1 files changed, 103 insertions, 0 deletions
diff --git a/src/common/input.c b/src/common/input.c
new file mode 100644
index 0000000..eac4d1a
--- /dev/null
+++ b/src/common/input.c
@@ -0,0 +1,103 @@
+#include "input.h"
+
+#include <stdlib.h>
+#include <string.h>
+
+static const char *event_text(const struct yasl_input_event *ev, size_t *len)
+{
+    switch (ev->kind) {
+    case YASL_INPUT_TEXT: *len = ev->text.len; return ev->text.text;
+    case YASL_INPUT_PASTE: *len = ev->paste.len; return ev->paste.text;
+    case YASL_INPUT_DROP_FILES: *len = ev->drop_files.len; return ev->drop_files.files;
+    default: *len = 0; return NULL;
+    }
+}
+
+static void set_text(struct yasl_input_event *ev, const char *text)
+{
+    switch (ev->kind) {
+    case YASL_INPUT_TEXT: ev->text.text = text; break;
+    case YASL_INPUT_PASTE: ev->paste.text = text; break;
+    case YASL_INPUT_DROP_FILES: ev->drop_files.files = text; break;
+    default: break;
+    }
+}
+
+static void discard_pending(struct input_queue *q)
+{
+    for (size_t i = 0; i < q->count; i++) {
+        size_t len;
+        free((void *)event_text(&q->events[(q->head + i) % q->capacity], &len));
+    }
+    q->head = q->count = 0;
+}
+
+bool input_queue_push(struct input_queue *q, const struct yasl_input_event *ev)
+{
+    struct yasl_input_event copy = *ev;
+    size_t len;
+    const char *text = event_text(ev, &len);
+    char *owned = NULL;
+    if (ev->kind == YASL_INPUT_TEXT || ev->kind == YASL_INPUT_PASTE ||
+        ev->kind == YASL_INPUT_DROP_FILES) {
+        if ((!text && len) || len == SIZE_MAX) goto failed;
+        owned = malloc(len + 1);
+        if (!owned) goto failed;
+        if (len) memcpy(owned, text, len);
+        owned[len] = '\0';
+        set_text(&copy, owned);
+    }
+    if (q->count == q->capacity) {
+        size_t capacity = q->capacity ? q->capacity * 2 : 32;
+        if (capacity < q->capacity || capacity > SIZE_MAX / sizeof(*q->events))
+            goto failed;
+        struct yasl_input_event *events = malloc(capacity * sizeof(*events));
+        if (!events) goto failed;
+        for (size_t i = 0; i < q->count; i++)
+            events[i] = q->events[(q->head + i) % q->capacity];
+        free(q->events);
+        q->events = events;
+        q->capacity = capacity;
+        q->head = 0;
+    }
+    q->events[(q->head + q->count) % q->capacity] = copy;
+    q->count++;
+    return true;
+
+failed:
+    free(owned);
+    /* A missing release must never silently leave app input state stuck.
+     * Discard the old stream and deliver an allocation-free reset first. */
+    discard_pending(q);
+    q->reset_surface = ev->surface;
+    q->reset_pending = true;
+    return false;
+}
+
+bool input_queue_pop(struct input_queue *q, struct yasl_input_event *ev)
+{
+    if (!ev || (!q->count && !q->reset_pending)) return false;
+    free(q->last_text);
+    q->last_text = NULL;
+    if (q->reset_pending) {
+        *ev = (struct yasl_input_event){
+            .surface = q->reset_surface, .kind = YASL_INPUT_RESET,
+        };
+        q->reset_pending = false;
+        return true;
+    }
+    *ev = q->events[q->head];
+    size_t len;
+    q->last_text = (char *)event_text(ev, &len);
+    q->head = (q->head + 1) % q->capacity;
+    q->count--;
+    return true;
+}
+
+void input_queue_clear(struct input_queue *q)
+{
+    discard_pending(q);
+    free(q->last_text);
+    free(q->events);
+    *q = (struct input_queue){0};
+}