Mobile Phone Programming

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Tracy Preston
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1 Mobile Phone Programming Free Study Activity Day 3 Part 2 J2ME in a nutshell J2ME in a nutshell

2 Objects In real world: object is your car, your bicycle, your cat.. Object has state and behavior State: variables (car: color, model) Behavior: methods (car: accelerating, braking) Object is created by using class Class In real world: all cars have some state and behavior in common Class defines the variables and the methods common to all objects of a certain kind Defining object Dog Billy; Creating object Billy = new Dog();

3 Object-oriented programming fundamentals public class Car int MaxSpeed; public void speed_up() #code for speeding up Car Corvette = new Car(); Corvette. MaxSpeed =280; Corvette. speed_up() ; Car Ferrari = new Car(); Ferrari. MaxSpeed=320; Ferrari.speed_up(); if statement If-Then Statement: if ( boolean Expression ) //code If-Then-Else Statement: if ( boolean Expression ) //code else if ( boolean Expression ) //code else //code

4 for statement for Statement: for (i = 0; i < 10; i++) //code while statement while Statement: while (boolean expression) //code [iteration;] Switch statement Switch Statement: switch (variable) case value_1: //code (only one line); break; case value_2: //code (more than one line); break;

MIDlet GUI Instead of dividing the display into multiple windows (like MS Windows) MIDP

fixed-size window whose content are controlled by one application at any time MyMIDlet

look and feel Low-level API Full control of graphics elements and low-level input events

5 MIDlet GUI Instead of dividing the display into multiple windows (like MS Windows) MIDP GUI could be seen as a deck of screens - only one active at a time Display has a single, fixed-size window whose content are controlled by one application at any time MyMIDlet YourMIDlet GUI High-level API Portability key issue Easy-to-use Little control over GUI s look and feel Low-level API Full control of graphics elements and low-level input events Four classes: Canvas, Graphics, Image, Font Game API provides additional classes for low-level drawing

6 Display Major Classes of LCDUI Displayable MIDP 1.0 Screen Canvas ChoiceGroup DateField TextBox Alert List Form Ticker Item Gauge ImageItem StringItem TextField Major Classes of LCDUI MIDP 2.0 CustomItem Display Displayable Spacer Screen TextBox Canvas Ticker ChoiceGroup DateField Gauge Alert ImageItem List Form Item StringItem TextField

7 public class TextBox_Example extends MIDlet //TextBox(title,text,size,contrains) TextBox textbox = new TextBox("Text Box Example","This is an example of a TextBox",50,0); display.setcurrent(textbox); TextBox Alert public class Alert_Example extends MIDlet // Alert(label,text,Image,type) Alert alert= new Alert("Error Alert","This is an Error Alert example",null,alerttype.error); alert.settimeout(alert.forever); display.setcurrent(alert);

8 public class Multiple_List extends MIDlet List 1 //List(label,type,items,Images) List list = new List("Multiple list", List.MULTIPLE,new String[] "Python", "J2ME", "Symbian", null); display.setcurrent(list); public class Implicit_List extends MIDlet List 2 //List(label,type,items,Images) List list = new List("Implicit list", List.IMPLICIT,new String[] "Python", "J2ME", "Symbian", null); display.setcurrent(list);

9 public class Exclusive_List extends MIDlet List 3 //List(label,type,items,Images) List list = new List("Exclusive list", List.EXCLUSIVE,new String[] "Python", "J2ME", "Symbian", null); display.setcurrent(list); public class Empty_Form extends MIDlet Form form = new Form("Empty Form"); Empty Form

Form with ChoiceGroup 1 public class Choice_Group extends MIDlet Form form = new Form("Form example"); //ChoiceGroup(label,type,elements,image) ChoiceGroup CourseEXCL = new ChoiceGroup ("Exclusive

