Android TagFlowLayout完全解析 一款针对Tag的布局
2016-03-25 19:55
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Android TagFlowLayout完全解析 一款针对Tag的布局
标签： android标签FlowLayout2015-09-14 09:22 32971人阅读 评论(68) 收藏 举报
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【Android 自定义控件实战】（28）
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本文出自:【张鸿洋的博客】
一、概述
本文之前，先提一下关于上篇博文的100多万访问量请无视，博文被刷，我也很郁闷，本来想把那个文章放到草稿箱，结果放不进去，还把日期弄更新了，实属无奈。ok，开始今天的博文，今天要说的是TagFlowLayout，说这个之前必须提一下FlowLayout，如果你不了解，可以先阅读之前的博文：Android 自定义ViewGroup 实战篇 -> 实现FlowLayout或者观看视频
打造Android中的流式布局和热门标签 。
因为本身FlowLayout本身的预期是提供一种新的布局的方式，但是呢，在实际的开发中，大家更多的是使用在商品标签，搜索关键字的场景，那么就涉及到一些交互：
比如用户选择了某个标签，首先你要去改变标签的样子给用户一个反馈，其次你需要记录用户的选择。
那么在选择过程中还有多选的情况，比如4选2，4选3等等。
还有…
类似京东的这个选择商品的图：
对于上述的情况呢，FlowLayout只能说能够实现View的显示没有问题，而对于点击某个Tag，以及修改某个Tag的样子，可能需要编写大量的代码，且设计只要稍微的改下显示的效果，估计就得加班了。
既然这么多的不方便，那么我们现在就在FlowLayout的基础上，编写TagFlowLayout去完善，目前支持：
以setAdapter形式注入数据
直接设置selector为background即可完成标签选则的切换，类似CheckBox
支持控制选择的Tag数量，比如：单选、多选
支持setOnTagClickListener，当点击某个Tag回调
支持setOnSelectListener，当选择某个Tag后回调
支持adapter.notifyDataChanged
Activity重建（或者旋转）后，选择的状态自动保存
我们的效果图：
github地址：FlowLayout
我需要思考几分钟本文的叙述方式…
ok，由于本文并非从无到有的去构造一个新的东西，所以你肯定没有办法根据我的分析，然后就能完整的写出来。这样的话，就非常建议大家下载源码，拿着源码比对着看；或者看完本文后去下载源码；或者仅仅是看看思路学学知识点（eclipse的用户，拷贝几个类不是难事，不要私聊我问我怎么整~）。
二、以setAdapter形式注入数据
首先我们完成的就是，去除大家痛苦的添加数据的方式。类似ListView，提供Adapter的方式，为我们的TagFlowLayout去添加数据，这种方式，大家用的肯定比较熟练了，而且也比较灵活。
（1） TagAdapter
那么首先我们得有个Adapter，这里叫做TagAdapter
<code class="language-java hljs has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">package</span> com.zhy.view.flowlayout;
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">import</span> android.view.View;
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">import</span> java.util.ArrayList;
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">import</span> java.util.Arrays;
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">import</span> java.util.List;
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">abstract</span> <span class="hljs-class" style="box-sizing: border-box;"><span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">class</span> <span class="hljs-title" style="box-sizing: border-box; color: rgb(102, 0, 102);">TagAdapter</span><<span class="hljs-title" style="box-sizing: border-box; color: rgb(102, 0, 102);">T</span>>
{</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">private</span> List<T> mTagDatas;
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">private</span> OnDataChangedListener mOnDataChangedListener;
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-title" style="box-sizing: border-box;">TagAdapter</span>(List<T> datas)
{
mTagDatas = datas;
}
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-title" style="box-sizing: border-box;">TagAdapter</span>(T[] datas)
{
mTagDatas = <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> ArrayList<T>(Arrays.asList(datas));
}
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">static</span> interface OnDataChangedListener
{
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">void</span> onChanged();
}
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">void</span> setOnDataChangedListener(OnDataChangedListener listener)
{
mOnDataChangedListener = listener;
}
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span> <span class="hljs-title" style="box-sizing: border-box;">getCount</span>()
{
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">return</span> mTagDatas == <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">null</span> ? <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span> : mTagDatas.size();
}
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">void</span> <span class="hljs-title" style="box-sizing: border-box;">notifyDataChanged</span>()
{
mOnDataChangedListener.onChanged();
}
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> T <span class="hljs-title" style="box-sizing: border-box;">getItem</span>(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span> position)
{
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">return</span> mTagDatas.get(position);
}
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">abstract</span> View <span class="hljs-title" style="box-sizing: border-box;">getView</span>(FlowLayout parent, <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span> position, T t);
