From 924e803d167b5b4dd485a3e42ac944ea15eea8be Mon Sep 17 00:00:00 2001
From: Nolan Lawson <nolan@nolanlawson.com>
Date: Sun, 21 Jan 2018 16:07:11 -0800
Subject: [PATCH] add loading footer

---
 routes/_components/LoadingFooter.html     | 26 ++++++++++++++++++++++
 routes/_components/LoadingSpinner.html    |  6 ++---
 routes/_components/Timeline.html          |  6 ++++-
 routes/_components/VirtualList.html       | 22 ++++++++++++------
 routes/_components/VirtualListFooter.html | 27 +++++++++++++++++++++++
 routes/_utils/virtualListStore.js         | 13 ++++++++++-
 6 files changed, 88 insertions(+), 12 deletions(-)
 create mode 100644 routes/_components/LoadingFooter.html
 create mode 100644 routes/_components/VirtualListFooter.html

diff --git a/routes/_components/LoadingFooter.html b/routes/_components/LoadingFooter.html
new file mode 100644
index 00000000..c9c3e39b
--- /dev/null
+++ b/routes/_components/LoadingFooter.html
@@ -0,0 +1,26 @@
+<div class="loading-footer">
+  <LoadingSpinner size={{48}} />
+  <span class="loading-footer-info">
+    Loading more...
+  </span>
+</div>
+<style>
+  .loading-footer {
+    padding: 20px 0 10px;
+    display: flex;
+    align-items: center;
+    justify-content: center;
+  }
+  .loading-footer-info {
+    margin-left: 20px;
+    font-size: 1.3em;
+  }
+</style>
+<script>
+  import LoadingSpinner from './LoadingSpinner.html'
+  export default {
+    components: {
+      LoadingSpinner
+    }
+  }
+</script>
\ No newline at end of file
diff --git a/routes/_components/LoadingSpinner.html b/routes/_components/LoadingSpinner.html
index fb2e844e..c9ef9963 100644
--- a/routes/_components/LoadingSpinner.html
+++ b/routes/_components/LoadingSpinner.html
@@ -1,10 +1,10 @@
-<svg class="loading-spinner-icon {{maskStyle ? 'mask-style' : ''}}">
+<svg class="loading-spinner-icon {{maskStyle ? 'mask-style' : ''}}"
+     style="width: {{size || 64}}px; height: {{size || 64}}px;"
+>
   <use xlink:href="#fa-spinner" />
 </svg>
 <style>
   .loading-spinner-icon {
-    width: 64px;
-    height: 64px;
     fill: var(--svg-fill);
     animation: spin 2s infinite linear;
   }
diff --git a/routes/_components/Timeline.html b/routes/_components/Timeline.html
index 1ba903fe..c284a0af 100644
--- a/routes/_components/Timeline.html
+++ b/routes/_components/Timeline.html
@@ -4,6 +4,8 @@
                items="{{keyedStatuses}}"
                on:scrollToBottom="onScrollToBottom()"
                shown="{{initialized}}"
+               footerComponent="{{LoadingFooter}}"
+               showFooter="{{initialized && runningUpdate}}"
   />
 </div>
 <style>
@@ -15,6 +17,7 @@
   import { store } from '../_utils/store'
   import { getTimeline } from '../_utils/mastodon/timelines'
   import StatusListItem from './StatusListItem.html'
+  import LoadingFooter from './LoadingFooter.html'
   import VirtualList from './VirtualList.html'
   import { splice, push } from 'svelte-extras'
   import worker from 'workerize-loader!../_utils/database/database'
@@ -40,6 +43,7 @@
     },
     data: () => ({
       StatusListItem: StatusListItem,
+      LoadingFooter: LoadingFooter,
       statuses: [],
       runningUpdate: false,
       initialized: false
@@ -69,8 +73,8 @@
         mark('onScrollToBottom')
         this.set({ runningUpdate: true })
         let newStatuses = await this.fetchStatusesAndPossiblyFallBack()
-        this.addStatuses(newStatuses)
         this.set({ runningUpdate: false })
+        this.addStatuses(newStatuses)
         stop('onScrollToBottom')
       },
       addStatuses(newStatuses) {
diff --git a/routes/_components/VirtualList.html b/routes/_components/VirtualList.html
index 9c444bbf..1d8c311c 100644
--- a/routes/_components/VirtualList.html
+++ b/routes/_components/VirtualList.html
@@ -1,13 +1,16 @@
 <!-- TODO: setting height is hacky, just make this element the scroller -->
 <div class="virtual-list {{shown ? '' : 'hidden'}}" style="height: {{$height}}px;">
   {{#each $visibleItems as item @key}}
-  <VirtualListItem :component
-                   offset="{{item.offset}}"
-                   props="{{item.props}}"
-                   key="{{item.key}}"
-                   index="{{item.index}}"
-  />
+    <VirtualListItem :component
+                     offset="{{item.offset}}"
+                     props="{{item.props}}"
+                     key="{{item.key}}"
+                     index="{{item.index}}"
+    />
   {{/each}}
+  {{#if $showFooter}}
+    <VirtualListFooter component="{{footerComponent}}"/>
+  {{/if}}
 </div>
 <style>
   .virtual-list {
@@ -17,6 +20,7 @@
 </style>
 <script>
   import VirtualListItem from './VirtualListItem'
+  import VirtualListFooter from './VirtualListFooter.html'
   import { virtualListStore } from '../_utils/virtualListStore'
   import throttle from 'lodash/throttle'
   import { mark, stop } from '../_utils/marks'
@@ -26,6 +30,9 @@
 
