纸复选框和-webkit-column-count

Question

这是我已经研究了一段时间但我无法弄清楚这里发生了什么。

在这个example上，您可以看到如何使用css规则-webkit-column-count分布在div上的复选框列表。

问题在于，除了第一个列之外，所有列都出于某种原因隐藏了复选标记。你有任何提示要解决这个问题吗？

这里我附上一个小例子，但请查看我的jsfiddle以获得更好的描述性情况。谢谢！

.valueLabel {
  /* height: 24px; */
  padding: 7px 12px;
  width: 400px;
}
.valueLabel paper-checkbox {
  margin-right: 12px;
}
.valueLabel paper-checkbox::shadow #ink[checked] {
  color: #f39200;
}
.valueLabel paper-checkbox::shadow #checkbox.checked {
  border-color: #f39200;
  background-color: #f39200;
  /* Version 0.7 paper-checkbox */
}
/* COLUMNS */

.valuesContainer {
  overflow-y: scroll;
  padding: 0px 16px;
}
.valuesContainer > #valuesDiv {
  -webkit-column-break-inside: avoid;
  -moz-column-break-inside: avoid;
  column-break-inside: avoid;
  -webkit-column-count: 4;
  -moz-column-count: 4;
  column-count: 4;
  -webkit-column-gap: 0px;
  -moz-column-gap: 0px;
  column-gap: 0px;
}
.valuesContainer > #valuesDiv .valuesGroup {
  display: inline-block;
}
.valuesContainer > #valuesDiv .valuesGroup > span {
  text-transform: uppercase;
}
/* LAYOUT WRAP */

.valuesContainer > core-label {
  width: 30%;
  /* 3 COLUMNS */
  line-height: 16px;
  font-size: small;
}
.valuesContainer > #valuesDiv core-label.valueLabel {
  display: inline-flex;
}
/* FIX THAT I USED TO SHOW ALL CHECKS WHEN THEY ARE ON COLUMNS, USED ON PAPER ELEMENTS >= v0.7 */

/* IT DOES NOT WORK ANYMORE */

.valueLabel paper-checkbox::shadow #checkbox.checked #checkmark {
  position: fixed;
  margin-top: 2px;
  margin-left: 2px;
}

<script src="https://www.polymer-project.org/0.5/components/webcomponentsjs/webcomponents.js"></script>
<link rel="import" href="https://www.polymer-project.org/0.5/components/polymer/polymer.html">
<link rel="import" href="https://www.polymer-project.org/0.5/components/paper-elements/paper-elements.html">
<link rel="import" href="https://www.polymer-project.org/0.5/components/core-elements/core-elements.html">
<div class="valuesContainer">
  <div id="valuesDiv">
    <core-label class="valueLabel" horizontal="" layout="" id="core-label-0">
      <paper-checkbox id="1" checked></paper-checkbox>
      <div>January</div>
    </core-label>

    <core-label class="valueLabel" horizontal="" layout="" id="core-label-1">
      <paper-checkbox id="2"></paper-checkbox>
      <div>February</div>
    </core-label>

    <core-label class="valueLabel" horizontal="" layout="" id="core-label-2">
      <paper-checkbox id="3" checked></paper-checkbox>
      <div>March</div>
    </core-label>

    <core-label class="valueLabel" horizontal="" layout="" id="core-label-3">
      <paper-checkbox id="4" checked></paper-checkbox>
      <div>April</div>
    </core-label>

    <core-label class="valueLabel" horizontal="" layout="" id="core-label-4">
      <paper-checkbox id="5"></paper-checkbox>
      <div>May</div>
    </core-label>

  </div>
</div>

Answer 1

你遇到了渲染错误。尝试纠正此问题的一种方法是强制GPU渲染。有几种方法可以做到这一点，我最喜欢的是使用transform:translate3d(0,0,0)。然而，问题在于需要它的元素（#checkbox.checked #checkmark）已经有了变换。您可以通过设置背面可见性来获得相同的结果。我在下面的演示中使用以下规则执行此操作：

.valueLabel paper-checkbox::shadow #checkbox.checked #checkmark {
   ...
   -webkit-backface-visibility: hidden;
   -moz-backface-visibility: hidden;
   -ms-backface-visibility: hidden;
   backface-visibility: hidden;
}

演示

.valueLabel {
  /* height: 24px; */
  padding: 7px 12px;
  width: 400px;
}
.valueLabel paper-checkbox {
  margin-right: 12px;
}
.valueLabel paper-checkbox::shadow #ink[checked] {
  color: #f39200;
}
.valueLabel paper-checkbox::shadow #checkbox.checked {
  border-color: #f39200;
  background-color: #f39200;
  /* Version 0.7 paper-checkbox */
}
/* COLUMNS */

.valuesContainer {
  overflow-y: scroll;
  padding: 0px 16px;
}
.valuesContainer > #valuesDiv {
  -webkit-column-break-inside: avoid;
  -moz-column-break-inside: avoid;
  column-break-inside: avoid;
  -webkit-column-count: 4;
  -moz-column-count: 4;
  column-count: 4;
  -webkit-column-gap: 0px;
  -moz-column-gap: 0px;
  column-gap: 0px;
}
.valuesContainer > #valuesDiv .valuesGroup {
  display: inline-block;
}
.valuesContainer > #valuesDiv .valuesGroup > span {
  text-transform: uppercase;
}
/* LAYOUT WRAP */

.valuesContainer > core-label {
  width: 30%;
  /* 3 COLUMNS */
  line-height: 16px;
  font-size: small;
}
.valuesContainer > #valuesDiv core-label.valueLabel {
  display: inline-flex;
}
/* FIX THAT I USED TO SHOW ALL CHECKS WHEN THEY ARE ON COLUMNS, USED ON PAPER ELEMENTS >= v0.7 */

/* IT DOES NOT WORK ANYMORE */

.valueLabel paper-checkbox::shadow #checkbox.checked #checkmark {
  position: fixed;
  margin-top: 2px;
  margin-left: 2px;
  -webkit-backface-visibility: hidden;
  -moz-backface-visibility: hidden;
  -ms-backface-visibility: hidden;
  backface-visibility: hidden;
}

<script src="https://www.polymer-project.org/0.5/components/webcomponentsjs/webcomponents.js"></script>
<link rel="import" href="https://www.polymer-project.org/0.5/components/polymer/polymer.html">
<link rel="import" href="https://www.polymer-project.org/0.5/components/paper-elements/paper-elements.html">
<link rel="import" href="https://www.polymer-project.org/0.5/components/core-elements/core-elements.html">
<div class="valuesContainer">
  <div id="valuesDiv">
    <core-label class="valueLabel" horizontal="" layout="" id="core-label-0">
      <paper-checkbox id="1" checked></paper-checkbox>
      <div>January</div>
    </core-label>

    <core-label class="valueLabel" horizontal="" layout="" id="core-label-1">
      <paper-checkbox id="2"></paper-checkbox>
      <div>February</div>
    </core-label>

    <core-label class="valueLabel" horizontal="" layout="" id="core-label-2">
      <paper-checkbox id="3" checked></paper-checkbox>
      <div>March</div>
    </core-label>

    <core-label class="valueLabel" horizontal="" layout="" id="core-label-3">
      <paper-checkbox id="4" checked></paper-checkbox>
      <div>April</div>
    </core-label>

    <core-label class="valueLabel" horizontal="" layout="" id="core-label-4">
      <paper-checkbox id="5"></paper-checkbox>
      <div>May</div>
    </core-label>

  </div>
</div>