}</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li><li style="box-sizing: border-box; padding: 0px 5px;">15</li><li style="box-sizing: border-box; padding: 0px 5px;">16</li><li style="box-sizing: border-box; padding: 0px 5px;">17</li><li style="box-sizing: border-box; padding: 0px 5px;">18</li><li style="box-sizing: border-box; padding: 0px 5px;">19</li><li style="box-sizing: border-box; padding: 0px 5px;">20</li><li style="box-sizing: border-box; padding: 0px 5px;">21</li><li style="box-sizing: border-box; padding: 0px 5px;">22</li><li style="box-sizing: border-box; padding: 0px 5px;">23</li><li style="box-sizing: border-box; padding: 0px 5px;">24</li><li style="box-sizing: border-box; padding: 0px 5px;">25</li><li style="box-sizing: border-box; padding: 0px 5px;">26</li><li style="box-sizing: border-box; padding: 0px 5px;">27</li><li style="box-sizing: border-box; padding: 0px 5px;">28</li><li style="box-sizing: border-box; padding: 0px 5px;">29</li><li style="box-sizing: border-box; padding: 0px 5px;">30</li><li style="box-sizing: border-box; padding: 0px 5px;">31</li><li style="box-sizing: border-box; padding: 0px 5px;">32</li><li style="box-sizing: border-box; padding: 0px 5px;">33</li><li style="box-sizing: border-box; padding: 0px 5px;">34</li><li style="box-sizing: border-box; padding: 0px 5px;">35</li><li style="box-sizing: border-box; padding: 0px 5px;">36</li><li style="box-sizing: border-box; padding: 0px 5px;">37</li><li style="box-sizing: border-box; padding: 0px 5px;">38</li><li style="box-sizing: border-box; padding: 0px 5px;">39</li><li style="box-sizing: border-box; padding: 0px 5px;">40</li><li style="box-sizing: border-box; padding: 0px 5px;">41</li><li style="box-sizing: border-box; padding: 0px 5px;">42</li><li style="box-sizing: border-box; padding: 0px 5px;">43</li><li style="box-sizing: border-box; padding: 0px 5px;">44</li><li style="box-sizing: border-box; padding: 0px 5px;">45</li><li style="box-sizing: border-box; padding: 0px 5px;">46</li><li style="box-sizing: border-box; padding: 0px 5px;">47</li><li style="box-sizing: border-box; padding: 0px 5px;">48</li><li style="box-sizing: border-box; padding: 0px 5px;">49</li><li style="box-sizing: border-box; padding: 0px 5px;">50</li><li style="box-sizing: border-box; padding: 0px 5px;">51</li></ul>可以看到很简单，这是一个抽象类，那么具体的View的展示需要大家通过复写getView,用法和ListView及其类似，同时我们提供了notifyDataChanged()的方法，当你的数据集发生变化的时候，你可以调用该方法，UI会自动刷新。
当然，仅仅有了Adapter是不行的，我们需要添加相应的代码对其进行支持。
(2)TagFlowLayout对Adapter的支持
那么最主要就是提供一个setAdapter的方法：<code class="language-java hljs has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">void</span> <span class="hljs-title" style="box-sizing: border-box;">setAdapter</span>(TagAdapter adapter)
{
mTagAdapter = adapter;
mTagAdapter.setOnDataChangedListener(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">this</span>);
changeAdapter();
}
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">private</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">void</span> <span class="hljs-title" style="box-sizing: border-box;">changeAdapter</span>()
{
removeAllViews();
TagAdapter adapter = mTagAdapter;
TagView tagViewContainer = <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">null</span>;
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">for</span> (<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span> i = <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>; i < adapter.getCount(); i++)
{
View tagView = adapter.getView(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">this</span>, i, adapter.getItem(i));
tagView.setDuplicateParentStateEnabled(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">true</span>);
tagViewContainer.setLayoutParams(tagView.getLayoutParams());
tagViewContainer.addView(tagView);
addView(tagViewContainer);
}
}
<span class="hljs-annotation" style="color: rgb(155, 133, 157); box-sizing: border-box;">@Override</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">void</span> <span class="hljs-title" style="box-sizing: border-box;">onChanged</span>()
{
changeAdapter();
