message_list: Convert MessageList to an ES6 class.

Signed-off-by: Anders Kaseorg <anders@zulip.com>

static/js/message_list.js

@@ -5,7 +5,8 @@ exports.set_narrowed = function (value) {
     exports.narrowed = value;
 };
 
-exports.MessageList = function (opts) {
+class MessageList {
+    constructor(opts) {
         if (opts.data) {
             this.muting_enabled = opts.data.muting_enabled;
             this.data = opts.data;
@@ -29,12 +30,9 @@ exports.MessageList = function (opts) {
         this.num_appends = 0;
 
         return this;
-};
+    }
-
-exports.MessageList.prototype = {
-    add_messages: function MessageList_add_messages(messages, opts) {
-        const self = this;
 
+    add_messages(messages, opts) {
         // This adds all messages to our data, but only returns
         // the currently viewable ones.
         const info = this.data.add_messages(messages);
@@ -50,77 +48,77 @@ exports.MessageList.prototype = {
         let render_info;
 
         if (interior_messages.length > 0) {
-            self.view.rerender_preserving_scrolltop(true);
+            this.view.rerender_preserving_scrolltop(true);
             return true;
         }
         if (top_messages.length > 0) {
-            self.view.prepend(top_messages);
+            this.view.prepend(top_messages);
         }
 
         if (bottom_messages.length > 0) {
-            render_info = self.append_to_view(bottom_messages, opts);
+            render_info = this.append_to_view(bottom_messages, opts);
         }
 
-        if (self === exports.narrowed && !self.empty()) {
+        if (this === exports.narrowed && !this.empty()) {
             // If adding some new messages to the message tables caused
             // our current narrow to no longer be empty, hide the empty
             // feed placeholder text.
             narrow.hide_empty_narrow_message();
         }
 
-        if (self === exports.narrowed && !self.empty() && self.selected_id() === -1) {
+        if (this === exports.narrowed && !this.empty() && this.selected_id() === -1) {
             // And also select the newly arrived message.
-            self.select_id(self.selected_id(), {then_scroll: true, use_closest: true});
+            this.select_id(this.selected_id(), {then_scroll: true, use_closest: true});
         }
 
         return render_info;
-    },
+    }
 
     get(id) {
         return this.data.get(id);
-    },
+    }
 
     num_items() {
         return this.data.num_items();
-    },
+    }
 
     empty() {
         return this.data.empty();
-    },
+    }
 
     first() {
         return this.data.first();
-    },
+    }
 
     last() {
         return this.data.last();
-    },
+    }
 
     prev() {
         return this.data.prev();
-    },
+    }
 
     next() {
         return this.data.next();
-    },
+    }
 
     is_at_end() {
         return this.data.is_at_end();
-    },
+    }
 
     nth_most_recent_id(n) {
         return this.data.nth_most_recent_id(n);
-    },
+    }
 
     is_search() {
         return this.data.is_search();
-    },
+    }
 
     can_mark_messages_read() {
         return this.data.can_mark_messages_read();
-    },
+    }
 
-    clear: function MessageList_clear(opts) {
+    clear(opts) {
         opts = {clear_selected_id: true, ...opts};
 
         this.data.clear();
@@ -129,13 +127,13 @@ exports.MessageList.prototype = {
         if (opts.clear_selected_id) {
             this.data.clear_selected_id();
         }
-    },
+    }
 
     selected_id() {
         return this.data.selected_id();
-    },
+    }
 
-    select_id: function MessageList_select_id(id, opts) {
+    select_id(id, opts) {
         opts = {
             then_scroll: false,
             target_scroll_offset: undefined,
@@ -149,13 +147,13 @@ exports.MessageList.prototype = {
             previously_selected: this.data.selected_id(),
         };
 
-        function convert_id(str_id) {
+        const convert_id = (str_id) => {
             const id = parseFloat(str_id);
             if (isNaN(id)) {
                 blueslip.fatal("Bad message id " + str_id);
             }
             return id;
-        }
+        };
 
         id = convert_id(id);
 
@@ -198,48 +196,48 @@ exports.MessageList.prototype = {
         }
 
         $(document).trigger($.Event("message_selected.zulip", opts));
-    },
+    }
 
-    reselect_selected_id: function MessageList_select_closest_id() {
+    reselect_selected_id() {
         this.select_id(this.data.selected_id(), {from_rendering: true});
-    },
+    }
 
-    selected_message: function MessageList_selected_message() {
+    selected_message() {
         return this.get(this.data.selected_id());
-    },
+    }
 
-    selected_row: function MessageList_selected_row() {
+    selected_row() {
         return this.get_row(this.data.selected_id());
-    },
+    }
 
     closest_id(id) {
         return this.data.closest_id(id);
-    },
+    }
 
     advance_past_messages(msg_ids) {
         return this.data.advance_past_messages(msg_ids);
-    },
+    }
 
     selected_idx() {
         return this.data.selected_idx();
-    },
+    }
 
     subscribed_bookend_content(stream_name) {
         return i18n.t("You subscribed to stream __stream__", {stream: stream_name});
-    },
+    }
 
     unsubscribed_bookend_content(stream_name) {
         return i18n.t("You unsubscribed from stream __stream__", {stream: stream_name});
-    },
+    }
 
     not_subscribed_bookend_content(stream_name) {
         return i18n.t("You are not subscribed to stream __stream__", {stream: stream_name});
-    },
+    }
 
