zulip/static/js/message_list_view.js

1313 lines
51 KiB
JavaScript

import {isSameDay} from "date-fns";
import $ from "jquery";
import _ from "lodash";
import render_bookend from "../templates/bookend.hbs";
import render_message_group from "../templates/message_group.hbs";
import render_recipient_row from "../templates/recipient_row.hbs";
import render_single_message from "../templates/single_message.hbs";
import * as activity from "./activity";
import * as blueslip from "./blueslip";
import * as color_class from "./color_class";
import * as compose from "./compose";
import * as compose_fade from "./compose_fade";
import * as condense from "./condense";
import * as hash_util from "./hash_util";
import {$t} from "./i18n";
import * as message_edit from "./message_edit";
import * as message_lists from "./message_lists";
import * as message_store from "./message_store";
import * as message_viewport from "./message_viewport";
import * as muting from "./muting";
import * as narrow_state from "./narrow_state";
import {page_params} from "./page_params";
import * as people from "./people";
import * as popovers from "./popovers";
import * as reactions from "./reactions";
import * as recent_topics from "./recent_topics";
import * as rendered_markdown from "./rendered_markdown";
import * as rows from "./rows";
import * as stream_data from "./stream_data";
import * as sub_store from "./sub_store";
import * as submessage from "./submessage";
import * as timerender from "./timerender";
import * as util from "./util";
function same_day(earlier_msg, later_msg) {
if (earlier_msg === undefined || later_msg === undefined) {
return false;
}
return isSameDay(earlier_msg.msg.timestamp * 1000, later_msg.msg.timestamp * 1000);
}
function same_sender(a, b) {
if (a === undefined || b === undefined) {
return false;
}
return util.same_sender(a.msg, b.msg);
}
function same_recipient(a, b) {
if (a === undefined || b === undefined) {
return false;
}
return util.same_recipient(a.msg, b.msg);
}
function render_group_display_date(group, message_container) {
const time = new Date(message_container.msg.timestamp * 1000);
const today = new Date();
const date_element = timerender.render_date(time, undefined, today)[0];
group.date = date_element.outerHTML;
}
function update_group_date_divider(group, message_container, prev) {
const time = new Date(message_container.msg.timestamp * 1000);
const today = new Date();
if (prev !== undefined) {
const prev_time = new Date(prev.msg.timestamp * 1000);
if (!isSameDay(time, prev_time)) {
// NB: group_date_divider_html is HTML, inserted into the document without escaping.
group.group_date_divider_html = timerender.render_date(
time,
prev_time,
today,
)[0].outerHTML;
group.show_group_date_divider = true;
}
} else {
// Show the date in the recipient bar, but not a date separator bar.
group.show_group_date_divider = false;
group.group_date_divider_html = timerender.render_date(time, undefined, today)[0].outerHTML;
}
}
function clear_group_date_divider(group) {
group.show_group_date_divider = false;
group.group_date_divider_html = undefined;
}
function clear_message_date_divider(msg) {
// see update_message_date_divider for how
// these get set
msg.want_date_divider = false;
msg.date_divider_html = undefined;
}
function update_message_date_divider(opts) {
const prev_msg_container = opts.prev_msg_container;
const curr_msg_container = opts.curr_msg_container;
if (!prev_msg_container || same_day(curr_msg_container, prev_msg_container)) {
clear_message_date_divider(curr_msg_container);
return;
}
const prev_time = new Date(prev_msg_container.msg.timestamp * 1000);
const curr_time = new Date(curr_msg_container.msg.timestamp * 1000);
const today = new Date();
curr_msg_container.want_date_divider = true;
curr_msg_container.date_divider_html = timerender.render_date(
curr_time,
prev_time,
today,
)[0].outerHTML;
}
function set_timestr(message_container) {
const time = new Date(message_container.msg.timestamp * 1000);
message_container.timestr = timerender.stringify_time(time);
}
function set_topic_edit_properties(group, message) {
group.realm_allow_message_editing = page_params.realm_allow_message_editing;
group.always_visible_topic_edit = false;
group.on_hover_topic_edit = false;
// Messages with no topics should always have an edit icon visible
// to encourage updating them. Admins can also edit any topic.
if (message.topic === compose.empty_topic_placeholder()) {
group.always_visible_topic_edit = true;
} else if (message_edit.is_topic_editable(message)) {
group.on_hover_topic_edit = true;
}
}
function populate_group_from_message_container(group, message_container) {
group.is_stream = message_container.msg.is_stream;
group.is_private = message_container.msg.is_private;
if (group.is_stream) {
group.background_color = stream_data.get_color(message_container.msg.stream);
group.color_class = color_class.get_css_class(group.background_color);
group.invite_only = stream_data.get_invite_only(message_container.msg.stream);
group.topic = message_container.msg.topic;
group.match_topic = util.get_match_topic(message_container.msg);
group.stream_url = message_container.stream_url;
group.topic_url = message_container.topic_url;
const sub = sub_store.get(message_container.msg.stream_id);
if (sub === undefined) {
// Hack to handle unusual cases like the tutorial where
// the streams used don't actually exist in the subs
// module. Ideally, we'd clean this up by making the
// tutorial populate subs.js "properly".
