d_list_proc(3alleg4)

💅 d_list_proc — bestie edition

okay so real talk, this is from the Allegro manual, and it's about a little dialog thing called d_list_proc. It's a dialog procedure that implements a list box object 🎀 — part of the Allegro game programming library, iykyk.

✨ SYNOPSIS ✨

#include <allegro.h>

int d_list_proc(int msg, DIALOG *d, int c);

🦋 DESCRIPTION 🦋

It's giving list box object. 💖 What that means is: your user can scroll through a whole list of items, and pick one — either by clicking on it, or with the arrow keys. Both work, no cap.

If the D_EXIT flag is set, then double clicking on a list item closes the dialog. Iconic behaviour honestly.

Here's the tea on where everything lives:

• d1 — holds the index of the item that's currently selected 👑
• d2 — used to store how far it has scrolled through the list
• dp — points to a function that gets called to obtain info about the contents of the list

That function in dp should follow this form, fr fr:

char *foobar(int index, int *list_size);

How it works, step by step bestie:

• If index is zero or positive, the function should return a pointer to the string that's to be displayed at position index in the list. ✨
• If index is negative, it should return NULL, and list_size should be set to the number of items in the list.

🌸 MULTIPLE SELECTION LISTBOX 🌸

Wanna let your user pick more than one thing? Obsessed. Do this:

Set the dp2 field to an array of byte flags indicating the selection state of each list item — non-zero means that entry is selected. 💅

⚠️ bestie this is the important bit: this table must be at least as big as the number of objects in the list! Not smaller. Do not play with this. 😭

🫶 SEE ALSO 🫶

• exgui(3alleg4)

that's the whole vibe 🌈 this page was living in Allegro version 4.4.3, mwah 💜 stay hydrated, read your man pages, periodt. 🎀