# Connecting from custom Sender applications on Android

In general, the following flow should be followed:

1. Set up Google Cast context with correct receiver application ID.
2. Connect to Chromecast device.
3. Set up Google Cast MediaInfo object with correct contentID and contentType.
4. Send Google Cast LoadRequest with a serialized THEOplayer SourceDescription object as a key in the customData of the LoadRequest. So something like `{sourceDescription: ${SourceDescription you want to cast}}`.

## Usage

First, set up your `CastOptionsProvider`:

```kotlin
package com.yourcomp.chromecastSender

import android.content.Context
import com.google.android.gms.cast.framework.CastOptions
import com.google.android.gms.cast.framework.OptionsProvider
import com.google.android.gms.cast.framework.SessionProvider

class THEOCastOptionsProvider : OptionsProvider {

    override fun getCastOptions(context: Context): CastOptions =
        CastOptions.Builder()
            .setReceiverApplicationId(DEFAULT_APP_ID)
            .build()

    override fun getAdditionalSessionProviders(context: Context): List<SessionProvider>? = null

    companion object {
        const val DEFAULT_APP_ID = "8E80B9CE"
    }
}
```

And link to it in your `AndroidManifest.xml` file:

```xml
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.yourcomp.chromecastSenderApp">
    <uses-permission android:name="android.permission.INTERNET" />
    <uses-permission android:name="android.permission.WAKE_LOCK" />

    <application
    ...
        <meta-data
            android:name="com.google.android.gms.cast.framework.OPTIONS_PROVIDER_CLASS_NAME"
            android:value="com.yourcomp.chromecastSender.CastOptionsProvider" />
    </application>

</manifest>
```

Fill in the correct class name by replacing `com.yourcomp.chromecastSender.CastOptionsProvider`! You can change the `DEFAULT_APP_ID` to direct to your own Chromecast app. Next you can actually do the casting like the following:

```kotlin
package com.yourcomp.chromecastSender

import android.app.Activity
import androidx.mediarouter.app.MediaRouteChooserDialog
import com.google.android.gms.cast.MediaInfo
import com.google.android.gms.cast.MediaLoadOptions
import com.google.android.gms.cast.framework.CastContext
import com.google.android.gms.cast.framework.CastSession
import com.google.android.gms.cast.framework.SessionManagerListener
import org.json.JSONObject

private const val SOURCE_URL =
    "https://amssamples.streaming.mediaservices.windows.net/622b189f-ec39-43f2-93a2-201ac4e31ce1/BigBuckBunny.ism/manifest(format=mpd-time-csf)"

class ChromecastSender {

    fun sendSourceToChromecast(context: Activity) {
        val castContext = CastContext.getSharedInstance(context)
        showCastChooserDialog(context, castContext)

        val sourceDescriptionJson = JSONObject(
            """
            {
              "sourceDescription": {
                "sources": [
                  {
                    "src": "$SOURCE_URL",
                    "type": "application/dash+xml",
                    "contentProtection": {
                      "widevine": {
                        "licenseAcquisitionURL": "https://amssamples.keydelivery.mediaservices.windows.net/Widevine/?KID=1ab45440-532c-4399-94dc-5c5ad9584bac"
                      }
                    }
                  }
                ]
              }
            }
            """.trimIndent()
        )
        val mediaLoadOptions = MediaLoadOptions.Builder().setCustomData(sourceDescriptionJson).build()
        val mediaInfo = MediaInfo.Builder(SOURCE_URL)
            .setContentType("application/dash+xml")
            .build()

        castContext.sessionManager.addSessionManagerListener(
            object : SessionManagerListener<CastSession> {
                override fun onSessionStarting(castSession: CastSession) {}

                override fun onSessionStarted(castSession: CastSession, sessionId: String) {
                    castSession.remoteMediaClient?.load(mediaInfo, mediaLoadOptions)
                }

                override fun onSessionStartFailed(castSession: CastSession, error: Int) {}

                override fun onSessionEnding(castSession: CastSession) {}

                override fun onSessionEnded(castSession: CastSession, error: Int) {}

                override fun onSessionResuming(castSession: CastSession, sessionId: String) {}

                override fun onSessionResumed(castSession: CastSession, wasSuspended: Boolean) {}

                override fun onSessionResumeFailed(castSession: CastSession, error: Int) {}

                override fun onSessionSuspended(castSession: CastSession, reason: Int) {}
            },
            CastSession::class.java
        )
    }

    private fun showCastChooserDialog(context: Activity, castContext: CastContext) {
        MediaRouteChooserDialog(context).apply {
            routeSelector = castContext.mergedSelector!!
        }.show()
    }
}
```

Instantiate this class and then connect to a device. This will start casting the source listed in the class to the Chromecast receiver.

## Related articles

* [How can we track the first play(ing) event?](https://optiview.dolby.com/docs/theoplayer/how-to-guides/android/player/track-first-playing-event.md)

* [How to start with a specific quality?](https://optiview.dolby.com/docs/theoplayer/how-to-guides/android/media-tracks/start-with-specific-quality.md)

* [Pass subtitle selection on to Chromecast](https://optiview.dolby.com/docs/theoplayer/how-to-guides/android/cast/chromecast/pass-subtitle-section-on-to-chromecast.md)

* [How to know whether a live stream is playing?](https://optiview.dolby.com/docs/theoplayer/faq/how-to-know-when-livestream-is-playing.md)

* [Getting started on Chromecast](https://optiview.dolby.com/docs/theoplayer/getting-started/sdks/chromecast/getting-started.md)