group.stream_id = -1;
} else {
group.stream_id = sub.stream_id;
}
group.topic_muted = muting.is_topic_muted(group.stream_id, group.topic);
} else if (group.is_private) {
group.pm_with_url = message_container.pm_with_url;
group.display_reply_to = message_store.get_pm_full_names(message_container.msg);
}
group.display_recipient = message_container.msg.display_recipient;
group.topic_links = message_container.msg.topic_links;
set_topic_edit_properties(group, message_container.msg);
render_group_display_date(group, message_container);
}
export class MessageListView {
constructor(list, table_name, collapse_messages) {
this.list = list;
this.collapse_messages = collapse_messages;
this._rows = new Map();
this.message_containers = new Map();
this.table_name = table_name;
if (this.table_name) {
this.clear_table();
}
this._message_groups = [];
// Half-open interval of the indices that define the current render window
this._render_win_start = 0;
this._render_win_end = 0;
}
// Number of messages to render at a time
_RENDER_WINDOW_SIZE = 400;
// Number of messages away from edge of render window at which we
// trigger a re-render
_RENDER_THRESHOLD = 50;
_get_msg_timestring(message_container) {
let last_edit_timestamp;
if (message_container.msg.local_edit_timestamp !== undefined) {
last_edit_timestamp = message_container.msg.local_edit_timestamp;
} else {
last_edit_timestamp = message_container.msg.last_edit_timestamp;
}
if (last_edit_timestamp !== undefined) {
const last_edit_time = new Date(last_edit_timestamp * 1000);
const today = new Date();
return (
timerender.render_date(last_edit_time, undefined, today)[0].textContent +
" at " +
timerender.stringify_time(last_edit_time)
);
}
return undefined;
}
_add_msg_edited_vars(message_container) {
// This adds variables to message_container object which calculate bools for
// checking position of "(EDITED)" label as well as the edited timestring
// The bools can be defined only when the message is edited
// (or when the `last_edit_timestr` is defined). The bools are:
// * `edited_in_left_col` -- when label appears in left column.
// * `edited_alongside_sender` -- when label appears alongside sender info.
// * `edited_status_msg` -- when label appears for a "/me" message.
const last_edit_timestr = this._get_msg_timestring(message_container);
const include_sender = message_container.include_sender;
const status_message = Boolean(message_container.status_message);
if (last_edit_timestr !== undefined) {
message_container.last_edit_timestr = last_edit_timestr;
message_container.edited_in_left_col = !include_sender;
message_container.edited_alongside_sender = include_sender && !status_message;
message_container.edited_status_msg = include_sender && status_message;
} else {
delete message_container.last_edit_timestr;
message_container.edited_in_left_col = false;
message_container.edited_alongside_sender = false;
message_container.edited_status_msg = false;
}
}
set_calculated_message_container_variables(message_container) {
set_timestr(message_container);
// Make sure the right thing happens if the message was edited to mention us.
message_container.contains_mention = message_container.msg.mentioned;
this._maybe_format_me_message(message_container);
// Once all other variables are updated
this._add_msg_edited_vars(message_container);
}
add_subscription_marker(group, last_msg_container, first_msg_container) {
if (last_msg_container === undefined) {
return;
}
const last_subscribed = !last_msg_container.msg.historical;
const first_subscribed = !first_msg_container.msg.historical;
const stream = first_msg_container.msg.stream;
if (!last_subscribed && first_subscribed) {
group.bookend_top = true;
group.subscribed = stream;
group.bookend_content = this.list.subscribed_bookend_content(stream);
return;
}
if (last_subscribed && !first_subscribed) {
group.bookend_top = true;
group.unsubscribed = stream;
group.bookend_content = this.list.unsubscribed_bookend_content(stream);
return;
}
}
build_message_groups(message_containers) {
const start_group = () => ({
message_containers: [],
message_group_id: _.uniqueId("message_group_"),
});
let current_group = start_group();
const new_message_groups = [];
let prev;
const add_message_container_to_group = (message_container) => {
if (same_sender(prev, message_container)) {
prev.next_is_same_sender = true;
}
current_group.message_containers.push(message_container);
};
const finish_group = () => {
if (current_group.message_containers.length > 0) {
populate_group_from_message_container(
current_group,
current_group.message_containers[0],
);
current_group.message_containers[
current_group.message_containers.length - 1
].include_footer = true;
new_message_groups.push(current_group);
}
};
for (const message_container of message_containers) {
const message_reactions = reactions.get_message_reactions(message_container.msg);
message_container.msg.message_reactions = message_reactions;
message_container.include_recipient = false;
message_container.include_footer = false;
if (
same_recipient(prev, message_container) &&
this.collapse_messages &&
prev.msg.historical === message_container.msg.historical
) {