}</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li><li style="box-sizing: border-box; padding: 0px 5px;">15</li><li style="box-sizing: border-box; padding: 0px 5px;">16</li><li style="box-sizing: border-box; padding: 0px 5px;">17</li><li style="box-sizing: border-box; padding: 0px 5px;">18</li><li style="box-sizing: border-box; padding: 0px 5px;">19</li><li style="box-sizing: border-box; padding: 0px 5px;">20</li><li style="box-sizing: border-box; padding: 0px 5px;">21</li><li style="box-sizing: border-box; padding: 0px 5px;">22</li><li style="box-sizing: border-box; padding: 0px 5px;">23</li><li style="box-sizing: border-box; padding: 0px 5px;">24</li><li style="box-sizing: border-box; padding: 0px 5px;">25</li><li style="box-sizing: border-box; padding: 0px 5px;">26</li><li style="box-sizing: border-box; padding: 0px 5px;">27</li><li style="box-sizing: border-box; padding: 0px 5px;">28</li><li style="box-sizing: border-box; padding: 0px 5px;">29</li></ul>ok，可以看到当你调用setAdapter进来，首先我们会注册
mTagAdapter.setOnDataChangedListener这个回调，主要是用于响应
notifyDataSetChanged()。然后进入
changeAdapter方法，在这里首先移除所有的子View，然后根据mAdapter.getView的返回，开始逐个构造子View，然后进行添加。
这里注意下：我们的上述的代码，对mAdapter.getView返回的View，外围报了一层TagView，这里暂时不要去想，我们后面会细说。
到此，我们的Adapter添加完毕。
三、支持onTagClickListener
ok，这个接口也非常重要，当然我私下了解了下，很多同学都加上了，但是基本都是对单个标签View去setOnClickListener，然后去比对Tag确定点击的是哪个标签，最后回调出来。当然，我们这里考虑一种更优雅的方式：我们从父控件下手，当我们确定用户点击在我们的TagFlowLayout上时，我们根据用户点击的坐标，看看是否点击的是我们的某个View，然后进行click回调。是不是有点像事件分发，哈，我们这里可以称为点击分发。
那么，我们需要关注的就是
onTouchEvent和
performClick方法。
<code class="language-java hljs has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"> <span class="hljs-annotation" style="color: rgb(155, 133, 157); box-sizing: border-box;">@Override</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">boolean</span> <span class="hljs-title" style="box-sizing: border-box;">onTouchEvent</span>(MotionEvent event)
{
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (event.getAction() == MotionEvent.ACTION_UP)
{
mMotionEvent = MotionEvent.obtain(event);
}
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">return</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">super</span>.onTouchEvent(event);
}
<span class="hljs-annotation" style="color: rgb(155, 133, 157); box-sizing: border-box;">@Override</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">boolean</span> <span class="hljs-title" style="box-sizing: border-box;">performClick</span>()
{
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (mMotionEvent == <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">null</span>) <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">return</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">super</span>.performClick();
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span> x = (<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span>) mMotionEvent.getX();
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span> y = (<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span>) mMotionEvent.getY();
mMotionEvent = <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">null</span>;
TagView child = findChild(x, y);
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span> pos = findPosByView(child);
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (child != <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">null</span>)
{
doSelect(child, pos);
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (mOnTagClickListener != <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">null</span>)
{
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">return</span> mOnTagClickListener.onTagClick(child.getTagView(), pos, <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">this</span>);
}
}
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">return</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">super</span>.performClick();
}
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">private</span> TagView <span class="hljs-title" style="box-sizing: border-box;">findChild</span>(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span> x, <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span> y)
{
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">final</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span> cCount = getChildCount();
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">for</span> (<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span> i = <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>; i < cCount; i++)
{
TagView v = (TagView) getChildAt(i);
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (v.getVisibility() == View.GONE) <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">continue</span>;
Rect outRect = <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> Rect();
v.getHitRect(outRect);
