brlapi_parameterManagement - Parameter management

Generated automatically by Doxygen for BrlAPI from the source code. BrlAPI Version 0.8 brlapi_parameterManagement(3)

There are several kinds of parameters: • states associated with the braille device itself, such as its size or parameters of the device port • states of the BrlAPI connection itself, such as the displaying level or key passing preferences. • general states such as the cut buffer, • braille parameters: braille table, contraction, cursor shape, etc, • browse parameters: line skip, beep, etc. Some of them are subdivided in subparameters. Others have only subparameter 0. Some of them are read-only, others are read/write. A client can either request the immediate content of a parameter by using brlapi_getParameter(); set the content of a parameter by using brlapi_setParameter(); or register a callback that may be called immediately and on each change of a given parameter, by using brlapi_watchParameter().

enumbrlapi_param_tEnumeratorBRLAPI_PARAM_SERVER_VERSION Version of the server: uint32_t BRLAPI_PARAM_CLIENT_PRIORITY Priority of the client: uint32_t (from 0 through 100, default is 50) BRLAPI_PARAM_DRIVER_NAME Full name of the driver: string BRLAPI_PARAM_DRIVER_CODE Code (short name) of the driver: string BRLAPI_PARAM_DRIVER_VERSION Version of the driver: string BRLAPI_PARAM_DEVICE_MODEL Model of the device: string BRLAPI_PARAM_DEVICE_CELL_SIZE Number of dots in a cell: uint8_t BRLAPI_PARAM_DISPLAY_SIZE Dimensions of the braille display: { uint32_t columns; uint32_t rows; } BRLAPI_PARAM_DEVICE_IDENTIFIER Identifier of the device: string BRLAPI_PARAM_DEVICE_SPEED Speed of the device: uint32_t BRLAPI_PARAM_DEVICE_ONLINE Device is online: boolean BRLAPI_PARAM_RETAIN_DOTS Pass dot combinations (rather than characters): boolean BRLAPI_PARAM_COMPUTER_BRAILLE_CELL_SIZE Number of dots used to render a computer braille character: uint8_t (8 or 6) BRLAPI_PARAM_LITERARY_BRAILLE Whether braille is literary (rather than computer): boolean BRLAPI_PARAM_CURSOR_DOTS Representation of the cursor: uint8_t (ISO 11548-1) BRLAPI_PARAM_CURSOR_BLINK_PERIOD Blinking period of the cursor: uint32_t (milliseconds) BRLAPI_PARAM_CURSOR_BLINK_PERCENTAGE Portion of the blinking period that the cursor is visible: uint8_t (from 0 through 100) BRLAPI_PARAM_RENDERED_CELLS Cells rendered by the client: uint8_t[] (ISO 11548-1), one cell per element BRLAPI_PARAM_SKIP_IDENTICAL_LINES Whether to skip identical screen lines: boolean BRLAPI_PARAM_AUDIBLE_ALERTS Whether to use audible alerts: boolean BRLAPI_PARAM_CLIPBOARD_CONTENT Content of the clipboard: UTF-8 string BRLAPI_PARAM_BOUND_COMMAND_KEYCODES Commands bound by the driver: uint64_t[], one command keycode per element BRLAPI_PARAM_COMMAND_KEYCODE_NAME Name for a command keycode (specified via the subparam argument): string (usually a few characters) BRLAPI_PARAM_COMMAND_KEYCODE_SUMMARY Description for a command keycode (specified via the subparam argument): string (usually a few words) BRLAPI_PARAM_DEFINED_DRIVER_KEYCODES Keycodes defined by the driver: uint64_t[], one keycode per element BRLAPI_PARAM_DRIVER_KEYCODE_NAME Name for a driver keycode (specified via the subparam argument): string (usually a few characters) BRLAPI_PARAM_DRIVER_KEYCODE_SUMMARY Description for a driver keycode (specified via the subparam argument): string (usually a few words) BRLAPI_PARAM_COMPUTER_BRAILLE_ROWS_MASK Set of Unicode rows that are defined for computer braille (from U+0000 through U+10FFFF): uint8_t[544], one bit per row, eight rows per element BRLAPI_PARAM_COMPUTER_BRAILLE_ROW_CELLS Computer braille cells for a Unicode row (specified via the subparam argument): uint8_t[256] (ISO 11548-1), one cell per element BRLAPI_PARAM_COMPUTER_BRAILLE_TABLE Name of the computer braille table: string BRLAPI_PARAM_LITERARY_BRAILLE_TABLE Name of the literary braille table: string BRLAPI_PARAM_MESSAGE_LOCALE Locale to use for messages: string BRLAPI_PARAM_DRIVER_PROPERTY_VALUE Value of a driver-specific property: uint32_t BRLAPI_PARAM_COUNT

