Unit HIDKEYBOARD

Return to Unit Reference

Description

---

Ultibo HID Keyboard Consumer unit

This is a consumer for any generic HID keyboard device, it accepts HID application collections in the generic desktop page (HID_PAGE_GENERIC_DESKTOP) with the usage set to keyboard (HID_DESKTOP_KEYBOARD).

The consumer will bind to any keyboard collection that includes at a minimum an input report containing a field that provides keypress data from the keyboard / keypad page (HID_PAGE_KEYBOARD_KEYPAD) and a field providing modifier keys from the same page.

The consumer will also look for an output report containing a field from the LED page (HID_PAGE_LED) and will use this to set the keyboard LEDs if found.

Up to 16 keypresses per report can be accepted (see HID_KEYBOARD_MAX_KEYS) but most keyboards will commonly report up to 6 which is the size defined in the USB HID usage tables for boot mode keyboard reports.

Constants

---

HID keyboard specific constants HID_KEYBOARD_*

HID_KEYBOARD_CONSUMER_NAME = 'HID Keyboard Consumer';	Name of HID Keyboard consumer
HID_KEYBOARD_DESCRIPTION = 'HID Keyboard';	Description of HID Keyboard device
HID_KEYBOARD_MAX_KEYS = 16;	Maximum number of keys allowed in any report

Type definitions

---

HID keyboard keys

PHIDKeyboardKeys = ^THIDKeyboardKeys;

THIDKeyboardKeys = array[0..HID_KEYBOARD_MAX_KEYS - 1] of Byte;

HID keyboard device

PHIDKeyboardDevice = ^THIDKeyboardDevice;

THIDKeyboardDevice = record

Keyboard Properties
Keyboard:TKeyboardDevice;
HID Properties
Collection:PHIDCollection;	The HID collection this keyboard is bound to
Definitions:PHIDDefinition;	The input report definitions that can be accepted as keyboard reports
LEDDefinition:PHIDDefinition;	The report definition that corresponds to the LED output
LastCode:Word;	The scan code of the last key pressed
LastCount:LongWord;	The repeat count of the last key pressed
LastKeys:THIDKeyboardKeys;	The keys from the last keyboard report received

Public variables

---

None defined

Function declarations

---

Initialization functions

procedure HIDKeyboardInit;

Description: Initialize the HID Keyboard unit and HID Keyboard driver

Note	Called only during system startup

HID keyboard functions

function HIDKeyboardDeviceControl(Keyboard:PKeyboardDevice; Request:Integer; Argument1:LongWord; var Argument2:LongWord):LongWord;

Description: Implementation of KeyboardDeviceControl API for HID Keyboard

Note	Not intended to be called directly by applications, use KeyboardDeviceControl instead.

HID keyboard helper functions

function HIDKeyboardCheckCollection(Collection:PHIDCollection):LongWord;

Description: Check if a HID collection is suitable for use as a keyboard device

Note	None documented

function HIDKeyboardCheckInputDefinition(Definition:PHIDDefinition):LongWord;

Description: Check if a HID definition is suitable for use as a keyboard input report

Note	None documented

function HIDKeyboardCheckOutputDefinition(Definition:PHIDDefinition):LongWord;

Description: Check if a HID definition is suitable for use as a keyboard output (LED) report

Note	None documented

function HIDKeyboardCheckPressed(Keyboard:PHIDKeyboardDevice; ScanCode:Byte):Boolean;

Description: Check if the passed scan code has been pressed (True if not pressed in last report

Keyboard	The HID keyboard device to check for
ScanCode	The keyboard scan code to check
Note	Caller must hold the keyboard lock

function HIDKeyboardCheckRepeated(Keyboard:PHIDKeyboardDevice; ScanCode:Byte):Boolean;

Description: Check if the passed scan code was the last key pressed and if the repeat delay has expired

Keyboard	The HID keyboard device to check for
ScanCode	The keyboard scan code to check
Note	Caller must hold the keyboard lock

function HIDKeyboardCheckReleased(Keyboard:PHIDKeyboardDevice; Keys:PHIDKeyboardKeys; ScanCode:Byte):Boolean;

Description: Check if the passed scan code has been released (True if not pressed in current report)

Keyboard	The HID keyboard device to check for
Keys	The HID keyboard keys to compare against (Current)
ScanCode	The keyboard scan code to check
Note	Caller must hold the keyboard lock

function HIDKeyboardDeviceSetLEDs(Keyboard:PHIDKeyboardDevice; LEDs:Byte):LongWord;

Description: Set the state of the LEDs for a HID keyboard device

Keyboard	The HID keyboard device to set the LEDs for
LEDs	The LED state to set (eg KEYBOARD_LED_NUMLOCK)
Return	ERROR_SUCCESS if completed or another error code on failure

function HIDKeyboardDeviceSetIdle(Keyboard:PHIDKeyboardDevice; Duration,ReportId:Byte):LongWord;

Description: Set the idle duration (Time between reports when no changes) for a HID keyboard device

Keyboard	The HID keyboard device to set the idle duration for
Duration	The idle duration to set (Milliseconds divided by 4)
ReportId	The report Id to set the idle duration for (eg HID_REPORTID_NONE)
Return	ERROR_SUCCESS if completed or another error code on failure

Return to Unit Reference