我想制作信使,信息在聊天中显示,从下到上滚动。当您滚动到限制的顶部时,系统将加载更多消息。
加载新项目后scrollTop
的控制位置问题。如何计算这个位置?
HTML
<template name='chatBox'>
<div class='chat-box'><!--viewport-->
{{> chatBoxItem}}
{{/each}}
</div>
</template>
<template name='chatBoxItem'>
<div class='chat-box-wrapper'><!--content block-->
{{#each messeges}}
<p>{{messege}}</p> <!--each messege-->
{{/each}}
</div>
</template>
JS
Template.chatBox.onRendered(function() {
// viewport template
$('.chat-box').scroll(function(e) {
var chatBoxHeight = $('.chat-box').innerHeight();
var wrapperHeight = $('#chat-box-wrapper').innerHeight();
var chatBoxScroll = $('.chat-box').scrollTop();
var currentScrollFromBottom = wrapperHeight - chatBoxScroll; //don't sure if this formula is correct but it's count how many pixels was scrolled from bottom to top
if (currentScrollFromBottom == wrapperHeight && MESSAGES_LIMIT < amountOfMessages) {
//here some code to increase limit of queue
}
});
Template.chatBoxItem.onRendered(function () {
// content template
var $heightOfBlock = $('#chat-box-wrapper').height();
$('.chat-box').scrollTop($heightOfBlock);
// Here I have the most problem,
// I need to scroll to bottom when page is load (work good)
// but after loaded new items, it's need to stand still, but
// it's not. I don't know which formula i need
// to use to count current scroll position
});
也许这个例子完全错了,但我不明白如何反向无限滚动 - 从下到上。
更新:
我找到了这个公式,但它适用于普通滚动,我需要如何重建这个以进行反向滚动?
$(window).scrollTop() + $(window).height() > $(document).height() - 100
答案 0 :(得分:0)
我用jquery解决了这个问题:
var st=$("#chat").scrollTop();
$("#chat").prepend(me);
$("#chat").scrollTop(st+me.outerHeight());