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (outRect.contains(x, y))
{
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">return</span> v;
}
}
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">return</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">null</span>;
}</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li><li style="box-sizing: border-box; padding: 0px 5px;">15</li><li style="box-sizing: border-box; padding: 0px 5px;">16</li><li style="box-sizing: border-box; padding: 0px 5px;">17</li><li style="box-sizing: border-box; padding: 0px 5px;">18</li><li style="box-sizing: border-box; padding: 0px 5px;">19</li><li style="box-sizing: border-box; padding: 0px 5px;">20</li><li style="box-sizing: border-box; padding: 0px 5px;">21</li><li style="box-sizing: border-box; padding: 0px 5px;">22</li><li style="box-sizing: border-box; padding: 0px 5px;">23</li><li style="box-sizing: border-box; padding: 0px 5px;">24</li><li style="box-sizing: border-box; padding: 0px 5px;">25</li><li style="box-sizing: border-box; padding: 0px 5px;">26</li><li style="box-sizing: border-box; padding: 0px 5px;">27</li><li style="box-sizing: border-box; padding: 0px 5px;">28</li><li style="box-sizing: border-box; padding: 0px 5px;">29</li><li style="box-sizing: border-box; padding: 0px 5px;">30</li><li style="box-sizing: border-box; padding: 0px 5px;">31</li><li style="box-sizing: border-box; padding: 0px 5px;">32</li><li style="box-sizing: border-box; padding: 0px 5px;">33</li><li style="box-sizing: border-box; padding: 0px 5px;">34</li><li style="box-sizing: border-box; padding: 0px 5px;">35</li><li style="box-sizing: border-box; padding: 0px 5px;">36</li><li style="box-sizing: border-box; padding: 0px 5px;">37</li><li style="box-sizing: border-box; padding: 0px 5px;">38</li><li style="box-sizing: border-box; padding: 0px 5px;">39</li><li style="box-sizing: border-box; padding: 0px 5px;">40</li><li style="box-sizing: border-box; padding: 0px 5px;">41</li><li style="box-sizing: border-box; padding: 0px 5px;">42</li><li style="box-sizing: border-box; padding: 0px 5px;">43</li><li style="box-sizing: border-box; padding: 0px 5px;">44</li><li style="box-sizing: border-box; padding: 0px 5px;">45</li><li style="box-sizing: border-box; padding: 0px 5px;">46</li><li style="box-sizing: border-box; padding: 0px 5px;">47</li><li style="box-sizing: border-box; padding: 0px 5px;">48</li></ul>可以看到我们这里巧妙的利用了
performClick这个回调，来确定的确是触发了click事件，而不是自己去判断什么算click的条件。但是呢，我们的
performClick没有提供MotionEvent的参数，不过不要紧，我们都清楚click的事件发生在ACTION_UP之后，所以我们提供一个变量去记录最后一次触发ACTION_UP的mMotionEvent。
我们在
performClick里面，根据mMotionEvent，去查找是否落在某个子View身上，如果落在，那么就确定点击在它身上了，直接回调即可，关于接口的定义如下，（ps：关于doSelect方法，我们后面说）：
<code class="language-java hljs has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-class" style="box-sizing: border-box;"><span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">interface</span> <span class="hljs-title" style="box-sizing: border-box; color: rgb(102, 0, 102);">OnTagClickListener</span>
{</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">boolean</span> onTagClick(View view, <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span> position, FlowLayout parent);
}
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">private</span> OnTagClickListener mOnTagClickListener;
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">void</span> <span class="hljs-title" style="box-sizing: border-box;">setOnTagClickListener</span>(OnTagClickListener onTagClickListener)
{
mOnTagClickListener = onTagClickListener;
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (onTagClickListener != <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">null</span>) setClickable(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">true</span>);
}</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li></ul>可以看到，如果设置了
setOnTagClickListener，我们显示的设置了父View
setClickable(true)。以防万一父View不具备消费事件的能力。
四、全面支持Checked
这一节呢，主要包含支持几个功能：* 直接设置selector为background即可完成标签选则的切换，类似CheckBox
* 支持控制选择的Tag数量，比如：单选、多选
* 支持setOnSelectListener，当选择某个Tag后回调
首先，我们提供了两个自定义的属性，
multi_suppout和
max_select。一个是指出是否支持选择（如果为false，意味着你只能通过setOnTagClickListener去做一些操作），一个是设置最大的选择数量，-1为不限制数量。
ok，那么核心的代码依然在performClick中被调用的：
<code class="language-java hljs has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;">
