# CharShift

CharShift allows you to independently assign symbols to shifted and unshifted
positions of keymap entries.  Either or both symbols can be ones that normally
requires the `shift` modifier, and either or both symbols can be ones normally
produced without it.

For example you can configure your keyboard so that a single key produces `,`
when pressed unshifted, but `;` when pressed with `shift` held.  Or `(`
unshifted, and `[` shifted.  Or `+`/`*` — all without changing your OS keyboard
layout.

## Using the plugin

Using the plugin with its defaults is as simple as including the header, and
enabling the plugin:

```c++
#include <Kaleidoscope.h>
#include <Kaleidoscope-CharShift.h>

KALEIDOSCOPE_INIT_PLUGINS(CharShift);
```

Further configuration is required, of course; see below.

Note: CharShift should be registered in `KALEIDOSCOPE_INIT_PLUGINS()` after any
plugin that changes the event's `Key` value to that of an CharShift key.

## Configuring CharShift keys

To use CharShift, we must first define `KeyPair` objects, which can then be
referenced by entries in the keymap.  This is easiest to do by using the
`UNKEYS()` preprocessor macro in the sketch's `setup()` function, as follows:

```c++
void setup() {
  Kaleidoscope.setup();
  UNKEYS(
    kaleidoscope::plugin::KeyPair(Key_Comma, Key_Semicolon),                   // `,`/`;`
    kaleidoscope::plugin::KeyPair(Key_Period, LSHIFT(Key_Semicolon)),          // `.`/`:`
    kaleidoscope::plugin::KeyPair(LSHIFT(Key_9), Key_LeftBracket),             // `(`/`[`
    kaleidoscope::plugin::KeyPair(LSHIFT(Key_Comma), LSHIFT(Key_LeftBracket)), // `<`/`{`
  );
}
```

The first argument to the `KeyPair()` constructor is the value for when the key is
pressed without `shift` held, the second is what you'll get if a `shift`
modifier is being held when the key toggles on.  If that second ("upper") value
doesn't have the `shift` modifier flag (i.e. `LSHIFT()`) applied to it, the held
`shift` modifier will be suppressed when the key is pressed, allowing the
"unshifted" symbol to be produced.

These `KeyPair`s can be referred to in the sketch's keymap by using the `UK()`
preprocessor macro, which takes an integer argument, referring to items in the
`UNKEYS()` array, starting with zero.  With the example above, an entry of
`UK(2)` will output `(` when pressed without `shift`, and `[` if `shift` is
being held.

## Further reading

Starting from the [example][plugin:example] is the recommended way of getting
started with the plugin.

 [plugin:example]: /examples/Keystrokes/CharShift/CharShift.ino