ssize_tBRLAPI_STDCALLbrlapi__getParameter(brlapi_handle_t*handle,brlapi_param_tparameter,brlapi_param_subparam_tsubparam,brlapi_param_flags_tflags,void*data,size_tlen)void*BRLAPI_STDCALLbrlapi__getParameterAlloc(brlapi_handle_t*handle,brlapi_param_tparameter,brlapi_param_subparam_tsubparam,brlapi_param_flags_tflags,size_t*len)intBRLAPI_STDCALLbrlapi__setParameter(brlapi_handle_t*handle,brlapi_param_tparameter,brlapi_param_subparam_tsubparam,brlapi_param_flags_tflags,constvoid*data,size_tlen)intBRLAPI_STDCALLbrlapi__unwatchParameter(brlapi_handle_t*handle,brlapi_paramCallbackDescriptor_tdescriptor)brlapi_paramCallbackDescriptor_tBRLAPI_STDCALLbrlapi__watchParameter(brlapi_handle_t*handle,brlapi_param_tparameter,brlapi_param_subparam_tsubparam,brlapi_param_flags_tflags,brlapi_paramCallback_tfunc,void*priv,void*data,size_tlen)ssize_tBRLAPI_STDCALLbrlapi_getParameter(brlapi_param_tparameter,brlapi_param_subparam_tsubparam,brlapi_param_flags_tflags,void*data,size_tlen) Get the content of a parameter brlapi_getParameter gets the current content of a parameter Parametersparameter is the parameter whose content shall be gotten; subparam is a specific instance of the parameter; flags specify which value and how it should be returned; data is a buffer where content of the parameter shall be stored; len is the size of the buffer. Returns the real size of the parameter's content. If the parameter does not fit in the provided buffer, it is truncated to len bytes (but the real size of the parameter is still returned). In that case, the client must call brlapi_getParameter again with a big enough buffer. void*BRLAPI_STDCALLbrlapi_getParameterAlloc(brlapi_param_tparameter,brlapi_param_subparam_tsubparam,brlapi_param_flags_tflags,size_t*len) Return the content of a parameter brlapi_getParameterAlloc gets the current content of a parameter, by returning it as a newly-allocated buffer. The buffer is allocated to one byte more than the parameter value. This byte is set to zero. This allows, for string parameters, to be able to immediately use it as a C string. Parametersparameter is the parameter whose content shall be gotten; subparam is a specific instance of the parameter; flags specify which value and how it should be returned; len is the address where to store the size of the parameter value. Returns a newly-allocated buffer that contains the value of the parameter. The caller must call free() on it after use. NULL is returned on errors intBRLAPI_STDCALLbrlapi_setParameter(brlapi_param_tparameter,brlapi_param_subparam_tsubparam,brlapi_param_flags_tflags,constvoid*data,size_tlen) Set the content of a parameter brlapi_setParameter sets the content of a parameter Parametersparameter is the parameter to set; subparam is a specific instance of the parameter; flags specify which value and how it should be set; data is a buffer containing the data to store in the parameter; len is the size of the data. Returns 0 on success, -1 on error (read-only parameter for instance). intBRLAPI_STDCALLbrlapi_unwatchParameter(brlapi_paramCallbackDescriptor_tdescriptor) Clear a parameter change callback brlapi_unwatchParameter unregisters a parameter change callback: the callback function previously registered with brlapi_watchParameter will not be called any longer. Parametersdescriptor refers to the callback to be removed. Returns 0 on success, -1 on error. brlapi_paramCallbackDescriptor_tBRLAPI_STDCALLbrlapi_watchParameter(brlapi_param_tparameter,brlapi_param_subparam_tsubparam,brlapi_param_flags_tflags,brlapi_paramCallback_tfunc,void*priv,void*data,size_tlen) Set a parameter change callback brlapi_watchParameter registers a parameter change callback: whenever the given parameter changes, the given function is called. Parametersparameter is the parameter to watch; subparam is a specific instance of the parameter; flags specify which value and how it should be monitored; func is the function to call on parameter change; priv is a void pointer which will be passed as such to the function; data is a buffer where the current content of the parameter shall be stored; len is the size of the buffer. Returns the callback descriptor (to be passed to brlapi_unwatchParameter to unregister the callback), or NULL on error. Note Default parameter callbacks don't do anything, except the ones for display size which just raise SIGWINCH. If data is NULL, the callback will be called immediately by brlapi_watchParameter, for providing the initial value

