dashboard: suspend when not visible

1 files changed, 27 insertions, 0 deletions

diff --git a/src/api/dashboard/dashboard.html b/src/api/dashboard/dashboard.html
index 1a11a25..03fa177 100644
--- a/src/api/dashboard/dashboard.html
+++ b/src/api/dashboard/dashboard.html
@@ -1230,6 +1230,33 @@ function connect() {
   });
 }
 connect();
+// A page not shown (another tab, a minimised window) is paused: hidden for a while, it
+// closes its stream, so the node stops building updates and asking members for their
+// links for it; shown again, it reconnects. Briefly hidden, nothing changes.
+const PAUSE_AFTER = 30000;
+let paused = false;
+let pausing = null;
+document.addEventListener("visibilitychange", () => {
+  if (document.hidden) {
+    pausing = setTimeout(() => {
+      pausing = null;
+      paused = true;
+      clearTimeout(retry);
+      retry = null;
+      if (events) events.close();
+      live = false;
+      status("paused while hidden", false);
+    }, PAUSE_AFTER);
+  } else {
+    clearTimeout(pausing);
+    pausing = null;
+    if (paused) {
+      paused = false;
+      status("reconnecting…", false);
+      connect();
+    }
+  }
+});
 // A click on the status: live, everything now (a tick on the node, the members asked
 // again, what's open of the document read again); otherwise, reconnecting now.
 connection.title = "Click to refresh now";