Cable-Desktop/js/views/message_list_view.js
lilia 9e79ecddf8 Fix scroll stickiness while hidden
Fix bug: Open thread A, open thread B, receive message in thread A, open
thread A. Scroll bar has reset to the top.
2015-08-27 16:25:35 -07:00

64 lines
2.5 KiB
JavaScript

/* vim: ts=4:sw=4:expandtab
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
(function () {
'use strict';
window.Whisper = window.Whisper || {};
Whisper.MessageListView = Whisper.ListView.extend({
tagName: 'ul',
className: 'message-list',
itemView: Whisper.MessageView,
events: {
'add': 'onAdd',
'update *': 'scrollToBottom',
'scroll': 'measureScrollPosition',
'reset-scroll': 'resetScrollPosition'
},
onAdd: function() {
this.$el.removeClass('loading');
this.scrollToBottom();
},
measureScrollPosition: function() {
if (this.el.scrollHeight === 0) { // hidden
return;
}
this.scrollPosition = this.$el.scrollTop() + this.$el.outerHeight();
this.scrollHeight = this.el.scrollHeight;
this.shouldStickToBottom = this.scrollPosition === this.scrollHeight;
},
resetScrollPosition: function() {
var scrollPosition = this.scrollPosition;
if (this.scrollHeight !== this.el.scrollHeight) {
scrollPosition = this.el.scrollHeight * this.scrollPosition / this.scrollHeight;
}
this.$el.scrollTop(scrollPosition - this.$el.outerHeight());
},
scrollToBottomIfNeeded: function() {
if (this.shouldStickToBottom) {
this.$el.scrollTop(this.scrollHeight);
}
},
scrollToBottom: function() {
// TODO: Avoid scrolling if user has manually scrolled up?
this.$el.scrollTop(this.el.scrollHeight);
this.measureScrollPosition();
},
addAll: function() {
Whisper.ListView.prototype.addAll.apply(this, arguments); // super()
this.scrollToBottom();
}
});
})();