ThumbnailGenerator.kt

    @ReactMethod
    fun generate(imagePath: String,
                 renderSettings: ReadableArray,
                 width: Int,
                 height: Int,
                 promise: Promise
    ) {
        Log.d("Thumbnail", "====== called $renderSettings $imagePath")
        launch(CommonPool) {
            try {
                val uri = Uri.parse(imagePath)
                val projection = arrayOf(MediaStore.Images.Media._ID)
                var imageId: Long? = null
                Log.d("Thumbnail", "===== image $uri path $imagePath")
                // associate Looper
                Looper.prepare()
                val cursorLoader = CursorLoader(
                    reactApplicationContext,
                    uri, projection, null, null, null)
                cursorLoader.loadInBackground()?.apply {
                    imageId = async {
                        use {
                            val columnIndex =
                                getColumnIndexOrThrow(MediaStore.Images.Media._ID)
                            moveToFirst()
                            return@async getLong(columnIndex)
                        }
                    }.await()
                }
                Log.d("Thumbnail", "===== imageId $imageId")
                if (imageId == null) {
                    Log.d("Thumbnail", "===== No thumbnail")
                    promise.reject(IllegalAccessException("No thumbnail"))
                    return@launch
                }


                val miniThumbCursor = MediaStore.Images.Thumbnails.queryMiniThumbnail(
                    reactApplicationContext.contentResolver,
                    imageId!!,
                    MediaStore.Images.Thumbnails.MINI_KIND,
                    null)
                if (miniThumbCursor != null && miniThumbCursor.count > 0) {
                    Log.d("Thumbnail", "===== ok")
                    miniThumbCursor.moveToFirst()
                    val result = miniThumbCursor.getString(
                        miniThumbCursor.getColumnIndexOrThrow(MediaStore.Images.Thumbnails.DATA))
                    val map = Arguments.createMap()
                    map.putString("path", imagePath)
                    map.putString("thumbnail", result)
                    promise.resolve(map)
                    miniThumbCursor.close()
                }
                Log.d("Thumbnail", "===== end")
            } catch (e: Exception) {
                promise.reject(e)
            }
        }
    }