Start timer on view for reminders

* Do this in case someone hotlinks lower in the page and ends up missing these when traversing

Applies to #573 and #484 and more for #567 and start of #568

Author: Martii

views/includes/scripts/hideReminders.html

@@ -1,11 +1,44 @@
 <script type="text/javascript">
   (function () {
+    function isElementInViewport(aEl) {
+      if (aEl instanceof jQuery) {
+        aEl = aEl[0];
+      }
 
-    setTimeout(function () {
-      $('.reminders .alert .close').each(function () {
-        this.click();
-      });
-    }, 7000);
+      var rect = aEl.getBoundingClientRect();
+
+      return (
+        rect.top >= 0 &&
+        rect.left >= 0 &&
+        rect.bottom <= (window.innerHeight || document.documentElement.clientHeight) && /*or $(window).height() */
+        rect.right <= (window.innerWidth || document.documentElement.clientWidth) /*or $(window).width() */
+      );
+    }
+
+    var hasShownReminders = false;
+    function callback(aEl) {
+      if (!hasShownReminders) {
+        hasShownReminders = true;
+
+        setTimeout(function () {
+          $('.reminders .alert .close').each(function () {
+            this.click();
+          });
+        }, 7000);
+      }
+    }
+
+    function fireIfElementVisible(aEl, aCallback) {
+      return function () {
+        if (isElementInViewport(aEl)) {
+          aCallback(aEl);
+        }
+      }
+    }
+
+    var handler = fireIfElementVisible($('.reminders'), callback);
+
+    $(window).on('DOMContentLoaded load resize scroll', handler);
 
   })();
 </script>