Pixel-Composer/objects/o_main/KeyPress_1.gml

/// @description 
kb_hkey = keyboard_key == 0? keyboard_lastkey : keyboard_key;
kb_time = 0;
kb_hold = false;

KEYBOARD_PRESSED = kb_hkey;

if(keyboard_check(vk_backspace)) KEYBOARD_STRING  = string_copy(KEYBOARD_STRING, 1, string_length(KEYBOARD_STRING) - 1);
else                             KEYBOARD_STRING += keyboard_lastchar;
	
if(KEYBOARD_PRESSED == -1) {
	for( var i = 0, n = array_length(global.KEYS_VK); i < n; i++ ) {
		if(keyboard_check(global.KEYS_VK[i]))
			KEYBOARD_PRESSED = global.KEYS_VK[i];
	}
}