XPropertyEvent(3)

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

🌸 NAME 🌸

XPropertyEvent(3) is the PropertyNotify event structure from the XLIB FUNCTIONS manual — aka the little C struct that tells you a window’s property just got changed or deleted. 💅 bestie, it’s giving “I know what happened to that atom,” and we’re obsessed.

🦋 STRUCTURES 🦋

The structure for PropertyNotify events contains:

typedef struct {
        int type;       /* PropertyNotify */
        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;
        Atom atom;
        Time time;
        int state;      /* PropertyNewValue or PropertyDelete */
} XPropertyEvent;

When you receive this event, the structure members are set as follows. no cap, here’s the member-by-member tea:

  • 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. iconic behavior, honestly.
  • 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.
  • window — set to the window that is most useful to toolkit dispatchers. yes, that’s the general boilerplate member vibe, iykyk.
  • window — okay but for real, the property-specific one: set to the window whose associated property was changed. main character energy.
  • atom — set to the property’s atom and indicates which property was changed or desired.
  • time — set to the server time when the property was changed.
  • state — set to indicate whether the property was changed to a new value or deleted, and can be PropertyNewValue or PropertyDelete.

The state member is set to PropertyNewValue when a property of the window is changed using XChangeProperty or XRotateWindowProperties (even when adding zero-length data using XChangeProperty) and when replacing all or part of a property with identical data using XChangeProperty or XRotateWindowProperties. slay, even identical-data replacements count. ✨

The state member is set to PropertyDelete when a property of the window is deleted using XDeleteProperty or, if the delete argument is True, XGetWindowProperty. so yeah, that’s the deletion pipeline, periodt.

🎀 SEE ALSO 🎀

Go give these siblings a read, bestie — full guest list, in order:

And the big classic: Xlib - C Language X Interface. 🫶

kisses and property-change notifications 💖 this little page is serving X Version 11, libX11 1.8.14, and XPropertyEvent(3) energy. periodt. 🎀

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