#defineBRLAPI_PARAMF_GLOBAL0X01 Refer to the global value instead of the value local to the connection #defineBRLAPI_PARAMF_LOCAL0X00 Refer to the value local to the connection instead of the global value #defineBRLAPI_PARAMF_SELF0X02 Specify whether to receive notifications of value self-changes

brlapi_parameterManagement - Parameter management - How to manage BrlAPI parameters.

Macros #define BRLAPI_PARAMF_LOCAL 0X00 #define BRLAPI_PARAMF_GLOBAL 0X01 #define BRLAPI_PARAMF_SELF 0X02 Typedefs typedef uint32_t brlapi_param_flags_t typedef void(* brlapi_paramCallback_t) (brlapi_param_t parameter, brlapi_param_subparam_t subparam, brlapi_param_flags_t flags, void *priv, const void *data, size_t len) typedef void * brlapi_paramCallbackDescriptor_tFunctions ssize_t BRLAPI_STDCALLbrlapi_getParameter (brlapi_param_t parameter, brlapi_param_subparam_t subparam, brlapi_param_flags_t flags, void *data, size_t len) ssize_t BRLAPI_STDCALLbrlapi__getParameter (brlapi_handle_t *handle, brlapi_param_t parameter, brlapi_param_subparam_t subparam, brlapi_param_flags_t flags, void *data, size_t len) void *BRLAPI_STDCALLbrlapi_getParameterAlloc (brlapi_param_t parameter, brlapi_param_subparam_t subparam, brlapi_param_flags_t flags, size_t *len) void *BRLAPI_STDCALLbrlapi__getParameterAlloc (brlapi_handle_t *handle, brlapi_param_t parameter, brlapi_param_subparam_t subparam, brlapi_param_flags_t flags, size_t *len) int BRLAPI_STDCALLbrlapi_setParameter (brlapi_param_t parameter, brlapi_param_subparam_t subparam, brlapi_param_flags_t flags, const void *data, size_t len) int BRLAPI_STDCALLbrlapi__setParameter (brlapi_handle_t *handle, brlapi_param_t parameter, brlapi_param_subparam_t subparam, brlapi_param_flags_t flags, const void *data, size_t len) brlapi_paramCallbackDescriptor_tBRLAPI_STDCALLbrlapi_watchParameter (brlapi_param_t parameter, brlapi_param_subparam_t subparam, brlapi_param_flags_t flags, brlapi_paramCallback_t func, void *priv, void *data, size_t len) brlapi_paramCallbackDescriptor_tBRLAPI_STDCALLbrlapi__watchParameter (brlapi_handle_t *handle, brlapi_param_t parameter, brlapi_param_subparam_t subparam, brlapi_param_flags_t flags, brlapi_paramCallback_t func, void *priv, void *data, size_t len) int BRLAPI_STDCALLbrlapi_unwatchParameter (brlapi_paramCallbackDescriptor_t descriptor) int BRLAPI_STDCALLbrlapi__unwatchParameter (brlapi_handle_t *handle, brlapi_paramCallbackDescriptor_t descriptor)

typedefuint32_tbrlapi_param_flags_t Flags for parameter requests typedefvoid(*brlapi_paramCallback_t)(brlapi_param_tparameter,brlapi_param_subparam_tsubparam,brlapi_param_flags_tflags,void*priv,constvoid*data,size_tlen) Callback for parameter changes When a parameter gets changed, application-defined callbacks set by the brlapi_watchParameter() function are called. Parametersparameter is the parameter that changed; subparam is a specific instance of the parameter; flags specify which value and how it was changed; priv is the void pointer that was passed to the brlapi_watchParameter call which registered the callback; data is a buffer containing the new value of the parameter; len is the size of the data. This callback only gets called when the application calls some brlapi_ function (i.e. BrlAPI gets direct control of the execution). typedefvoid*brlapi_paramCallbackDescriptor_t Type for callback descriptors This is returned by brlapi_watchParameter, to be passed to brlapi_unwatchParameter.