zulip/static/js/message_list_view.js

1276 lines
50 KiB
JavaScript

function MessageListView(list, table_name, collapse_messages) {
this.list = list;
this.collapse_messages = collapse_messages;
this._rows = {};
this.message_containers = {};
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;
}
(function () {
function get_user_id_for_mention_button(elem) {
var user_id = $(elem).attr('data-user-id');
// Handle legacy markdown that was rendered before we cut
// over to using data-user-id.
var email = $(elem).attr('data-user-email');
if (user_id === "*" || email === "*") {
return "*";
}
if (user_id) {
return user_id;
}
if (email) {
// Will return undefined if there's no match
var user = people.get_by_email(email);
if (user) {
return user.user_id;
}
return;
}
return;
}
function get_user_group_id_for_mention_button(elem) {
var user_group_id = $(elem).attr('data-user-group-id');
if (user_group_id) {
return user_group_id;
}
return;
}
function same_day(earlier_msg, later_msg) {
if (earlier_msg === undefined || later_msg === undefined) {
return false;
}
var earlier_time = new XDate(earlier_msg.msg.timestamp * 1000);
var later_time = new XDate(later_msg.msg.timestamp * 1000);
return earlier_time.toDateString() === later_time.toDateString();
}
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) {
var time = new XDate(message_container.msg.timestamp * 1000);
var today = new XDate();
var date_element = timerender.render_date(time, undefined, today)[0];
group.date = date_element.outerHTML;
}
function update_group_date_divider(group, message_container, prev) {
var time = new XDate(message_container.msg.timestamp * 1000);
var today = new XDate();
if (prev !== undefined) {
var prev_time = new XDate(prev.msg.timestamp * 1000);
if (time.toDateString() !== prev_time.toDateString()) {
// 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) {
var prev_msg_container = opts.prev_msg_container;
var 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;
}
var prev_time = new XDate(prev_msg_container.msg.timestamp * 1000);
var curr_time = new XDate(curr_msg_container.msg.timestamp * 1000);
var today = new XDate();
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) {
var time = new XDate(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 (util.get_message_topic(message) === 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 = stream_color.get_color_class(group.background_color);
group.invite_only = stream_data.get_invite_only(message_container.msg.stream);
group.topic = util.get_message_topic(message_container.msg);
group.match_topic = util.get_match_topic(message_container.msg);
group.stream_url = message_container.stream_url;
group.topic_url = message_container.topic_url;
var sub = stream_data.get_sub(message_container.msg.stream);
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;
}
} 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 = util.get_topic_links(message_container.msg);
set_topic_edit_properties(group, message_container.msg);
render_group_display_date(group, message_container);
}
MessageListView.prototype = {
// 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,
_add_msg_timestring: function (message_container) {
if (message_container.msg.last_edit_timestamp !== undefined) {
// Add or update the last_edit_timestr
var last_edit_time = new XDate(message_container.msg.last_edit_timestamp * 1000);
var today = new XDate();
message_container.last_edit_timestr =
timerender.render_date(last_edit_time, undefined, today)[0].textContent
+ " at " + timerender.stringify_time(last_edit_time);
}
},
add_subscription_marker: function (group, last_msg_container, first_msg_container) {
if (last_msg_container === undefined) {
return;
}
var last_subscribed = !last_msg_container.msg.historical;
var first_subscribed = !first_msg_container.msg.historical;
var 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: function (message_containers) {
function start_group() {
return {
message_containers: [],
message_group_id: _.uniqueId('message_group_'),
};
}
var self = this;
var current_group = start_group();
var new_message_groups = [];
var prev;
function 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);
}
function 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);
}
}
_.each(message_containers, function (message_container) {
var 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) && self.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 home_msg_list 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 (self.list !== home_msg_list) {
self.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,
util.get_message_topic(message_container.msg));
} else {
message_container.pm_with_url =
message_container.msg.pm_with_url;
}
}
set_timestr(message_container);
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);
self._add_msg_timestring(message_container);
message_container.small_avatar_url = people.small_avatar_url(message_container.msg);
if (message_container.msg.stream !== undefined) {
message_container.background_color =
stream_data.get_color(message_container.msg.stream);
}
message_container.contains_mention = message_container.msg.mentioned;
self._maybe_format_me_message(message_container);
prev = message_container;
});
finish_group();
return new_message_groups;
