zulip/static/js/pointer.js

125 lines
4.0 KiB
JavaScript

// See http://zulip.readthedocs.io/en/latest/subsystems/pointer.html for notes on
// how this system is designed.
var pointer = (function () {
var exports = {};
exports.recenter_pointer_on_display = false;
// Toggles re-centering the pointer in the window
// when Home is next clicked by the user
exports.suppress_scroll_pointer_update = false;
exports.furthest_read = -1;
exports.server_furthest_read = -1;
var pointer_update_in_flight = false;
function update_pointer() {
if (!pointer_update_in_flight) {
pointer_update_in_flight = true;
return channel.post({
url: '/json/users/me/pointer',
idempotent: true,
data: {pointer: pointer.furthest_read},
success: function () {
pointer.server_furthest_read = pointer.furthest_read;
pointer_update_in_flight = false;
},
error: function () {
pointer_update_in_flight = false;
},
});
}
// Return an empty, resolved Deferred.
return $.when();
}
exports.send_pointer_update = function () {
// Only bother if you've read new messages.
if (pointer.furthest_read > pointer.server_furthest_read) {
update_pointer();
}
};
function unconditionally_send_pointer_update() {
if (pointer_update_in_flight) {
// Keep trying.
var deferred = $.Deferred();
setTimeout(function () {
deferred.resolve(unconditionally_send_pointer_update());
}, 100);
return deferred;
}
return update_pointer();
}
exports.fast_forward_pointer = function () {
channel.get({
url: '/json/users/me',
idempotent: true,
success: function (data) {
unread_ops.mark_all_as_read(function () {
pointer.furthest_read = data.max_message_id;
unconditionally_send_pointer_update().then(function () {
reload.initiate({immediate: true,
save_pointer: false,
save_narrow: true,
save_compose: true});
});
});
},
});
};
exports.initialize = function initialize() {
pointer.server_furthest_read = page_params.pointer;
if (page_params.orig_initial_pointer !== undefined &&
page_params.orig_initial_pointer > pointer.server_furthest_read) {
pointer.server_furthest_read = page_params.orig_initial_pointer;
}
pointer.furthest_read = pointer.server_furthest_read;
// We only send pointer updates when the user has been idle for a
// short while to avoid hammering the server
$(document).idle({idle: 1000,
onIdle: pointer.send_pointer_update,
keepTracking: true});
$(document).on('message_selected.zulip', function (event) {
// Only advance the pointer when not narrowed
if (event.id === -1) {
return;
}
// Additionally, don't advance the pointer server-side
// if the selected message is local-only
if (event.msg_list === home_msg_list && page_params.narrow_stream === undefined) {
if (event.id > pointer.furthest_read) {
var msg = home_msg_list.get(event.id);
if (!msg.locally_echoed) {
pointer.furthest_read = event.id;
}
}
}
if (event.mark_read && event.previously_selected !== -1) {
// Mark messages between old pointer and new pointer as read
var messages;
if (event.id < event.previously_selected) {
messages = event.msg_list.message_range(event.id, event.previously_selected);
} else {
messages = event.msg_list.message_range(event.previously_selected, event.id);
}
unread_ops.mark_messages_as_read(messages, {from: 'pointer'});
}
});
};
return exports;
}());
if (typeof module !== 'undefined') {
module.exports = pointer;
}