Split conversation display style into two different settings

linear => linear (now default)
simple_tree => tree / conversationTreeAdvanced=false
tree => tree / conversationTreeAdvanced=true

src/components/conversation/conversation.js

@@ -81,10 +81,10 @@ const conversation = {
       return this.$store.getters.mergedConfig.conversationDisplay
     },
     isTreeView () {
-      return this.displayStyle === 'tree' || this.displayStyle === 'simple_tree'
+      return !this.isLinearView
     },
     treeViewIsSimple () {
-      return this.displayStyle === 'simple_tree'
+      return !this.$store.getters.mergedConfig.conversationTreeAdvanced
     },
     isLinearView () {
       return this.displayStyle === 'linear'

src/components/settings_modal/tabs/general_tab.js

@@ -20,7 +20,7 @@ const GeneralTab = {
         value: mode,
         label: this.$t(`settings.subject_line_${mode === 'masto' ? 'mastodon' : mode}`)
       })),
-      conversationDisplayOptions: ['tree', 'simple_tree', 'linear'].map(mode => ({
+      conversationDisplayOptions: ['tree', 'linear'].map(mode => ({
         key: mode,
         value: mode,
         label: this.$t(`settings.conversation_display_${mode}`)

src/components/settings_modal/tabs/general_tab.vue

@@ -165,6 +165,11 @@
           v-if="conversationDisplay !== 'linear'"
           class="setting-list suboptions"
         >
+          <li>
+            <BooleanSetting path="conversationTreeAdvanced">
+              {{ $t('settings.tree_advanced') }}
+            </BooleanSetting>
+          </li>
           <li>
             <label for="maxDepthInThread">
               {{ $t('settings.max_depth_in_thread') }}

src/modules/config.js

@@ -85,6 +85,7 @@ export const defaultState = {
   virtualScrolling: undefined, // instance default
   sensitiveByDefault: undefined, // instance default
   conversationDisplay: undefined, // instance default
+  conversationTreeAdvanced: undefined, // instance default
   conversationOtherRepliesButton: undefined, // instance default
   maxDepthInThread: 6
 }

src/modules/instance.js

@@ -53,7 +53,8 @@ const defaultState = {
   theme: 'pleroma-dark',
   virtualScrolling: true,
   sensitiveByDefault: false,
-  conversationDisplay: 'simple_tree',
+  conversationDisplay: 'linear',
+  conversationTreeAdvanced: false,
   conversationOtherRepliesButton: 'below',
   maxDepthInThread: 6,