Speak Coroutines with Deferred

YourOldSyncLibrary.kt

class YourOldSyncLibrary {
    val imageCompressor = ImageCompressor()
    
    fun compress(): Deferred<String> {
        val deferred = CompletableDeferred<String>()
        imageCompressor.compress(object: OnCompressListener {
           override fun onCompress(filePath: String) {
               deferred.complete(filePath)
           }
           
           override fun onError(exception: Exception) {
               deferred.completeExceptionally(exception)
           }
        })
        return deferred
    }
}

YourViewModel.kt

class YourViewModel {

  private val _compressionPath = MutableLiveData<String>()
  val compressionPath: LiveData<String>
  get() = _compressionPath
  
  fun compressImage() {
      viewModelScope.launch {
          withContext(Dispatchers.Default) {
             _compressionPath.postValue(compress().await())
          }
      }
  }
  
}