Grid Music

Check out the code at the project repo
https://github.com/sdocy/GridMusic

Send me feedback, questions, or ideas

A unique approach to music players, using gridviews to provide customizable music playlists. Normal playlists must be played in order, randomly, or by the rules of some unknown so-called genius algorithm. This app gives listeners control over the flow of their playlists, while still retaining some randomness in the playback to keep playback from getting stale and predictable.

Listeners lay out the songs, artists or albums for their playlist in a grid pattern. Once playback has commenced, the next song to play will be randomly chosen from adjacent playlist grids (vertically and horizontally adjacent grids only). If an unplayed choice is not available adjacent to the last played song, a new grid to start from is randomly chosen. By creating their own grid patterns, users can control which songs will follow other songs.

When the current grid is done playing, an adjacent, unplayed grid is chosen to be played next.

Current implemented features :

Pause and resume playback.
Choose to play a single song per grid or all songs on the grid.
Tap on a grid to choose it to be played next.
Reset played grids so that they may be played again.
Toggle individual grids between played / not-played.
Settings may be changed while the grid choosing algorithm is running.

Flowchart v1.0 for play_music activity.

Version 2.0 March 14, 2018

It plays music !!

Added a static set of songs matching my static Grid playlist to the app and figured out basic MediaPlayer controls, starting and pausing music playback
Added an OnCompletion listener for the MediaPlayer to start the next song when the current one finishes
Hooked up the skip-fastforward button to skip to the next song by stopping the current playback and explicitly calling the MedioPlayer's OnCompletion() method
Fixed a bug when switching from single-play to album-play. The album would use an old value for albumPlayIndex, left-over from a previous album-play setting. I had to implement a method to get the index of a song from a grid, add a class variable to store the current playing song, and update albumPlayIndex when the album-play setting is chosen.

Version 2.1 March 15, 2018

Removed rewind / fastfoward buttons for now
Added stop button and implemented stop playing functionality
Implemented Audio Focus
- app grabs focus when user presses PLAY
- focus is kept until
  - player presses PAUSE
  - player presses STOP
  - player enters DONE state after playing all grids
- music playback pauses when the app losses focus (i.e. incoming phone call)
- music playback continues when the app regains focus
Highlight main menu button text when pressed
Highlight settings options text when pressed.
Got a code snippet working that discovers music files on the phone
Added custom app icon

Project implementation timeline. Grid Music has come so far since
I started working on it as a class project less than a month ago.

Version 2.2 March 20, 2018

App now plays songs from the phone rather than needing music resources contained within the app. The pathnames are still hard-coded until I get the activity for creating playlists working.
Introduced code to handle errors when trying to play a song from the phone. The grid is colored red to highlight the error and a new song is chosen to play, according to the current grid play setting.

Flowchart v2.0 for play_music activity.

Version 3.0 March 28, 2018

Prototyped Create Grid activity

Designed a very complex XML layout, which includes two ListViews and a GridView, for the Grid you are building, the list of grids to add, and a list of songs on the selected grid
Got a code gist working which retrieves meta-data for all music files on the device via MediaStore
Got another code gist working which extracts album art present on the device
Many of my songs were ripped from my CD collection and didn't have associated cover art, so I downloaded "Album Art Grabber", a simple app which finds album art for your music files. It did not do a perfect job, it got very confused with songs from "Greatest Hits" albums, giving them all the same cover art, but did find art for just about everything.
I sort the song list by artist name, album name and track number and remove duplicates (created a custom Comparator for this)
Controls are pretty intuitive
- tap on a grid in the to-place list, then an empty Grid spot to place it
- long press a grid in the to-place list to delete it from the to-place list
- long press a grid on the Grid to move it back to its original position in the to-place list
- press any grid to see a list of songs on that grid
There are options to undelete the last grid you deleted or all grids you deleted, placing them back in the to-place list
Provided options to combine all songs in the to-place list by the same artist or the same album into one grid
To-place list includes a counter of how many grids there are to place
Reworked the GridAdapter to handle images specified as either a bitmap path or a resource id

Misc other changes

Show a toast message when unable to play a song on the Grid
Refactored XML id tags to make it easier to track them, there are getting to be a lot of them
Add album name and track number to Song class
Tweaked onBackPressed() over-ride
Replaced ArrayList declarations with List declarations

