XSetInputFocus 3X11 __xorgversion__ XLIB FUNCTIONS XSetInputFocus XGetInputFocus control input focus int XSetInputFocus ( Display *display , Window focus , int revert_to , Time time ); int XGetInputFocus ( Display *display , Window *focus_return , int *revert_to_return ); display Specifies the connection to the X server. focus Specifies the window,  PointerRoot , or  None . focus_return Returns the focus window,  PointerRoot , or  None . revert_to Specifies where the input focus reverts to if the window becomes not viewable. You can pass  RevertToParent ,  RevertToPointerRoot , or  RevertToNone . revert_to_return Returns the current focus state ( RevertToParent ,  RevertToPointerRoot , or  RevertToNone ). time Specifies the time. You can pass either a timestamp or  CurrentTime . The  XSetInputFocus  function changes the input focus and the 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).  XSetInputFocus  causes the X server to generate  FocusIn  and  FocusOut  events. Depending on the focus argument, the following occurs: If focus is  None , all keyboard 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 keyboard's focus window. If a generated keyboard 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 keyboard event. In this case, the revert_to argument is ignored. The specified focus window must be viewable at the time  XSetInputFocus  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  or  RevertToNone , the focus reverts to  PointerRoot  or  None , respectively. When the focus reverts, the X server generates  FocusIn  and  FocusOut  events, but the last-focus-change time is not affected.  XSetInputFocus  can generate  BadMatch ,  BadValue , and  BadWindow  errors. The  XGetInputFocus  function returns the focus window and the current focus state.  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. XWarpPointer(3X11) Xlib - C Language X Interface