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Description
Ultibo Keymap Interface unit
Keymaps
Keymaps define the translation of a keyboard scan code (the SCAN_CODE_* values) to a key code value (the KEY_CODE_* values) and provide the ability to handle different keyboard layouts in different countries and regions.
The keyboard scan codes are based on the values in Section 10 of the Universal Serial Bus HID Usage Tables v1.12 and are the actual values returned by the keyboard when a key is pressed.
The key code values are based on the Unicode standard with each key code mapped to the code point for that character.
This allows almost infinite flexibility in the way keyboard scan codes are mapped to actual characters and avoids the need to make unreliable assumptions about ASCII characters and upper or lower case handling.
Since the output of the keyboard is a stream of TKeyboardData structures containing both the scan code and the key code then higher level functions can retranslate the data in any way required.
Caps Keys
Caps keys account for the set of keys which are affected by Caps Lock in any given keyboard layout.
In some layouts only the alphabetic keys are affected, in other layouts some or all of the numeric and punctuation keys are also affected.
The caps keys data for any keyboard layout allows defining ranges of keys that are affected by the Caps Lock state.
Dead Keys
Dead keys account for the set of keys which behave as dead keys in any given keyboard layout.
On pressing a deadkey it will be recognized by the keyboard as such and stored until the next key press occurs. If the next keypress is one of the resolves for the pressed dead key then the output character will be the key code value of the resolve not for the key itself.
If the next keypress after a dead key is not one of the resolves that the dead key and the pressed key will both be output to the keyboard buffer.
Setting the default keymap for the system
Additional keymaps are provided as units which can be included in a program and will auto load themselves if included.
All keymap units are configured to check for both the environment variable KEYMAP_DEFAULT and the global configuration variable KEYMAP_DEFAULT to determine if either of them is set to the name of that keymap. If either is set to the keymap name then that keymap will also set itself as the default during system startup.
The environment variable KEYMAP_DEFAULT can be set by adding KEYMAP_DEFAULT=XX (where XX is the name of the keymap, eg DE for Keymap_DE) to the command line of the application (dependent on the system, for a Raspberry Pi use the cmdline.txt file on the SD card).
The global configuration variable KEYMAP_DEFAULT can be set in code by including the GlobalConfig unit in a program and setting the variable during startup.
At any time after startup the default keymap can be changed by call the KeymapSetDefault function.
Constants
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Keymap specific constants KEYMAP_*
KEYMAP_KEY_COUNT = 256;
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Number of key mappings in a keymap entry
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KEYMAP_ROW_COUNT = 4;
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Number of mapping rows per key in a keymap entry (Normal, Shift, AltGr, Shift_AltGr)
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KEYMAP_ROW_SIZE = SizeOf(Word);
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KEYMAP_MAX_CAPSKEYS = 50;
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Maximum number of keys that can be listed in the TKeymapCapskeys structure
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KEYMAP_MAX_DEADKEYS = 5;
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Maximum number of keys that can be listed in the TKeymapDeadkeys structure
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KEYMAP_MAX_RESOLVES = 20;
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Maximum number of resolves that can be listed in the TKeymapDeadkey structure
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Keymap signature KEYMAP_SIGNATURE_*
KEYMAP_SIGNATURE = $863FDBA1;
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Keymap name length KEYMAP_*_LENGTH
KEYMAP_NAME_LENGTH = SIZE_64;
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Length of keymap name
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KEYMAP_DESC_LENGTH = SIZE_128;
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Length of keymap description
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Keymap mode KEYMAP_MODE_*
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Keymap flag KEYMAP_FLAG_*
KEYMAP_FLAG_NONE = $00000000;
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KEYMAP_FLAG_ALTGR = $00000001;
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The key mapping uses the AltGr key
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KEYMAP_FLAG_CAPS_ALL = $00000002;
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Caps Lock shifts all characters not just alphabetic
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KEYMAP_FLAG_CAPS_ASCII = $00000004;
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Caps Lock shifts only ASCII characters A to Z
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[Expand]
Keymap index KEYMAP_INDEX_*
KEYMAP_INDEX_NORMAL = 0;
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Normal (unshifted) value
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KEYMAP_INDEX_SHIFT = 1;
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Shifted value
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KEYMAP_INDEX_ALTGR = 2;
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AltGr value
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KEYMAP_INDEX_SHIFT_ALTGR = 3;
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Shift plus AltGr value
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Type definitions
Keymap header
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PKeymapHeader = ^TKeymapHeader;
TKeymapHeader = record
Mode:LongWord;
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Keymap mode (eg KEYMAP_MODE_NONE)
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Flags:LongWord;
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Keymap flags (eg KEYMAP_FLAG_ALTGR)
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KeyCount:LongWord;
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Number of keys in keymap (Default: KEYMAP_KEY_COUNT)
