PreviewChannelHelper
@WorkerThread
class PreviewChannelHelper
From a user's perspective, the TV home screen has two types of channels: the single Live Channels row versus the App preview Channels. This class is concerned with App Channels; or more precisely: your app's preview Channels. In API 26+, all TV apps are allowed to create multiple channels and publish those Channels to the home screen.
This class provides convenience methods to help you publish, update and delete channels; add, update or remove programs in a channel. You do not need to know anything about Content Providers, Content Resolvers, Cursors or such to publish your channels. This class abstracts away all database interactions for you.
To make it easy for you to distinguish classes that help you build App Channels, the support library uses the prefix Preview- to denote the classes that pertain to app Channels. Hence, the classes PreviewChannel and PreviewProgram help your app add channels to the TV home page. All calls to methods in the class should be made on worker threads.
Summary
Public constructors |
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PreviewChannelHelper(context: Context!) |
PreviewChannelHelper( |
Public functions |
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Unit |
deletePreviewChannel(channelId: Long)Removes a preview channel from the system's content provider (aka TvProvider). |
Unit |
deletePreviewProgram(programId: Long)Removes programs from a preview channel. |
(Mutable)List<PreviewChannel!>! |
The TvProvider does not allow select queries. |
PreviewChannel? |
getPreviewChannel(channelId: Long)Retrieves a single preview channel from the TvProvider. |
PreviewProgram? |
getPreviewProgram(programId: Long)Retrieves a single preview program from the system content provider (aka TvProvider). |
WatchNextProgram? |
getWatchNextProgram(programId: Long)Retrieves a single WatchNext program from the system content provider (aka TvProvider). |
Long |
publishChannel(channel: PreviewChannel)Publishing a channel to the TV home screen is a two step process: first, you add the channel to the TV content provider; second, you make the channel browsable (i.e. visible). |
Long |
publishDefaultChannel(channel: PreviewChannel)This is a convenience method that simply publishes your first channel for you. |
Long |
publishPreviewProgram(program: PreviewProgram)Adds programs to a preview channel. |
Long |
publishWatchNextProgram(program: WatchNextProgram)Adds a program to the Watch Next channel |
Unit |
updatePreviewChannel(channelId: Long, update: PreviewChannel)To update a preview channel, you need to use the |
Unit |
updatePreviewProgram(programId: Long, update: PreviewProgram)Updates programs in a preview channel. |
Unit |
updateWatchNextProgram(upgrade: WatchNextProgram, programId: Long)Updates a WatchNext program. |
Protected functions |
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Bitmap! |
downloadBitmap(logoUri: Uri)Downloads a Bitmap from a remote server. |
Public constructors
PreviewChannelHelper
PreviewChannelHelper(
context: Context!,
urlConnectionTimeoutMillis: Int,
urlReadTimeoutMillis: Int
)
| Parameters | |
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urlConnectionTimeoutMillis: Int |
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urlReadTimeoutMillis: Int |
see |
Public functions
deletePreviewChannel
fun deletePreviewChannel(channelId: Long): Unit
Removes a preview channel from the system's content provider (aka TvProvider).
deletePreviewProgram
fun deletePreviewProgram(programId: Long): Unit
Removes programs from a preview channel.
getAllChannels
fun getAllChannels(): (Mutable)List<PreviewChannel!>!
The TvProvider does not allow select queries. Hence, unless you are querying for a single PreviewChannel by id, you must get all of your channels at once and then use the returned list as necessary.
getPreviewChannel
fun getPreviewChannel(channelId: Long): PreviewChannel?
Retrieves a single preview channel from the TvProvider. When you publish a preview channel, the TvProvider assigns an ID to it. That's the channelId to use here.
| Parameters | |
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channelId: Long |
ID of preview channel in TvProvider |
| Returns | |
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PreviewChannel? |
PreviewChannel or null if not found |
getPreviewProgram
fun getPreviewProgram(programId: Long): PreviewProgram?
Retrieves a single preview program from the system content provider (aka TvProvider).
getWatchNextProgram
fun getWatchNextProgram(programId: Long): WatchNextProgram?
Retrieves a single WatchNext program from the system content provider (aka TvProvider).
publishChannel
fun publishChannel(channel: PreviewChannel): Long
Publishing a channel to the TV home screen is a two step process: first, you add the channel to the TV content provider; second, you make the channel browsable (i.e. visible). This method adds the channel to the TV content provider for you and returns a channelId. Next you must use the channelId to make the channel browsable. There are two ways you can make a channel browsable: a) For your first channel, simply ask the system to make the channel browsable: TvContractCompat.requestChannelBrowsable(context,channelId) b) For any additional channel beyond the first channel, you must get permission from the user. So if this channel is not your first channel, you must request user permission through the following intent. So take the channelId returned by this method and do the following inside an Activity or Fragment:
intent = new Intent(TvContractCompat.ACTION_REQUEST_CHANNEL_BROWSABLE); intent.putExtra(TvContractCompat.EXTRA_CHANNEL_ID, channelId); startActivityForResult(intent, REQUEST_CHANNEL_BROWSABLE);
Creating a PreviewChannel, you may pass to the builder a url as your logo. In such case, updatePreviewChannel will load the logo over the network. To use your own networking code, override downloadBitmap.
| Returns | |
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Long |
channelId or -1 if insertion fails. This is the id the system assigns to your published channel. You can use it later to get a reference to this published PreviewChannel. |
| Throws | |
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java.io.IOException |
publishDefaultChannel
fun publishDefaultChannel(channel: PreviewChannel): Long
This is a convenience method that simply publishes your first channel for you. After calling publishChannel to add the channel to the TvProvider, it calls requestChannelBrowsable to make the channel visible.
Only use this method to publish your first channel as you do not need user permission to make your first channel browsable (i.e. visible on home screen). For additional channels, see the documentations for publishChannel.
Creating a PreviewChannel, you may pass to the builder a url as your logo. In such case, updatePreviewChannel will load the logo over the network. To use your own networking code, override downloadBitmap.
| Returns | |
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Long |
channelId: This is the id the system assigns to your published channel. You can use it later to get a reference to this published PreviewChannel. |
| Throws | |
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java.io.IOException |
publishPreviewProgram
fun publishPreviewProgram(program: PreviewProgram): Long
Adds programs to a preview channel.
publishWatchNextProgram
fun publishWatchNextProgram(program: WatchNextProgram): Long
Adds a program to the Watch Next channel
updatePreviewChannel
fun updatePreviewChannel(channelId: Long, update: PreviewChannel): Unit
To update a preview channel, you need to use the PreviewChannel.Builder to set the attributes you wish to change. Then simply pass in the built channel and the channelId of the preview channel. (The channelId is the ID you received when you originally published the preview channel.)
Creating a PreviewChannel, you may pass to the builder a url as your logo. In such case, updatePreviewChannel will load the logo over the network. To use your own networking code, override downloadBitmap.
| Throws | |
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java.io.IOException |
updatePreviewProgram
fun updatePreviewProgram(programId: Long, update: PreviewProgram): Unit
Updates programs in a preview channel.
updateWatchNextProgram
fun updateWatchNextProgram(upgrade: WatchNextProgram, programId: Long): Unit
Updates a WatchNext program.
Protected functions
downloadBitmap
protected fun downloadBitmap(logoUri: Uri): Bitmap!
Downloads a Bitmap from a remote server. It is declared protected to allow you to override it to use your own networking implementation if you so wish.
| Throws | |
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java.io.IOException |