framework/ember/app/views/discussion.js
2015-01-02 11:46:40 +10:30

254 lines
10 KiB
JavaScript

import Ember from 'ember';
import NamedContainerView from '../utils/named-container-view';
import Menu from '../utils/menu';
import MenuItem from '../components/menu-item';
import DropdownSplit from '../components/dropdown-split';
import DropdownButton from '../components/dropdown-button';
import DiscussionScrollbar from '../components/discussion-scrollbar';
import PostStreamMixin from '../mixins/post-stream';
export default Ember.View.extend(Ember.Evented, PostStreamMixin, {
sidebar: Ember.ContainerView,
// Set up a new menu view that will contain controls to be shown in the
// footer. The template will only render these controls if the last post is
// showing.
construct: function() {
// this.set('footerControls', this.createChildView(Menu));
// this.set('footerControls.controller', this.get('controller'));
// console.log(this.get('controller'));
}.on('init'),
// Whenever the model's title changes, we want to update that document's
// title the reflect the new title.
updateTitle: function() {
this.set('controller.controllers.application.pageTitle', this.get('controller.model.title'));
}.observes('controller.model.title'),
didInsertElement: function() {
// We've just inserted the discussion view.
this.trigger('populateSidebar', this.get('sidebar'));
// Whenever the window's scroll position changes, we want to check to
// see if any terminal 'gaps' are in the viewport and trigger their
// loading mechanism if they are. We also want to update the
// controller's 'start' query param with the current position.
$(window).on('scroll', {view: this}, this.windowWasScrolled);
// We need to listen for some events on the controller. Whenever the
// controller says that it's loading or has loaded posts near a certain
// post number, we want to scroll down to this post (or the gap which
// the post is in) and highlight it.
var controller = this.get('controller');
controller.on('loadingNumber', this, this.loadingNumber);
controller.on('loadedNumber', this, this.loadedNumber);
controller.on('loadingIndex', this, this.loadingIndex);
controller.on('loadedIndex', this, this.loadedIndex);
},
willDestroyElement: function() {
$(window).off('scroll', this.windowWasScrolled);
var controller = this.get('controller');
controller.off('loadingNumber', this, this.loadingNumber);
controller.off('loadedNumber', this, this.loadedNumber);
controller.off('loadingIndex', this, this.loadingIndex);
controller.off('loadedIndex', this, this.loadedIndex);
},
setupSidebar: function(sidebar) {
this.set('controls', Menu.create());
this.trigger('populateControls', this.get('controls'));
sidebar.pushObject(DropdownSplit.create({
items: this.get('controls'),
icon: 'reply',
buttonClass: 'btn-primary',
menuClass: 'pull-right'
}));
sidebar.pushObject(DropdownButton.create({items: this.get('controls')}));
sidebar.pushObject(DiscussionScrollbar.create());
}.on('populateSidebar'),
setupControls: function(controls) {
var view = this;
var ReplyItem = MenuItem.extend({
title: 'Reply',
icon: 'reply',
classNameBindings: ['className', 'replying:disabled'],
replying: function() {
return this.get('parentController.controllers.composer.showing');
}.property('parentController.controllers.composer.showing'),
action: function() {
var lastPost = $('.posts .item:last');
$('html, body').animate({scrollTop: lastPost.offset().top + lastPost.outerHeight() - $(window).height() + $('.composer').height() + 19}, 'fast');
view.get('controller').send('reply');
},
parentController: this.get('controller'),
});
controls.addItem('reply', ReplyItem);
}.on('populateControls'),
// This function handles the window's scroll event. We check to see if any
// terminal 'gaps' are in the viewport and trigger their loading mechanism
// if they are. We also update the controller's 'start' query param with the
// current position.
windowWasScrolled: function(event) {
var view = event.data.view;
if (! view.get('controller.loaded') || $(window).data('disableScrollHandler')) {
return;
}
var posts = view.$().find('.posts'),
$this = $(this),
scrollTop = $this.scrollTop(),
viewportHeight = $this.height(),
firstItem = posts.find('.item[data-start=0]'),
firstItemOffset = firstItem.length ? firstItem.offset().top : 0,
currentNumber;
// Loop through each of the items in the discussion. An 'item' is
// either a single post or a 'gap' of one or more posts that haven't
// been loaded yet.
