Revised Design - Essential Widget List (Sep. 25, 2006) (work in progress as of 5:13PM!)

Visual Widgets

ListBox widget

Actions: refresh(no params), show(no params)
Emits:
Receives: listSorted

FileBrowser widget

Actions: refresh(no params), show(no params)
Emits:
Receives:

Non-Visual Widgets

MP3Sorter widget

Container that encapsulates the entire MP3 Sorter application widget.

Actions:
Emits:
Receives:

MainWindow widget

Container that encapsulates all visual widget components of the main window.

Actions:
Emits:
Receives:

CategorizerDialogWindow widget

Container that encapsulates all visual widget components of the Categorizer dialog window.

Actions:
Emits:
Receives:

ID3Reader widget

Delegates to an 3rd party ID3 reader library.

Actions: getID3Info(path to file, list of fields to fetch?)
Emits: gotID3Info - a DataEvent that contains the fetched ID3 info
Receives:

Database widget

Manages the DBMS.

Actions: populate(list of paths from the FileBrowser widget) - creates a new set of records in the DB for the requested list of files obtained from FileBrowser
Emits: databasePopulated
Receives: gotID3Info

CategorySort widget

Uses the strategy pattern to employ a number of different sorting algorithms.

Actions: sort(list of MP3s in some representation, ID3 field by which to sort)
Emits: listSorted
Receives:

SortingAlgorithm widget

Widgets that implement this type would delegate to a particular sorting algorithm such as qsort, heap sort, radix sort, which the CategorySort widget could employ to accomplish its task depending on the size of its input list.

Actions: sort(list of MP3s in some representation, ID3 field by which to sort)
Emits:
Receives:

Preliminary Discussion

Our design is fairly straightforward - the main interface consists of a parent window with a listbox widget, and a button to show a file finder dialog, and a button to refresh the list. Some central points:

For the filefinder (visual) widget, there is a treeview, which is piped to the textbox just above it, so that the textbox will always reflect what is selected in the treeview, but can also be used alone to manually enter a path. There is also the possibility for including a tab-autocompletion widget to work with it. Once "OK" is pressed, the selected directory will be sent out to the "Recurser" widget as its root to begin its recursive search of mp3's. The Recurser widget should be designed as a general tool for filesystem search, thus we will be passing the "if ends with .mp3" argument as its search condition.

As the Recurser finds files matching its criteria, it will interface with the DB widget to have them added to the database with blank ID3 information.After all files are added, the DB will then go through all its entries and populate their Artist/Genre/etc. fields via interface with the ID3 Reader Widget, which will be a wrapper for some freely available library.

For a database backend, we are tentatively going for Apache Derby (tentatively because we really know jack about database engine features). Each DB entry will contain a filename, as well as artist, album, genre, year, etc. from the ID3 tag (if present). This will allow quick and easy sorting into the gui display for browsing. The general goal (from my perspective) is to enable a utility similar to Windows Media Player or Amarok to be realized using Fluency. This means that after scanning the directory tree, no more interaction will occur with the filesystem-- instead resorting to the database for all file information.

Our sorting is controlled by a master sorting widget which employs the strategy pattern to switch between different sorting algorithms, based on which is appropriate for the size of the user's music collection. The sorting algorithms are of course encapsulated by their own widgets. The master sorting widget in addition knows about ID3 information on which the user might like to sort - for instance, the user might click a tab in the list box indicating that the user would like to sort the files based on this ID3 property (genre, length, bitrate, etc.) The list box would then fire an event to the master sorting widget to execute the proper sorting.

All of the individual widgets are registered with a master container widget that represents the MP3 Sorter, which handles some of the overarching logic.