Make the collapsed by default read messages a user setting

enabled by default

Author: dutow

app/controllers/settings/preferences_controller.rb

@@ -13,7 +13,7 @@ def update
     private
 
     def preferences_params
-      params.require(:user).permit(:mention_restriction, :open_threads_at_first_unread)
+      params.require(:user).permit(:mention_restriction, :open_threads_at_first_unread, :collapse_read_messages)
     end
   end
 end

app/views/settings/profiles/show.html.slim

@@ -49,4 +49,13 @@
             span.radio-text
               strong Open at first unread
               span.radio-description Jump to first unread message in the thread if the title was clicked
+      h2 Thread Display
+      p.settings-hint Control how messages are displayed in threads.
+      .form-group
+        .radio-group
+          label
+            = f.check_box :collapse_read_messages
+            span.radio-text
+              strong Collapse read messages
+              span.radio-description Automatically collapse already-read messages when opening a thread
       = f.submit "Save", class: "button-primary"

app/views/topics/_message.html.slim

@@ -1,6 +1,7 @@
 - render_mode = local_assigns.fetch(:render_mode, :inline)
 - is_read = local_assigns.fetch(:is_read, false)
-- is_collapsed = (render_mode == :collapsed) || (render_mode == :shell && is_read)
+- collapse_read = local_assigns.fetch(:collapse_read, true)
+- is_collapsed = (render_mode == :collapsed) || (render_mode == :shell && is_read && collapse_read)
 - message_classes = [("reply-message" if message.reply_to_id), ("message-branch-#{local_assigns[:branch_index]}" unless local_assigns[:branch_index].nil?), ("is-collapsed" if is_collapsed)].compact.join(" ")
 .message-card id=message_dom_id(message) class=message_classes data-controller="message-collapse" data-message-collapse-collapsed-value=is_collapsed data-message-id=message.id data-read=(is_read ? "true" : "false")
   - if (mid_anchor = message_id_anchor(message))

app/views/topics/show.html.slim

@@ -197,6 +197,7 @@
       - if user_signed_in?
         = link_to "Jump to unread", "#first-unread", class: "button button-secondary button-small", title: "Jump to first unread message", "aria-label": "Jump to first unread message"
 
+  - collapse_read = !user_signed_in? || current_user.collapse_read_messages?
   - first_unread_found = false
   - unread_inline_count = 0
   - @messages.each do |message|
@@ -213,7 +214,7 @@
     - else
       - render_mode = :shell
     - branch_index = @message_branch_index&.dig(message.id)
-    = render 'message', message: message, number: @message_numbers[message.id], is_first_unread: is_first_unread, branch_index: branch_index, render_mode: render_mode, is_read: !!is_read
+    = render 'message', message: message, number: @message_numbers[message.id], is_first_unread: is_first_unread, branch_index: branch_index, render_mode: render_mode, is_read: !!is_read, collapse_read: collapse_read
 
 .topic-navigation
   = link_to "← Back to Topics", topics_path, class: "back-link"

db/migrate/20260304120000_add_collapse_read_messages_to_users.rb

@@ -0,0 +1,7 @@
+# frozen_string_literal: true
+
+class AddCollapseReadMessagesToUsers < ActiveRecord::Migration[7.1]
+  def change
+    add_column :users, :collapse_read_messages, :boolean, default: true, null: false
+  end
+end