BlackBerry Concepts

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BlackBerry Development Fundamentals using Eclipse IDE

This is a practical introduction to build BlackBerry applications.

(modified based on Alan Wong - January 13, 2011 presentation).


Steps Actions
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 The steps to install, configure and check your installation are defined at: Install, Configuration, Check section.
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 One can download the software for developing BlackBerry applications using Eclipse from: BlackBerry Java Plug-in for Eclipse

Note: You have to register as a developer prior to downloading process

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 The goals of the Project is to create basic Java code that has the capabilities to:
  • run the application by adding it to the event dispatcher
  • create a Screen and push it onto the Screen stack
  • specify the title of a Screen
  • display text on the screen using a RichTextField
  • display a dialog box when the user closes the application

Configuring the Project

Steps Actions
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<Properties ModelVersion="1.1.2">
  <General Title="Hello World Demo" Version="0.9" Vendor="Research In Motion Ltd." Description=""/>
  <Application Type="BlackBerry Application" MainMIDletName="" MainArgs="" HomeScreenPosition="0" StartupTier="7" IsSystemModule="false" IsAutostartup="false"/>
  <Resources hasTitleResource="false" TitleResourceBundleName="" TitleResourceBundleRelativePath="" TitleResourceBundleClassName="" TitleResourceBundleKey="" DescriptionId="">
    <Icons>
      <Icon CanonicalFileName="res\img\helloworld_jde.png" IsFocus="false"/>
    </Icons>
  </Resources>
  <Compile OutputCompilerMessages="false" ConvertImages="true" CreateWarningForNoExportedRoutine="true" CompressResources="false">
    <PreprocessorDefines/>
  </Compile>
  <Packaging OutputFileName="HelloWorldDemo" OutputFolder="deliverables" PreBuildStep="" PostBuildStep="" CleanStep="" GenerateALXFile="true">
    <AlxFiles/>
  </Packaging>
  <HiddenProperties>
    <ClassProtection/>
    <PackageProtection/>
  </HiddenProperties>
  <AlternateEntryPoints/>
</Properties>
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 This class extends the UiApplication class, providing a graphical user interface.
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 UiApplication

Base class for all device applications that provide a user interface.

  • A UI application maintains a stack of Screen objects.

As it pushes screens onto the stack, it draws them on top of any other screens already on the stack. When the application pops a screen off the stack, it redraws the underlying screens as necessary. Only the screen on the top of the stack receives input events.

  • Each screen may appear only once in the display stack.

The application throws a runtime exception if you attempt to push a single screen onto the stack more than once.

Note that a UI application must follow rules similar to those of traditional Swing applications.

Development Fundamentals

Steps Actions
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 Package net.rim.device.api.ui

Provides fundamental functionality for constructing the user interface of a RIM Device application.

The members of this package are all abstract classes or interfaces

They are not intended for direct instantiation.

You should rather use (or extend) the classes in net.rim.device.api.ui.component and net.rim.device.api.ui.container. 

import net.rim.device.api.ui.UiApplication;

/**
 * This class extends the UiApplication class, providing a graphical user
 * interface.
 */
public class HelloWorldDemo extends UiApplication {
    /**
Ui basic arch.png
 There are three main UI primitives:

Screen class is the base class for all screens. Each UiEngine presents an interface to the user by pushing screens onto its display stack, and popping them off when interaction with the managed fields on that screen is finished.

Delegate manager Each screen object has a delegate manager, the single Manager object directly controlled by the screen to handle layout and scrolling for the entire screen.

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 enterEventDispatcher

The thread that calls this method (typically the main thread in the application)

becomes theevent-dispatching thread, which will execute all drawing and event-handling code.

Note: under normal circumstances this method does not return. 

public class HelloWorldDemo extends UiApplication {
    /**
     * Entry point for application
     * @param args Command line arguments (not used)
     */
    public static void main(String[] args) {
        // Create a new instance of the application and make the currently
        // running thread the application's event dispatch thread.
        HelloWorldDemo theApp = new HelloWorldDemo();
        theApp.enterEventDispatcher();
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 Class MainScreen

The MainScreen class defines the full screen providing features common to standard RIM device applications. 

