2 Simple DirectMedia Layer
3 Copyright (C) 1997-2018 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"
27 /* Assuming there aren't many hints set and they aren't being queried in
28 critical performance paths, we'll just use linked lists here.
30 typedef struct SDL_HintWatch {
31 SDL_HintCallback callback;
33 struct SDL_HintWatch *next;
36 typedef struct SDL_Hint {
39 SDL_HintPriority priority;
40 SDL_HintWatch *callbacks;
41 struct SDL_Hint *next;
44 static SDL_Hint *SDL_hints;
47 SDL_SetHintWithPriority(const char *name, const char *value,
48 SDL_HintPriority priority)
54 if (!name || !value) {
58 env = SDL_getenv(name);
59 if (env && priority < SDL_HINT_OVERRIDE) {
63 for (hint = SDL_hints; hint; hint = hint->next) {
64 if (SDL_strcmp(name, hint->name) == 0) {
65 if (priority < hint->priority) {
68 if (!hint->value || !value || SDL_strcmp(hint->value, value) != 0) {
69 for (entry = hint->callbacks; entry; ) {
70 /* Save the next entry in case this one is deleted */
71 SDL_HintWatch *next = entry->next;
72 entry->callback(entry->userdata, name, hint->value, value);
75 SDL_free(hint->value);
76 hint->value = value ? SDL_strdup(value) : NULL;
78 hint->priority = priority;
83 /* Couldn't find the hint, add a new one */
84 hint = (SDL_Hint *)SDL_malloc(sizeof(*hint));
88 hint->name = SDL_strdup(name);
89 hint->value = value ? SDL_strdup(value) : NULL;
90 hint->priority = priority;
91 hint->callbacks = NULL;
92 hint->next = SDL_hints;
98 SDL_SetHint(const char *name, const char *value)
100 return SDL_SetHintWithPriority(name, value, SDL_HINT_NORMAL);
104 SDL_GetHint(const char *name)
109 env = SDL_getenv(name);
110 for (hint = SDL_hints; hint; hint = hint->next) {
111 if (SDL_strcmp(name, hint->name) == 0) {
112 if (!env || hint->priority == SDL_HINT_OVERRIDE) {
122 SDL_GetHintBoolean(const char *name, SDL_bool default_value)
124 const char *hint = SDL_GetHint(name);
125 if (!hint || !*hint) {
126 return default_value;
128 if (*hint == '0' || SDL_strcasecmp(hint, "false") == 0) {
135 SDL_AddHintCallback(const char *name, SDL_HintCallback callback, void *userdata)
138 SDL_HintWatch *entry;
141 if (!name || !*name) {
142 SDL_InvalidParamError("name");
146 SDL_InvalidParamError("callback");
150 SDL_DelHintCallback(name, callback, userdata);
152 entry = (SDL_HintWatch *)SDL_malloc(sizeof(*entry));
157 entry->callback = callback;
158 entry->userdata = userdata;
160 for (hint = SDL_hints; hint; hint = hint->next) {
161 if (SDL_strcmp(name, hint->name) == 0) {
166 /* Need to add a hint entry for this watcher */
167 hint = (SDL_Hint *)SDL_malloc(sizeof(*hint));
173 hint->name = SDL_strdup(name);
175 hint->priority = SDL_HINT_DEFAULT;
176 hint->callbacks = NULL;
177 hint->next = SDL_hints;
181 /* Add it to the callbacks for this hint */
182 entry->next = hint->callbacks;
183 hint->callbacks = entry;
185 /* Now call it with the current value */
186 value = SDL_GetHint(name);
187 callback(userdata, name, value, value);
191 SDL_DelHintCallback(const char *name, SDL_HintCallback callback, void *userdata)
194 SDL_HintWatch *entry, *prev;
196 for (hint = SDL_hints; hint; hint = hint->next) {
197 if (SDL_strcmp(name, hint->name) == 0) {
199 for (entry = hint->callbacks; entry; entry = entry->next) {
200 if (callback == entry->callback && userdata == entry->userdata) {
202 prev->next = entry->next;
204 hint->callbacks = entry->next;
216 void SDL_ClearHints(void)
219 SDL_HintWatch *entry;
223 SDL_hints = hint->next;
225 SDL_free(hint->name);
226 SDL_free(hint->value);
227 for (entry = hint->callbacks; entry; ) {
228 SDL_HintWatch *freeable = entry;
236 /* vi: set ts=4 sw=4 expandtab: */