View source for Amarok/Development/Architecture

[[Category:Amarok]]

{|! Images from the meeting || ||
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=== 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 ===

==== Prevent Circular Referencing ====

Meta::Album::tracks() > implemented using QueryMaker (blocking until result is ready)<br/>

==== Simplify Compilation ====

Album::artist(): null > compilation, empty > bad tag, normal

==== Simplify ====

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/>

==== Playlists Folded into Meta ====

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)