You cannot select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
65 lines
2.5 KiB
JavaScript
65 lines
2.5 KiB
JavaScript
/*
|
|
* vim: ts=4:sw=4:expandtab
|
|
*/
|
|
(function () {
|
|
'use strict';
|
|
window.Whisper = window.Whisper || {};
|
|
|
|
Whisper.MessageListView = Whisper.ListView.extend({
|
|
tagName: 'ul',
|
|
className: 'message-list',
|
|
itemView: Whisper.MessageView,
|
|
events: {
|
|
'scroll': 'onScroll',
|
|
'reset-scroll': 'resetScrollPosition'
|
|
},
|
|
onScroll: function() {
|
|
this.measureScrollPosition();
|
|
if (this.$el.scrollTop() === 0) {
|
|
this.$el.trigger('loadMore');
|
|
}
|
|
},
|
|
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;
|
|
if (this.shouldStickToBottom) {
|
|
this.bottomOffset = 0;
|
|
} else {
|
|
this.bottomOffset = this.scrollHeight - this.$el.scrollTop();
|
|
}
|
|
},
|
|
resetScrollPosition: function() {
|
|
var scrollPosition = this.scrollPosition;
|
|
if (this.scrollHeight !== this.el.scrollHeight) {
|
|
scrollPosition = this.el.scrollHeight * this.scrollPosition / this.scrollHeight;
|
|
}
|
|
this.$el.scrollTop(scrollPosition - this.$el.outerHeight());
|
|
},
|
|
scrollToBottomIfNeeded: function() {
|
|
this.$el.scrollTop(this.el.scrollHeight - this.bottomOffset);
|
|
},
|
|
addOne: function(model) {
|
|
if (this.itemView) {
|
|
var view = new this.itemView({model: model}).render();
|
|
this.listenTo(view, 'beforeChangeHeight', this.measureScrollPosition);
|
|
this.listenTo(view, 'afterChangeHeight', this.scrollToBottomIfNeeded);
|
|
if (this.collection.indexOf(model) === this.collection.length - 1) {
|
|
// add to the bottom.
|
|
this.$el.append(view.el);
|
|
this.$el.scrollTop(this.el.scrollHeight); // TODO: Avoid scrolling if user has manually scrolled up?
|
|
this.measureScrollPosition();
|
|
} else {
|
|
// add to the top.
|
|
this.measureScrollPosition();
|
|
this.$el.prepend(view.el);
|
|
this.scrollToBottomIfNeeded();
|
|
}
|
|
}
|
|
},
|
|
});
|
|
})();
|