• API References

• Designing Applications

• Implementing Application Features

• Testing Applications

This topic is intended for developers with experience in creating Web applications.

To begin application development with the Tizen SDK:

1. Set up the development environment:
   a. Installing Tizen SDK.
   a. Create a certificate profile.
   According to the Tizen policy, all applications must be signed with valid certificates before they can be installed or run. The signature verifies the source of the application and makes sure it has not been tampered with since its publication.
   ::: caution
   Keep your certificates backed up in a safe location. When you update your published applications, the update must be signed with the same author certificate as the original application. If the applications are signed with different author certificates, the update can be recognized as a different application and not an update.
   :::
2. Design your application.
3. Create a project.
   You can select from various predefined templates.
4. Implement application features.
5. Test the application.

If you have questions about using the SDK, share them in the community forum.

Designing Applications

When designing a Web application for a KIOSK, pay attention to the following application characteristics:

• Remote control functionality
  The remote control is the main way for users to interact with the Signage. For more information, see User Interaction.

• Simple UI
  The KIOSK has a simpler user interface (UI) than a mobile device. You must consider the user experience when designing the UI.

• Scalable application resolution
  On KIOSK, the screen aspect ratio is 16:9. For the UHD KIOSK model groups, the standard application resolution is 1920x1080 px, and for the FHD KIOSK model groups, it is 1280x720 px.
  To prevent whitespace and scroll bars from appearing when the application screen is scaled, keep the aspect ratio at 16:9 even when the application resolution is different from the standard.

• Common Web application features
  KIOSK Web applications can have most of the same features as Web applications for other devices. You can use Web standard functions, such as mouse support, video elements, animations, and visibility change notifications. You can also use Tizen Web Device APIs and Samsung Product APIs supported by KIOSK. For more information, see the API References.

Implementing Application Features

A Tizen Web application consists of HTML, CSS, and JS files, and a "config.xml" file.

Figure 1. Application structure

All Tizen Web application projects must have a "config.xml" file in the project root directory. The configuration file is composed of XML elements, including the element as its root. These elements represent the application information, such as version, features, and privileges available for the application. The configuration information is used when you install or run the Tizen Web application. For more information, see Configuring Applications.

You can implement the following features in your application:

• Tizen Web Device API and KIOSK features
  The following Tizen APIs are useful for KIOSK service applications:
  • TVWindow API
    You can use Tizen Web Device APIs to show the KIOSK screen or external inputs in an application.
    For example, you can implement picture-in-picture (PiP) using the show() function of the TVWindow API:

    tizen.tvwindow.show(function(){}, null, ['0', '0', '50%', '50%'], 'MAIN'); 
    

    For more information, see Implementing PiP.

• TVAudioControl API
  You can control the volume level or mute status of the KIOSK, using the TVAudioControl API:

  tizen.tvaudiocontrol.setMute(true); 
  tizen.tvaudiocontrol.setVolume(10); 
  

• Samsung Product API and VOD features
  The Samsung Product API provides additional functionalities beyond those offered by the Tizen Web API, such as retrieving information about the device and platform, displaying subtitles, and playing VODs.
  You can implement VOD playback in 2 ways:

  • Using video elements
    You can use the HTML5 standard video element. For more information, see Using Video Elements.
  • Using the AVPlay API
    VOD playback can be implemented using the AVPlay API, which has additional features, such as support for DRM technologies. For more information, see Using AVPlay.

  The following remote control keys are needed to control VOD playback:

  • Volume control
    To control VOD playback volume levels, you can use the volume keys of the remote control without registering them, because they are handled at the platform level. Volume control can also be implemented using the Tizen API. For more information, see TVAudioControl API.
  • "Play/Pause" key
    The Smart Control "Play/Pause" key combines the functions of the "Play" and the "Pause" keys. Its KeyName is MediaPlayPause and the KeyCode is "10252". VOD service applications must handle this key to toggle between play and pause modes.

• Screensaver
  To prevent screen burn, the screensaver is shown after a defined amount of time, if the KIOSK screen has been displaying a still image or if there has been no user input. For more information, see Setting Screensaver.

• Viewport scaling
  If you create an application for resolutions different than the standard resolutions, you can scale the resolution up or down, using the viewport meta element. For more information, see Managing Screen Resolution.

• Input method editor (IME)
  When an input or textarea element is focused, the virtual keyboard is shown. The virtual keyboard is automatically hidden when a key on a connected external keyboard is pressed. For more information, see Keyboard/IME.

• Multitasking
  When the user switches from your application to another application or KIOSK channel, your application must save its current state to RAM and enter the hidden state.
  You can receive notifications when an application is shown or hidden by registering a callback for the visibilitychange event:

  document.addEventListener( 
    'visibilitychange', function() { 
      if (document.hidden) { 
        ... 
      } else { 
        ... 
      } 
    } 
  ); 
  

  For more information, see Multitasking.

• iframe elements
  You can insert remote pages into your application using the Web standard iframe element. For more information, see the W3C/HTML5 API References.

  <iframe width='960px' height='540' src='https://www.youtube.com/embed/7xBT-UDAHX8'></iframe> 
  

  Note

  When using iframe elements in KIOSK applications, the following limitations apply:

  • Only the following sandbox attributes are available: allow-same-origin, allow-scripts, allow-forms, allow-top-navigation
  • Tizen and Samsung Product APIs cannot be used in iframe elements.
  • The "frame flattening" feature, supported in Tizen mobile Web applications, is not supported in KIOSK applications.
  • On the emulator, iframe elements for remote sources do not work as expected.

• Web storage and KIOSK file system
  You can store application content and data, such as user information, in Web storage and the KIOSK file system. For more information, see Using Web Storage and Managing File Operation.

  Note

  For your application to be published on KIOSK, you must make sure that all user login information is deleted when the application is uninstalled. After deleting and reinstalling the application, there must be no user login information available from the previous installation.

• TLS support
  To transmit encrypted information between Web browsers and Web servers, KIOSK supports TLS (Transport Layer Security) versions 1.0, 1.1, and 1.2. SSL (Secure Sockets Layer) is not supported.

Testing Applications

To test your application during development, you can use the KIOSK simulator and emulator tools provided in the Samsung Smart Signage SDK, or an actual Signage:

• TV Simulator
  The TV simulator is a light-weight tool that simulates KIOSK APIs using a JavaScript backend. The simulator is useful when quick prototype development is required, such as when developing the UI. You can modify the HTML5, JS, and CSS code, and quickly reload the simulator to view your changes.
  API support on the simulator is limited; the simulator does not support any features that have strict dependencies on Signage hardware or core Tizen modules. Some API functions return dummy values.

• KIOSK device
  If you have tested your application on the simulator, it is ready for uploading and testing on a Signage. Even though it is possible to complete most application testing on the emulator, it is highly recommended that you also test your application on a target device. The emulator and Signage environments are very similar, but there are some differences at the hardware level.