Hello everybody!

Today a friend of mine started experimenting with one of the latest versions of bada’s SDK and IDE. Samsung shortly will release the SDK/IDE for public use. The versions he has, though, may differ slightly to those released at a later date, therefore it is thinkable that you might encounter slight inconsistencies.

The idea was to go somewhat beyond a simple hello world app and test bada’s IDE as well as its GUI building tool. We want to create a simple greeting app that asks your name and responds with a simple greeting. Something that looks like this:

Having installed the SDK/IDE and after re-starting the computer we start with an empty workspace in the IDE

Go to File->New->Bada Application Project, this will open a wizard. Type “SimpleGreeting” for the project’s name and select bada Application as the project’s type. The wizard will create a new project for you.

For now we only need to open the files SimpleGreeting.cpp and SimpleGreeting.h that hold the definitions and declarations for the bare-bone sample project. Next let us create a form for the app. In the resource window (left bottom corner on the screenshot), right click Form->Insert Resource.

This will create a new emtpy form and open the GUI editor.

Here we need to add three controls to the form: an input box, a button and a label. We start with the input box by clicking on Edit Field in the Palette and dragging a box at the top of the empty form.

Double click the edit field and you’ll see the properties tab coming to front underneath. There change the id to “NAME_FIELD“. Next draw a button below the edit field and a label below the button. In the same way change the id of the button to “HELLO_BUTTON” and the id of the label to “GREETING_LABEL“. Besides, in the properties of the button, for the text property insert something meaningful like “Say Hello!” . Now we are ready with the form!

Let’s go to the SimpleGreeting.h header file. Here you will have to do a few things. First, let’s define a constant that we will use afterwards to identify the action event of the button. Do it right after the using-statements of all the bada namespaces.

using namespace Osp::App;
using namespace Osp::Base;
using namespace Osp::Graphics;
using namespace Osp::Io;
using namespace Osp::Locales;
using namespace Osp::System;
using namespace Osp::Text;
using namespace Osp::Ui;
using namespace Osp::Ui::Controls;

static const int BUTTON_ACTION_GREET = 1;

Then, since c++ allows us multiple inheritance and we want to keep things simple and straight forward, let us implement the IActionEventListener directly with our application’s class. This will allow our app class to take care of the events all by itself without the need to provide a separate listener (we are lazy today ). Further let us define a few private variables for the controls we use, so that we can reference them later in our code.

/**
 * [SimpleGreeting] application must inherit from Application class
 * which provides basic features necessary to define an application.
 */
class SimpleGreeting :
	public Application, public IActionEventListener
{
private:
		Frame *pFrame;
		Form *pForm;
		Button *pButton;
		Label *pLabel;
		EditField *pField;

Finally declare a handler function at the end that will handle the action events later:

/**
* Called when the battery level changes.
*/
void OnBatteryLevelChanged(BatteryLevel batteryLevel);

/**
* Called on Actions
*/
virtual void OnActionPerformed(const Osp::Ui::Control& source, int actionId);
};

#endif

Well… We are ready with the header file. Let’s switch to the SimpleGreeting.cpp . Here we need to bind the variables for controls we declared earlier in the header to the actual objects we designed in the GUI editor + the object for the app’s frame (look into the tutorials for UI: each app has a single frame which holds all forms and controls and stuff within it). Let’s put it all into the OnAppInitializing function.

bool
SimpleGreeting::OnAppInitializing(AppRegistry& appRegistry)
{
    // get the frame of the app
    pFrame = GetAppFrame()->GetFrame();

    // bind pForm to the Form we designed in resources
    pForm = new Form();
    pForm->Construct("IDF_FORM1");

    // add the form as child to the app's frame and set it as current
    pFrame->AddControl(*pForm);
    pFrame->SetCurrentForm(*pForm);

    // bind name input field
    pField = (EditField*)pForm->GetControl("NAME_FIELD", true);
    pField->SetText("Your name in here!");

    // bind label
    pLabel = (Label*)pForm->GetControl("GREETING_LABEL", true);

    // bind button, set its action id
    //  and the action listener (this app's class itself)
    pButton = (Button*)pForm->GetControl("HELLO_BUTTON", true);
    pButton->SetActionId(BUTTON_ACTION_GREET);
    pButton->AddActionEventListener(*this);

    return true;
}

Now the events sent by the button clicks will be forwarded to this app’s class directly to the function you’ll need to add at the end of this file:

void
SimpleGreeting::OnActionPerformed(const Osp::Ui::Control& source, int actionId)
{
    String greeting = "Hello ";
    switch (actionId)
    {
        case BUTTON_ACTION_GREET:
            // Set the greeting
            greeting.Append(pField->GetText());
            pLabel->SetText(greeting);

            // redraw app's frame
            pFrame->Draw();
            pFrame->Show();
        break;

        default:
        break;
    }
} 

Finally we need to tell the app to draw the Frame (and all in it) as soon as it is brought to the foreground (and/or as soon as the app starts).

void
SimpleGreeting::OnForeground(void)
{
    // draw and show the app's frame
    pFrame->Draw();
    pFrame->Show();
}

That’s all! Save all three files and build the project (Ctrl+B).

Now we are ready to test this app in the bada simulator. Right-click the project->Run As->Bada Simulator Application. The simulator will open up and run our app shortly.