},
join_message_groups: function (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;
}
var last_msg_container = _.last(first_group.message_containers);
var 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 !== home_msg_list &&
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: function (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
var message_actions = {
append_groups: [],
prepend_groups: [],
rerender_groups: [],
append_messages: [],
rerender_messages: [],
};
var first_group;
var second_group;
var curr_msg_container;
var 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);
}
var was_joined = this.join_message_groups(first_group, second_group);
if (was_joined) {
update_message_date_divider({
prev_msg_container: prev_msg_container,
curr_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.push(prev_msg_container);
message_actions.append_messages = _.first(new_message_groups).message_containers;
new_message_groups = _.rest(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: function (row) {
// row is a jQuery object wrapping one message row
if (row.hasClass('message_row')) {
this._rows[row.attr('zid')] = row;
}
},
_post_process: function ($message_rows) {
// $message_rows wraps one or more message rows
if ($message_rows.constructor !== jQuery) {
// An assertion check that we're calling this properly
blueslip.error('programming error--pass in jQuery objects');
}
var self = this;
_.each($message_rows, function (dom_row) {
var row = $(dom_row);
self._put_row(row);
self._post_process_single_row(row);
});
},
_post_process_single_row: function (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');
}
var content = row.find('.message_content');
// Set the rtl class if the text has an rtl direction
if (rtl.get_direction(content.text()) === 'rtl') {
content.addClass('rtl');
}
content.find('.user-mention').each(function () {
var user_id = get_user_id_for_mention_button(this);
// We give special highlights to the mention buttons
// that refer to the current user.
if (user_id === "*" || people.is_my_user_id(user_id)) {
// Either a wildcard mention or us, so mark it.
$(this).addClass('user-mention-me');
}
if (user_id && user_id !== "*" && !$(this).find(".highlight").length) {
// If it's a mention of a specific user, edit the
// mention text to show the user's current name,
// assuming that you're not searching for text
// inside the highlight.
var person = people.get_person_from_user_id(user_id);
if (person !== undefined) {
// Note that person might be undefined in some
// unpleasant corner cases involving data import.
$(this).text("@" + person.full_name);
}
}
});
content.find('.user-group-mention').each(function () {
var user_group_id = get_user_group_id_for_mention_button(this);
var my_user_id = people.my_current_user_id();
// Mark user group you're a member of.
if (user_groups.is_member_of(user_group_id, my_user_id)) {
$(this).addClass('user-mention-me');
}
if (user_group_id && !$(this).find(".highlight").length) {
// Edit the mention to show the current name for the
// user group, if its not in search.
$(this).text("@" + user_groups.get_user_group_from_id(user_group_id).name);
}
});
content.find('a.stream').each(function () {
var stream_id = $(this).attr('data-stream-id');
if (stream_id && !$(this).find(".highlight").length) {
// Display the current name for stream if it is not
// being displayed in search highlight.
$(this).text("#" + stream_data.maybe_get_stream_name(stream_id));
}
});
// Display emoji (including realm emoji) as text if
// page_params.emojiset is 'text'.
if (page_params.emojiset === 'text') {
content.find(".emoji").replaceWith(function () {
var text = $(this).attr("title");
return ":" + text + ":";
});
}
var id = rows.id(row);
message_edit.maybe_show_edit(row, id);
submessage.process_submessages({
row: row,
message_id: id,
});
},
_get_message_template: function (message_container) {
var msg_reactions = reactions.get_message_reactions(message_container.msg);
message_container.msg.message_reactions = msg_reactions;
var msg_to_render = _.extend(message_container, {
table_name: this.table_name,
});
return templates.render('single_message', msg_to_render);
},
render: function (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;
}
var list = this.list; // for convenience
var table_name = this.table_name;
var table = rows.get_table(table_name);
var orig_scrolltop_offset;
var message_containers;
var self = this;
// 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.
var 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.
message_containers = _.map(messages, function (message) {
if (message.starred) {
message.starred_status = i18n.t("Unstar");
} else {
message.starred_status = i18n.t("Star");
}
return {msg: message};
});
function save_scroll_position() {
if (orig_scrolltop_offset === undefined && self.selected_row().length > 0) {
orig_scrolltop_offset = self.selected_row().offset().top;
}
}
function restore_scroll_position() {
if (list === current_msg_list && orig_scrolltop_offset !== undefined) {
list.view.set_message_offset(orig_scrolltop_offset);
list.reselect_selected_id();
}
}
// This function processes messages into chunks with separators between them,
// and templates them to be inserted as table rows into the DOM.
