圆头像处理~开发中经常遇到
原文出处：http://blog.csdn.net/zhoubin1992/article/details/47258639
本文分为三大部分：
- CircleImageView的使用
- CircleImageView源码分析
- Android自定义View总结
CircleImageView项目源码下载：
https://github.com/hdodenhof/CircleImageView
打开源码会发现主要就是一个继承了ImageView 的类——CircleImageView .java，代码优雅精致，效果很nice。下面会进行源码分析，让我加深了不少Canvas、BitmapShader、Matrix相关知识。
CircleImageView的使用
我这里一步步展示使用步骤，记录下当时遇到的问题。
- 按照上面的地址下载，项目文件名CircleImageView-master。目录下的circleimageview为库文件，sample为官方demo，使用fragment比较繁琐。这里我自己新建demo学会使用。
-
新建一个Android项目CircleImageViewDemo_1，复制上一步circleimageview文件夹里的CircleImageView.java到CircleImageViewDemo_1中。
CircleImageView.java地址：
CircleImageView-master\circleimageview\src\main\java\de\hdodenhof\circleimageview
项目src中：
-
此时会发现CircleImageView.java里报错，出错为没有R.styleable.CircleImageView。这是因为我们缺少自定义View的属性attrs.xml。在CircleImageView-master中找到attrs.xml并复制到项目里的res/values下。错误消失。
attrs.xml地址：
CircleImageView-master\circleimageview\src\main\res\values
<code class="hljs xml 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);">resources</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);">declare-styleable</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">name</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"CircleImageView"</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);">attr</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">name</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"border_width"</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">format</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"dimension"</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);">attr</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">name</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"border_color"</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">format</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"color"</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);">attr</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">name</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"border_overlay"</span> <span class="hljs-attribute" style="box-sizing: border-box; color: rgb(102, 0, 102);">format</span>=<span class="hljs-value" style="box-sizing: border-box; color: rgb(0, 136, 0);">"boolean"</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);">declare-styleable</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);">resources</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><li style="box-sizing: border-box; padding: 0px 5px;">8</li></ul>
4 接下来就要在activity_main.xml里使用CircleImageView了。我仿照官方demo进行layout布局，同时引用官方图片。
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" xmlns:app="http://schemas.android.com/apk/res-auto" android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="vertical" tools:context="com.example.circleimageviewdemo_1.MainActivity" >
<RelativeLayout android:layout_width="match_parent" android:layout_height="0dp" android:layout_weight="1" android:padding="@dimen/base_padding" android:background="@color/light">
<com.example.library.CircleImageView android:layout_width="160dp" android:layout_height="160dp" android:layout_centerInParent="true" android:src="@drawable/hugh" app:border_width="2dp" app:border_color="@color/dark" />
</RelativeLayout>
<RelativeLayout android:layout_width="match_parent" android:layout_height="0dp" android:layout_weight="1" android:padding="@dimen/base_padding" android:background="@color/dark">
<com.example.library.CircleImageView android:layout_width="160dp" android:layout_height="160dp" android:layout_centerInParent="true" android:src="@drawable/hugh" app:border_width="2dp" app:border_color="@color/light" />
</RelativeLayout>
</LinearLayout>
- 1
- 2
- 3
- 4
- 5
- 6
- 7
- 8
- 9
- 10
- 11
- 12
- 13
- 14
- 15
- 16
- 17
- 18
- 19
- 20
- 21
- 22
- 23
- 24
- 25
- 26
- 27
- 28
- 29
- 30
- 31
- 32
- 33
- 34
- 35
- 36
- 37
- 38
- 39
- 40
- 41
- 42
- 43
- 44
- 45
注意两点：
- 在xml布局文件中，声明我们的自定义View，路径要正确。
com.example.library.CircleImageView - 一定要引入命名空间，xmlns:app=”http://schemas.android.com/apk/res-auto”，不然无法使用自定义属性。
MainActivity里不用修改，因为我直接在XML里面用src设置了图片，你也可以在MainActivity中用setImageXXX设置。直接运行看效果。
总结下CircleImageView的使用：
- 将CircleImageView.java拷贝到项目工程中
- attrs.xml拷贝到res/values/目录下
- 在布局文件中声明自定义View，一定要引入命名空间xmlns:app=”http://schemas.android.com/apk/res-auto”。
Demo下载：
http://download.csdn.net/detail/zhoubin1992/8956647
CircleImageView源码分析
一直很好奇这个开源库是怎么自定义圆形ImageView，结果最近花了很多功夫进行分析，现在也非常迫切想整理出来，希望能帮到一些人。我也看了网络上的一些源码分析，有些分析是错误的会误导大家，有些说的不详细还是无法理解。