<span class="hljs-annotation" style="color: rgb(155, 133, 157); box-sizing: border-box;">@Override</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">boolean</span> <span class="hljs-title" style="box-sizing: border-box;">performClick</span>()
{
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//省略了一些代码...</span>
doSelect(child, pos);
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (mOnTagClickListener != <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">null</span>)
{
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">return</span> mOnTagClickListener.onTagClick(child.getTagView(), pos, <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">this</span>);
}
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//省略了一些代码...</span>
}
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">private</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">void</span> <span class="hljs-title" style="box-sizing: border-box;">doSelect</span>(TagView child, <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span> position)
{
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (mSupportMulSelected)
{
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (!child.isChecked())
{
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (mSelectedMax > <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span> && mSelectedView.size() >= mSelectedMax)
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">return</span>;
child.setChecked(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">true</span>);
mSelectedView.add(position);
} <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">else</span>
{
child.setChecked(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">false</span>);
mSelectedView.remove(position);
}
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (mOnSelectListener != <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">null</span>)
{
mOnSelectListener.onSelected(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> HashSet<Integer>(mSelectedView));
}
}
}
</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li><li style="box-sizing: border-box; padding: 0px 5px;">15</li><li style="box-sizing: border-box; padding: 0px 5px;">16</li><li style="box-sizing: border-box; padding: 0px 5px;">17</li><li style="box-sizing: border-box; padding: 0px 5px;">18</li><li style="box-sizing: border-box; padding: 0px 5px;">19</li><li style="box-sizing: border-box; padding: 0px 5px;">20</li><li style="box-sizing: border-box; padding: 0px 5px;">21</li><li style="box-sizing: border-box; padding: 0px 5px;">22</li><li style="box-sizing: border-box; padding: 0px 5px;">23</li><li style="box-sizing: border-box; padding: 0px 5px;">24</li><li style="box-sizing: border-box; padding: 0px 5px;">25</li><li style="box-sizing: border-box; padding: 0px 5px;">26</li><li style="box-sizing: border-box; padding: 0px 5px;">27</li><li style="box-sizing: border-box; padding: 0px 5px;">28</li><li style="box-sizing: border-box; padding: 0px 5px;">29</li><li style="box-sizing: border-box; padding: 0px 5px;">30</li><li style="box-sizing: border-box; padding: 0px 5px;">31</li><li style="box-sizing: border-box; padding: 0px 5px;">32</li><li style="box-sizing: border-box; padding: 0px 5px;">33</li><li style="box-sizing: border-box; padding: 0px 5px;">34</li><li style="box-sizing: border-box; padding: 0px 5px;">35</li><li style="box-sizing: border-box; padding: 0px 5px;">36</li></ul>ok，可以看到，如果点击了某个标签，进入doSelect方法，首先判断你是否开启了多选的支持（默认支持），然后判断当前的View是否是
非Checked的状态,如果是
非Checked状态，则判断最大的选择数量，如果没有达到，则设置checked=true，同时加入已选择的集合；反之已经是checked状态，就是取消选择状态了。同时如果设置了mOnSelectListener，回调一下。
ok，其实这里隐藏了一些东西，关于接口回调我们不多赘述了，大家都明白。这里主要看Checked。首先你肯定有几个问题：
childView哪来的isChecked(),setChecked()方法？
这么做就能改变UI了？
下面我一一解答：首先，我们并非知道adapter#getView返回的是什么View，但是可以肯定的是，大部分View都是没有isChecked(),setChecked()方法的。但是我们需要有，怎么做？还记得我们setAdapter的时候，给getView外层包了一层TagView么，没错，就是TagView起到的作用：
<code class="language-java hljs has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">package</span> com.zhy.view.flowlayout;
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">import</span> android.content.Context;
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">import</span> android.view.View;
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">import</span> android.widget.Checkable;
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">import</span> android.widget.FrameLayout;
<span class="hljs-javadoc" style="color: rgb(136, 0, 0); box-sizing: border-box;">/**
* Created by zhy on 15/9/10.
