Import of the watch repository from Pebble

applib-targets/emscripten/emscripten_tick_timer_service.c

@@ -0,0 +1,108 @@
+/*
+ * Copyright 2024 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "applib/app_logging.h"
+#include "applib/tick_timer_service_private.h"
+
+#include <emscripten/emscripten.h>
+#include <stdio.h>
+#include <time.h>
+
+time_t time(time_t *time);
+
+static TickTimerServiceState s_state;
+
+static void prv_schedule_next_update(void);
+
+static void prv_do_update(void *data) {
+  if (!s_state.handler) {
+    return;
+  }
+
+  // The data pointer value is used to pass a boolean value directly:
+  const bool is_update_due_to_time_change = (uintptr_t)data;
+
+  struct tm currtime;
+  time_t t = time(NULL);
+  localtime_r(&t, &currtime);
+
+  TimeUnits units_changed;
+  if (is_update_due_to_time_change) {
+    units_changed = (SECOND_UNIT | MINUTE_UNIT | HOUR_UNIT | DAY_UNIT | YEAR_UNIT);
+  } else {
+    prv_schedule_next_update();
+    units_changed = 0;
+    if (!s_state.first_tick) {
+      if (s_state.last_time.tm_sec != currtime.tm_sec) {
+        units_changed |= SECOND_UNIT;
+      }
+      if (s_state.last_time.tm_min != currtime.tm_min) {
+        units_changed |= MINUTE_UNIT;
+      }
+      if (s_state.last_time.tm_hour != currtime.tm_hour) {
+        units_changed |= HOUR_UNIT;
+      }
+      if (s_state.last_time.tm_mday != currtime.tm_mday) {
+        units_changed |= DAY_UNIT;
+      }
+      if (s_state.last_time.tm_mon != currtime.tm_mon) {
+        units_changed |= MONTH_UNIT;
+      }
+      if (s_state.last_time.tm_year != currtime.tm_year) {
+        units_changed |= YEAR_UNIT;
+      }
+    }
+  }
+
+  s_state.last_time = currtime;
+  s_state.first_tick = false;
+
+  if ((s_state.tick_units & units_changed) || (units_changed == 0)) {
+    s_state.handler(&currtime, units_changed);
+  }
+}
+
+static void prv_schedule_next_update(void) {
+  // Schedule this to fire again at the top of the next second
+  const int ms_into_s = EM_ASM_INT_V({
+      return Date.now().getMilliseconds;
+    });
+  const double wait_ms = 1000 - ms_into_s;
+  const bool is_update_due_to_time_change = false;
+  emscripten_async_call(prv_do_update, (void *)(uintptr_t)is_update_due_to_time_change, wait_ms);
+}
+
+void tick_timer_service_handle_time_change(void) {
+  const bool is_update_due_to_time_change = true;
+  prv_do_update((void *)(uintptr_t)is_update_due_to_time_change);
+}
+
+void tick_timer_service_subscribe(TimeUnits tick_units, TickHandler handler) {
+  const bool first = (s_state.handler == NULL);
+  s_state = (TickTimerServiceState) {
+    .handler = handler,
+    .tick_units = tick_units,
+    .first_tick = true,
+  };
+
+  if (first && handler != NULL) {
+    prv_schedule_next_update();
+  }
+}
+
+void emx_tick_timer_service_init(void) {
+  s_state = (TickTimerServiceState){};
+}