//: Menu1.java ////////////////////////////////////////////////// // Copyright (c) Bruce Eckel, 1998 // Source code file from the book "Thinking in Java" // All rights reserved EXCEPT as allowed by the // following statements: You can freely use this file // for your own work (personal or commercial), // including modifications and distribution in // executable form only. Permission is granted to use // this file in classroom situations, including its // use in presentation materials, as long as the book // "Thinking in Java" is cited as the source. // Except in classroom situations, you cannot copy // and distribute this code; instead, the sole // distribution point is http://www.BruceEckel.com // (and official mirror sites) where it is // freely available. You cannot remove this // copyright and notice. You cannot distribute // modified versions of the source code in this // package. You cannot use this file in printed // media without the express permission of the // author. Bruce Eckel makes no representation about // the suitability of this software for any purpose. // It is provided "as is" without express or implied // warranty of any kind, including any implied // warranty of merchantability, fitness for a // particular purpose or non-infringement. The entire // risk as to the quality and performance of the // software is with you. Bruce Eckel and the // publisher shall not be liable for any damages // suffered by you or any third party as a result of // using or distributing software. In no event will // Bruce Eckel or the publisher be liable for any // lost revenue, profit, or data, or for direct, // indirect, special, consequential, incidental, or // punitive damages, however caused and regardless of // the theory of liability, arising out of the use of // or inability to use software, even if Bruce Eckel // and the publisher have been advised of the // possibility of such damages. Should the software // prove defective, you assume the cost of all // necessary servicing, repair, or correction. If you // think you've found an error, please email all // modified files with clearly commented changes to: // Bruce@EckelObjects.com. (Please use the same // address for non-code errors found in the book.) ///////////////////////////////////////////////// // Menus work only with Frames. // Shows submenus, checkbox menu items // and swapping menus. import java.awt.*; public class Menu1 extends Frame { String[] flavors = { "Chocolate", "Strawberry", "Vanilla Fudge Swirl", "Mint Chip", "Mocha Almond Fudge", "Rum Raisin", "Praline Cream", "Mud Pie" }; TextField t = new TextField("No flavor", 30); MenuBar mb1 = new MenuBar(); Menu f = new Menu("File"); Menu m = new Menu("Flavors"); Menu s = new Menu("Safety"); // Alternative approach: CheckboxMenuItem[] safety = { new CheckboxMenuItem("Guard"), new CheckboxMenuItem("Hide") }; MenuItem[] file = { new MenuItem("Open"), new MenuItem("Exit") }; // A second menu bar to swap to: MenuBar mb2 = new MenuBar(); Menu fooBar = new Menu("fooBar"); MenuItem[] other = { new MenuItem("Foo"), new MenuItem("Bar"), new MenuItem("Baz"), }; Button b = new Button("Swap Menus"); public Menu1() { for(int i = 0; i < flavors.length; i++) { m.add(new MenuItem(flavors[i])); // Add separators at intervals: if((i+1) % 3 == 0) m.addSeparator(); } for(int i = 0; i < safety.length; i++) s.add(safety[i]); f.add(s); for(int i = 0; i < file.length; i++) f.add(file[i]); mb1.add(f); mb1.add(m); setMenuBar(mb1); t.setEditable(false); add("Center", t); // Set up the system for swapping menus: add("North", b); for(int i = 0; i < other.length; i++) fooBar.add(other[i]); mb2.add(fooBar); } public boolean handleEvent(Event evt) { if(evt.id == Event.WINDOW_DESTROY) System.exit(0); else return super.handleEvent(evt); return true; } public boolean action(Event evt, Object arg) { if(evt.target.equals(b)) { MenuBar m = getMenuBar(); if(m == mb1) setMenuBar(mb2); else if (m == mb2) setMenuBar(mb1); } else if(evt.target instanceof MenuItem) { if(arg.equals("Open")) { String s = t.getText(); boolean chosen = false; for(int i = 0; i < flavors.length; i++) if(s.equals(flavors[i])) chosen = true; if(!chosen) t.setText("Choose a flavor first!"); else t.setText("Opening "+ s +". Mmm, mm!"); } else if(evt.target.equals(file[1])) System.exit(0); // CheckboxMenuItems cannot use String // matching; you must match the target: else if(evt.target.equals(safety[0])) t.setText("Guard the Ice Cream! " + "Guarding is " + safety[0].getState()); else if(evt.target.equals(safety[1])) t.setText("Hide the Ice Cream! " + "Is it cold? " + safety[1].getState()); else t.setText(arg.toString()); } else return super.action(evt, arg); return true; } public static void main(String[] args) { Menu1 f = new Menu1(); f.resize(300,200); f.show(); } } ///:~