*/</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-class" style="box-sizing: border-box;"><span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">class</span> <span class="hljs-title" style="box-sizing: border-box; color: rgb(102, 0, 102);">TagView</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">extends</span> <span class="hljs-title" style="box-sizing: border-box; color: rgb(102, 0, 102);">FrameLayout</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">implements</span> <span class="hljs-title" style="box-sizing: border-box; color: rgb(102, 0, 102);">Checkable</span>
{</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">private</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">boolean</span> isChecked;
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">private</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">static</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">final</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span>[] CHECK_STATE = <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span>[]{android.R.attr.state_checked};
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-title" style="box-sizing: border-box;">TagView</span>(Context context)
{
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">super</span>(context);
}
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> View <span class="hljs-title" style="box-sizing: border-box;">getTagView</span>()
{
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">return</span> getChildAt(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>);
}
<span class="hljs-annotation" style="color: rgb(155, 133, 157); box-sizing: border-box;">@Override</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span>[] <span class="hljs-title" style="box-sizing: border-box;">onCreateDrawableState</span>(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span> extraSpace)
{
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span>[] states = <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">super</span>.onCreateDrawableState(extraSpace + <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>);
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (isChecked())
{
mergeDrawableStates(states, CHECK_STATE);
}
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">return</span> states;
}
<span class="hljs-javadoc" style="color: rgb(136, 0, 0); box-sizing: border-box;">/**
* Change the checked state of the view
*
*<span class="hljs-javadoctag" style="color: rgb(102, 0, 102); box-sizing: border-box;"> @param</span> checked The new checked state
*/</span>
<span class="hljs-annotation" style="color: rgb(155, 133, 157); box-sizing: border-box;">@Override</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">void</span> <span class="hljs-title" style="box-sizing: border-box;">setChecked</span>(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">boolean</span> checked)
{
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">this</span>.isChecked != checked)
{
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">this</span>.isChecked = checked;
refreshDrawableState();
}
}
<span class="hljs-javadoc" style="color: rgb(136, 0, 0); box-sizing: border-box;">/**
*<span class="hljs-javadoctag" style="color: rgb(102, 0, 102); box-sizing: border-box;"> @return</span> The current checked state of the view
*/</span>
<span class="hljs-annotation" style="color: rgb(155, 133, 157); box-sizing: border-box;">@Override</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">boolean</span> <span class="hljs-title" style="box-sizing: border-box;">isChecked</span>()
{
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">return</span> isChecked;
}
<span class="hljs-javadoc" style="color: rgb(136, 0, 0); box-sizing: border-box;">/**
* Change the checked state of the view to the inverse of its current state
*/</span>
<span class="hljs-annotation" style="color: rgb(155, 133, 157); box-sizing: border-box;">@Override</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">void</span> <span class="hljs-title" style="box-sizing: border-box;">toggle</span>()
{
setChecked(!isChecked);
}