add_message_container_to_group(message_container);
update_message_date_divider({
prev_msg_container: prev,
curr_msg_container: message_container,
});
} else {
finish_group();
current_group = start_group();
add_message_container_to_group(message_container);
update_group_date_divider(current_group, message_container, prev);
clear_message_date_divider(message_container);
message_container.include_recipient = true;
message_container.subscribed = false;
message_container.unsubscribed = false;
// This message_lists.home condition can be removed
// once we filter historical messages from the
// home view on the server side (which requires
// having an index on UserMessage.flags)
if (this.list !== message_lists.home) {
this.add_subscription_marker(current_group, prev, message_container);
}
if (message_container.msg.stream) {
message_container.stream_url = hash_util.by_stream_uri(
message_container.msg.stream_id,
);
message_container.topic_url = hash_util.by_stream_topic_uri(
message_container.msg.stream_id,
message_container.msg.topic,
);
} else {
message_container.pm_with_url = message_container.msg.pm_with_url;
}
}
message_container.include_sender = true;
if (
!message_container.include_recipient &&
!prev.status_message &&
same_day(prev, message_container) &&
same_sender(prev, message_container)
) {
message_container.include_sender = false;
}
message_container.sender_is_bot = people.sender_is_bot(message_container.msg);
message_container.sender_is_guest = people.sender_is_guest(message_container.msg);
message_container.small_avatar_url = people.small_avatar_url(message_container.msg);
if (message_container.msg.stream) {
message_container.background_color = stream_data.get_color(
message_container.msg.stream,
);
}
this.set_calculated_message_container_variables(message_container);
prev = message_container;
}
finish_group();
return new_message_groups;
}
join_message_groups(first_group, second_group) {
// join_message_groups will combine groups if they have the
// same_recipient and the view supports collapsing, otherwise
// it may add a subscription_marker if required. It returns
// true if the two groups were joined in to one and the
// second_group should be ignored.
if (first_group === undefined || second_group === undefined) {
return false;
}
const last_msg_container = _.last(first_group.message_containers);
const first_msg_container = _.first(second_group.message_containers);
// Join two groups into one.
if (
this.collapse_messages &&
same_recipient(last_msg_container, first_msg_container) &&
last_msg_container.msg.historical === first_msg_container.msg.historical
) {
if (
!last_msg_container.status_message &&
!first_msg_container.msg.is_me_message &&
same_day(last_msg_container, first_msg_container) &&
same_sender(last_msg_container, first_msg_container)
) {
first_msg_container.include_sender = false;
}
if (same_sender(last_msg_container, first_msg_container)) {
last_msg_container.next_is_same_sender = true;
}
first_group.message_containers = first_group.message_containers.concat(
second_group.message_containers,
);
return true;
// Add a subscription marker
} else if (
this.list !== message_lists.home &&
last_msg_container.msg.historical !== first_msg_container.msg.historical
) {
second_group.bookend_top = true;
this.add_subscription_marker(second_group, last_msg_container, first_msg_container);
}
return false;
}
merge_message_groups(new_message_groups, where) {
// merge_message_groups takes a list of new messages groups to add to
// this._message_groups and a location where to merge them currently
// top or bottom. It returns an object of changes which needed to be
// rendered in to the page. The types of actions are append_group,
// prepend_group, rerender_group, append_message.
//
// append_groups are groups to add to the top of the rendered DOM
// prepend_groups are group to add to the bottom of the rendered DOM
// rerender_groups are group that should be updated in place in the DOM
// append_messages are messages which should be added to the last group in the DOM
// rerender_messages are messages which should be updated in place in the DOM
const message_actions = {
append_groups: [],
prepend_groups: [],
rerender_groups: [],
append_messages: [],
rerender_messages_next_same_sender: [],
};
let first_group;
let second_group;
let curr_msg_container;
let prev_msg_container;
if (where === "top") {
first_group = _.last(new_message_groups);
second_group = _.first(this._message_groups);
} else {
first_group = _.last(this._message_groups);
second_group = _.first(new_message_groups);
}
if (first_group) {
prev_msg_container = _.last(first_group.message_containers);
}
if (second_group) {
curr_msg_container = _.first(second_group.message_containers);
}
const was_joined = this.join_message_groups(first_group, second_group);
if (was_joined) {
update_message_date_divider({
prev_msg_container,
curr_msg_container,
});
} else {
clear_message_date_divider(curr_msg_container);
}
if (where === "top") {
if (was_joined) {
// join_message_groups moved the old message to the end of the
// new group. We need to replace the old rendered message
// group. So we will reuse its ID.