首先我先总结下CircleImageView的主要流程，让大家有个整体把握。然后再一步步进入源码分析。
CircleImageView的主要流程：
1. 首先通过setImageXxx()方法设置图片Bitmap；
2. 进入构造函数CircleImageView()获取自定义参数，以及调用setup()函数；
3. 进入setup()函数（非常关键），进行图片画笔边界画笔(Paint)一些重绘参数初始化：构建渲染器BitmapShader用Bitmap来填充绘制区域,设置样式和内外圆半径计算等，以及调用updateShaderMatrix()函数和 invalidate()函数；
4. 进入updateShaderMatrix()函数，计算缩放比例和平移，设置BitmapShader的Matrix参数等；
5. 触发ondraw()函数完成最终的绘制。使用配置好的Paint先画出绘制内圆形来以后再画边界圆形。
下面来详细分析一下源码：
1. 首先从项目里调用CircleImageView开始分析，我们要么在XML里面用src，要么调用CircleImageView的setImageXXX()方法设置图片。那我们的源码的运行入口在哪里呢，是从构造函数CircleImageView()开始呢还是从setImageXXX()开始？一开始就卡壳了。一开始我以为是从构造函数CircleImageView()开始跑，结果分析下来发现并不会进入setup();所以这是行不通的，那接下来就要论证是不是从setImageXXX()开始呢？我的方法是分别在两者进行System.out.println测试，看看谁先执行。测试结果会发现是从setImageXXX()开始。
那我们看下源码：
<code class="hljs java 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-javadoc" style="color: rgb(136, 0, 0); box-sizing: border-box;">/**
* 以下四个函数都是
* 复写ImageView的setImageXxx()方法
* 注意这个函数先于构造函数调用之前调用
*<span class="hljs-javadoctag" style="color: rgb(102, 0, 102); box-sizing: border-box;"> @param</span> bm
*/</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;">setImageBitmap</span>(Bitmap bm) {
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">super</span>.setImageBitmap(bm);
mBitmap = bm;
setup();
}
<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;">setImageDrawable</span>(Drawable drawable) {
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">super</span>.setImageDrawable(drawable);
mBitmap = getBitmapFromDrawable(drawable);
System.out.println(<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"setImageDrawable -- setup"</span>);
setup();
}
<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;">setImageResource</span>(@DrawableRes <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span> resId) {
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">super</span>.setImageResource(resId);
mBitmap = getBitmapFromDrawable(getDrawable());
setup();
}
<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;">setImageURI</span>(Uri uri) {
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">super</span>.setImageURI(uri);
mBitmap = getBitmapFromDrawable(getDrawable());
setup();
}</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></ul>
看上面代码会发现，四个函数都是获取图片Bitmap，调用setup()。
接下来那我们查看setup()源码：
<code class="hljs bash 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;"> //因为mReady默认值为<span class="hljs-literal" style="color: rgb(0, 102, 102); box-sizing: border-box;">false</span>,所以第一次进这个函数的时候<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span>语句为真进入括号体内
//设置mSetupPending为<span class="hljs-literal" style="color: rgb(0, 102, 102); box-sizing: border-box;">true</span>然后直接返回，后面的代码并没有执行。
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (!mReady) {
mSetupPending = <span class="hljs-literal" style="color: rgb(0, 102, 102); box-sizing: border-box;">true</span>;
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">return</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></ul>
会发现第一次进入时，第一个if语句为真，进入括号体内设置mSetupPending为true然后直接返回，后面的代码并没有执行。为什么要这样设置mReady和mSetupPending呢不执行下面的代码呢，不要急，后面再解释。
2. 接下来我们会进入构造函数CircleImageView()。查看源码：
<code class="hljs java 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-javadoc" style="color: rgb(136, 0, 0); box-sizing: border-box;">/**
* 构造函数
*/</span>
<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;">CircleImageView</span>(Context context, AttributeSet attrs, <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span> defStyle) {
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">super</span>(context, attrs, defStyle);
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//通过obtainStyledAttributes 获得一组值赋给 TypedArray（数组） , 这一组值来自于res/values/attrs.xml中的name="CircleImageView"的declare-styleable中。</span>
TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.CircleImageView, defStyle, <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>);
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//通过TypedArray提供的一系列方法getXXXX取得我们在xml里定义的参数值；</span>
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">// 获取边界的宽度</span>
mBorderWidth = a.getDimensionPixelSize(R.styleable.CircleImageView_border_width, DEFAULT_BORDER_WIDTH);
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">// 获取边界的颜色</span>
mBorderColor = a.getColor(R.styleable.CircleImageView_border_color, DEFAULT_BORDER_COLOR);
mBorderOverlay = a.getBoolean(R.styleable.CircleImageView_border_overlay, DEFAULT_BORDER_OVERLAY);