Create Grid TODO

Create an AsyncTask or CursorLoader for loading music
Add ProgressBar for loading music
Add grid counter for the Grid
We'll also need an interface for splitting a grid back into individual songs
Serialize and save the Grid to disk
It might be nice to add the ability to play music in the Create Grid activity, at least snippets, in case the user is unsure what a particular song they have is

Version 4.0 June 7, 2018

Prototyped Cover Art Downloader activity

Searches your device for music files and associated cover art, and allows you to search the internet for additional cover art and download any art missing from your music library
Uses MediaStore Content Provider to discover music files and associated cover art on your device
Combines music from the same album to provide a list of unique albums present on the device
Uses public JSON APIs to query and download album cover art
Integrated google search as an alternative method for searching for missing cover art

Android development techniques I explored with this project

My first use of ViewHolders with ListViews......love it...will definitely integrate them into the rest of GridMusic
Use of LoaderManagers to asynchronously perform network tasks
Retrieval and parsing of JSON data from public web APIs
Use of progressbars and empty list views to enhance ListView presentation
The use of RelativeLayouts and selective view visibility to efficiently switch between view content
Having multiple clickable view elements within a ListView element
Use of custom class comparators and Collection.sort() to organize ListView data

Cover Art Downloader TODO

Make use of CursorLoader to asynchronously search device for music and art
Provide option to save downloaded art to device

Version 4.02 June 10, 2018

Switched from GridViews to RecyclerViews for GridAdapter
Figured out how to use Context to call a method in the instantiating class
Created my own interface for CreateGridActivity and PlayGridActivity to implement so that GridAdapter (used by both classes) could call the same method (as far as GridAdapter is concerned) when a Grid element is clicked regardless of which Activity had created it. This is required because it seems you have to implement onClick() and onLongClick() inside the RecyclerView Adapter since it does not provide onItemClick() and onItemLongClick()
Replaced setTag / getTag with getAdapterPosition() for RecyclerViews
Replaced notifyDataSetChanged() with notifyItemRemoved() where applicable
When adding items back to the gridList, instead of adding to the end and then re-sorting, I now use my GridComparator to find the correct insertion index to insert at. Also changed from notifyDataSetChanged() to notifyItemInserted() when putting items back on the gridList. This was done when moving a grid back to the gridList from theGrid and when 'Undeleting Last'. 'Undelete All' still adds to the end and re-sorts since many items may be getting put back on the gridList.
Set up empty music view for CreateGridActivity
Switched gridList image and text to be vertically laid out, instead of horizontally, to provide more space for the Grid

Version 5.0 July 28, 2018

Implemented save grid functionality in Create Grid activity and load grid functionality in Play Grid Activity
- Save data is converted to JSON and written as a string to a save file
- Play Grid reads in the save file and retrieves the specific JSON values
- Had to switch GridElement from using drawable resources to exclusively converting a filepath to a bitmap
- Removed hardcoded grid initialization in Play Grid and all the drawable resources associated with it

Save grid TODO

Investigate caching cover art bitmaps so we don't have to constantly read the cover art file
Check available space on device before trying to save the file
Investigate save file size for large Grids, to make sure it is acceptable
Research other Android save file best practices
Investigate current hack of removing storage part of music path name in order to get music file to play

TODO

Play Grid - interface for seeing what songs are in a grid
Create Grid - prompt to save Grid or auto-save Grid when we need to, i.e. app closing, loading new Grid for editing
Play Grid Activity - save current loaded Grid and re-load same Grid next time app is started
In single play mode, if a user selects a grid, we skip that grid if all songs from it have already been played, perhaps we should reset all songs to not played in this case and then choose a random one?
Create Grid Activity - break apart grids with multiple songs
Figure out how to replace existing or missing cover art with downloaded cover art
New feature - play all songs on a grid, in random order
Get rewind and fast-forward working
Go through the guides I found for building Android Audio Players
Go back and retry supporting different grid sizes
Replace implementing onClickListener with just creating an onClickListener that includes a switch statement for use by multiple UI objects
Enable backbutton even if no music was found