[MBL-19554][Student][Teacher] Video playback conflict: previous MP4 keeps playing when a new one starts

refs: MBL-19554
affects: Student, Teacher
release note: Fixed issue where multiple videos would play simultaneously.

Author: kristofnemere

libs/pandautils/src/main/java/com/instructure/pandautils/activities/BaseViewMediaActivity.kt

@@ -215,6 +215,9 @@ abstract class BaseViewMediaActivity : BaseCanvasActivity() {
     override fun onResume() {
         super.onResume()
 
+        // Pause all other playing videos to prevent multiple videos playing simultaneously
+        ExoAgent.pauseAllOtherAgents(mUri)
+
         val fileFolderDeletedEvent = EventBus.getDefault().getStickyEvent(FileFolderDeletedEvent::class.java)
         if (fileFolderDeletedEvent != null)
             finish()

libs/pandautils/src/main/java/com/instructure/pandautils/utils/ExoPlayerHelper.kt

@@ -251,5 +251,18 @@ class ExoAgent private constructor(val uri: Uri) {
         fun releaseAllAgents() {
             agentInstances.values.forEach { it.release() }
         }
+
+        /** Pauses all agents except the one associated with the specified Uri */
+        fun pauseAllOtherAgents(currentUri: Uri) {
+            agentInstances.forEach { (uriString, agent) ->
+                if (uriString != currentUri.toString()) {
+                    agent.mPlayer?.let {
+                        if (it.isPlaying) {
+                            it.playWhenReady = false
+                        }
+                    }
+                }
+            }
+        }
     }
 }