libui/common/events.c

190 lines
4.6 KiB
C

// 15 may 2019
#include "uipriv.h"
struct handler {
int id;
uiEventHandler f;
void *sender;
void *data;
bool blocked;
};
static int handlerCmp(const void *a, const void *b)
{
const struct handler *ha = (const struct handler *) a;
const struct handler *hb = (const struct handler *) b;
// This could be ha->id - hb->id, but let's do it the explicit way to avoid integer overflow/underflow.
if (ha->id < hb->id)
return -1;
if (ha->id > hb->id)
return 1;
return 0;
}
struct uiEvent {
uiEventOptions opts;
uiprivArray handlers;
uiprivArray unusedIDs;
bool firing;
};
uiEvent *uiNewEvent(const uiEventOptions *options)
{
uiEvent *e;
if (!uiprivCheckInitializedAndThread())
return NULL;
if (options == NULL) {
uiprivProgrammerError(uiprivProgrammerErrorNullPointer, "uiEventOptions", uiprivFunc);
return NULL;
}
if (options->Size != sizeof (uiEventOptions)) {
uiprivProgrammerError(uiprivProgrammerErrorWrongStructSize, options->Size, "uiEventOptions");
return NULL;
}
e = (uiEvent *) uiprivAlloc(sizeof (uiEvent), "uiEvent");
e->opts = *options;
uiprivArrayInit(e->handlers, struct handler, 32, "uiEvent handlers");
uiprivArrayInit(e->unusedIDs, int, 32, "uiEvent handler unused IDs");
return e;
}
#define checkEventNonnull(e, ret) if ((e) == NULL) { \
uiprivProgrammerError(uiprivProgrammerErrorNullPointer, "uiEvent", uiprivFunc); \
return ret; \
}
#define checkEventNotFiring(e, ret) if ((e)->firing) { \
uiprivProgrammerError(uiprivProgrammerErrorChangingEventDuringFire, uiprivFunc); \
return ret; \
}
static bool checkEventSender(const uiEvent *e, void *sender, const char *func)
{
if (e->opts.Global && sender != NULL) {
uiprivProgrammerError(uiprivProgrammerErrorBadSenderForEvent, "non-NULL", "global", func);
return false;
}
if (!e->opts.Global && sender == NULL) {
uiprivProgrammerError(uiprivProgrammerErrorBadSenderForEvent, "NULL", "non-global", func);
return false;
}
return true;
}
int uiEventAddHandler(uiEvent *e, uiEventHandler handler, void *sender, void *data)
{
struct handler *h;
int id;
if (!uiprivCheckInitializedAndThread())
return 0;
checkEventNonnull(e, 0);
checkEventNotFiring(e, 0);
if (handler == NULL) {
uiprivProgrammerError(uiprivProgrammerErrorNullPointer, "uiEventHandler", uiprivFunc);
return 0;
}
if (!checkEventSender(e, sender, uiprivFunc))
return 0;
id = 0;
if (e->unusedIDs.len > 0) {
int *p;
p = uiprivArrayAt(e->unusedIDs, int, e->unusedIDs.len - 1);
id = *p;
uiprivArrayDeleteItem(&(e->unusedIDs), p, 1);
} else if (e->handlers.len != 0)
id = uiprivArrayAt(e->handlers, struct handler, e->handlers.len - 1)->id + 1;
h = (struct handler *) uiprivArrayAppend(&(e->handlers), 1);
h->id = id;
h->f = handler;
h->sender = sender;
h->data = data;
uiprivArrayQsort(&(e->handlers), handlerCmp);
return id;
}
static struct handler *findHandler(const uiEvent *e, int id, const char *func)
{
struct handler key;
struct handler *ret;
memset(&key, 0, sizeof (struct handler));
key.id = id;
ret = (struct handler *) uiprivArrayBsearch(&(e->handlers), &key, handlerCmp);
if (ret == NULL)
uiprivProgrammerError(uiprivProgrammerErrorIntIDNotFound, "uiEvent handler", id, func);
return ret;
}
void uiEventDeleteHandler(uiEvent *e, int id)
{
struct handler *h;
if (!uiprivCheckInitializedAndThread())
return;
checkEventNonnull(e, /* nothing */);
checkEventNotFiring(e, /* nothing */);
h = findHandler(e, id, uiprivFunc);
if (h == NULL)
return;
uiprivArrayDeleteItem(&(e->handlers), h, 1);
*((int *) uiprivArrayAppend(&(e->unusedIDs), 1)) = id;
}
void uiEventFire(uiEvent *e, void *sender, void *args)
{
struct handler *h;
size_t i;
if (!uiprivCheckInitializedAndThread())
return;
checkEventNonnull(e, /* nothing */);
if (e->firing) {
uiprivProgrammerError(uiprivProgrammerErrorRecursiveEventFire);
return;
}
if (!checkEventSender(e, sender, uiprivFunc))
return;
e->firing = true;
h = (struct handler *) (e->handlers.buf);
for (i = 0; i < e->handlers.len; i++) {
if (h->sender == sender && !h->blocked)
(*(h->f))(sender, args, h->data);
h++;
}
e->firing = false;
}
bool uiEventHandlerBlocked(const uiEvent *e, int id)
{
struct handler *h;
if (!uiprivCheckInitializedAndThread())
return false;
checkEventNonnull(e, false);
h = findHandler(e, id, uiprivFunc);
if (h == NULL)
return false;
return h->blocked;
}
void uiEventSetHandlerBlocked(uiEvent *e, int id, bool blocked)
{
struct handler *h;
if (!uiprivCheckInitializedAndThread())
return;
checkEventNonnull(e, /* nothing */);
checkEventNotFiring(e, /* nothing */);
h = findHandler(e, id, uiprivFunc);
if (h == NULL)
return;
h->blocked = blocked;
}