first_group.message_group_id = second_group.message_group_id;
message_actions.rerender_groups.push(first_group);
// Swap the new group in
this._message_groups.shift();
this._message_groups.unshift(first_group);
new_message_groups = _.initial(new_message_groups);
} else if (
!same_day(second_group.message_containers[0], first_group.message_containers[0])
) {
// The groups did not merge, so we need up update the date row for the old group
update_group_date_divider(second_group, curr_msg_container, prev_msg_container);
// We could add an action to update the date row, but for now rerender the group.
message_actions.rerender_groups.push(second_group);
}
message_actions.prepend_groups = new_message_groups;
this._message_groups = new_message_groups.concat(this._message_groups);
} else {
if (was_joined) {
// rerender the last message
message_actions.rerender_messages_next_same_sender.push(prev_msg_container);
message_actions.append_messages = _.first(new_message_groups).message_containers;
new_message_groups = _.tail(new_message_groups);
} else if (first_group !== undefined && second_group !== undefined) {
if (same_day(prev_msg_container, curr_msg_container)) {
clear_group_date_divider(second_group);
} else {
// If we just sent the first message on a new day
// in a narrow, make sure we render a date separator.
update_group_date_divider(second_group, curr_msg_container, prev_msg_container);
}
}
message_actions.append_groups = new_message_groups;
this._message_groups = this._message_groups.concat(new_message_groups);
}
return message_actions;
}
_put_row(row) {
// row is a jQuery object wrapping one message row
if (row.hasClass("message_row")) {
this._rows.set(rows.id(row), row);
}
}
_post_process($message_rows) {
// $message_rows wraps one or more message rows
if (!($message_rows instanceof $)) {
// An assertion check that we're calling this properly
blueslip.error("programming error--pass in jQuery objects");
}
for (const dom_row of $message_rows) {
const row = $(dom_row);
this._put_row(row);
this._post_process_single_row(row);
}
}
_post_process_single_row(row) {
// For message formatting that requires some post-processing
// (and is not possible to handle solely via CSS), this is
// where we modify the content. It is a goal to minimize how
// much logic is present in this function; wherever possible,
// we should implement features with the Markdown processor,
// HTML and CSS.
if (row.length !== 1) {
blueslip.error("programming error--expected single element");
}
const content = row.find(".message_content");
rendered_markdown.update_elements(content);
const id = rows.id(row);
message_edit.maybe_show_edit(row, id);
submessage.process_submessages({
row,
message_id: id,
});
}
_get_message_template(message_container) {
const msg_reactions = reactions.get_message_reactions(message_container.msg);
message_container.msg.message_reactions = msg_reactions;
const msg_to_render = {
...message_container,
table_name: this.table_name,
};
return render_single_message(msg_to_render);
}
_render_group(opts) {
const message_groups = opts.message_groups;
const use_match_properties = opts.use_match_properties;
const table_name = opts.table_name;
return $(
render_message_group({
message_groups,
use_match_properties,
table_name,
}),
);
}
render(messages, where, messages_are_new) {
// This function processes messages into chunks with separators between them,
// and templates them to be inserted as table rows into the DOM.
if (messages.length === 0 || this.table_name === undefined) {
return undefined;
}
const list = this.list; // for convenience
const table_name = this.table_name;
const table = rows.get_table(table_name);
let orig_scrolltop_offset;
// If we start with the message feed scrolled up (i.e.
// the bottom message is not visible), then we will respect
// the user's current position after rendering, rather
// than auto-scrolling.
const started_scrolled_up = message_viewport.is_scrolled_up();
// The messages we are being asked to render are shared with between
// all messages lists. To prevent having both list views overwriting
// each others data we will make a new message object to add data to
// for rendering.
