View source for Amarok/Development/ArchitectureReview

= Amarok @ Randa 2012: Architecture review =

== Source Structure ==
* only main.cpp/App.cpp/etc in src/
** group collections, providers, ... together in libraries or plugins
* get rid of core-impl.
** some stuff should be in core
** organize by libraries/plugins
* One CMakeFiles.txt per sub-folder: limited link target, faster linking
* Clean up includes: less files touched for rebuild

== Components ==
Can be expected to always be there. Are created by main.cpp in the order needed or are interfaces with stub implementation until the real one is registered.
* CollectionManager
* PlaylistManager
* defaultPlaylistProvider
* PlaybackController, PlaybackQueue
* MainWindow: parent of the dialogs, keybindings, etc
* Notifier (ACTION: rename Logger) Stub implementation until MainWindow is ready.

== Meta ==
Meta::Genre > QString<br/>
Meta::Label > QString<br/>
Meta::Year > QString<br/>
Track::Artist() -> QString (display only)<br/>
Album::Artist() -> Meta::Artist (has it's own properties: rating, year, image, ...)<br/>
Meta::Playlist inheriting Meta::Base.<br/>
PlaylistObserver methods moved into Meta::Observer

=== MultiSource tracks ===
QList<KUrl> playableUrls() in the order of priority. Handled in PlaybackController.

== File Layout Dialog ==
* Presets for Amarok, iTunes, Windows MediaPlayer standard layout. Useful for imported collections.
* Basic Layout Mode: Tokens in vertical list, small icons.
* Separate preset config, main dialog just showing selector and edit buttons.

== Popup Dropper ==
* Remove overlay on more...
* 3 items max, easy muscle memory targets.
* PlaylistBrowser: 2 common actions: load, replace + most sensible (first?) provider action.

== PlaylistFileProvider ==
* Use as export option:
** Open export playlist dialog
** Option to copy tracks to containing folder.
** Don't show playlist files from collection by default. Alternatives?

== Services ==
* Easy to write
* 1 instance per service plugin > no factory pattern needed
* pre-init data can be read from desktop files (icon, name, description)
* Auto-init optional for C++ plugins, not possible for scripts to prevent UI blocking and such
* Unit tested
=== Service Plugin Structure ===
* TrackProvider or PlaylistProvider (or multiple) when needed
* QAbstractItemModel free from UI elements.
** Custom roles for Amarok: uidUrl (for file/playlist load)
* QActions for toolbar (next to search box)
* Custom UI per platform
** Delegate for ItemModel
** UI or QML for custom interaction (location determined by platform implementation)