}</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li><li style="box-sizing: border-box; padding: 0px 5px;">15</li><li style="box-sizing: border-box; padding: 0px 5px;">16</li><li style="box-sizing: border-box; padding: 0px 5px;">17</li><li style="box-sizing: border-box; padding: 0px 5px;">18</li><li style="box-sizing: border-box; padding: 0px 5px;">19</li><li style="box-sizing: border-box; padding: 0px 5px;">20</li><li style="box-sizing: border-box; padding: 0px 5px;">21</li><li style="box-sizing: border-box; padding: 0px 5px;">22</li><li style="box-sizing: border-box; padding: 0px 5px;">23</li><li style="box-sizing: border-box; padding: 0px 5px;">24</li><li style="box-sizing: border-box; padding: 0px 5px;">25</li><li style="box-sizing: border-box; padding: 0px 5px;">26</li><li style="box-sizing: border-box; padding: 0px 5px;">27</li><li style="box-sizing: border-box; padding: 0px 5px;">28</li><li style="box-sizing: border-box; padding: 0px 5px;">29</li><li style="box-sizing: border-box; padding: 0px 5px;">30</li><li style="box-sizing: border-box; padding: 0px 5px;">31</li><li style="box-sizing: border-box; padding: 0px 5px;">32</li><li style="box-sizing: border-box; padding: 0px 5px;">33</li><li style="box-sizing: border-box; padding: 0px 5px;">34</li><li style="box-sizing: border-box; padding: 0px 5px;">35</li><li style="box-sizing: border-box; padding: 0px 5px;">36</li><li style="box-sizing: border-box; padding: 0px 5px;">37</li><li style="box-sizing: border-box; padding: 0px 5px;">38</li><li style="box-sizing: border-box; padding: 0px 5px;">39</li><li style="box-sizing: border-box; padding: 0px 5px;">40</li><li style="box-sizing: border-box; padding: 0px 5px;">41</li><li style="box-sizing: border-box; padding: 0px 5px;">42</li><li style="box-sizing: border-box; padding: 0px 5px;">43</li><li style="box-sizing: border-box; padding: 0px 5px;">44</li><li style="box-sizing: border-box; padding: 0px 5px;">45</li><li style="box-sizing: border-box; padding: 0px 5px;">46</li><li style="box-sizing: border-box; padding: 0px 5px;">47</li><li style="box-sizing: border-box; padding: 0px 5px;">48</li><li style="box-sizing: border-box; padding: 0px 5px;">49</li><li style="box-sizing: border-box; padding: 0px 5px;">50</li><li style="box-sizing: border-box; padding: 0px 5px;">51</li><li style="box-sizing: border-box; padding: 0px 5px;">52</li><li style="box-sizing: border-box; padding: 0px 5px;">53</li><li style="box-sizing: border-box; padding: 0px 5px;">54</li><li style="box-sizing: border-box; padding: 0px 5px;">55</li><li style="box-sizing: border-box; padding: 0px 5px;">56</li><li style="box-sizing: border-box; padding: 0px 5px;">57</li><li style="box-sizing: border-box; padding: 0px 5px;">58</li><li style="box-sizing: border-box; padding: 0px 5px;">59</li><li style="box-sizing: border-box; padding: 0px 5px;">60</li><li style="box-sizing: border-box; padding: 0px 5px;">61</li><li style="box-sizing: border-box; padding: 0px 5px;">62</li><li style="box-sizing: border-box; padding: 0px 5px;">63</li><li style="box-sizing: border-box; padding: 0px 5px;">64</li><li style="box-sizing: border-box; padding: 0px 5px;">65</li><li style="box-sizing: border-box; padding: 0px 5px;">66</li><li style="box-sizing: border-box; padding: 0px 5px;">67</li><li style="box-sizing: border-box; padding: 0px 5px;">68</li><li style="box-sizing: border-box; padding: 0px 5px;">69</li><li style="box-sizing: border-box; padding: 0px 5px;">70</li></ul>我们的TagView实现了Checkable接口，所以提供了问题一的方法。
下面解释问题二： 这么做就能改变UI了？
我们继续看TagView这个类，这个类中我们复写了
onCreateDrawableState，在里面添加了
CHECK_STATE的支持。当我们调用setChecked方法的时候，我们会调用
refreshDrawableState()来更新我们的UI。
但是你可能又会问了，你这个是TagView支持了CHECKED状态，关它的子View什么事？我们的background可是设置在子View上的。
没错，这个问题问的相当好，你还记得我们在setAdapter，addView之前有一行非常核心的代码：
#mAdapter.getView().setDuplicateParentStateEnabled(true);，
setDuplicateParentStateEnabled这个方法允许我们的CHECKED状态向下传递。
到这，你应该明白了吧~~
所以我们对于UI的变化，只需要设置View的Backgroud为：
<code class="language-xml hljs has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-pi" style="color: rgb(0, 102, 102); box-sizing: border-box;"><?xml version="1.0" encoding="utf-8"?