if (message_containers.length === 0 || this.table_name === undefined) {
return;
}
var new_message_groups = this.build_message_groups(message_containers, this.table_name);
var message_actions = this.merge_message_groups(new_message_groups, where);
var new_dom_elements = [];
var rendered_groups;
var dom_messages;
var last_message_row;
var last_group_row;
_.each(message_containers, function (message_container) {
self.message_containers[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 = $(templates.render('message_group', {
message_groups: message_actions.prepend_groups,
use_match_properties: self.list.is_search(),
table_name: self.table_name,
}));
dom_messages = rendered_groups.find('.message_row');
new_dom_elements = new_dom_elements.concat(rendered_groups);
self._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();
_.each(message_actions.rerender_groups, function (message_group) {
var old_message_group = $('#' + 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 = $(templates.render('message_group', {
message_groups: [message_group],
use_match_properties: self.list.is_search(),
table_name: self.table_name,
}));
dom_messages = rendered_groups.find('.message_row');
// Not adding to new_dom_elements it is only used for autoscroll
self._post_process(dom_messages);
old_message_group.replaceWith(rendered_groups);
condense.condense_and_collapse(dom_messages);
});
}
// Rerender message rows
if (message_actions.rerender_messages.length > 0) {
_.each(message_actions.rerender_messages, function (message_container) {
var old_row = self.get_row(message_container.msg.id);
var row = $(self._get_message_template(message_container));
self._post_process(row);
old_row.replaceWith(row);
condense.condense_and_collapse(row);
list.reselect_selected_id();
});
}
// 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 = $(_.map(message_actions.append_messages, function (message_container) {
return self._get_message_template(message_container);
}).join('')).filter('.message_row');
self._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
self.clear_trailing_bookend();
rendered_groups = $(templates.render('message_group', {
message_groups: message_actions.append_groups,
use_match_properties: self.list.is_search(),
table_name: self.table_name,
}));
dom_messages = rendered_groups.find('.message_row');
new_dom_elements = new_dom_elements.concat(rendered_groups);
self._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();
var last_message_group = _.last(self._message_groups);
if (last_message_group !== undefined) {
list.last_message_historical =
_.last(last_message_group.message_containers).msg.historical;
}
var stream_name = narrow_state.stream();
if (stream_name !== undefined) {
// If user narrows to a stream, doesn't update
// trailing bookend if user is subscribed.
var sub = stream_data.get_sub(stream_name);
if (sub === undefined || !sub.subscribed) {
list.update_trailing_bookend();
}
}
if (list === current_msg_list) {
// Update the fade.
var get_element = function (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.
var message_row = self.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 === current_msg_list && 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()) {
var selected_id = list.selected_id();
var 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) {
var 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,
};
}
var new_messages_height = self._new_messages_height(new_dom_elements);
var need_user_to_scroll = self._maybe_autoscroll(new_messages_height);
if (need_user_to_scroll) {
return {
need_user_to_scroll: true,
};
}
}
},
_new_messages_height: function (rendered_elems) {
var new_messages_height = 0;
var id_of_last_message_sent_by_us = -1;
// C++ iterators would have made this less painful
_.each(rendered_elems.reverse(), function (elem) {
// 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();
// starting from the last message, ignore message heights that weren't sent by me.
if (id_of_last_message_sent_by_us > -1) {
return;
}
var row_id = rows.id(elem);
// check for `row_id` NaN in case we're looking at a date row or bookend row
if (row_id > -1 &&
people.is_current_user(this.get_message(row_id).sender_email)) {
id_of_last_message_sent_by_us = rows.id(elem);
}
}
}, this);
return new_messages_height;
},
_scroll_limit: function (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.
var selected_row_top = selected_row.offset().top;
var 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: function (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
var selected_row = this.selected_row();
var 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.has_focus) {
// 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;
}
var info = message_viewport.message_viewport_info();
var 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
var scroll_amount;
var 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;
var 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.
