Gsoc2016 Keyboard Classes Overview

Controller

Abstract class representing a controller. For each controller type there's a subclass: HidController, MidiController... Jordi will need to create a KeyboardController subclass.

ControllerDebug

This class is used to provide the controllerDebug(String s) macro. This macro prints controller debug messages. It is only needed to include the header file in each file where you want to use this macro. There's nothing that needs to be instantiated.

ControllerPreset

Abstract class representing a controller preset. For each controller type there's a subclass: HidControllerPreset, MidiControllerPreset... Jordi will need to create a KeyboardControllerPreset subclass.

ControllerPresetFileHandler

Handles loading and saving of Controller presets.

ControllerPresetVisitor

Controller inherits from it. This class defines a series of pure virtual methods called visit. Controller subclasses must implement these visit methods according to their ability to handle each preset type. Like this:

https://github.com/mixxxdj/mixxx/blob/master/src/controllers/midi/midicontroller.cpp#L34

https://github.com/mixxxdj/mixxx/blob/master/src/controllers/midi/midicontroller.cpp#L44

Here's the explanation of why this is needed:

https://github.com/mixxxdj/mixxx/blob/master/src/controllers/controller.h#L34

More info: Visitor pattern

ControllerEngine

It manages the loading and execution of a script. Controller class holds a ControllerEngine instance.

ControllerEnumerator

Abstract class that looks for available controllers. For each controller type there's a subclass: HidEnumerator, MidiEnumerator... Jordi will need to create a KeyboardEnumerator subclass.

For example if a user has two MIDI controllers connected to the computer, MidiEnumerator::queryDevices() returns a list with two instances of MidiController.

Here is were Jordi will have to figure out if two keyboards connected to the same computer can be used as two controllers or the OS presents them as a single one.

ControllerManager class holds a list of ControllerEnumerator instances.

ControllerManager

Manages creation/enumeration/deletion of hardware controllers. When a class wants to access a controller or query the available ones, it asks ControllerManager. There's only one instance of ControllerManager that is created in MixxxMainWindow (mixxx.cpp) and gets its slotSetUpDevices method called, at Mixxx start.