callbacks chaining, by returning a pointer to this

[lathoub]

Current
inline void setHandleMessage(void (*fptr)(const MidiMessage&)) { mMessageCallback = fptr; };
Suggestion:
inline MidiInterface& setHandleMessage(void (*fptr)(const MidiMessage&)) { mMessageCallback = fptr; return *this; };

(add MidiInterface& for all callbacks)

This would allow for:

MIDI
.setHandleNoteOn([](byte channel, byte note, byte velocity) {
})
.setHandleNoteOff([](byte channel, byte note, byte velocity) {
});

Shorter and syntactically nicer

A suggestion for a next release.

This has no impact on the use of dynamic memory usage or program storage space.
And no impact on existing code and examples

[franky47]

Great idea!

[lathoub]

Can also be done for begin, send* and turnThruOff (and all commands returning void)

[franky47]

Implemented in #247, thanks @lathoub !