10 Form with ChoiceGroup 1 public class Choice_Group extends MIDlet Form form = new Form("Form example"); //ChoiceGroup(label,type,elements,image) ChoiceGroup CourseEXCL = new ChoiceGroup ("Exclusive choice", Choice.EXCLUSIVE,new String[] "Python", "J2ME", "Symbian", null); form.append(courseexcl); ChoiceGroup CourseMULT = new ChoiceGroup ("Multiple choice", Choice.MULTIPLE,new String[] "Python", "J2ME", "Symbian", null); form.append(coursemult); Form with ChoiceGroup 2 public class Choice_Group extends MIDlet Form form = new Form("Form example"); //ChoiceGroup(label,type,elements,image) ChoiceGroup CoursePOP = new ChoiceGroup ("Pop Up choice", Choice.POPUP,new String[] "Python", "J2ME", "Symbian", null); form.append(coursepop);

11 Form with DateField public class Date_Field extends MIDlet Form form = new Form("Form example"); // DateField(label,type); DateField datefield = new DateField("Date Field Example", DateField.DATE_TIME); form.append(datefield); public class Gauge_ex extends MIDlet Form with Gauge Form form = new Form( Gauge example"); //Gauge(label,interaction,maxValue,InitialValue) Gauge gauge = new Gauge("Gauge example", false, 20, 4); form.append(gauge);

12 Form with ImageItem import java.io.ioexception; public class Image_Item extends MIDlet Form form = new Form("Form example"); try Image Logo = Image.createImage("/images/logo.png"); //ImageItem(label,Image,layout,alternative text) ImageItem imageitem =new ImageItem("ImageItem Example",Logo,ImageItem.LAYOUT_CENTER,""); form.append(imageitem); catch (IOException ex) System.out.println("Exception occurred: "+ex); Form with StringItem public class String_Item extends MIDlet Form form = new Form("Form example"); // StringItem(title,text) StringItem stringitem= new StringItem("String Item", "This is an example of StringItem"); form.append(stringitem);

13 Form with TextField public class Text_Field extends MIDlet Form form = new Form("Form example"); // TextField(label,text,size,constrains); TextField textfield =new TextField("TEXT FIELD","",25,TextField.ANY); form.append(textfield); public class Canvas_Example extends MIDlet CanvasDemo canvas = new CanvasDemo(); display.setcurrent(canvas); class CanvasDemo extends Canvas public void paint (Graphics g) g.setcolor(50,50,255); g.fillrect (0, 0, getwidth (), getheight ()); g.setcolor(200,200,200); g.drawstring("example of Canvas",0,20,0); g.setcolor(0,0,100); g.drawline (0, 40, 100, 200); g.setcolor(200,0,0); g.fillrect (50, 70, 80, 50); Canvas

Adding Command Buttons import javax.microedition.midlet.

EXIT,7); Command CheckCmd = new Command ("Check",Command.SCREEN,1); Form form = new Form("Commands example"); form.

setcommandlistener(this); public void destroyapp(boolean unconditional) notifydestroyed();.

14 Adding Command Buttons import javax.microedition.midlet.midlet; public class Command_ex extends MIDlet implements CommandListener Command ExitCmd = new Command ("Exit",Command.EXIT,7); Command CheckCmd = new Command ("Check",Command.SCREEN,1); Form form = new Form("Commands example"); form.append("this is a Command button example. Please press the Check button "); form.addcommand(exitcmd); form.addcommand(checkcmd); form.setcommandlistener(this); public void destroyapp(boolean unconditional) notifydestroyed();. public void commandaction(command c, Displayable d) if (c==exitcmd) destroyapp(true); else if (c==checkcmd) Alert alert = new Alert("Alert"); alert.setstring("check button test"); alert.settimeout(3000); // 3 seconds display.setcurrent(alert, display.getcurrent() ); Example: smszipper

Objects. Phone. Programming. Mobile DAY 3 J2ME. Module 2. In real world: object is your car, your bicycle, your cat.. Object has state and behavior

Objects. Phone. Programming. Mobile DAY 3 J2ME. Module 2. In real world: object is your car, your bicycle, your cat.. Object has state and behavior DAY 3 J2ME Mobile Phone Programming Module 2 J2ME DAY 3 in aj2me nutshell Objects In real world: object is your car, your bicycle, your cat.. Object has state and behavior State: variables (car: color,