We continue our exploration into the bada API. Today we have a simple bada tutorial to display a map control on a form. Unfortunately, as of today, there is no map control available in the GUI editor, therefore you have to create one within your code. You may want to take a look into this simple UI bada app first, it might make things easier to understand.

First of all you will need to get a developer account at deCarta, as it is the maps service provider that we are going to use. They do take up to a few hours to send you the login information, so you may want to do that right away.

By the way, later on you will be able to define and download the app’s manifest directly through the official site, for not we have to edit them ourselves. An app dealing with maps needs a special privilege. Open the manifest.xml with a text editor and modify the relevant part as follows:

<Privileges>
 <Privilege><Name>MAP_SERVICE</Name></Privilege>
 </Privileges>

I have created an empty form (as described in another bada tutorial) for this one and linked FLocations and FLocationControls libraries in the project settings as descibed on our bada forums. Then, you need to add a few declarations to your app’s header (assuming you used the wizard to create a bare-bone bada project).

1. Namespaces and Headers for the Location features

#include <FApp.h>
#include <FBase.h>
#include <FLocations.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::Base::Collection;
using namespace Osp::Locations;
using namespace Osp::Locations::Controls;
using namespace Osp::Locations::Services;
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;

2. Add two private variables to the app’s class for a frame and a form

class SimpleLocation :
 public Application
{
private:
    Frame *pFrame;
    Form *pForm;

3.Finally change the OnForeground function of the app to create and display the map. This is surely not the best way (it’s better to put most of this code in app’s initialization function), nevertheless this will do for a simple demo.

void
SimpleLocation::OnForeground(void)
{
     result r;
     String providerName = L"deCarta";
     String extraInfo = L"ClientName=your-log-in;ClientPassword=your-password;HostUrl=http://ws.decarta.com/openls/openls";
     int width = 0;
     int height = 0;
     Coordinates center = Coordinates();
     center.Set(37.786505, -122.39862, 0);
     Map * pMap = null;

     pFrame = this->GetAppFrame()->GetFrame();
     pForm = new Form();
     pForm->Construct("IDF_FORM1");
     pFrame->AddControl(*pForm);
     pFrame->SetCurrentForm(*pForm);

     // we will use all available space of the form for our map control
     width=pForm->GetCanvasN()->GetBounds().width;
     height=pForm->GetCanvasN()->GetBounds().height;

     // Connect to map service provider
     IMapServiceProvider* pProvider =
         static_cast<IMapServiceProvider*>(ProviderManager::ConnectToServiceProviderN
         (providerName, LOC_SVC_PROVIDER_TYPE_MAP, extraInfo));
     if (null == pProvider) goto CATCH;

     // Create map
     pMap = new Map();
     if (null == pMap)  goto CATCH;

     // Specify map's size (all space available on the form)
     r = pMap->Construct(Osp::Graphics::Rectangle(0, 0, width, height), *pProvider);
     if (IsFailed(r)) goto CATCH;

     // Set desired zoom level (high, street)
     r = pMap->SetZoomLevel(17, false);
     if (IsFailed(r)) goto CATCH;

     // Set center position to display
     r = pMap->SetCenter(center, false);
     if (IsFailed(r)) goto CATCH;

     // Enable my location
     pMap->SetMyLocationEnabled(true);

     // Render a map (add it to the form first)
     pForm->AddControl(*pMap);
     r = pMap->Draw();
     if (IsFailed(r)) goto CATCH;

     pFrame->Draw();
     pFrame->Show();

     return;

CATCH:
     delete pMap;
     delete pProvider;
}

Keep in mind that you need to input your own login details for deCarta into the connection string. Build, run and you shall see something like this:

Related posts:

1. bada Tutorial: zooming a map with softkeys
2. bada Tutorial: displaying a transparent image on a form
3. Bada how-to: map marker overlay