void mouseExited(MouseEvent e)  { log(e); }
    public void mousePressed(MouseEvent e) { log(e); }
    public void mouseReleased(MouseEvent e){ log(e); }
    
    //====================================================================== log
    // Utility method to handle common logging action by all listeners.
    private void log(MouseEvent e) {
        _loggingTA.append(e.paramString() + '\n');
    }
    
    //////////////////////////////////////////////////////////////// ClearAction
    class ClearAction implements ActionListener {
        public void actionPerformed(ActionEvent e) {
            _loggingTA.setText("");  // Clear text in logging area.
            _display.clear();        // Clear graphics area.
        }
    }
}

// File:   gui-lowlevel/mouse/mousedemo/MouseGraphicsComponent.java
// Purpose: Demonstrate mouse listeners.
// Author: Fred Swartz - 2006-10-03 - Placed in public domain.

package mousedemo;

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

/////////////////////////////////////////////////// class MouseGraphicsComponent
class MouseGraphicsComponent extends JComponent implements MouseMotionListener {
    
    //======================================================= instance variables
    //... The appropriate listener sets the instance variables,
    //    then calls repaint(), which schedules a call to paintComponent,
    //    which uses these variable values.
    private int _lastMovedX   = 0;  // x coord of mouse move
    private int _lastMovedY   = 0;  // y coord of mouse move
    
    //... List of points for line constructed by dragging.
    ArrayList<Point> _points = new ArrayList<Point>(1000);
    
    //============================================================== constructor
    public MouseGraphicsComponent() {
        this.setPreferredSize(new Dimension(200, 200));
        this.addMouseMotionListener(this); // Listen to mouse moves, drags.
    }
    
    //================================================== override paintComponent
    @Override public void paintComponent(Graphics g) {
        //... Paint background.
        g.setColor(Color.YELLOW);
        g.fillRect(0, 0, this.getWidth(), this.getHeight());
        g.setColor(Color.BLACK);
        
        //... Draw coordinates of the mouse as it moves.
        String coords = "x=" + _lastMovedX   + ", y=" + _lastMovedY;
        g.drawString(coords, _lastMovedX, _lastMovedY);
        
        //... Draw lines between each of the points (if any).
        if (_points.size() > 1) {
            Point previousPoint = _points.get(0);
            for (int i = 1; i < _points.size(); i++) {
                Point thisPoint = _points.get(i);
                g.drawLine(previousPoint.x, previousPoint.y
                        , thisPoint.x, thisPoint.y);
                previousPoint = thisPoint;
            }
        }
    }
    
    //====================================================== listener mouseMoved
    // This sets the x, y coordinate that are used by paintComponent.
    // Could also save as a Point object, but ints are sometimes simpler.
    public void mouseMoved(MouseEvent e) {
        //log(e);
        _lastMovedX = e.getX();
        _lastMovedY = e.getY();
        this.repaint();  // Show the change.  Indirectly calls paintComponent.
    }
    
    //==================================================== listener mouseDragged
    // Save each point we dragged over to show as a "line" in paintComponent.
    // Saved as a Point object instead of ints because ArrayList needs object.
    public void mouseDragged(MouseEvent e) {
        _points.add(e.getPoint()); // Save the point for drawing.
        this.repaint();  // Show the change.  Indirectly calls paintComponent.
    }
    
    //==================================================================== clear
    // Clear the points that dragging recorded.
    public void clear() {
        _points.clear();
        this.repaint();  // Show the change.  Indirectly calls paintComponent.
    }
}