Made it so that unfocused tab doesn't autostream posts when scrolled to the top

This only affects when browser window doesn't have tab in focus, whether window has focus or not doesn't matter - it will think tab is focused.

src/components/timeline/timeline.js

@@ -13,7 +13,8 @@ const Timeline = {
   ],
   data () {
     return {
-      paused: false
+      paused: false,
+      unfocused: false
     }
   },
   computed: {
@@ -65,8 +66,15 @@ const Timeline = {
       this.fetchFollowers()
     }
   },
+  mounted () {
+    if (typeof document.hidden !== 'undefined') {
+      document.addEventListener('visibilitychange', this.handleVisibilityChange, false)
+      this.unfocused = document.hidden
+    }
+  },
   destroyed () {
     window.removeEventListener('scroll', this.scrollLoad)
+    if (typeof document.hidden !== 'undefined') document.removeEventListener('visibilitychange', this.handleVisibilityChange, false)
     this.$store.commit('setLoading', { timeline: this.timelineName, value: false })
   },
   methods: {
@@ -113,6 +121,9 @@ const Timeline = {
           (window.innerHeight + window.pageYOffset) >= (height - 750)) {
         this.fetchOlderStatuses()
       }
+    },
+    handleVisibilityChange () {
+      this.unfocused = document.hidden
     }
   },
   watch: {
@@ -122,7 +133,7 @@ const Timeline = {
       }
       if (count > 0) {
         // only 'stream' them when you're scrolled to the top
-        if (window.pageYOffset < 15 && !this.paused) {
+        if (window.pageYOffset < 15 && !this.paused && !this.unfocused) {
           this.showNewStatuses()
         } else {
           this.paused = true