diaspora/app/assets/javascripts/app/views/infinite_stream_view.js
2012-05-30 16:58:21 -07:00

77 lines
2.1 KiB
JavaScript

// Abstract Infinite Scroll View Super Class
// Requires:
// a stream model, assigned to this.stream
// a stream's posts, assigned to this.collection
// a postClass to be declared
// a #paginate div in the layout
// a call to setupInfiniteScroll
app.views.InfScroll = app.views.Base.extend({
setupInfiniteScroll : function() {
this.postViews = this.postViews || []
this.bind("loadMore", this.fetchAndshowLoader, this)
this.stream.bind("fetched", this.hideLoader, this)
this.stream.bind("allItemsLoaded", this.unbindInfScroll, this)
this.collection.bind("add", this.addPostView, this);
var throttledScroll = _.throttle(_.bind(this.infScroll, this), 200);
$(window).scroll(throttledScroll);
},
postRenderTemplate : function() {
if(this.stream.isFetching()) { this.showLoader() }
},
createPostView : function(post){
var postView = new this.postClass({ model: post, stream: this.stream });
this.postViews.push(postView)
return postView
},
addPostView : function(post) {
var placeInStream = (this.collection.at(0).id == post.id) ? "prepend" : "append";
this.$el[placeInStream](this.createPostView(post).render().el);
},
unbindInfScroll : function() {
$(window).unbind("scroll");
},
renderTemplate : function(){
this.renderInitialPosts()
},
renderInitialPosts : function(){
this.$el.empty()
this.stream.items.each(_.bind(function(post){
this.$el.append(this.createPostView(post).render().el);
}, this))
},
fetchAndshowLoader : function(){
if(this.stream.isFetching()) { return false }
this.stream.fetch()
this.showLoader()
},
showLoader: function(){
$("#paginate .loader").removeClass("hidden")
},
hideLoader: function() {
$("#paginate .loader").addClass("hidden")
},
infScroll : function() {
var $window = $(window)
, distFromTop = $window.height() + $window.scrollTop()
, distFromBottom = $(document).height() - distFromTop
, bufferPx = 500;
if(distFromBottom < bufferPx) {
this.trigger("loadMore")
}
}
});