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RowCount:LongWord;
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Number of index rows in keymap (Default: KEYMAP_ROW_COUNT)
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Name:String[255];
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Keymap name
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Description:String[255];
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Keymap description
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Keymap data
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PKeymapData = ^TKeymapData;
TKeymapData = record
Data:array[0..255,KEYMAP_INDEX_NORMAL..KEYMAP_INDEX_SHIFT_ALTGR] of Word;
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Key mapping data, 4 words for Normal, Shift, AltGr, Shift+AltGr for each of the 256 keys (See KEY_CODE_* constants)
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Keymap chars
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PKeymapChars = ^TKeymapChars;
TKeymapChars = array[0..0] of Word;
Keymap capskey
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PKeymapCapskey = ^TKeymapCapskey;
TKeymapCapskey = record
| Note: Keymap Capskey (Keys affected by the Caps Lock function)
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First:Word;
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First key in caps key range (SCAN_CODE_* value)
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Last:Word;
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Last key in caps key range (SCAN_CODE_* value)(Make first and last the same for a single key)
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Keymap capskeys
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PKeymapCapskeys = ^TKeymapCapskeys;
TKeymapCapskeys = record
Count:LongWord;
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Keys:array[0..KEYMAP_MAX_CAPSKEYS - 1] of TKeymapCapskey;
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Keymap resolve
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PKeymapResolve = ^TKeymapResolve;
TKeymapResolve = record
Key:Word;
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The scan code of the key pressed after the deadkey (SCAN_CODE_* value)
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Index:Byte;
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The index state of the key pressed after the deadkey (eg KEYMAP_INDEX_NORMAL)
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Code:Word;
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The key code of the resulting character (KEY_CODE_* value)
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Keymap deadkey
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PKeymapDeadkey = ^TKeymapDeadkey;
TKeymapDeadkey = record
| Note: Keymap Deadkey (Keys which behave as dead keys)
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Key:Word;
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The scan code of the key which behaves as a deadkey (SCAN_CODE_* value)
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Index:Byte;
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The index state in which the key behaves as a deadkey (eg KEYMAP_INDEX_NORMAL)
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Resolves:array[0..KEYMAP_MAX_RESOLVES - 1] of TKeymapResolve;
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Keymap deadkeys
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PKeymapDeadkeys = ^TKeymapDeadkeys;
TKeymapDeadkeys = record
Count:LongWord;
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Keys:array[0..KEYMAP_MAX_DEADKEYS - 1] of TKeymapDeadkey;
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Keymap properties
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PKeymapProperties = ^TKeymapProperties;
TKeymapProperties = record
KeymapMode:LongWord;
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Keymap mode (eg KEYMAP_MODE_NONE)
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KeymapFlags:LongWord;
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Keymap flags (eg KEYMAP_FLAG_ALTGR)
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KeyCount:LongWord;
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Number of keys in keymap (Default: KEYMAP_KEY_COUNT)
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RowCount:LongWord;
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Number of index rows in keymap (Default: KEYMAP_ROW_COUNT)
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KeymapName:array[0..KEYMAP_NAME_LENGTH - 1] of Char;
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Keymap name
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KeymapDescription:array[0..KEYMAP_DESC_LENGTH - 1] of Char;
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Keymap description
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Keymap enumeration callback
TKeymapEnumerate = function(Handle:TKeymapHandle; Data:Pointer):LongWord;
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Keymap entry
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PKeymapEntry = ^TKeymapEntry;
TKeymapEntry = record
| Keymap Properties
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Signature:LongWord;
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Signature for entry validation
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KeymapMode:LongWord;
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Keymap mode (eg KEYMAP_MODE_NONE)
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KeymapFlags:LongWord;
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Keymap flags (eg KEYMAP_FLAG_ALTGR)
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KeymapName:array[0..KEYMAP_NAME_LENGTH - 1] of Char;
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Keymap name
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KeymapDescription:array[0..KEYMAP_DESC_LENGTH - 1] of Char;
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Keymap description
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| Driver Properties
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KeyData:Pointer;
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Keymap key data
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KeyCount:LongWord;
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Number of keys in key data (Default: KEYMAP_KEY_COUNT)
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RowCount:LongWord;
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Number of index rows in key data (Default: KEYMAP_ROW_COUNT)
