Implement web worker to keep timer running even when page is inactive

1 files changed, 24 insertions, 0 deletions

diff --git a/public/timer_worker.js b/public/timer_worker.js
new file mode 100644
index 0000000..3d3e79a
--- /dev/null
+++ b/public/timer_worker.js
@@ -0,0 +1,24 @@
+let timerInterval = null;
+
+function setTimerInterval() {
+  if (!timerInterval) {
+    timerInterval = setInterval(function() {
+      postMessage("timerTick");
+    }, 10);
+  }
+}
+
+function clearTimerInterval() {
+  clearInterval(timerInterval);
+  timerInterval = null;
+}
+
+onmessage = function(event) {
+  if ("run_flag" in event.data) {
+    if (event.data["run_flag"]) {
+      setTimerInterval();
+    } else {
+      clearTimerInterval();
+    }
+  }
+}