1XSETDEVICEFOCUS(libmansuffix)
2=============================
3
4NAME
5----
6
7   XSetDeviceFocus, XGetDeviceFocus - control extension input
8   device focus
9
10SYNOPSIS
11--------
12
13   #include <X11/extensions/XInput.h>
14
15   XSetDeviceFocus( Display *display,
16                    XDevice *device,
17                    Window focus,
18                    int revert_to,
19                    Time time);
20   
21   XGetDeviceFocus( Display *display,
22                    XDevice *device,
23                    Window *focus_return,
24                    int *revert_to_return,
25                    int * time_return);
26
27Arguments
28
29   display
30          Specifies the connection to the X server.
31
32   device
33          Specifies the device whose focus is to be queried or
34          changed.
35
36   focus
37          Specifies the window, PointerRoot, FollowKeyboard, or
38          None.
39
40   focus_return
41          Returns the focus window, PointerRoot, FollowKeyboard, or
42          None.
43
44   revert_to
45          Specifies where the input focus reverts to if the window
46          becomes not viewable. You can pass RevertToParent,
47          RevertToPointerRoot, RevertToFollowKeyboard, or
48          RevertToNone.
49
50   revert_to_return
51          Returns the current focus state RevertToParent,
52          RevertToPointerRoot, RevertToFollowKeyboard, or
53          RevertToNone.
54
55   time_return
56          Returns the last_focus_time for the device.
57
58   time
59          Specifies the time. You can pass either a timestamp or
60          CurrentTime.
61
62DESCRIPTION
63-----------
64
65   The XSetDeviceFocus request changes the focus of the specified
66   device and its last-focus-change time. It has no effect if the
67   specified time is earlier than the current last-focus-change
68   time or is later than the current X server time. Otherwise, the
69   last-focus-change time is set to the specified time CurrentTime
70   is replaced by the current X server time). XSetDeviceFocus
71   causes the X server to generate DeviceFocusIn and
72   DeviceFocusOut events.
73
74   Depending on the focus argument, the following occurs:
75     * If focus is None , all device events are discarded until a
76       new focus window is set, and the revert_to argument is
77       ignored.
78     * If focus is a window, it becomes the device's focus window.
79       If a generated device event would normally be reported to
80       this window or one of its inferiors, the event is reported
81       as usual. Otherwise, the event is reported relative to the
82       focus window.
83     * If focus is PointerRoot, the focus window is dynamically
84       taken to be the root window of whatever screen the pointer
85       is on at each event from the specified device. In this
86       case, the revert_to argument is ignored.
87     * If focus is FollowKeyboard, the focus window is dynamically
88       taken to be the window to which the X keyboard focus is set
89       at each input event.
90
91   The specified focus window must be viewable at the time
92   XSetDeviceFocus is called, or a BadMatch error results. If the
93   focus window later becomes not viewable, the X server evaluates
94   the revert_to argument to determine the new focus window as
95   follows:
96     * If revert_to is RevertToParent, the focus reverts to the
97       parent (or the closest viewable ancestor), and the new
98       revert_to value is taken to be RevertToNone.
99     * If revert_to is RevertToPointerRoot,
100       RevertToFollowKeyboard, or RevertToNone, the focus reverts
101       to PointerRoot, FollowKeyboard, or None, respectively.
102
103   When the focus reverts, the X server generates DeviceFocusIn
104   and DeviceFocusOut events, but the last-focus-change time is
105   not affected.
106
107   Input extension devices are not required to support the ability
108   to be focused. Attempting to set the focus of a device that
109   does not support this request will result in a BadMatch error.
110   Whether or not given device can support this request can be
111   determined by the information returned by XOpenDevice. For
112   those devices that support focus, XOpenDevice will return an
113   XInputClassInfo structure with the input_class field equal to
114   the constant FocusClass (defined in the file XI.h).
115
116   XSetDeviceFocus can generate BadDevice, BadMatch, BadValue, and
117   BadWindow errors.
118
119   The XGetDeviceFocus request returns the focus window and the
120   current focus state.
121
122   Not all input extension devices can be focused. Attempting to
123   query the focus state of a device that can't be focused results
124   in a BadMatch error. A device that can be focused returns
125   information for input Class Focus when an XOpenDevice request
126   is made.
127
128   XGetDeviceFocus can generate BadDevice, and BadMatch errors.
129
130DIAGNOSTICS
131-----------
132
133   BadDevice
134          An invalid device was specified. The specified device
135          does not exist or has not been opened by this client via
136          XOpenInputDevice. This error may also occur if the
137          specified device is the X keyboard or X pointer device.
138
139   BadValue
140          Some numeric value falls outside the range of values
141          accepted by the request. Unless a specific range is
142          specified for an argument, the full range defined by the
143          argument's type is accepted. Any argument defined as a
144          set of alternatives can generate this error.
145
146   BadWindow
147          A value for a Window argument does not name a defined
148          Window.
149
150   BadMatch
151          This error may occur if an XGetDeviceFocus or
152          XSetDeviceFocus request was made specifying a device
153          that the server implementation does not allow to be
154          focused.
155