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CapskeysData:PKeymapCapskeys;
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Keymap Capskeys data (Keys affected by Caps Lock)
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DeadkeysData:PKeymapDeadkeys;
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Keymap Deadkeys data (Keys which behave as Dead keys)
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| Internal Properties
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Prev:PKeymapEntry;
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Previous entry in Keymap table
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Next:PKeymapEntry;
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Next entry in Keymap table
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Public variables
None defined
Function declarations
Initialization functions
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procedure KeymapInit;
Description: Initialize the keymap unit, keymap table and default keymap
| Note
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Called only during system startup
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Keymap functions
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function KeymapLoad(Header:PKeymapHeader; Data:PKeymapData; Size:LongWord):TKeymapHandle;
Description: Load a Keymap from a keymap data block and add to the Keymap table
| Header
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Pointer to the keymap header
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| Data
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Pointer to the keymap data
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| Size
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Size of the keymap data
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| Return
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Handle of the newly loaded keymap or INVALID_HANDLE_VALUE on failure
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function KeymapLoadEx(Header:PKeymapHeader; Data:PKeymapData; Capskeys:PKeymapCapskeys; Deadkeys:PKeymapDeadkeys; Size:LongWord; Properties:PKeymapProperties):TKeymapHandle;
Description: Load a Keymap from a keymap data block and add to the Keymap table
| Header
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Pointer to the keymap header (See TKeymapHeader)
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| Data
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Pointer to the keymap data (See TKeymapData)
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| Capskeys
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Pointer to the capskeys table (Optional)
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| Deadkeys
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Pointer to the deadkeys table (Optional)
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| Size
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Size of the keymap data
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| Properties
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Pointer to a keymap properties record to use instead of the header (Optional)
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| Return
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Handle of the newly loaded keymap or INVALID_HANDLE_VALUE on failure
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function KeymapUnload(Handle:TKeymapHandle):LongWord;
Description: Unload an existing keymap and remove from the Keymap table
| Handle
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The handle of the keymap to unload
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| Return
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ERROR_SUCCESS if completed or another error code on failure
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function KeymapGetName(Handle:TKeymapHandle):String;
Description: Get the name of the specified keymap
| Handle
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The handle of the keymap to get the name for
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| Return
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The name of the keymap (eg US)
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function KeymapGetDescription(Handle:TKeymapHandle):String;
Description: Get the description of the specified keymap
| Handle
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The handle of the keymap to get the description for
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| Return
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The description of the keymap (eg US English)
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function KeymapCheckFlag(Handle:TKeymapHandle; Flag:LongWord):Boolean;
Description: Check if a specified keymap has a particular flag set or not
| Handle
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The handle of the keymap to check the flag for
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| Flag
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The flag value to check (eg KEYMAP_FLAG_CAPS_ASCII)
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| Return
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True if the flag is set and False if not set
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function KeymapGetKeyCode(Handle:TKeymapHandle; ScanCode:Word; Index:Byte):Word;
Description: Resolve a scan code and index value to a key code using the specified keymap
| Handle
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The handle of the keymap to use for translation
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| ScanCode
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The keyboard scan code value to resolve (eg SCAN_CODE_A)
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| Index
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The keymap index to use for the translation (eg KEYMAP_INDEX_SHIFT)
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| Return
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The translated key code value (eg KEY_CODE_A) or KEY_CODE_NONE on failure
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function KeymapGetCharCode(Handle:TKeymapHandle; KeyCode:Word):Char;
Description: Resolve a key code value to an ANSI character code using the specified keymap
| Handle
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The handle of the keymap to use for translation
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| KeyCode