const message_containers = messages.map((message) => {
if (message.starred) {
message.starred_status = $t({defaultMessage: "Unstar"});
} else {
message.starred_status = $t({defaultMessage: "Star"});
}
return {msg: message};
});
const save_scroll_position = () => {
if (orig_scrolltop_offset === undefined && this.selected_row().length > 0) {
orig_scrolltop_offset = this.selected_row().offset().top;
}
};
const restore_scroll_position = () => {
if (
!recent_topics.is_visible() &&
list === message_lists.current &&
orig_scrolltop_offset !== undefined
) {
list.view.set_message_offset(orig_scrolltop_offset);
list.reselect_selected_id();
}
};
if (message_containers.length === 0) {
return undefined;
}
const new_message_groups = this.build_message_groups(message_containers, this.table_name);
const message_actions = this.merge_message_groups(new_message_groups, where);
let new_dom_elements = [];
let rendered_groups;
let dom_messages;
let last_message_row;
let last_group_row;
for (const message_container of message_containers) {
this.message_containers.set(message_container.msg.id, message_container);
}
// Render new message groups on the top
if (message_actions.prepend_groups.length > 0) {
save_scroll_position();
rendered_groups = this._render_group({
message_groups: message_actions.prepend_groups,
use_match_properties: this.list.is_search(),
table_name: this.table_name,
});
dom_messages = rendered_groups.find(".message_row");
new_dom_elements = new_dom_elements.concat(rendered_groups);
this._post_process(dom_messages);
// The date row will be included in the message groups or will be
// added in a rerenderd in the group below
table.find(".recipient_row").first().prev(".date_row").remove();
table.prepend(rendered_groups);
condense.condense_and_collapse(dom_messages);
}
// Rerender message groups
if (message_actions.rerender_groups.length > 0) {
save_scroll_position();
for (const message_group of message_actions.rerender_groups) {
const old_message_group = $(`#${CSS.escape(message_group.message_group_id)}`);
// Remove the top date_row, we'll re-add it after rendering
old_message_group.prev(".date_row").remove();
rendered_groups = this._render_group({
message_groups: [message_group],
use_match_properties: this.list.is_search(),
table_name: this.table_name,
});
dom_messages = rendered_groups.find(".message_row");
// Not adding to new_dom_elements it is only used for autoscroll
this._post_process(dom_messages);
old_message_group.replaceWith(rendered_groups);
condense.condense_and_collapse(dom_messages);
}
}
// Update the rendering for message rows which used to be last
// and now know whether the following message has the same
// sender.
//
// It is likely the case that we can just remove the block
// entirely, since it appears the next_is_same_sender CSS
// class doesn't do anything.
if (message_actions.rerender_messages_next_same_sender.length > 0) {
const targets = message_actions.rerender_messages_next_same_sender;
for (const message_container of targets) {
const row = this.get_row(message_container.msg.id);
$(row)
.find("div.messagebox")
.toggleClass("next_is_same_sender", message_container.next_is_same_sender);
}
}
// Insert new messages in to the last message group
if (message_actions.append_messages.length > 0) {
last_message_row = table.find(".message_row").last().expectOne();
last_group_row = rows.get_message_recipient_row(last_message_row);
dom_messages = $(
message_actions.append_messages
.map((message_container) => this._get_message_template(message_container))
.join(""),
).filter(".message_row");
this._post_process(dom_messages);
last_group_row.append(dom_messages);
condense.condense_and_collapse(dom_messages);
new_dom_elements = new_dom_elements.concat(dom_messages);
}
// Add new message groups to the end
if (message_actions.append_groups.length > 0) {
// Remove the trailing bookend; it'll be re-added after we do our rendering
this.clear_trailing_bookend();
rendered_groups = this._render_group({
message_groups: message_actions.append_groups,
use_match_properties: this.list.is_search(),
table_name: this.table_name,
});
dom_messages = rendered_groups.find(".message_row");
new_dom_elements = new_dom_elements.concat(rendered_groups);
this._post_process(dom_messages);
// This next line is a workaround for a weird scrolling
// bug on Chrome. Basically, in Chrome 64, we had a
// highly reproducible bug where if you hit the "End" key
// 5 times in a row in a `near:1` narrow (or any other
// narrow with enough content below to try this), the 5th
// time (because RENDER_WINDOW_SIZE / batch_size = 4,
// i.e. the first time we need to rerender to show the
// message "End" jumps to) would trigger an unexpected
// scroll, resulting in some chaotic scrolling and
// additional fetches (from bottom_whitespace ending up in
// the view). During debugging, we found that this adding
// this next line seems to prevent the Chrome bug from firing.
message_viewport.scrollTop();
table.append(rendered_groups);
condense.condense_and_collapse(dom_messages);
}
restore_scroll_position();
const last_message_group = _.last(this._message_groups);
if (last_message_group !== undefined) {
list.last_message_historical = _.last(
last_message_group.message_containers,
).msg.historical;
}
const stream_name = narrow_state.stream();
if (stream_name !== undefined) {
// If user narrows to a stream, doesn't update
// trailing bookend if user is subscribed.
const sub = stream_data.get_sub(stream_name);
if (sub === undefined || !sub.subscribed) {
list.update_trailing_bookend();
}
}
if (list === message_lists.current) {
// Update the fade.
const get_element = (message_group) => {
// We don't have a MessageGroup class, but we can at least hide the messy details
// of rows.js from compose_fade. We provide a callback function to be lazy--
// compose_fade may not actually need the elements depending on its internal
// state.
const message_row = this.get_row(message_group.message_containers[0].msg.id);
return rows.get_message_recipient_row(message_row);
};
compose_fade.update_rendered_message_groups(new_message_groups, get_element);
}
if (list === message_lists.current && messages_are_new) {
// First, in single-recipient narrows, potentially
// auto-scroll to the latest message if it was sent by us.
if (narrow_state.narrowed_by_reply()) {
const selected_id = list.selected_id();
let i;
// Iterate backwards to find the last message
// sent_by_me, stopping at the pointer position.
