2 Simple DirectMedia Layer
3 Copyright (C) 1997-2020 Sam Lantinga <slouken@libsdl.org>
5 This software is provided 'as-is', without any express or implied
6 warranty. In no event will the authors be held liable for any damages
7 arising from the use of this software.
9 Permission is granted to anyone to use this software for any purpose,
10 including commercial applications, and to alter it and redistribute it
11 freely, subject to the following restrictions:
13 1. The origin of this software must not be misrepresented; you must not
14 claim that you wrote the original software. If you use this software
15 in a product, an acknowledgment in the product documentation would be
16 appreciated but is not required.
17 2. Altered source versions must be plainly marked as such, and must not be
18 misrepresented as being the original software.
19 3. This notice may not be removed or altered from any source distribution.
21 #include "./SDL_internal.h"
23 #include "SDL_hints.h"
24 #include "SDL_error.h"
25 #include "SDL_hints_c.h"
28 /* Assuming there aren't many hints set and they aren't being queried in
29 critical performance paths, we'll just use linked lists here.
31 typedef struct SDL_HintWatch {
32 SDL_HintCallback callback;
34 struct SDL_HintWatch *next;
37 typedef struct SDL_Hint {
40 SDL_HintPriority priority;
41 SDL_HintWatch *callbacks;
42 struct SDL_Hint *next;
45 static SDL_Hint *SDL_hints;
48 SDL_SetHintWithPriority(const char *name, const char *value,
49 SDL_HintPriority priority)
55 if (!name || !value) {
59 env = SDL_getenv(name);
60 if (env && priority < SDL_HINT_OVERRIDE) {
64 for (hint = SDL_hints; hint; hint = hint->next) {
65 if (SDL_strcmp(name, hint->name) == 0) {
66 if (priority < hint->priority) {
69 if (!hint->value || !value || SDL_strcmp(hint->value, value) != 0) {
70 for (entry = hint->callbacks; entry; ) {
71 /* Save the next entry in case this one is deleted */
72 SDL_HintWatch *next = entry->next;
73 entry->callback(entry->userdata, name, hint->value, value);
76 SDL_free(hint->value);
77 hint->value = value ? SDL_strdup(value) : NULL;
79 hint->priority = priority;
84 /* Couldn't find the hint, add a new one */
85 hint = (SDL_Hint *)SDL_malloc(sizeof(*hint));
89 hint->name = SDL_strdup(name);
90 hint->value = value ? SDL_strdup(value) : NULL;
91 hint->priority = priority;
92 hint->callbacks = NULL;
93 hint->next = SDL_hints;
99 SDL_SetHint(const char *name, const char *value)
101 return SDL_SetHintWithPriority(name, value, SDL_HINT_NORMAL);
105 SDL_GetHint(const char *name)
110 env = SDL_getenv(name);
111 for (hint = SDL_hints; hint; hint = hint->next) {
112 if (SDL_strcmp(name, hint->name) == 0) {
113 if (!env || hint->priority == SDL_HINT_OVERRIDE) {
123 SDL_GetStringBoolean(const char *value, SDL_bool default_value)
125 if (!value || !*value) {
126 return default_value;
128 if (*value == '0' || SDL_strcasecmp(value, "false") == 0) {
135 SDL_GetHintBoolean(const char *name, SDL_bool default_value)
137 const char *hint = SDL_GetHint(name);
138 return SDL_GetStringBoolean(hint, default_value);
142 SDL_AddHintCallback(const char *name, SDL_HintCallback callback, void *userdata)
145 SDL_HintWatch *entry;
148 if (!name || !*name) {
149 SDL_InvalidParamError("name");
153 SDL_InvalidParamError("callback");
157 SDL_DelHintCallback(name, callback, userdata);
159 entry = (SDL_HintWatch *)SDL_malloc(sizeof(*entry));
164 entry->callback = callback;
165 entry->userdata = userdata;
167 for (hint = SDL_hints; hint; hint = hint->next) {
168 if (SDL_strcmp(name, hint->name) == 0) {
173 /* Need to add a hint entry for this watcher */
174 hint = (SDL_Hint *)SDL_malloc(sizeof(*hint));
180 hint->name = SDL_strdup(name);
182 hint->priority = SDL_HINT_DEFAULT;
183 hint->callbacks = NULL;
184 hint->next = SDL_hints;
188 /* Add it to the callbacks for this hint */
189 entry->next = hint->callbacks;
190 hint->callbacks = entry;
192 /* Now call it with the current value */
193 value = SDL_GetHint(name);
194 callback(userdata, name, value, value);
198 SDL_DelHintCallback(const char *name, SDL_HintCallback callback, void *userdata)
201 SDL_HintWatch *entry, *prev;
203 for (hint = SDL_hints; hint; hint = hint->next) {
204 if (SDL_strcmp(name, hint->name) == 0) {
206 for (entry = hint->callbacks; entry; entry = entry->next) {
207 if (callback == entry->callback && userdata == entry->userdata) {
209 prev->next = entry->next;
211 hint->callbacks = entry->next;
223 void SDL_ClearHints(void)
226 SDL_HintWatch *entry;
230 SDL_hints = hint->next;
232 SDL_free(hint->name);
233 SDL_free(hint->value);
234 for (entry = hint->callbacks; entry; ) {
235 SDL_HintWatch *freeable = entry;
243 /* vi: set ts=4 sw=4 expandtab: */