driver.hid.keyboard¶

Keyboard event abstraction and modifier state tracking.

Overview¶

This unit provides a hardware-independent keyboard event interface. Lower-level keyboard drivers (PS/2, USB HID) translate raw scan codes or HID keycodes into TKeyInfo records and call reportKeyEvent. This unit maintains global modifier key state and dispatches events to a registered hook callback.

Dependencies¶

(none — foundational HID unit)

Types¶

TKeyInfo¶

Describes a single key event.

Field	Type	Description
`key_code`	`char`	ASCII character produced by this key
`is_down_code`	`boolean`	`true` if the key was pressed, `false` if released
`SHIFT_DOWN`	`boolean`	State of the Shift modifier at event time
`CTRL_DOWN`	`boolean`	State of the Ctrl modifier at event time
`ALT_DOWN`	`boolean`	State of the Alt modifier at event time

Functions and Procedures¶

hook¶

procedure hook(proc: pp_hook_method);

Registers a callback to receive TKeyInfo events. Only one hook is active at a time; calling hook again replaces the previous registration.

reportKeyEvent¶

procedure reportKeyEvent(info: TKeyInfo);

Called by a lower-level keyboard driver to report a key press or release. Updates the global modifier state (is_shift, is_ctrl, is_alt) based on the event, then invokes the registered hook callback if one is set.

Notes¶

is_shift, is_ctrl, and is_alt are module-level globals updated on every event and can be read directly to check current modifier state.
The single-hook design means only one consumer (typically the terminal or a foreground application) receives keyboard input at a time.