PieSender

Synopsis

PieSender is an android file manager that allows easily transferring files or directories via wifi:

• Android Device --> Personal Computer
• Personal Computer --> Android Device
• Android Device --> Android Device

The only requirement is for both devices to share the same connection.

Interest and Reason to be

Android devices do not allow sending files via wifi but through wifi-direct, which is not provided by a wide range of devices. I wanted to make it easy to use wifi for most of android devices to transfer files, considering:

• most of them can create a wifi hotspot (allowing Android to Android transfers with no need of an intermediate router)
• all of them can connect to a wifi network (for Android --> Computer and Computer --> Android transfers)

There already exist some other solutions which I had the chance to try out, such as Dukto, but I though I could achieve a better user experience, add a few extra functionalities, and in the meanwhile have fun and gain more insight into the android development world.

Screenshots

Main Functionalities

• Browse directories from your file system (having informations such as name and size for file system entries)
• Automatic network discovery (A simple network broadcast based protocol to automatically discover all avaiable devices)
• Send a single file
• Send multiple files (in parallel using threads)
• Receive multiple files (in parallel)
• Search top bar for filtering current directory
• Web server (By building it respecting the same API contract from my django file server project cappuccino-server I can simply make re-use of the client from that project cappuccino-web and statically serve that to any browser that can reach the Android device through the network): this would make possible to transfer files from and to a computer with no need of having the Desktop version of the app
• Extra module for cappuccino-server if self-hosted on a RaspBerryPi
• Tag directories to synchronize
• Search top bar to look recursively into sub-directories
• Search top bar REGEX file filtering

Architectural hints and design patterns

• Model-View-Presenter Pattern
• View Holder Pattern - Efficient view caching
• Recycler View - next generation ListView
• File transfer demands handled with a queue (to limit parallel transfers number)
• All transfer threads inform the model of their progress, while transfers view refresh within controlled rate (storing last refresh request timestamp one can ignore further requests within a delay)
• Services handle background operations
• Progress bar effect through view overlay (exploting transparence and background color)
• Swipeable interface composed of 3 views: FileManager, Downloads, Uploads

Some helpful sources to thank

• Android Databinding: Goodbye Presenter, hello ViewModel!
• Android Code That Scales, With MVP
• Using an ArrayAdapter with ListView
• AVLoadingIndicatorView
• Using lists and grids in Android with RecylerView - Tutorial
• Using the RecycleView
• RecycleView animations
• Bound Services
• MVP for Android: how to organize the presentation layer
• ViewHolder pattern
• Simple ListFragment with ArrayAdapter
• Creating a File Browser in Android
• File Sender and Receiver + File name
• Bytes -> Long Conversion
• Long -> Bytes Conversion
• Network Discovery
• Async Task Loaders
• Check connection available
• Folder
• File Type Material pack