posts.find('.item').each(function() {
var $this = $(this),
top = $this.offset().top - firstItemOffset,
height = $this.outerHeight();
// If this item is above the top of the viewport, skip to the
// next one. If it's below the bottom of the viewport, break
// out of the loop.
if (top + height < scrollTop) {
return;
}
if (top > scrollTop + viewportHeight) {
return false;
}
// Now we know that this item is in the viewport. If we haven't
// yet stored a post's number, then this item must be the FIRST
// item in the viewport. Therefore, we'll grab its post number
// so we can update the controller's state later.
! currentNumber && (currentNumber = $this.data('number'));
// If this item is a gap, then we may proceed to check if it's
// a *terminal* gap and trigger its loading mechanism.
var gapView;
if ($this.hasClass('gap') && (gapView = Ember.View.views[$this.attr('id')])) {
if ($this.is(':first-of-type')) {
gapView.set('direction', 'up').load();
}
else if ($this.is(':last-of-type')) {
gapView.set('direction', 'down').load();
}
}
});
// Finally, we want to update the controller's state with regards to the
// current viewing position of the discussion. However, we don't want to
// do this on every single scroll event as it will slow things down. So,
// let's do it at a minimum of 250ms by clearing and setting a timeout.
clearTimeout(this.updateStateTimeout);
this.updateStateTimeout = setTimeout(function() {
view.get('controller').set('start', currentNumber || 1);
}, 250);
},
loadingNumber: function(number) {
// The post with this number is being loaded. We want to scroll to where
// we think it will appear. We may be scrolling to the edge of the page,
// but we don't want to trigger any terminal post gaps to load by doing
// that. So, we'll disable the window's scroll handler for now.
$(window).data('disableScrollHandler', true);
this.jumpToNumber(number);
},
loadedNumber: function(number) {
// The post with this number has been loaded. After we scroll to this
// post, we want to resume scroll events.
var view = this;
this.jumpToNumber(number, function() {
$(window).data('disableScrollHandler', false).scroll();
});
},
// Scroll down to a certain post (or the gap which the post is in) and
// highlight it.
jumpToNumber: function(number, finish) {
// Clear the highlight class from all posts, and attempt to find and
// highlight a post with the specified number.
var item = this.$()
.find('.posts .item').removeClass('highlight')
.filter('[data-number='+number+']');
if (number > 1) {
item.addClass('highlight');
}
// If we didn't have any luck, then a post with this number either
// doesn't exist, or it hasn't been loaded yet. We'll find the item
// that's closest to the post with this number and scroll to that
// instead.
if (! item.length) {
item = this.findNearestToNumber(number);
}
// We have an item to scroll to now. Let's get its position and animate
// a scroll-down!
if (item.length) {
$('html, body').stop(true).animate({scrollTop: number > 1 ? item.offset().top : 0});
}
if (finish) {
$('html, body').promise().done(finish);
}
},
loadingIndex: function(index) {
// The post at this index is being loaded. We want to scroll to where we
// think it will appear. We may be scrolling to the edge of the page,
// but we don't want to trigger any terminal post gaps to load by doing
// that. So, we'll disable the window's scroll handler for now.
$(window).data('disableScrollHandler', true);
this.jumpToIndex(index);
},
loadedIndex: function(index) {
// The post at this index has been loaded. After we scroll to this post,
// we want to resume scroll events.
var view = this;
this.jumpToIndex(index, function() {
$(window).data('disableScrollHandler', false).scroll();
});
},
jumpToIndex: function(index, finish) {
var item = this.findNearestToIndex(index);
// We have an item to scroll to now. Let's get its position and animate
// a scroll-down!
if (item.length) {
$('html, body').stop(true).animate({scrollTop: index > 0 ? item.offset().top : 0});
}
if (finish) {
$('html, body').promise().done(finish);
}
},
// Right after the controller finished loading a discussion, we want to
// trigger a scroll event on the window so the interface is kept up-to-date.
loadedChanged: function() {
if (this.get('controller.loaded')) {
Ember.run.scheduleOnce('afterRender', function() {
$(window).scroll();
});
}
}.observes('controller.loaded')
});