var compose_textarea_default_height = 42;
var compose_textarea_current_height = $("#compose-textarea").height();
var expected_change = compose_textarea_current_height - compose_textarea_default_height;
var 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: function (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: function (selected_idx, check_for_changed) {
var 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: function () {
if (this.table_name === undefined) {
return false;
}
var 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: function () {
// old_offset is the number of pixels between the top of the
// viewable window and the selected message
var old_offset;
var selected_row = this.selected_row();
var selected_in_view = selected_row.length > 0;
if (selected_in_view) {
old_offset = selected_row.offset().top;
}
return this.rerender_with_target_scrolltop(selected_row, old_offset);
},
set_message_offset: function (offset) {
var msg = this.selected_row();
message_viewport.scrollTop(message_viewport.scrollTop() + msg.offset().top - offset);
},
rerender_with_target_scrolltop: function (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);
}
},
_rerender_header: function (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;
}
var 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;
}
var recipient_row = rows.get_message_recipient_row(first_row);
var header = recipient_row.find('.message_header');
var group = {message_containers: message_containers};
populate_group_from_message_container(group, message_containers[0]);
var rendered_recipient_row = $(templates.render('recipient_row', group));
header.replaceWith(rendered_recipient_row);
},
_rerender_message: function (message_container, message_content_edited) {
var row = this.get_row(message_container.msg.id);
var was_selected = this.list.selected_message() === message_container.msg;
// Re-render just this one message
this._add_msg_timestring(message_container);
this._maybe_format_me_message(message_container);
// Make sure the right thing happens if the message was edited to mention us.
message_container.contains_mention = message_container.msg.mentioned;
var 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: function (messages, message_content_edited) {
var self = this;
// Convert messages to list messages
var message_containers = _.map(messages, function (message) {
return self.message_containers[message.id];
});
// We may not have the message_container if the stream or topic was muted
message_containers = _.reject(message_containers, function (message_container) {
return message_container === undefined;
});
var message_groups = [];
var current_group = [];
_.each(message_containers, function (message_container) {
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 = [];
}
self._rerender_message(message_container, message_content_edited);
});
if (current_group.length !== 0) {
message_groups.push(current_group);
}
_.each(message_groups, function (messages_in_group) {
self._rerender_header(messages_in_group, message_content_edited);
});
},
append: function (messages, messages_are_new) {
var cur_window_size = this._render_win_end - this._render_win_start;
var render_info;
if (cur_window_size < this._RENDER_WINDOW_SIZE) {
var 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.
var needed_rerender = this.maybe_rerender();
if (needed_rerender) {
render_info = {need_user_to_scroll: true};
}
return render_info;
},
prepend: function (messages) {
this._render_win_start += messages.length;
this._render_win_end += messages.length;
var cur_window_size = this._render_win_end - this._render_win_start;
if (cur_window_size < this._RENDER_WINDOW_SIZE) {
var msgs_to_render_count = this._RENDER_WINDOW_SIZE - cur_window_size;
var 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();
},
rerender_the_whole_thing: function () {
// TODO: Figure out if we can unify this with this.list.rerender().
this.clear_rendering_state(true);
this.update_render_window(this.list.selected_idx(), false);
this.render(this.list.all_messages().slice(this._render_win_start, this._render_win_end), 'bottom');
},
clear_table: function () {
// 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 = {};
this._message_groups = [];
this.message_containers = {};
},
get_row: function (id) {
var row = this._rows[id];
if (row === undefined) {
// For legacy reasons we need to return an empty
// jQuery object here.
return $(undefined);
}
return row;
},
clear_trailing_bookend: function () {
var trailing_bookend = rows.get_table(this.table_name).find('.trailing_bookend');
trailing_bookend.remove();
},
render_trailing_bookend: function (trailing_bookend_content, subscribed, show_button) {
var rendered_trailing_bookend = $(templates.render('bookend', {
bookend_content: trailing_bookend_content,
trailing: show_button,
subscribed: subscribed,
}));
rows.get_table(this.table_name).append(rendered_trailing_bookend);
},
selected_row: function () {
return this.get_row(this.list.selected_id());
},
get_message: function (id) {
return this.list.get(id);
},
change_message_id: function (old_id, new_id) {
if (this._rows[old_id] !== undefined) {
var row = this._rows[old_id];
delete this._rows[old_id];
row.attr('zid', new_id);
row.attr('id', this.table_name + new_id);
row.removeClass('local');
this._rows[new_id] = row;
}
if (this.message_containers[old_id] !== undefined) {
var message_container = this.message_containers[old_id];
delete this.message_containers[old_id];
this.message_containers[new_id] = message_container;
}
},
_maybe_format_me_message: function (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
var msg_content = message_container.msg.content;
var 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;
}
},
};
}());
if (typeof module !== 'undefined') {
module.exports = MessageListView;
}
window.MessageListView = MessageListView;