// There's a reasonable argument that this search
// should be limited in how far offscreen it's willing
// to go.
for (i = messages.length - 1; i >= 0; i -= 1) {
const id = messages[i].id;
if (id <= selected_id) {
break;
}
if (messages[i].sent_by_me && list.get(id) !== undefined) {
// If this is a reply we just sent, advance the pointer to it.
list.select_id(messages[i].id, {then_scroll: true, from_scroll: true});
return {
need_user_to_scroll: false,
};
}
}
}
if (started_scrolled_up) {
return {
need_user_to_scroll: true,
};
}
const new_messages_height = this._new_messages_height(new_dom_elements);
const need_user_to_scroll = this._maybe_autoscroll(new_messages_height);
if (need_user_to_scroll) {
return {
need_user_to_scroll: true,
};
}
}
return undefined;
}
_new_messages_height(rendered_elems) {
let new_messages_height = 0;
for (const elem of rendered_elems.reverse()) {
// Sometimes there are non-DOM elements in rendered_elems; only
// try to get the heights of actual trs.
if (elem.is("div")) {
new_messages_height += elem.height();
}
}
return new_messages_height;
}
_scroll_limit(selected_row, viewport_info) {
// This scroll limit is driven by the TOP of the feed, and
// it's the max amount that we can scroll down (or "skooch
// up" the messages) before knocking the selected message
// out of the feed.
const selected_row_top = selected_row.offset().top;
let scroll_limit = selected_row_top - viewport_info.visible_top;
if (scroll_limit < 0) {
// This shouldn't happen, but if we're off by a pixel or
// something, we can deal with it, and just warn.
blueslip.warn("Selected row appears too high on screen.");
scroll_limit = 0;
}
return scroll_limit;
}
_maybe_autoscroll(new_messages_height) {
// If we are near the bottom of our feed (the bottom is visible) and can
// scroll up without moving the pointer out of the viewport, do so, by
// up to the amount taken up by the new message.
//
// returns `true` if we need the user to scroll
const selected_row = this.selected_row();
const last_visible = rows.last_visible();
// Make sure we have a selected row and last visible row. (defensive)
if (!(selected_row && selected_row.length > 0 && last_visible)) {
return false;
}
if (new_messages_height <= 0) {
return false;
}
if (!activity.client_is_active) {
// Don't autoscroll if the window hasn't had focus
// recently. This in intended to help protect us from
// auto-scrolling downwards when the window is in the
// background and might be having some functionality
// throttled by modern Chrome's aggressive power-saving
// features.
blueslip.log("Suppressing scrolldown due to inactivity");
return false;
}
// do not scroll if there are any active popovers.
if (popovers.any_active()) {
// If a popover is active, then we are pretty sure the
// incoming message is not from the user themselves, so
// we don't need to tell users to scroll down.
return false;
}
const info = message_viewport.message_viewport_info();
const scroll_limit = this._scroll_limit(selected_row, info);
// This next decision is fairly debatable. For a big message that
// would push the pointer off the screen, we do a partial autoscroll,
// which has the following implications:
// a) user sees scrolling (good)
// b) user's pointer stays on screen (good)
// c) scroll amount isn't really tied to size of new messages (bad)
// d) all the bad things about scrolling for users who want messages
// to stay on the screen
let scroll_amount;
let need_user_to_scroll;
if (new_messages_height <= scroll_limit) {
// This is the happy path where we can just scroll
// automatically, and the user will see the new message.
scroll_amount = new_messages_height;
need_user_to_scroll = false;
} else {
// Sometimes we don't want to scroll the entire height of
// the message, but our callers can give appropriate
// warnings if the message is gonna be offscreen.
// (Even if we are somewhat constrained here, the message may
// still end up being visible, so we do some arithmetic.)
scroll_amount = scroll_limit;
const offset = message_viewport.offset_from_bottom(last_visible);
// For determining whether we need to show the user a "you
// need to scroll down" notification, the obvious check
// would be `offset > scroll_amount`, and that is indeed
// correct with a 1-line message in the compose box.
