XkbGetMap − Allocate an XkbDescRec structure and populate it with the server’s keyboard client map and server map
(Display *display, unsigned int which, unsigned
connection to X server
mask selecting subcomponents to populate
device_id, or XkbUseCoreKbd
Xkb provides two functions to obtain the keyboard mapping components from the server. The first function, XkbGetMap, allocates an XkbDescRec structure, retrieves mapping components from the server, and stores them in the XkbDescRec structure it just allocated. The second function, XkbGetUpdatedMap, retrieves mapping components from the server and stores them in an XkbDescRec structure that has previously been allocated.
To allocate an XkbDescRec structure and populate it with the server’s keyboard client map and server map, use XkbGetMap. XkbGetMap is similar to XkbGetKeyboard, but is used only for obtaining the address of an XkbDescRec structure that is populated with keyboard mapping components. It allows finer control over which substructures of the keyboard mapping components are to be populated. XkbGetKeyboard always returns fully populated components, while XkbGetMap can be instructed to return a partially populated component.
The which mask is a bitwise inclusive OR of the masks defined in Table 14.1. Only those portions of the keyboard server map and the keyboard client maps that are specified in which are allocated and populated.
In addition to allocating and obtaining the server map and the client map, XkbGetMap also sets the device_spec, the min_key_code, and max_key_code fields of the keyboard description.
XkbGetMap is synchronous; it queries the server for the desired information, waits for a reply, and then returns. If successful, XkbGetMap returns a pointer to the XkbDescRec structure it allocated. If unsuccessful, XkbGetMap returns NULL. When unsuccessful, one of the following protocol errors is also generated: BadAlloc (unable to allocate the XkbDescRec structure), BadValue (some mask bits in which are undefined), or BadImplementation (a compatible version of the Xkb extension is not available in the server). To free the returned data, use XkbFreeClientMap.
Xkb also provides convenience functions to get partial component definitions from the server. These functions are specified in the "convenience functions" column in Table 1. Refer to the sections listed in the table for more information on these functions.
Xkb defines combinations of these masks for convenience:
#define XkbAllClientInfoMask (XkbKeyTypesMask | XkbKeySymsMask |
#define XkbAllServerInfoMask (XkbExplicitComponentsMask |
#define XkbAllMapComponentsMask XkbAllClientInfoMask |
Key types, symbol maps, and actions are all interrelated: changes in one require changes in the others. The convenience functions make it easier to edit these components and handle the interdependencies.
The complete description of an Xkb keyboard is given by an XkbDescRec. The component structures in the XkbDescRec represent the major Xkb components.
struct _XDisplay * display; /∗ connection to X server */
unsigned short flags; /∗ private to Xkb, do not modify */
unsigned short device_spec; /∗ device of interest */
KeyCode min_key_code; /∗ minimum keycode for device */
KeyCode max_key_code; /∗ maximum keycode for device */
XkbControlsPtr ctrls; /∗ controls */
XkbServerMapPtr server; /∗ server keymap */
XkbClientMapPtr map; /∗ client keymap */
XkbIndicatorPtr indicators; /∗ indicator map */
XkbNamesPtr names; /∗ names for all components */
XkbCompatMapPtr compat; /∗ compatibility map */
XkbGeometryPtr geom; /∗ physical geometry of keyboard */
} XkbDescRec, *XkbDescPtr;
The display field points to an X display structure. The flags field is private to the library: modifying flags may yield unpredictable results. The device_spec field specifies the device identifier of the keyboard input device, or XkbUseCoreKeyboard, which specifies the core keyboard device. The min_key_code and max_key_code fields specify the least and greatest keycode that can be returned by the keyboard.
Each structure component has a corresponding mask bit that is used in function calls to indicate that the structure should be manipulated in some manner, such as allocating it or freeing it. These masks and their relationships to the fields in the XkbDescRec are shown in Table 2.
XkbChangeTypesOfKey(3), XkbCopyKeyType(3), XkbCopyKeyTypes(3), XkbFreeClientMap(3), XkbGetKeyActions(3), XkbGetKeyBehaviors(3), XkbGetKeyboard(3), XkbGetKeyExplicitComponents(3), XkbGetKeyModifierMap(3), XkbGetKeySyms(3), XkbGetKeyTypes(3), XkbGetUpdatedMap(3), XkbGetVirtualModMap(3), XkbGetVirtualMods(3), XkbResizeKeyActions(3), XkbResizeKeySyms(3), XkbResizeKeyType(3)
Personal Opportunity - Free software gives you access to billions of dollars of software at no cost. Use this software for your business, personal use or to develop a profitable skill. Access to source code provides access to a level of capabilities/information that companies protect though copyrights. Open source is a core component of the Internet and it is available to you. Leverage the billions of dollars in resources and capabilities to build a career, establish a business or change the world. The potential is endless for those who understand the opportunity.
Business Opportunity - Goldman Sachs, IBM and countless large corporations are leveraging open source to reduce costs, develop products and increase their bottom lines. Learn what these companies know about open source and how open source can give you the advantage.
Free Software provides computer programs and capabilities at no cost but more importantly, it provides the freedom to run, edit, contribute to, and share the software. The importance of free software is a matter of access, not price. Software at no cost is a benefit but ownership rights to the software and source code is far more significant.
Free Office Software - The Libre Office suite provides top desktop productivity tools for free. This includes, a word processor, spreadsheet, presentation engine, drawing and flowcharting, database and math applications. Libre Office is available for Linux or Windows.
The Free Books Library is a collection of thousands of the most popular public domain books in an online readable format. The collection includes great classical literature and more recent works where the U.S. copyright has expired. These books are yours to read and use without restrictions.
Source Code - Want to change a program or know how it works? Open Source provides the source code for its programs so that anyone can use, modify or learn how to write those programs themselves. Visit the GNU source code repositories to download the source.
Study at Harvard, Stanford or MIT - Open edX provides free online courses from Harvard, MIT, Columbia, UC Berkeley and other top Universities. Hundreds of courses for almost all major subjects and course levels. Open edx also offers some paid courses and selected certifications.
Linux Manual Pages - A man or manual page is a form of software documentation found on Linux/Unix operating systems. Topics covered include computer programs (including library and system calls), formal standards and conventions, and even abstract concepts.