Linux Manual Pages

Free Software * Books

Source Code

Free Media

Linux

XGrabKey

NAME
SYNTAX
ARGUMENTS
DESCRIPTION
DIAGNOSTICS
SEE ALSO

NAME

XGrabKey, XUngrabKey − grab keyboard keys

SYNTAX

	int XGrabKey(Display *display, int keycode, unsigned int modifiers, Window grab_window, Bool owner_events, int pointer_mode, int keyboard_mode);
	int XUngrabKey(Display *display, int keycode, unsigned int modifiers, Window grab_window);

ARGUMENTS


	display		Specifies the connection to the X server.

grab_window

Specifies the grab window.

keyboard_mode

Specifies further processing of keyboard events. You can pass GrabModeSync or GrabModeAsync.

	keycode		Specifies the KeyCode or AnyKey.
	modifiers		Specifies the set of keymasks or AnyModifier. The mask is the bitwise inclusive OR of the valid keymask bits.

owner_events

Specifies a Boolean value that indicates whether the keyboard events are to be reported as usual.

pointer_mode

Specifies further processing of pointer events. You can pass GrabModeSync or GrabModeAsync.

DESCRIPTION

The XGrabKey function establishes a passive grab on the keyboard. In the future, the keyboard is actively grabbed (as for XGrabKeyboard), the last-keyboard-grab time is set to the time at which the key was pressed (as transmitted in the KeyPress event), and the KeyPress event is reported if all of the following conditions are true:

	•		The keyboard is not grabbed and the specified key (which can itself be a modifier key) is logically pressed when the specified modifier keys are logically down, and no other modifier keys are logically down.
	•		Either the grab_window is an ancestor of (or is) the focus window, or the grab_window is a descendant of the focus window and contains the pointer.
	•		A passive grab on the same key combination does not exist on any ancestor of grab_window.

The interpretation of the remaining arguments is as for XGrabKeyboard. The active grab is terminated automatically when the logical state of the keyboard has the specified key released (independent of the logical state of the modifier keys), at which point a KeyRelease event is reported to the grabbing window.

Note that the logical state of a device (as seen by client applications) may lag the physical state if device event processing is frozen.

A modifiers argument of AnyModifier is equivalent to issuing the request for all possible modifier combinations (including the combination of no modifiers). It is not required that all modifiers specified have currently assigned KeyCodes. A keycode argument of AnyKey is equivalent to issuing the request for all possible KeyCodes. Otherwise, the specified keycode must be in the range specified by min_keycode and max_keycode in the connection setup, or a BadValue error results.

If some other client has issued a XGrabKey with the same key combination on the same window, a BadAccess error results. When using AnyModifier or AnyKey, the request fails completely, and a BadAccess error results (no grabs are established) if there is a conflicting grab for any combination.

XGrabKey can generate BadAccess, BadValue, and BadWindow errors.

The XUngrabKey function releases the key combination on the specified window if it was grabbed by this client. It has no effect on an active grab. A modifiers of AnyModifier is equivalent to issuing the request for all possible modifier combinations (including the combination of no modifiers). A keycode argument of AnyKey is equivalent to issuing the request for all possible key codes.

XUngrabKey can generate BadValue and BadWindow error.

DIAGNOSTICS

	BadAccess		A client attempted to grab a key/button combination already grabbed by another client.
	BadValue		Some numeric value falls outside the range of values accepted by the request. Unless a specific range is specified for an argument, the full range defined by the argument’s type is accepted. Any argument defined as a set of alternatives can generate this error.
	BadWindow		A value for a Window argument does not name a defined Window.

Opportunity

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

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.

Free Books

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.

Education

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.