// However, the compose box is open with the content of
// the message just sent when this code runs, and
// `offset_from_bottom` if an offset from the top of the
// compose box, which is about to be reset to empty. So
// to compute the offset at the time the user might see
// this notification, we need to adjust by the amount that
// the current compose is bigger than the empty, open
// compose box.
const compose_textarea_default_height = 42;
const compose_textarea_current_height = $("#compose-textarea").height();
const expected_change =
compose_textarea_current_height - compose_textarea_default_height;
const expected_offset = offset - expected_change;
need_user_to_scroll = expected_offset > scroll_amount;
}
// Ok, we are finally ready to actually scroll.
if (scroll_amount > 0) {
message_viewport.system_initiated_animate_scroll(scroll_amount);
}
return need_user_to_scroll;
}
clear_rendering_state(clear_table) {
if (clear_table) {
this.clear_table();
}
this.list.last_message_historical = false;
this._render_win_start = 0;
this._render_win_end = 0;
}
update_render_window(selected_idx, check_for_changed) {
const new_start = Math.max(selected_idx - this._RENDER_WINDOW_SIZE / 2, 0);
if (check_for_changed && new_start === this._render_win_start) {
return false;
}
this._render_win_start = new_start;
this._render_win_end = Math.min(
this._render_win_start + this._RENDER_WINDOW_SIZE,
this.list.num_items(),
);
return true;
}
maybe_rerender() {
if (this.table_name === undefined) {
return false;
}
const selected_idx = this.list.selected_idx();
// We rerender under the following conditions:
// * The selected message is within this._RENDER_THRESHOLD messages
// of the top of the currently rendered window and the top
// of the window does not abut the beginning of the message
// list
// * The selected message is within this._RENDER_THRESHOLD messages
// of the bottom of the currently rendered window and the
// bottom of the window does not abut the end of the
// message list
if (
!(
(selected_idx - this._render_win_start < this._RENDER_THRESHOLD &&
this._render_win_start !== 0) ||
(this._render_win_end - selected_idx <= this._RENDER_THRESHOLD &&
this._render_win_end !== this.list.num_items())
)
) {
return false;
}
if (!this.update_render_window(selected_idx, true)) {
return false;
}
this.rerender_preserving_scrolltop();
return true;
}
rerender_preserving_scrolltop(discard_rendering_state) {
// old_offset is the number of pixels between the top of the
// viewable window and the selected message
let old_offset;
const selected_row = this.selected_row();
const selected_in_view = selected_row.length > 0;
if (selected_in_view) {
old_offset = selected_row.offset().top;
}
if (discard_rendering_state) {
// If we know that the existing render is invalid way
// (typically because messages appear out-of-order), then
// we discard the message_list rendering state entirely.
this.clear_rendering_state(true);
this.update_render_window(this.list.selected_idx(), false);
}
return this.rerender_with_target_scrolltop(selected_row, old_offset);
}
set_message_offset(offset) {
const msg = this.selected_row();
message_viewport.scrollTop(message_viewport.scrollTop() + msg.offset().top - offset);
}
rerender_with_target_scrolltop(selected_row, target_offset) {
// target_offset is the target number of pixels between the top of the
// viewable window and the selected message
this.clear_table();
this.render(
this.list.all_messages().slice(this._render_win_start, this._render_win_end),
"bottom",
);
// If we could see the newly selected message, scroll the
// window such that the newly selected message is at the
// same location as it would have been before we
// re-rendered.
if (target_offset !== undefined) {
if (this.selected_row().length === 0 && this.list.selected_id() > -1) {
this.list.select_id(this.list.selected_id(), {use_closest: true});
}
this.set_message_offset(target_offset);
}
}
_find_message_group(message_group_id) {
// Ideally, we'd maintain this data structure with a hash
// table or at least a pointer from the message containers (in
// either case, updating the data structure when message
// groups are merged etc.) , but we only call this from flows
// like message editing, so it's not a big performance
// problem.
return this._message_groups.find(
// Since we don't have a way to get a message group from
// the containing message container, we just do a search
// to find it.
(message_group) => message_group.message_group_id === message_group_id,
);
}
_rerender_header(message_containers) {
// Given a list of messages that are in the **same** message group,
// rerender the header / recipient bar of the messages
if (message_containers.length === 0) {
return;
}
const first_row = this.get_row(message_containers[0].msg.id);
// We may not have the row if the stream or topic was muted
if (first_row.length === 0) {
return;
}
const recipient_row = rows.get_message_recipient_row(first_row);
const header = recipient_row.find(".message_header");
const message_group_id = recipient_row.attr("id");
// Since there might be multiple dates within the message
// group, it's important to lookup the original/full message
// group rather than doing an artificial rerendering of the
// message header from the set of message containers passed in
// here.
const group = this._find_message_group(message_group_id);
if (group === undefined) {
blueslip.error("Could not find message group for rerendering headers");
return;
}
// TODO: It's possible that we no longer need this populate
// call; it was introduced in an earlier version of this code
// where we constructed an artificial message group for this
// rerendering rather than looking up the original version.