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//调用 recycle() 回收TypedArray,以便后面重用</span>
a.recycle();
System.out.println(<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"CircleImageView -- 构造函数"</span>);
init();
}</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></ul>
分析上面代码会发现很简单，就是首先通过TypedArray获取自定义参数，再调用init()函数：
<code class="hljs java 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-javadoc" style="color: rgb(136, 0, 0); box-sizing: border-box;">/**
* 作用就是保证第一次执行setup函数里下面代码要在构造函数执行完毕时调用
*/</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;">init</span>() {
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//在这里ScaleType被强制设定为CENTER_CROP，就是将图片水平垂直居中，进行缩放。</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">super</span>.setScaleType(SCALE_TYPE);
mReady = <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">true</span>;
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (mSetupPending) {
setup();
mSetupPending = <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">false</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></ul>
因为在前面mSetupPending为真，则执行setup()，而且这里mReady 也为true，所以会执行setup()下面的代码。为什么要这样设置mSetupPending和mReady呢？
这是因为第一次进入setImageXXX()时候，我们无法获取自定义参数值，所以setup()下面的代码无法绘制我们想要的样式而是默认样式。而获取自定义参数只能在构造函数里，这样我们就能明白大神作者的意图了，通过设置mSetupPending和mReady控制第一次执行setup函数里下面代码要在构造函数执行完毕时。再者如果用户再进行setImageXXX()设置图片的话，就直接会执行setup()下面的代码，因为这之后mReady一直为true。
3 说了这么多，我们来看看setup()下面的代码到底是啥？没错，它就是这么酷炫，很关键：
<code class="hljs java 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-javadoc" style="color: rgb(136, 0, 0); box-sizing: border-box;">/**
* 这个函数很关键，进行图片画笔边界画笔(Paint)一些重绘参数初始化：
* 构建渲染器BitmapShader用Bitmap来填充绘制区域,设置样式以及内外圆半径计算等，
* 以及调用updateShaderMatrix()函数和 invalidate()函数；
*/</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;">setup</span>() {
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//因为mReady默认值为false,所以第一次进这个函数的时候if语句为真进入括号体内</span>
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//设置mSetupPending为true然后直接返回，后面的代码并没有执行。</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (!mReady) {
mSetupPending = <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">true</span>;
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">return</span>;
}
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//防止空指针异常</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (mBitmap == <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-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">// 构建渲染器，用mBitmap来填充绘制区域 ，参数值代表如果图片太小的话 就直接拉伸</span>
mBitmapShader = <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> BitmapShader(mBitmap, Shader.TileMode.CLAMP, Shader.TileMode.CLAMP);
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">// 设置图片画笔反锯齿</span>
mBitmapPaint.setAntiAlias(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">true</span>);
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">// 设置图片画笔渲染器</span>
mBitmapPaint.setShader(mBitmapShader);
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">// 设置边界画笔样式</span>
mBorderPaint.setStyle(Paint.Style.STROKE);
mBorderPaint.setAntiAlias(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">true</span>);
mBorderPaint.setColor(mBorderColor); <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//画笔颜色</span>
mBorderPaint.setStrokeWidth(mBorderWidth);<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//画笔边界宽度</span>
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//这个地方是取的原图片的宽高</span>
mBitmapHeight = mBitmap.getHeight();
mBitmapWidth = mBitmap.getWidth();
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">// 设置含边界显示区域，取的是CircleImageView的布局实际大小，为方形，查看xml也就是160dp(240px) getWidth得到是某个view的实际尺寸</span>
mBorderRect.set(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>, <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>, getWidth(), getHeight());
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//计算 圆形带边界部分（外圆）的最小半径，取mBorderRect的宽高减去一个边缘大小的一半的较小值（这个地方我比较纳闷为什么求外圆半径需要先减去一个边缘大小）</span>
mBorderRadius = Math.min((mBorderRect.height() - mBorderWidth) / <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>, (mBorderRect.width() - mBorderWidth) / <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>);
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">// 初始图片显示区域为mBorderRect（CircleImageView的布局实际大小）</span>
mDrawableRect.set(mBorderRect);
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (!mBorderOverlay) {
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//demo里始终执行</span>
