javascript - 如何知道文本区域光标是否到达字段的最后？

Question

在这个例子中，我想在光标到达或触摸发送按钮时添加边距，并且在触摸发送按钮时需要添加边距顶部。与当前的 facebook 评论字段一样，当光标触摸贴纸或表情符号图标时，图标将移动到字段的底部。

autosize($('textarea'));

textarea { width:99%;min-height:15px }
div { position:relative }
button { position:absolute;right:10px;bottom:8px }

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<script src="https://rawgit.com/jackmoore/autosize/master/dist/autosize.min.js"></script>

<div>
<textarea class="textarea"></textarea>
<button>
Send
</button>
</div>

Answer 1

这是你要找的，试试看:

autosize($('textarea'));

$("#send").on('click', function() {
  console.log("You clicked send!!");
  callSendFunction();
});

$('.textarea').keypress(function(e) {
  if (e.which == 13) {
    console.log("You hit enter!!");
    callSendFunction();
  }
});

function callSendFunction() {
  console.log('Yay, we got it. Do something here..  ');
}

textarea {
  width: 99%;
  min-height: 15px
}

div {
  position: relative
}

button {
  position: absolute;
  right: 10px;
  bottom: 8px
}

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<script src="https://rawgit.com/jackmoore/autosize/master/dist/autosize.min.js"></script>

<div>
  <textarea class="textarea"></textarea>
  <button id="send">
Send
</button>
</div>