populate_group_from_message_container(group, group.message_containers[0]);
const rendered_recipient_row = $(render_recipient_row(group));
header.replaceWith(rendered_recipient_row);
}
_rerender_message(message_container, message_content_edited) {
const row = this.get_row(message_container.msg.id);
const was_selected = this.list.selected_message() === message_container.msg;
this.set_calculated_message_container_variables(message_container);
const rendered_msg = $(this._get_message_template(message_container));
if (message_content_edited) {
rendered_msg.addClass("fade-in-message");
}
this._post_process(rendered_msg);
row.replaceWith(rendered_msg);
if (was_selected) {
this.list.select_id(message_container.msg.id);
}
}
rerender_messages(messages, message_content_edited) {
// Convert messages to list messages
let message_containers = messages.map((message) => this.message_containers.get(message.id));
// We may not have the message_container if the stream or topic was muted
message_containers = message_containers.filter(
(message_container) => message_container !== undefined,
);
const message_groups = [];
let current_group = [];
for (const message_container of message_containers) {
if (
current_group.length === 0 ||
same_recipient(current_group[current_group.length - 1], message_container)
) {
current_group.push(message_container);
} else {
message_groups.push(current_group);
current_group = [];
}
this._rerender_message(message_container, message_content_edited);
}
if (current_group.length !== 0) {
message_groups.push(current_group);
}
for (const messages_in_group of message_groups) {
this._rerender_header(messages_in_group, message_content_edited);
}
}
append(messages, messages_are_new) {
const cur_window_size = this._render_win_end - this._render_win_start;
let render_info;
if (cur_window_size < this._RENDER_WINDOW_SIZE) {
const slice_to_render = messages.slice(0, this._RENDER_WINDOW_SIZE - cur_window_size);
render_info = this.render(slice_to_render, "bottom", messages_are_new);
this._render_win_end += slice_to_render.length;
}
// If the pointer is high on the page such that there is a
// lot of empty space below and the render window is full, a
// newly received message should trigger a rerender so that
// the new message, which will appear in the viewable area,
// is rendered.
const needed_rerender = this.maybe_rerender();
if (needed_rerender) {
render_info = {need_user_to_scroll: true};
}
return render_info;
}
prepend(messages) {
this._render_win_start += messages.length;
this._render_win_end += messages.length;
const cur_window_size = this._render_win_end - this._render_win_start;
if (cur_window_size < this._RENDER_WINDOW_SIZE) {
const msgs_to_render_count = this._RENDER_WINDOW_SIZE - cur_window_size;
const slice_to_render = messages.slice(messages.length - msgs_to_render_count);
this.render(slice_to_render, "top", false);
this._render_win_start -= slice_to_render.length;
}
// See comment for maybe_rerender call in the append code path
this.maybe_rerender();
}
clear_table() {
// We do not want to call .empty() because that also clears
// jQuery data. This does mean, however, that we need to be
// mindful of memory leaks.
rows.get_table(this.table_name).children().detach();
this._rows.clear();
this._message_groups = [];
this.message_containers.clear();
}
get_row(id) {
const row = this._rows.get(id);
if (row === undefined) {
// For legacy reasons we need to return an empty
// jQuery object here.
return $(undefined);
}
return row;
}
clear_trailing_bookend() {
const trailing_bookend = rows.get_table(this.table_name).find(".trailing_bookend");
trailing_bookend.remove();
}
render_trailing_bookend(trailing_bookend_content, subscribed, show_button) {
const rendered_trailing_bookend = $(
render_bookend({
bookend_content: trailing_bookend_content,
trailing: show_button,
subscribed,
}),
);
rows.get_table(this.table_name).append(rendered_trailing_bookend);
}
selected_row() {
return this.get_row(this.list.selected_id());
}
get_message(id) {
return this.list.get(id);
}
change_message_id(old_id, new_id) {
if (this._rows.has(old_id)) {
const row = this._rows.get(old_id);
this._rows.delete(old_id);
row.attr("zid", new_id);
row.attr("id", this.table_name + new_id);
row.removeClass("local");
this._rows.set(new_id, row);
}
if (this.message_containers.has(old_id)) {
const message_container = this.message_containers.get(old_id);
this.message_containers.delete(old_id);
this.message_containers.set(new_id, message_container);
}
}
_maybe_format_me_message(message_container) {
if (message_container.msg.is_me_message) {
// Slice the '<p>/me ' off the front, and '</p>' off the first line
// 'p' tag is sliced off to get sender in the same line as the
// first line of the message
const msg_content = message_container.msg.content;
const p_index = msg_content.indexOf("</p>");
message_container.status_message =
msg_content.slice("<p>/me ".length, p_index) +
msg_content.slice(p_index + "</p>".length);
message_container.include_sender = true;
} else {
message_container.status_message = false;
}
}
}