lý thuyết java võ tấn dũng votandung

CheckboxMenuItem roundItem, squareItem, lineItem; MenuItem exitItem;. Button resetButton, exitButton; Label sizeLabel;[r]

Có hai lớp:

1) Painting

2) MyCanvas

import java.awt.*;

import java.awt.event.*;

class Painting extends Frame implements ActionListener {

Choice shapeChoice;

List colorList;

CheckboxGroup colorGroup;

Checkbox redCheckbox, greenCheckbox, blueCheckbox; Scrollbar sizeScrollbar;

MyCanvas paintCanvas;

MenuBar menubar;

Menu menu;

CheckboxMenuItem roundItem, squareItem, lineItem; MenuItem exitItem;

Button resetButton, exitButton;

Label sizeLabel;

Painting() {

setTitle("My Painting");

setLayout(null);

menubar = new MenuBar();

menu = new Menu("Shapes");

roundItem = new CheckboxMenuItem("Round"); squareItem = new CheckboxMenuItem("Square"); lineItem = new CheckboxMenuItem("Line");

exitItem = new MenuItem("Exit");

//lineItem.disable();

//roundItem.addActionListener(this);

menu.add(roundItem);

menu.add(squareItem);

menu.add(lineItem);

menu.addSeparator();

menu.add(exitItem);

menubar.add(menu);

shapeChoice = new Choice();

shapeChoice.setBounds(30,80,100,50);

shapeChoice.addItem("Round");

shapeChoice.addItem("Square");

shapeChoice.addItem("Line");

shapeChoice.setBackground(Color.GREEN);

add(shapeChoice);

colorList = new List();

colorList.setBounds(30,310,100,50);

colorList.add("Red");

colorList.add("Green");

colorList.add("Blue");

colorList.setBackground(Color.cyan);

add(colorList);

colorGroup = new CheckboxGroup();

redCheckbox = new Checkbox("Red",colorGroup,true);

greenCheckbox = new Checkbox("Green",colorGroup,false); blueCheckbox = new Checkbox("Blue",colorGroup,false); redCheckbox.setBounds(70,140,50,50);

greenCheckbox.setBounds(70,190,50,50);

blueCheckbox.setBounds(70,240,50,50);

add(redCheckbox);

add(greenCheckbox);

add(blueCheckbox);

sizeLabel = new Label("Size:");

sizeLabel.setBounds(30,110,50,30);

add(sizeLabel);

sizeScrollbar = new Scrollbar(Scrollbar.VERTICAL,60,10,20,110); sizeScrollbar.setBounds(30,140,20,150);

add(sizeScrollbar);

paintCanvas = new MyCanvas();

paintCanvas.setBounds(150,80,420,300);

add(paintCanvas);

resetButton = new Button("Reset");

resetButton.setBounds(450,390,50,40);

exitButton = new Button("Exit");

exitButton.setBackground(Color.YELLOW);

exitButton.setBounds(520,390,50,40);

add(resetButton);

add(exitButton);

//default values:

roundItem.setState(true);

shapeChoice.select(0);

colorList.select(0);

this.addWindowListener(new WindowAdapter() {

public void windowClosing(WindowEvent evt){System.exit(0);} });

}

public void actionPerformed(ActionEvent evt)

{

if(evt.getSource()==exitItem)

System.exit(0);

if(evt.getSource()==exitButton)

System.exit(0);

if(evt.getSource()==resetButton) {

roundItem.setState(true);

squareItem.setState(false);

lineItem.setState(false);

shapeChoice.select(0);

colorList.select(0);

redCheckbox.setState(true);

sizeScrollbar.setValue(60);

} }

public static void main (String[] args)

{

Painting p = new Painting();

p.setBounds(50,50,600,450);

p.setResizable(false);

p.setVisible(true);

}

}

import java.awt.*;

import java.awt.event.MouseEvent;

import java.awt.event.MouseListener;

class MyCanvas extends Canvas implements MouseListener {

int x,y;

MyCanvas()

{

super();

setBackground(Color.GRAY);

this.addMouseListener(this);

}

@Override

public void paint(Graphics g) {

g.setColor(Color.RED);

g.fillRect(x,y,100,50);

}

@Override

public void mouseClicked(MouseEvent e) {

x = e.getX();

y = e.getY();

repaint();

System.out.println("x="+x);

}

@Override

public void mousePressed(MouseEvent e) {;}

@Override

public void mouseReleased(MouseEvent e){;}

@Override

public void mouseEntered(MouseEvent e){;}

@Override

public void mouseExited(MouseEvent e){;}

}