//////////////////////////////////////////////////////////////// // // FourColors.java // // LIS533 Spring 1998 // // Places four buttons in a grid layout, each button // changes the color and message of a canvas. // ///////////////////////////////////////////////////////////////// import java.awt.*; import java.applet.*; ///////////////////////////////////////////////////////////////////// // // FourColors class public class FourColors extends Applet { Button redButton, blueButton, greenButton, pinkButton; String displayString; Panel buttonPanel; myCanvas showCanvas; Label titleLabel; public void init() { setLayout(new BorderLayout()); displayString = "Four Colors are Available"; titleLabel = new Label(displayString, Label.CENTER); titleLabel.setForeground(Color.white); titleLabel.setBackground(Color.darkGray); add("North",titleLabel); showCanvas = new myCanvas(); showCanvas.setBackground(Color.cyan); add("Center",showCanvas); redButton = new Button("Red"); blueButton = new Button("Blue"); greenButton = new Button("Green"); pinkButton = new Button("Pink"); buttonPanel = new Panel(); buttonPanel.setLayout(new GridLayout(2,2)); buttonPanel.add(redButton); buttonPanel.add(blueButton); buttonPanel.add(greenButton); buttonPanel.add(pinkButton); add("South",buttonPanel); } // init public boolean action (Event e, Object arg) { if ("Red".equals (arg)) { showCanvas.doRed(); showCanvas.setRed(); return true; } // Red button if ("Blue".equals(arg)) { showCanvas.doBlue(); showCanvas.setBlue(); return true; } // Blue button if ("Green".equals(arg)) { showCanvas.doGreen(); showCanvas.setGreen(); return true; } // green button if ("Pink".equals(arg)) { showCanvas.doPink(); showCanvas.setPink(); return true; } // Pink button return false; } // action } // FourButtons /////////////////////////////////////////////////////////////////////////////// // // myCanvas class class myCanvas extends Canvas { String showString; Color thisColor; //////// Default constructor ////////////////////////////// public myCanvas () { showString = "Please press a button"; thisColor = Color.black; } // default constructor /////////// Various methods //////////////////////////// public String doRed() { showString = "A Bright Shade of Red!"; return showString; } public Color setRed() { thisColor = Color.red; repaint(); return thisColor; } public String doBlue() { showString = "A Cool Shade of Blue!"; return showString; } public Color setBlue() { thisColor = Color.blue; repaint(); return thisColor; } public String doGreen() { showString = "A Sick Shade of green!"; return showString; } public Color setGreen() { thisColor = Color.green; repaint(); return thisColor; } public String doPink() { showString = "A Blushing Shade of Pink!"; return showString; } public Color setPink() { thisColor = Color.pink; repaint(); return thisColor; } public void paint (Graphics g) { g.setColor(thisColor); g.drawString(showString, 40, 45); } } // myCanvas