'\" t .\" Title: xsetdevicefocus .\" Author: [FIXME: author] [see http://docbook.sf.net/el/author] .\" Generator: DocBook XSL Stylesheets v1.79.1 .\" Date: 09/15/2021 .\" Manual: \ \& .\" Source: \ \& .\" Language: English .\" .TH "XSETDEVICEFOCUS" "libmansuffix" "09/15/2021" "\ \&" "\ \&" .\" ----------------------------------------------------------------- .\" * Define some portability stuff .\" ----------------------------------------------------------------- .\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .\" http://bugs.debian.org/507673 .\" http://lists.gnu.org/archive/html/groff/2009-02/msg00013.html .\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .ie \n(.g .ds Aq \(aq .el .ds Aq ' .\" ----------------------------------------------------------------- .\" * set default formatting .\" ----------------------------------------------------------------- .\" disable hyphenation .nh .\" disable justification (adjust text to left margin only) .ad l .\" ----------------------------------------------------------------- .\" * MAIN CONTENT STARTS HERE * .\" ----------------------------------------------------------------- .SH "NAME" XSetDeviceFocus, XGetDeviceFocus \- control extension input device focus .SH "SYNOPSIS" .sp .nf #include .fi .sp .nf XSetDeviceFocus( Display *display, XDevice *device, Window focus, int revert_to, Time time); .fi .sp .nf XGetDeviceFocus( Display *display, XDevice *device, Window *focus_return, int *revert_to_return, int * time_return); .fi .sp Arguments .sp .nf display Specifies the connection to the X server\&. .fi .sp .nf device Specifies the device whose focus is to be queried or changed\&. .fi .sp .nf focus Specifies the window, PointerRoot, FollowKeyboard, or None\&. .fi .sp .nf focus_return Returns the focus window, PointerRoot, FollowKeyboard, or None\&. .fi .sp .nf revert_to Specifies where the input focus reverts to if the window becomes not viewable\&. You can pass RevertToParent, RevertToPointerRoot, RevertToFollowKeyboard, or RevertToNone\&. .fi .sp .nf revert_to_return Returns the current focus state RevertToParent, RevertToPointerRoot, RevertToFollowKeyboard, or RevertToNone\&. .fi .sp .nf time_return Returns the last_focus_time for the device\&. .fi .sp .nf time Specifies the time\&. You can pass either a timestamp or CurrentTime\&. .fi .SH "DESCRIPTION" .sp .if n \{\ .RS 4 .\} .nf The XSetDeviceFocus request changes the focus of the specified device and its last\-focus\-change time\&. It has no effect if the specified time is earlier than the current last\-focus\-change time or is later than the current X server time\&. Otherwise, the last\-focus\-change time is set to the specified time CurrentTime is replaced by the current X server time)\&. XSetDeviceFocus causes the X server to generate DeviceFocusIn and DeviceFocusOut events\&. .fi .if n \{\ .RE .\} .sp .if n \{\ .RS 4 .\} .nf Depending on the focus argument, the following occurs: * If focus is None , all device events are discarded until a new focus window is set, and the revert_to argument is ignored\&. * If focus is a window, it becomes the device\*(Aqs focus window\&. If a generated device event would normally be reported to this window or one of its inferiors, the event is reported as usual\&. Otherwise, the event is reported relative to the focus window\&. * If focus is PointerRoot, the focus window is dynamically taken to be the root window of whatever screen the pointer is on at each event from the specified device\&. In this case, the revert_to argument is ignored\&. * If focus is FollowKeyboard, the focus window is dynamically taken to be the window to which the X keyboard focus is set at each input event\&. .fi .if n \{\ .RE .\} .sp .if n \{\ .RS 4 .\} .nf The specified focus window must be viewable at the time XSetDeviceFocus is called, or a BadMatch error results\&. If the focus window later becomes not viewable, the X server evaluates the revert_to argument to determine the new focus window as follows: * If revert_to is RevertToParent, the focus reverts to the parent (or the closest viewable ancestor), and the new revert_to value is taken to be RevertToNone\&. * If revert_to is RevertToPointerRoot, RevertToFollowKeyboard, or RevertToNone, the focus reverts to PointerRoot, FollowKeyboard, or None, respectively\&. .fi .if n \{\ .RE .\} .sp .if n \{\ .RS 4 .\} .nf When the focus reverts, the X server generates DeviceFocusIn and DeviceFocusOut events, but the last\-focus\-change time is not affected\&. .fi .if n \{\ .RE .\} .sp .if n \{\ .RS 4 .\} .nf Input extension devices are not required to support the ability to be focused\&. Attempting to set the focus of a device that does not support this request will result in a BadMatch error\&. Whether or not given device can support this request can be determined by the information returned by XOpenDevice\&. For those devices that support focus, XOpenDevice will return an XInputClassInfo structure with the input_class field equal to the constant FocusClass (defined in the file XI\&.h)\&. .fi .if n \{\ .RE .\} .sp .if n \{\ .RS 4 .\} .nf XSetDeviceFocus can generate BadDevice, BadMatch, BadValue, and BadWindow errors\&. .fi .if n \{\ .RE .\} .sp .if n \{\ .RS 4 .\} .nf The XGetDeviceFocus request returns the focus window and the current focus state\&. .fi .if n \{\ .RE .\} .sp .if n \{\ .RS 4 .\} .nf Not all input extension devices can be focused\&. Attempting to query the focus state of a device that can\*(Aqt be focused results in a BadMatch error\&. A device that can be focused returns information for input Class Focus when an XOpenDevice request is made\&. .fi .if n \{\ .RE .\} .sp .if n \{\ .RS 4 .\} .nf XGetDeviceFocus can generate BadDevice, and BadMatch errors\&. .fi .if n \{\ .RE .\} .SH "DIAGNOSTICS" .sp .if n \{\ .RS 4 .\} .nf BadDevice An invalid device was specified\&. The specified device does not exist or has not been opened by this client via XOpenInputDevice\&. This error may also occur if the specified device is the X keyboard or X pointer device\&. .fi .if n \{\ .RE .\} .sp .if n \{\ .RS 4 .\} .nf 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\*(Aqs type is accepted\&. Any argument defined as a set of alternatives can generate this error\&. .fi .if n \{\ .RE .\} .sp .if n \{\ .RS 4 .\} .nf BadWindow A value for a Window argument does not name a defined Window\&. .fi .if n \{\ .RE .\} .sp .if n \{\ .RS 4 .\} .nf BadMatch This error may occur if an XGetDeviceFocus or XSetDeviceFocus request was made specifying a device that the server implementation does not allow to be focused\&. .fi .if n \{\ .RE .\}