   export default {
     oncreate () {
+      this.observe('showFooter', showFooter => {
+        this.store.set({showFooter: showFooter})
+      })
       this.observe('items', (items) => {
         mark('set items')
         this.store.set({
@@ -55,7 +62,8 @@
     }),
     store: () => virtualListStore,
     components: {
-      VirtualListItem
+      VirtualListItem,
+      VirtualListFooter
     },
     computed: {
       distanceFromBottom: ($scrollHeight, $scrollTop, $offsetHeight) => {
diff --git a/routes/_components/VirtualListFooter.html b/routes/_components/VirtualListFooter.html
new file mode 100644
index 00000000..e95f18c2
--- /dev/null
+++ b/routes/_components/VirtualListFooter.html
@@ -0,0 +1,27 @@
+<div class="virtual-list-footer"
+  ref:node
+  style="transform: translateY({{$heightWithoutFooter}}px);" >
+  <:Component {component} />
+</div>
+<style>
+  .virtual-list-footer {
+    position: absolute;
+    top: 0;
+    width: 100%;
+  }
+</style>
+<script>
+  import { virtualListStore } from '../_utils/virtualListStore'
+  import { AsyncLayout } from '../_utils/AsyncLayout'
+
+  export default {
+    oncreate() {
+      const asyncLayout = new AsyncLayout(() => '__footer__')
+      asyncLayout.observe('__footer__', this.refs.node, (rect) => {
+        asyncLayout.disconnect()
+        this.store.set({footerHeight: rect.height})
+      })
+    },
+    store: () => virtualListStore,
+  }
+</script>
\ No newline at end of file
diff --git a/routes/_utils/virtualListStore.js b/routes/_utils/virtualListStore.js
index d0f18ee5..32b7ea72 100644
--- a/routes/_utils/virtualListStore.js
+++ b/routes/_utils/virtualListStore.js
@@ -42,6 +42,8 @@ class VirtualListStore extends Store {
 const virtualListStore = new VirtualListStore({
   items: [],
   itemHeights: {},
+  showFooter: false,
+  footerHeight: 0
 })
 
 virtualListStore.compute('visibleItems',
@@ -79,7 +81,9 @@ virtualListStore.compute('visibleItems',
   return visibleItems
 })
 
-virtualListStore.compute('height', ['items', 'itemHeights'], (items, itemHeights) => {
+virtualListStore.compute('heightWithoutFooter',
+    ['items', 'itemHeights'],
+    (items, itemHeights) => {
   let sum = 0
   let i = -1
   let len = items.length
@@ -89,6 +93,13 @@ virtualListStore.compute('height', ['items', 'itemHeights'], (items, itemHeights
   return sum
 })
 
+
+virtualListStore.compute('height',
+    ['heightWithoutFooter', 'showFooter', 'footerHeight'],
+    (heightWithoutFooter, showFooter, footerHeight) => {
+  return showFooter ? (heightWithoutFooter + footerHeight) : heightWithoutFooter
+})
+
 virtualListStore.compute('numItems', ['items'], (items) => items.length)
 
 if (process.browser && process.env.NODE_ENV !== 'production') {