Tk_SetClass(3)

okay bestie, welcome to the Tk_SetClass(3) page from the Tk Library Procedures manual — this one is short, iconic, and all about giving a window its class ✨

🌸 NAME 🌸

Tk_SetClass, Tk_Class — set or retrieve a window's class 💅

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✨ SYNOPSIS ✨

#include <tk.h>

Tk_SetClass(tkwin, class)

Tk_Uid
Tk_Class(tkwin)

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🎀 ARGUMENTS 🎀

• Tk_Window tkwin (in) — token for window 🪟
• char *class (in) — new class name for window 🏷️

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💖 DESCRIPTION 💖

Tk_SetClass is the function you call to associate a class with a particular window. The class string identifies the type of the window; all windows with the same general class of behavior (button, menu, etc.) should have the same class. By convention, all class names start with a capital letter, and there exists a Tcl command with the same name as each class (except all in lower-case) which can be used to create and manipulate windows of that class. A window's class string is initialized to NULL when the window is created.

For main windows, Tk automatically propagates the name and class to the WM_CLASS property used by window managers. This happens either when a main window is actually created (e.g. in Tk_MakeWindowExist), or when Tk_SetClass is called, whichever occurs later. If a main window has not been assigned a class then Tk will not set the WM_CLASS property for the window.

Tk_Class is a macro that returns the current value of tkwin's class. The value is returned as a Tk_Uid, which may be used just like a string pointer but also has the properties of a unique identifier (see the manual entry for Tk_GetUid for details). If tkwin has not yet been given a class, then Tk_Class will return NULL.

lowkey important: a fresh window starts with its class as NULL until you set it — no cap 🫶

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🔑 KEYWORDS 🔑

• class
• unique identifier
• window
• window manager

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That’s the whole vibe — source/version Tk, manual page Tk_SetClass(3), and the original footer doesn’t show a date, so we’re not inventing one 💖✨