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The key code value to resolve (eg KEY_CODE_A)
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| Return
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The ANSI character value for the keycode or 0 on failure
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function KeymapGetCharUnicode(Handle:TKeymapHandle; KeyCode:Word):WideChar;
Description: Resolve a key code value to a Unicode character code using the specified keymap
| Handle
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The handle of the keymap to use for translation
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| KeyCode
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The key code value to resolve (eg KEY_CODE_A)
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| Return
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The Unicode character value for the keycode or 0 on failure
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[Expand]
function KeymapCheckCapskey(Handle:TKeymapHandle; ScanCode:Word):Boolean;
Description: Check if a scan code is affected by the Caps Lock key in the specified keymap
| Handle
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The handle of the keymap to check
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| ScanCode
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The scan code value to check (eg SCAN_CODE_A)
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| Return
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True if affected by Caps Lock, False if not
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[Expand]
function KeymapCheckDeadkey(Handle:TKeymapHandle; ScanCode:Word; Index:Byte):Boolean;
Description: Check if a scan code represents a Dead Key in the specified keymap
| Handle
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The handle of the keymap to check
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| ScanCode
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The scan code value to check (eg SCAN_CODE_A)
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| Index
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The keymap index to check (eg KEYMAP_INDEX_SHIFT)
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| Return
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True if the scan key is a Dead Key, False if not
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function KeymapResolveDeadkey(Handle:TKeymapHandle; DeadCode,ScanCode:Word; DeadIndex,ScanIndex:Byte; var KeyCode:Word):Boolean;
Description: Resolve a Dead Key and the next scan code to a key code value
| Handle
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The handle of the keymap to use for resolution
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| DeadCode
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The scan code value of the dead key (eg SCAN_CODE_GRAVE)
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| ScanCode
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The scan code value of the next key (eg (SCAN_CODE_A)
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| DeadIndex
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The keymap index of the dead key (eg KEYMAP_INDEX_SHIFT)
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| ScanIndex
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The keymap index of the next key (eg KEYMAP_INDEX_SHIFT)
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| KeyCode
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Return value for the key code represented by the dead key/next key combination (or KEY_CODE_NONE)
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| Return
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True if the dead key/next key combination resolves to a key code or False if not
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function KeymapGetProperties(Handle:TKeymapHandle; Properties:PKeymapProperties):LongWord;
Description: Get the properties of the specified keymap
| Handle
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The handle of the keymap to get the properties for
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| Properties
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Pointer to a keymap properties structure to return the properties
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| Return
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ERROR_SUCCESS if completed or another error code on failure
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function KeymapFindByName(const Name:String):TKeymapHandle;
Description: Find a keymap by name
| Name
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The name of the keymap to find (eg US)
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| Return
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The handle of the matching keymap or INVALID_HANDLE_VALUE if not found
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function KeymapFindByDescription(const Description:String):TKeymapHandle;
Description: Find a keymap by description
| Description
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The description of the keymap to find (eg US English)
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| Return
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The handle of the matching keymap or INVALID_HANDLE_VALUE if not found
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function KeymapEnumerate(Callback:TKeymapEnumerate; Data:Pointer):LongWord;
Description: Enumerate all loaded keymaps
| Callback
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The function to call for each loaded keymap
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| Data
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A private data pointer to pass to callback for each loaded keymap
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Keymap helper functions
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function KeymapGetCount:LongWord;
Description: Get the current keymap count
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function KeymapGetDefault:TKeymapHandle;
Description: Get the current default keymap
[Expand]
function KeymapSetDefault(Handle:TKeymapHandle):LongWord;
Description: Set the current default keymap
[Expand]
function KeymapCheck(Keymap:PKeymapEntry):PKeymapEntry;
Description: Check if the supplied Keymap is in the Keymap table
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