This is a very brief, quick&dirty and straight-to-the-point example. Someone had to dig up his c++ know-how for this. Please bear with that person . There is no funky professional c++ stuff in here,… and I know that YOU would rather write much better code instead Comments are still welcome. Here are the complete two source code files:

SimpleGreeting.h

#ifndef __SIMPLEGREETING_H__
#define __SIMPLEGREETING_H__

#include <FApp.h>
#include <FBase.h>
#include <FGraphics.h>
#include <FIo.h>
#include <FLocales.h>
#include <FText.h>
#include <FSystem.h>
#include <FUi.h>

using namespace Osp::App;
using namespace Osp::Base;
using namespace Osp::Graphics;
using namespace Osp::Io;
using namespace Osp::Locales;
using namespace Osp::System;
using namespace Osp::Text;
using namespace Osp::Ui;
using namespace Osp::Ui::Controls;

static const int BUTTON_ACTION_GREET = 1;

/**
* [SimpleGreeting] application must inherit from Application class
* which provides basic features necessary to define an application.
*/
class SimpleGreeting :
public Application, public IActionEventListener
{
private:
Frame *pFrame;
Form *pForm;

Button *pButton;
Label *pLabel;
EditField *pField;
public:

/**
* [SimpleGreeting] application must have a factory method that creates an instance of itself.
*/
static Application* CreateInstance(void);

public:
SimpleGreeting();
~SimpleGreeting();

public:

/**
* The application must provides its name.
*/
String GetAppName(void) const;

protected:
/**
* The application must provide its ID.
*/
AppId GetAppId(void) const;

/**
* The application must provide a secret code.
*/
AppSecret GetAppSecret(void) const;

public:

/**
* Called when the application is initializing.
*/
bool OnAppInitializing(AppRegistry& appRegistry);

/**
* Called when the application is terminating.
*/
bool OnAppTerminating(AppRegistry& appRegistry, bool forcedTermination = false);

/**
* Called when the application's frame moves to the top of the screen.
*/
void OnForeground(void);

/**
* Called when this application's frame is moved from top of the screen to the background.
*/
void OnBackground(void);

/**
* Called when the system memory is not sufficient to run the application any further.
*/
void OnLowMemory(void);

/**
* Called when the battery level changes.
*/
void OnBatteryLevelChanged(BatteryLevel batteryLevel);

/**
* Called on Actions
*/
virtual void OnActionPerformed(const Osp::Ui::Control& source, int actionId);
};

#endif

SimpleGreeting.cpp

/**
 * Name        : SimpleGreeting
 * Version     : 1.0.0
 * Vendor      :
 * Description :
 */

#include "SimpleGreeting.h"

SimpleGreeting::SimpleGreeting()
{
}

SimpleGreeting::~SimpleGreeting()
{
}

Application*
SimpleGreeting::CreateInstance(void)
{
	// Create the instance through the constructor.
	return new SimpleGreeting();
}

String
SimpleGreeting::GetAppName(void) const
{
	//WARNING:
	// This method is automatically generated.
	// Please don't modify it!

	// Return the name of the application.
	static String appName(L"SimpleGreeting");
	return appName;
}

AppId
SimpleGreeting::GetAppId(void) const
{
	//WARNING:
	// This method is automatically generated.
	// Please don't modify it!

	// Return the application ID.
	static AppId appId(L"93bt1p123e");
	return appId;
}

AppSecret
SimpleGreeting::GetAppSecret(void) const
{
	//WARNING:
	// This method is automatically generated.
	// Please don't modify it!

	// Return the secret code of the application.
	static AppSecret appSecret(L"9C645DDBA19C71BAD1204DA4DAA7A0B9");
	return appSecret;
}

bool
SimpleGreeting::OnAppInitializing(AppRegistry& appRegistry)
{
	// get the frame of the app
	pFrame = GetAppFrame()->GetFrame();

	// bind pForm to the Form we designed in resources
	pForm = new Form();
	pForm->Construct("IDF_FORM1");

	// add the form as child to the app's frame and set it as current
	pFrame->AddControl(*pForm);
	pFrame->SetCurrentForm(*pForm);

	// bind name input field
	pField = (EditField*)pForm->GetControl("NAME_FIELD", true);
	pField->SetText("Your name in here!");

	// bind label
	pLabel = (Label*)pForm->GetControl("GREETING_LABEL", true);

	// bind button, set its action id
	//  and the action listener (this app's class itself)
	pButton = (Button*)pForm->GetControl("HELLO_BUTTON", true);
	pButton->SetActionId(BUTTON_ACTION_GREET);
	pButton->AddActionEventListener(*this);

	return true;
}

bool
SimpleGreeting::OnAppTerminating(AppRegistry& appRegistry, bool forcedTermination)
{
	// TODO:
	// Deallocate resources allocated by this application for termination.
	// The application's permanent data and context can be saved via appRegistry.
	return true;
}

void
SimpleGreeting::OnForeground(void)
{
	// draw and show the app's frame
	pFrame->Draw();
	pFrame->Show();
}

void
SimpleGreeting::OnBackground(void)
{
	// TODO:
	// Stop drawing when the application is moved to the background.
}

void
SimpleGreeting::OnLowMemory(void)
{
	// TODO:
	// Free unused resources or close the application.
}

void
SimpleGreeting::OnBatteryLevelChanged(BatteryLevel batteryLevel)
{
	// TODO:
	// Handle any changes in battery level here.
	// Stop using multimedia features(camera, mp3 etc.) if the battery level is CRITICAL.
}

void
SimpleGreeting::OnActionPerformed(const Osp::Ui::Control& source, int actionId)
{
	String greeting = "Hello ";
	switch (actionId)
	{
		case BUTTON_ACTION_GREET:
			// Set the greeting
			greeting.Append(pField->GetText());
			pLabel->SetText(greeting);

			// redraw app's frame
			pFrame->Draw();
			pFrame->Show();
			break;

	    default:
	        break;
	}
}

Have fun!

Related posts:

1. Bada Project: Simple Finger Drawing App
2. Bada tutorial: simple screen orientation example
3. Threads (part 1): Simple Example