/**
 * A class extending the MainScreen class, which provides default standard
 * behavior for BlackBerry GUI applications.
 */
final class HelloWorldScreen extends MainScreen {


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Main screen objects could contain:

  • a title section,
  • a separator element,
  • and a main scrollable section.
final class HelloWorldScreen extends MainScreen {
    /**
     * Creates a new HelloWorldScreen object
     */
    HelloWorldScreen() {
        // Set the displayed title of the screen
        setTitle("Eclipse Course");

Basic UI Elements - Package net.rim.device.api.ui.component

Class Name Description
ActiveAutoTextEditField

Field that uses a supplied set of string patterns to pick out 'active' regions.

ActiveFieldContext

An instance of this class is passed into factories that createActiveFieldCookie instances.

ActiveRichTextField

Field that uses a supplied set of string patterns to scan through a simple text string and pick out "active" regions.

AutoCompleteField

AutoCompleteField lets you create a text field that presents users with a changing list of words that are associated with the characters they have typed in the field.

AutoTextEditField

An editable text field designed to provide autotext support.

BasicEditField

An editable simple text field with no formatting.

BitmapField

Displays a bitmap.

ButtonField

Contains a button control.

ButtonFieldFactory

Assists in creation of ButtonField instances using information contained within Command instances.

CheckboxField

Contains a checkbox control.

ChoiceField

Base implementation of a choice field.

DateField

Stores date and time values.

Dialog

Provides a dialog box with predefined configurations.

EditField

An editable simple text field with no formatting.

EmailAddressEditField

An editable text field designed specifically to handle internet email addresses.

GaugeField

Displays a horizontal bar that you can use for numeric selection or as a progress indicator.

KeywordFilterField

Consists of a single keyword input field and a list of selectable elements.

LabelField

Contains a simple label.

ListField

Contains rows of selectable list items.

Menu

Provides a Menu.

NullField

A field of no size.

NumericChoiceField

A choice field that supports choosing from a range of numeric values.

ObjectChoiceField

Choice field that supports a list of object choices.

ObjectListField

List field to contain a list of objects.

PasswordEditField

An editable text field designed specifically to handle password input.

RadioButtonField

Field to provide a radio-button control.

RadioButtonGroup

Groups a set of related radio button fields.

RichTextField

Read-only field that supports richly formatted text.

SeparatorField

A field which draws a horizontal line across its width.

SpinBoxField

A user interface component for selecting a single item from a list where the user can spin through the various choices.

StandardTitleBar

Provides a standard title bar component with a standard set of optional title bar components and indicators.

Status

Simple dialog to show ongoing status.

TextField

A simple editable text field.

TextSpinBoxField

A SpinBoxField that renders text.

TitleBar

Provides an abstract TitleBar component.

TreeField

A simple field to show a tree structure.


Procedure to add UI Elements to Application

Steps Actions
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/**
     * Creates a new HelloWorldScreen object
     */
    HelloWorldScreen() {
        // Set the displayed title of the screen
        setTitle("Eclipse Course");

        // Add a read only text field (RichTextField) to the screen. The
        // RichTextField is focusable by default. Here we provide a style
        // parameter to make the field non-focusable.
        add(new RichTextField("Welcome to BlackBerry World!",
                Field.NON_FOCUSABLE));
    }
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 Dialog

Provides a dialog box with predefined configurations.

To get a standard, predefined dialog use

  • Dialog.alert(java.lang.String)
    • This method creates an alert dialog typically used to notify the user of an event or some important information. The dialog uses a exclamation mark bitmap.
  • Dialog.ask(int)
    • This method creates a standard inquiry dialog. The dialog uses a question mark bitmap.Creates a standard inquiry dialog.
  • Dialog.inform(java.lang.String).
    • Creates a notification dialog with the specified message. This method creates a notification dialog displaying the specified message. The dialog uses the "information" bitmap.

These pop up a predefined dialog and wait for user input. To get a more customized dialog, instantiate this class or extend it.

Pressing ESCAPE returns Dialog.CANCEL, but only if it was one of the choices specified in the values array.

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/**
     * Displays a dialog box to the user with the text "Goodbye!" when the
     * application is closed.
     *
     * @see net.rim.device.api.ui.Screen#close()
     */
    public void close() {
        // Display a farewell message before closing the application
        Dialog.alert("Goodbye!");
        super.close();
    }



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