Bitmaps

A user can create a custom Avatar in Open Event Android. We use Picasso Library for easy image loading and caching in Open Event Android. This blog post will help you understand how its implemented in Open Event Android. These are the steps we follow : Create UI element which allows the user to pick an avatar Checking and requesting Read External Storage permission Compress and Encode Image Use Picasso to display image on UI Upload it on the server on user’s command We will discuss the above steps in detail in the following section. Create UI element which allows the user to pick an avatar To display the selected avatar image as well as to fire image pick action when clicked we need a UI element. We display a placeholder in case no avatar image is provide, in this case, its ic_account_circle_grey_24dp which lies in drawable folder. Rest of the code is self explanatory. <ImageView        android:id="@+id/profilePhoto"        android:layout_width="@dimen/item_image_view_large"        android:layout_height="@dimen/item_image_view_large"        android:layout_gravity="center_horizontal"        android:contentDescription="Profile Photo"        android:padding="@dimen/padding_large"        app:srcCompat="@drawable/ic_account_circle_grey_24dp" /> Once we have created the UI we need to wire it with the action to pick an image, the following code snippet does that. When this ImageView is clicked permissionGranted variable is checked which keeps a track of read external storage permission if this is true file chooser is displayed to allows user to select an image else an dialog for requesting permissions is shown. rootView.profilePhoto.setOnClickListener { v ->            if (permissionGranted) {                showFileChooser()            } else {                requestPermissions(READ_STORAGE, REQUEST_CODE)            }        } Checking and requesting Read External Storage permission As discussed in the above section permission check is performed when ImageView is clicked and if not granted a dialog request for read external storage is displayed. Initially, the boolean permissionGranted is set to false which means clicking on ImageView fires requestPermission method with permissions array and request code and by overriding the onRequestPermissionResult method we can look at request status. override fun onRequestPermissionsResult(requestCode: Int, permissions: Array<String>, grantResults: IntArray) {        if (requestCode == REQUEST_CODE) {            if (grantResults.isNotEmpty() && grantResults[0] == PackageManager.PERMISSION_GRANTED) {                permissionGranted = true                Toast.makeText(context, "Permission to Access External Storage Granted !", Toast.LENGTH_SHORT).show()                showFileChooser()            } else {                Toast.makeText(context, "Permission to Access External Storage Denied :(", Toast.LENGTH_SHORT).show()            }        }    } onRequestPermissionsResult is called everytime requestPermission finishes, to check for which request it’s called we can check the Request code if it matches with the one we passed in our requestPermissions method that means the grant result carries information about our request. We can check the grantResult and if permission is granted we set our permissionGranted variable to true and display the file chooser menu. Compress and Encode Image Once the user picks the image from the file chooser we need to convert it into an input stream and we encode it into our JPEG format and specify the image quality. The following code snippet will help you understand how this happens. val imageUri = intentData.data            var imageStream: InputStream? = null            try {                imageStream = activity?.contentResolver?.openInputStream(imageUri)            } catch (e: FileNotFoundException) {                Timber.d(e, "File Not Found Exception")            } w            val…