Connected TV

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Chapter 13. JavaScript TV API

The JavaScript TV API provides access to Platform objects through a generated JavaScript wrapper interface.

TV System Object

The TVSystem object enables the apps to directly interact with the device hardware and get system specific information. Most functions are read-only.

When using the Simulator, the TV API porting layer has been implemented to emulate the TV device on the app developer's PC using a local properties file. The TVSystem properties which would normally come from the partner's device are stored in the file $HOME/YCTV-ADK/YCTV-SIM-XXX/TVSystemProperties.txt so that app developers can test these properties without the TV device. This file is only used in conjunction with the Simulator.

Special Settings

Certain tv.system properties are also provided by the specialSettings.get() function. Yahoo! recommends that app developers use the specialSettings.get() function in lieu of the tv.system properties when available. These include:

Properties

Properties returned from the specialSettings.get() function. Be sure to test for valid values. Not all properties are implemented by all device partners.

Property	Type	Description
`continentCode`	`String`	Returns the two character continent code ('AF' for Africa, 'AS' for Asia, 'EU' for Europe, 'NA' for North America, 'SA' for South America, 'OC' for Oceania, and 'AN' for Antarctica) obtained from the user of the device.
`countryCode`	`String`	Returns the two character country code (ISO 3166) obtained from the user of the device.
`locationCode`	`int`	Returns the five character postal/zip code integer where the device is located. Obtained from the user of the device. The code is interpreted by country.
`timezoneCode`	`blob`	Returns the time zone code blob. Obtained from the user of the device. For example, `{cc:"US", zn:widget.getLocalizedString("timezone_name_America_Los_Angeles"), zo:"UTC-08", zd:"07"}` is used for Pacific Daylight Time. This property may not be supported by all device partners.

Device Hardware Interface

You can use the tv.system global namespace to acces the device hardware interface for apps. Be sure to test for valid values. Not all properties are implemented by all device partners.

The TVSystem object is found in the global TVMasterControl object.

Example

log("Device Partner: " + tv.system.OEM);
log("Device Description: " + tv.system.deviceDescription);
log("Device Id: " + tv.system.deviceId);
log("Device Version: " + tv.system.deviceVersion);
log("Device Software Version: " + tv.system.deviceSoftwareVersion);
log("Clock: " + tv.system.clock);
log("Video Resolution: " + tv.system.videoResolution.horizontal + "x" +  tv.system.videoResolution.vertical);
log("Aspect Ratio: " + tv.system.aspectRatio);
log("Menu Language: " + tv.system.menuLanguage);
log("Country: " + tv.system.country);
log("Device Model: " + tv.system.deviceModel);
log("Device Class: " + tv.system.deviceClass);
log("Device Brand: " + tv.system.deviceBrand);
log("Network Type: " + tv.system.networkType);
log("WirelessSignalStrength: " + tv.system.wirelessSignalStrength);
log("DeviceDisplayType: " + tv.system.deviceDisplayType);
log("Network Status: " + tv.system.networkStatus(tv.system.networkType));
log("VChipStatus: " + tv.system.vChipStatus);
log("VChipRatingSystem: " + tv.system.vChipRatingSystem);
log("Location Code: " + tv.system.locationCode);
log("DeviceInfo: " + tv.system.deviceInfo);
tv.system.onAspectRatioChanged = function() {
   log("The new aspect ratio is: " + tv.system.aspectRatio);
}

Aspect Ratio Constants

The aspect ratio of the display.

Name	Description
`ASPECT_NOT_AVAILABLE`	The aspect is not available.
`ASPECT_OTHER`	The aspect is not defined.
`ASPECT_SQUARE`	The video aspect ratio is square.
`ASPECT_4X3`	The video aspect ration is standard video or 4x3.
`ASPECT_16X9`	The video aspect ration is widescreen or 16x9.

Display Type Constants

Specifies the type of the display. This information is often used by apps for determining capabilities for screensavers.

Name	Description
`DISPLAY_NOT_AVAILABLE`	The display type is not available.
`DISPLAY_PLASMA`	The display type is `PLASMA`.
`DISPLAY_DLP`	The display type is `DLP`.
`DISPLAY_LCD`	The display type is `LCD`.
`DISPLAY_OLED`	The display type is `OLED`.
`DISPLAY_OTHER`	The display type is not defined by this list.

VChipStatus Constants

V-chips read information encoded in the rated program and block programs from the device based upon the selected rating. This status indicates the availability and status of a V-Chip in the device.

Name	Description
`VCHIP_NOT_INSTALLED`	The device is not equipped with the VChip.
`VCHIP_ENABLED`	The VChip control has been enabled by the user.
`VCHIP_NOT_ENABLED`	The VChip control has not been enabled by the user.

Network Status Constants

Indicates the status of the device's connection to the network.

Name	Description
`NETWORK_STATUS_NOT_AVAILABLE`	The network status is not available.
`DISCONNECTED`	The network is disconnected. No uplink and no associated wireless network is available.
`CONNECTED`	The network status is connected. The uplink is available.