From c069e7754f9d2d2fa6cefba294cb4ab996d473f4 Mon Sep 17 00:00:00 2001 From: Bill Currie Date: Thu, 25 Nov 2021 10:46:42 +0900 Subject: [PATCH] [util] Add a listener object I decided cvars and input buttons/axes need listeners so any changes to them can be propagated. This will make using cvars in bindings feasible and I have an idea for automatic imt switching that would benefit from listeners attached to buttons and cvars. --- include/QF/listener.h | 158 +++++++++++++++++++++++++++++++++ libs/util/test/Makemodule.am | 5 ++ libs/util/test/test-listener.c | 59 ++++++++++++ 3 files changed, 222 insertions(+) create mode 100644 include/QF/listener.h create mode 100644 libs/util/test/test-listener.c diff --git a/include/QF/listener.h b/include/QF/listener.h new file mode 100644 index 000000000..553c79a3e --- /dev/null +++ b/include/QF/listener.h @@ -0,0 +1,158 @@ +/* + listener.h + + Listener objects + + Copyright (C) 2021 Bill Currie + + Author: Bill Currie + Date: 2021/11/25 + + This program is free software; you can redistribute it and/or + modify it under the terms of the GNU General Public License + as published by the Free Software Foundation; either version 2 + of the License, or (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. + + See the GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, write to: + + Free Software Foundation, Inc. + 59 Temple Place - Suite 330 + Boston, MA 02111-1307, USA + +*/ + +#ifndef __QF_listener_h +#define __QF_listener_h + +#include "QF/darray.h" + +/** \defgroup listener Listeners + \ingroup utils + + Listener objects +*/ +///@{ + +/** The structure defs for a listener set for an object of the given type. + + This is just the defs of a struct delcaration: it is useless on its own. + The intended usage is something like: + + typedef struct obj_listenerset_s LISTENER_SET_TYPE(obj_t) + obj_listenerset_t; + + This allows full flexibility in just how the actual type is used. + + The \a lfunc field is the function that will be called whenever the + listener is invoked. \a ldata is an aribtrary pointer that is passed to + the function as its \a data parameter. The function's \a obj parameter + is the \a obj parameter passed to LISTENER_INVOKE(), and is intended to + be the object being listened to. + + There can be any number of \a lfunc, \a ldata pairs, but they should be + unique, though this is not enforced. + + \param type The type of the listened objects. A pointer to an object + being listend to is passed to LISTENER_INVOKE() and that + pointer is passed on to each listener function in the + listener set. + \hideinitializer +*/ +#define LISTENER_SET_TYPE(type) \ + DARRAY_TYPE(struct { \ + void (*lfunc) (void *data, const type *obj); \ + void *ldata; \ + }) + +#define LISTENER_SET_STATIC_INIT(g) DARRAY_STATIC_INIT(g) + +/** Initialize the listener set. + + The set is initialized to be emtpy. + + \param lset The *address* of the listener set being initialized (ie, + a pointer to the listener set). + \param growSice Amount by which the underlying array will grow. + \hideinitializer +*/ +#define LISTENER_SET_INIT(lset, growSice) DARRAY_INIT(lset, growSice) + +/** Add a listener function/data par to the listener set. + + The function's first parameter is the \a data pointer in the \a func + \a data pair. The function's second parameter is the \a obj parameter + of LISTENER_INVOKE(). Thus each added listener function will be called + with its associated data pointer and the \a obj parameter from + LISTENER_INVOKE(). + + Each pair should be unique in order to avoid double-action and so + listeners can be removed properly. + + \param lset The *address* of the listener set being modified (ie, + a pointer to the listener set). + \param func The function to be called when the listener is invoked. + \param data Arbitrary pointer passed on to the function as its first + parameter when when the listener is invoked. + \hideinitializer +*/ +#define LISTENER_ADD(lset, func, data) \ + do { \ + __auto_type ls = (lset); \ + typeof(ls->a[0]) l = {(func), (data)}; \ + DARRAY_APPEND (ls, l); \ + } while (0) + +/** Remove a listener function/data pair from the listener set. + + Each individual listener is identifed by its \a func \a data pair. Only + the first instance of a pair is removed, thus only unique pairs should be + added. + + \param lset The *address* of the listener set being modified (ie, + a pointer to the listener set). + \param func The listener function being removed. + \param data The function's associated data pointer. + \hideinitializer +*/ +#define LISTENER_REMOVE(lset, func, data) \ + do { \ + __auto_type ls = (lset); \ + typeof(ls->a[0]) l = {(func), (data)}; \ + for (size_t i = 0; i < ls->size; i++) { \ + if (ls->a[i].lfunc == l.lfunc && ls->a[i].ldata == l.ldata) { \ + DARRAY_REMOVE_AT (ls, i); \ + break; \ + } \ + } \ + } while (0) + +/** Call all listener functions in the listener set. + + Each listener function is passed its data pointer as the first parameter + and \a obj as the second parameter. + + \param lset The *address* of the listener set being invoked (ie, + a pointer to the listener set). + \param obj Pointer passed to each listener function as its second + parameter. + \hideinitializer +*/ +#define LISTENER_INVOKE(lset, obj) \ + do { \ + __auto_type ls = (lset); \ + __auto_type o = (obj); \ + for (size_t i = 0; i < ls->size; i++) { \ + ls->a[i].lfunc (ls->a[i].ldata, o); \ + } \ + } while (0) + +///@} + +#endif//__QF_listener_h diff --git a/libs/util/test/Makemodule.am b/libs/util/test/Makemodule.am index ed3b0bb99..188239e11 100644 --- a/libs/util/test/Makemodule.am +++ b/libs/util/test/Makemodule.am @@ -10,6 +10,7 @@ libs_util_tests = \ libs/util/test/test-dq \ libs/util/test/test-half \ libs/util/test/test-heapsort \ + libs/util/test/test-listener \ libs/util/test/test-mat3 \ libs/util/test/test-mat4 \ libs/util/test/test-plist \ @@ -71,6 +72,10 @@ libs_util_test_test_heapsort_SOURCES=libs/util/test/test-heapsort.c libs_util_test_test_heapsort_LDADD=libs/util/libQFutil.la libs_util_test_test_heapsort_DEPENDENCIES=libs/util/libQFutil.la +libs_util_test_test_listener_SOURCES=libs/util/test/test-listener.c +libs_util_test_test_listener_LDADD=libs/util/libQFutil.la +libs_util_test_test_listener_DEPENDENCIES=libs/util/libQFutil.la + libs_util_test_test_mat3_SOURCES=libs/util/test/test-mat3.c libs_util_test_test_mat3_LDADD=libs/util/libQFutil.la libs_util_test_test_mat3_DEPENDENCIES=libs/util/libQFutil.la diff --git a/libs/util/test/test-listener.c b/libs/util/test/test-listener.c new file mode 100644 index 000000000..0c9654b38 --- /dev/null +++ b/libs/util/test/test-listener.c @@ -0,0 +1,59 @@ +#ifdef HAVE_CONFIG_H +# include "config.h" +#endif +#define remove remove_renamed +#include +#include +#include + +#include "QF/listener.h" +#include "QF/sys.h" +#undef remove + +typedef struct obj_s { + int count; +} obj_t; + +struct LISTENER_SET_TYPE (obj_t) listeners = LISTENER_SET_STATIC_INIT(8); + +static void +listener_a (void *data, const obj_t *obj) +{ + *(int *) data += 1; + ((obj_t *) obj)->count += 1; +} + +static void +listener_b (void *data, const obj_t *obj) +{ + *(int *) data += 2; + ((obj_t *) obj)->count += 2; +} + +int +main (int argc, const char **argv) +{ + int res = 0; + int a_count = 0; + int b_count = 0; + obj_t obj = { 0 }; + + LISTENER_ADD (&listeners, listener_a, &a_count); + LISTENER_ADD (&listeners, listener_b, &b_count); + LISTENER_INVOKE (&listeners, &obj); + if (a_count != 1 || b_count != 2) { + Sys_Error ("a_count = %d, b_count = %d", a_count, b_count); + } + if (obj.count != 3) { + Sys_Error ("obj.count = %d", obj.count); + } + LISTENER_REMOVE (&listeners, listener_b, &b_count); + LISTENER_INVOKE (&listeners, &obj); + if (a_count != 2 || b_count != 2) { + Sys_Error ("a_count = %d, b_count = %d", a_count, b_count); + } + if (obj.count != 4) { + Sys_Error ("obj.count = %d", obj.count); + } + return res; +}