XFocusChangeEvent(3)

📦
version 1.8.14 · 8 versions
, in alpine 3.24, arch rolling, nixos 26.05, nixpkgs unstable

🦋 XFocusChangeEvent(3) — XLIB FUNCTIONS 🦋

okay bestie, welcome to XFocusChangeEvent(3), the manual page from XLIB FUNCTIONS that explains the FocusIn and FocusOut event structure. This is not the whole Xlib saga — it’s the focus-event character arc, and it’s lowkey iconic. Let’s get into it. 💅

💖 NAME 💖

XFocusChangeEvent — FocusIn and FocusOut event structure. periodt.

✨ STRUCTURES ✨

The structure for FocusIn and FocusOut events contains this exact code, no cap:

       typedef struct {
               int type;       /* FocusIn or FocusOut */
               unsigned long serial;   /* # of last request processed by server */
               Bool send_event;        /* true if this came from a SendEvent request */
               Display *display;       /* Display the event was read from */
               Window window;  /* window of event */
               int mode;       /* NotifyNormal, NotifyGrab, NotifyUngrab */
               int detail;
                       /*
                       * NotifyAncestor, NotifyVirtual, NotifyInferior,
                       * NotifyNonlinear,NotifyNonlinearVirtual, NotifyPointer,
                       * NotifyPointerRoot, NotifyDetailNone
                       */
       } XFocusChangeEvent;
       typedef XFocusChangeEvent XFocusInEvent;
       typedef XFocusChangeEvent XFocusOutEvent;

When you receive these events, the structure members are set as follows. Vibe check each one:

  • type — set to the event type constant name that uniquely identifies it. For example, when the X server reports a GraphicsExpose event to a client application, it sends an XGraphicsExposeEvent structure with the type member set to GraphicsExpose.
  • display — set to a pointer to the display the event was read on.
  • send_event — set to True if the event came from a SendEvent protocol request.
  • serial — set from the serial number reported in the protocol, but expanded from the 16-bit least-significant bits to a full 32-bit value. numbers but make it full, iykyk.
  • window — set to the window that is most useful to toolkit dispatchers.

The window member is set to the window on which the FocusIn or FocusOut event was generated. This is the window used by the X server to report the event. The mode member is set to indicate whether the focus events are normal focus events, focus events while grabbed, focus events when a grab activates, or focus events when a grab deactivates. The X server can set the mode member to NotifyNormal, NotifyWhileGrabbed, NotifyGrab, or NotifyUngrab.

not me noticing the struct comment up top lists NotifyNormal, NotifyGrab, and NotifyUngrab, while the prose also names NotifyWhileGrabbed — both are in the original, bestie, so both stay. 🫶

🚨 ordering tea: All FocusOut events caused by a window unmap are generated after any UnmapNotify event; however, the X protocol does not constrain the ordering of FocusOut events with respect to generated EnterNotify, LeaveNotify, VisibilityNotify, and Expose events. That’s the rule, fr fr.

Depending on the event mode, the detail member is set to indicate the notify detail and can be NotifyAncestor, NotifyVirtual, NotifyInferior, NotifyNonlinear, NotifyNonlinearVirtual, NotifyPointer, NotifyPointerRoot, or NotifyDetailNone. ✨

👑 SEE ALSO 👑

cute sign-off: this page is from X Version 11, libX11 1.8.14, and the page is XFocusChangeEvent(3). the footer doesn’t show a date, so I’m not inventing one — no cap. bye bestie, go handle those focus events with main character energy. 💖🎀🦋

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