></span> <span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">selector</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">xmlns:android</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"http://schemas.android.com/apk/res/android"</span>></span> <span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">item </span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">android:drawable</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"@drawable/checked_bg"</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">android:state_checked</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"true"</span>></span><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">item</span>></span> <span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"><<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">item</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">android:drawable</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"@drawable/normal_bg"</span>></span><span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">item</span>></span> <span class="hljs-tag" style="color: rgb(0, 102, 102); box-sizing: border-box;"></<span class="hljs-title" style="box-sizing: border-box; color: rgb(0, 0, 136);">selector</span>></span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li></ul>
这样，如果你的设计稿发生变化，大部分情况下，你只需要改改xml文件就可以了。
ok，到此我们的核心部分的剖析就结束了，接下来贴贴用法：
五、用法
用法其实很简单，大家可以参考例子，我这里大致贴一下：（1）设置数据
<code class="language-java hljs has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;">mFlowLayout.setAdapter(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> TagAdapter<String>(mVals)
{
<span class="hljs-annotation" style="color: rgb(155, 133, 157); box-sizing: border-box;">@Override</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> View <span class="hljs-title" style="box-sizing: border-box;">getView</span>(FlowLayout parent, <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span> position, String s)
{
TextView tv = (TextView) mInflater.inflate(R.layout.tv,
mFlowLayout, <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">false</span>);
tv.setText(s);
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">return</span> tv;
}
});</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li></ul>getView中回调，类似ListView等用法。
（2）对于选中状态
你还在复杂的写代码设置选中后标签的显示效果么，翔哥说No!<code class="language-java hljs has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><?xml version=<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"1.0"</span> encoding=<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"utf-8"</span>?> <selector xmlns:android=<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"http://schemas.android.com/apk/res/android"</span>> <item android:color=<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"@color/tag_select_textcolor"</span> android:drawable=<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"@drawable/checked_bg"</span> android:state_checked=<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"true"</span>></item> <item android:drawable=<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"@drawable/normal_bg"</span>></item> </selector> </code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li></ul>
设置个background，上面一个状态为android:state_checked，另一个为正常。写写布局文件我都嫌慢，怎么能写一堆代码控制效果，设置改个效果，岂不是没时间dota了。
（3）事件
<code class="language-java hljs has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;">mFlowLayout.setOnTagClickListener(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> TagFlowLayout.OnTagClickListener()
{
<span class="hljs-annotation" style="color: rgb(155, 133, 157); box-sizing: border-box;">@Override</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">boolean</span> <span class="hljs-title" style="box-sizing: border-box;">onTagClick</span>(View view, <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span> position, FlowLayout parent)
{
Toast.makeText(getActivity(), mVals[position], Toast.LENGTH_SHORT).show();
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">return</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">true</span>;
}
});</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li></ul>点击标签时的回调。
<code class="language-java hljs has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;">mFlowLayout.setOnSelectListener(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> TagFlowLayout.OnSelectListener()
{
<span class="hljs-annotation" style="color: rgb(155, 133, 157); box-sizing: border-box;">@Override</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">void</span> <span class="hljs-title" style="box-sizing: border-box;">onSelected</span>(Set<Integer> selectPosSet)
{
getActivity().setTitle(<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"choose:"</span> + selectPosSet.toString());
}
});</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li></ul>选择多个标签时的回调。
最后肯定有人会问，支持字体变色吗？ScrollView会冲突吗？
附上最新效果图：
大家就自行查看源码了。
最后，源码下载地址：https://github.com/hongyangAndroid/FlowLayout
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