add support for five row chromatic accordions

Hi Erik,

Thanks for your suggestion. There is not really any constraint for this project, except the available time. With enough time and/or people involved, everything can be implemented.

There are two sides of this issue. First, display an alternate layout like the chromatic accordion keyboard instead of the current piano keys. Second, creating mapping files to use the alphanumeric computer keyboard to emulate the accordion keyboard layout. The second problem I think that can be solved using the keyboard map editor (Menu Edit->Keyboard map->Edit...) or loading the XML mapping file created by other means.

There was another user experimenting with alternate layouts. See:
https://sourceforge.net/forum/message.php?msg_id=5534905

I've collected some links about interesting alternate layouts. Here are a few ones:

* Harmonic table
http://www.synthtopia.com/content/tag/harmonic-table-keyboard/
http://www.c-thru-music.com/cgi/?page=layout

* Jankó
http://squeezehead.com/uniform-keyboard/

* Jammer
http://musicscienceguy.vox.com/library/post/a-jammer-key-lay-out-sound-byte.html

* Wicky-Hayden
http://www.concertina.com/gaskins/wicki/

Regards,
Pedro

Hi Pedro,

Maybe one way to go is to separate out as much as possible of the music instrument layout from the cpp files and put it into xml data files. For instance, these files

pianoscene.cpp
pianokey.cpp

have some GUI information in them ( how the piano keys look like ). Maybe it is possible to put this GUI information in some xml files?

A consequence would be that changing the number of octaves would be the same as loading in another instrument, e.g. a gui data definition for a piano with 3 octaves.

Just a sketch

<keydef>
<key id="blackkey">
<painter pen="black">
<rect x="15" y="15" x-offset="0" y-offset="0"/>
</painter>
</key>
<key id="whitekey">
<painter pen="white">
<rect x="15" y="15" x-offset="0" y-offset="0" />
<rect x="15" y="15" x-offset="20" y-offset="0"/>
</painter>
</key>
</keydef>
<keyboard>
<key note="c2" key-idref="whitekey" x="15" y="20"/>
<key note="c#2" key-idref="blackkey" x="20" y="20"/>
<key note="d2" key-idref="whitekey" x="25" y="20"/>
</keyboard>

Don't look at the coordinates.I just put some numbers there. And this sketch doesn't handle pressed vs. unpressed keys.

I don't know if SVG could be used somehow. There is a QSvgWidget. But at a first look it seems more suited for a background image of the music instrument.

cheers,
Erik