     // Maintains a trailing bookend element explaining any changes in
     // your subscribed/unsubscribed status at the bottom of the
     // message list.
-    update_trailing_bookend: function MessageList_update_trailing_bookend() {
+    update_trailing_bookend() {
         this.view.clear_trailing_bookend();
         if (!this.narrowed) {
             return;
@@ -273,16 +271,16 @@ exports.MessageList.prototype = {
         if (trailing_bookend_content !== undefined) {
             this.view.render_trailing_bookend(trailing_bookend_content, subscribed, show_button);
         }
-    },
+    }
 
     unmuted_messages(messages) {
         return this.data.unmuted_messages(messages);
-    },
+    }
 
-    append: function MessageList_append(messages, opts) {
+    append(messages, opts) {
         const viewable_messages = this.data.append(messages);
         this.append_to_view(viewable_messages, opts);
-    },
+    }
 
     append_to_view(messages, opts) {
         opts = {messages_are_new: false, ...opts};
@@ -290,14 +288,14 @@ exports.MessageList.prototype = {
         this.num_appends += 1;
         const render_info = this.view.append(messages, opts.messages_are_new);
         return render_info;
-    },
+    }
 
-    remove_and_rerender: function MessageList_remove_and_rerender(messages) {
+    remove_and_rerender(messages) {
         this.data.remove(messages);
         this.rerender();
-    },
+    }
 
-    show_edit_message: function MessageList_show_edit_message(row, edit_obj) {
+    show_edit_message(row, edit_obj) {
         if (row.find(".message_edit_form form").length !== 0) {
             return;
         }
@@ -305,14 +303,14 @@ exports.MessageList.prototype = {
         row.find(".message_content, .status-message, .message_controls").hide();
         row.find(".message_edit").css("display", "block");
         autosize(row.find(".message_edit_content"));
-    },
+    }
 
-    hide_edit_message: function MessageList_hide_edit_message(row) {
+    hide_edit_message(row) {
         row.find(".message_content, .status-message, .message_controls").show();
         row.find(".message_edit_form").empty();
         row.find(".message_edit").hide();
         row.trigger("mouseleave");
-    },
+    }
 
     show_edit_topic_on_recipient_row(recipient_row, form) {
         recipient_row.find(".topic_edit_form").append(form);
@@ -320,7 +318,7 @@ exports.MessageList.prototype = {
         recipient_row.find(".edit_content_button").hide();
         recipient_row.find(".stream_topic").hide();
         recipient_row.find(".topic_edit").show();
-    },
+    }
 
     hide_edit_topic_on_recipient_row(recipient_row) {
         recipient_row.find(".stream_topic").show();
@@ -328,7 +326,7 @@ exports.MessageList.prototype = {
         recipient_row.find(".edit_content_button").show();
         recipient_row.find(".topic_edit_form").empty();
         recipient_row.find(".topic_edit").hide();
-    },
+    }
 
     show_message_as_read(message, options) {
         const row = this.get_row(message.id);
@@ -338,9 +336,9 @@ exports.MessageList.prototype = {
             row.find(".unread_marker").addClass("slow_fade");
         }
         row.removeClass("unread");
-    },
+    }
 
-    rerender: function MessageList_rerender() {
+    rerender() {
         // We need to clear the rendering state, rather than just
         // doing clear_table, since we want to potentially recollapse
         // things.
@@ -358,7 +356,7 @@ exports.MessageList.prototype = {
 
         this.view.rerender_preserving_scrolltop();
         this.redo_selection();
-    },
+    }
 
     redo_selection() {
         const selected_id = this.data.selected_id();
@@ -366,73 +364,71 @@ exports.MessageList.prototype = {
         if (selected_id !== -1) {
             this.select_id(selected_id);
         }
-    },
+    }
 
-    update_muting_and_rerender: function MessageList_update_muting_and_rerender() {
+    update_muting_and_rerender() {
         if (!this.muting_enabled) {
             return;
         }
         this.data.update_items_for_muting();
         this.rerender();
-    },
+    }
 
-    all_messages: function MessageList_all_messages() {
+    all_messages() {
         return this.data.all_messages();
-    },
+    }
 
     first_unread_message_id() {
         return this.data.first_unread_message_id();
-    },
+    }
 
     message_range(start, end) {
         return this.data.message_range(start, end);
-    },
+    }
 
     get_row(id) {
         return this.view.get_row(id);
-    },
+    }
 
     update_user_full_name(user_id, full_name) {
         this.data.update_user_full_name(user_id, full_name);
         if (this.table_name !== undefined) {
             this.view.rerender_preserving_scrolltop();
         }
-    },
+    }
 
     update_user_avatar(user_id, avatar_url) {
         this.data.update_user_avatar(user_id, avatar_url);
         if (this.table_name !== undefined) {
             this.view.rerender_preserving_scrolltop();
         }
-    },
+    }
 
     update_stream_name(stream_id, new_stream_name) {
         this.data.update_stream_name(stream_id, new_stream_name);
         if (this.table_name !== undefined) {
             this.view.rerender_preserving_scrolltop();
         }
-    },
+    }
 
-    change_message_id: function MessageList_change_message_id(old_id, new_id) {
+    change_message_id(old_id, new_id) {
-        const self = this;
         const opts = {
-            is_current_list() {
+            is_current_list: () => current_msg_list === this,
-                return current_msg_list === self;
+            re_render: () => {
-            },
+                this.view.rerender_preserving_scrolltop();
-            re_render() {
+                this.redo_selection();
-                self.view.rerender_preserving_scrolltop();
-                self.redo_selection();
             },
         };
         this.data.change_message_id(old_id, new_id, opts);
-    },
+    }
 
     get_last_message_sent_by_me() {
         return this.data.get_last_message_sent_by_me();
-    },
+    }
-};
+}
+exports.MessageList = MessageList;
 
-exports.all = new exports.MessageList({
+exports.all = new MessageList({
     muting_enabled: false,
 });