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//通过inset方法 使得图片显示的区域从mBorderRect大小上下左右内移边界的宽度形成区域，查看xml边界宽度为2dp（3px）,所以方形边长为就是160-4=156dp(234px)</span>
mDrawableRect.inset(mBorderWidth, mBorderWidth);
}
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//这里计算的是内圆的最小半径，也即去除边界宽度的半径</span>
mDrawableRadius = Math.min(mDrawableRect.height() / <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>, mDrawableRect.width() / <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>);
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//设置渲染器的变换矩阵也即是mBitmap用何种缩放形式填充</span>
updateShaderMatrix();
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//手动触发ondraw()函数 完成最终的绘制</span>
invalidate();
}</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>
上面代码注释我写的很详细不再一步步解释了，进行图片画笔边界画笔(Paint)一些重绘参数初始化：构建渲染器BitmapShader用Bitmap来填充绘制区域,设置样式以及内外圆半径计算等，以及调用updateShaderMatrix()函数和 invalidate()函数。
这里关于半径的计算，我画图举个例子：CircleImageView的布局宽高度均为160，边界的宽度为10如图所示：
那么去除边界宽度的内圆半径为70，带边界部分的外圆半径为75。
4 根据上面，接下来进入updateShaderMatrix()函数，查看源码：
/** * 这个函数为设置BitmapShader的Matrix参数，设置最小缩放比例，平移参数。 * 作用：保证图片损失度最小和始终绘制图片正中央的那部分 */
private void updateShaderMatrix() {
float scale;
float dx = 0;
float dy = 0;
mShaderMatrix.set(null);
// 这里不好理解 这个不等式也就是(mBitmapWidth / mDrawableRect.width()) > (mBitmapHeight / mDrawableRect.height())
//取最小的缩放比例
if (mBitmapWidth * mDrawableRect.height() > mDrawableRect.width() * mBitmapHeight) {
//y轴缩放 x轴平移 使得图片的y轴方向的边的尺寸缩放到图片显示区域（mDrawableRect）一样）
scale = mDrawableRect.height() / (float) mBitmapHeight;
dx = (mDrawableRect.width() - mBitmapWidth * scale) * 0.5f;
} else {
//x轴缩放 y轴平移 使得图片的x轴方向的边的尺寸缩放到图片显示区域（mDrawableRect）一样）
scale = mDrawableRect.width() / (float) mBitmapWidth;
dy = (mDrawableRect.height() - mBitmapHeight * scale) * 0.5f;
}
// shaeder的变换矩阵，我们这里主要用于放大或者缩小。
mShaderMatrix.setScale(scale, scale);
// 平移
mShaderMatrix.postTranslate((int) (dx + 0.5f) + mDrawableRect.left, (int) (dy + 0.5f) + mDrawableRect.top);
// 设置变换矩阵
mBitmapShader.setLocalMatrix(mShaderMatrix);
}
- 1
- 2
- 3
- 4
- 5
- 6
- 7
- 8
- 9
- 10
- 11
- 12
- 13
- 14
- 15
- 16
- 17
- 18
- 19
- 20
- 21
- 22
- 23
- 24
- 25
- 26
- 27
- 28
通过updateShaderMatrix函数设置BitmapShader的Matrix参数，对图片mBitmap位置用何种缩放平移形式填充。
if判断语句里mBitmapWidth * mDrawableRect.height() > mDrawableRect.width() * mBitmapHeight写成(mBitmapWidth / mDrawableRect.width()) > (mBitmapHeight / mDrawableRect.height())更好理解。
目的是用最小的缩放比例，使得图片的某个方向的边的尺寸缩放到图片显示区域（mDrawableRect）一样。做到了图片损失度最小。同时scale保证Bitmap的宽或高和目标区域一致，那么高或宽就需要进行位移，使得Bitmap居中。这里写得很nice。
5 现在万事俱备，只欠ondraw()了。接着上面再setup()最后会调用invalidate()函数触发ondraw()函数完成最终的绘制。查看源码：
<code class="hljs java 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;">protected</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;">onDraw</span>(Canvas canvas) {
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//如果图片不存在就不画</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (getDrawable() == <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-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//绘制内圆形，参数内圆半径，图片画笔为mBitmapPaint</span>
canvas.drawCircle(getWidth() / <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>, getHeight() / <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>, mDrawableRadius, mBitmapPaint);
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//如果圆形边缘的宽度不为0 我们还要绘制带边界的外圆形 参数外圆半径，边界画笔为mBorderPaint</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (mBorderWidth != <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>) {
canvas.drawCircle(getWidth() / <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>, getHeight() / <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>, mBorderRadius, mBorderPaint);
}
}</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>
使用配置好的mBitmapPaint和mBorderPaint先画出绘制内圆形来以后再画边界圆形。源码还有一些自定义设置样式函数，很简单。
大功告成，是不是觉得思路比较简单，精致干练。
我总结下源码的精致之处：
- 流程控制的比较严谨，比如setup函数的使用
- updateShaderMatrix保证图片损失度最小和始终绘制图片正中央的那部分
- 作者思路是画圆用渲染器位图填充，而不是把Bitmap重绘切割成一个圆形图片。
附上完整源码：
<code class="hljs java 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.example.library;
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">import</span> com.example.circleimageviewdemo_1.R;
<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.content.res.TypedArray;
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">import</span> android.graphics.Bitmap;
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">import</span> android.graphics.BitmapShader;
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">import</span> android.graphics.Canvas;
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">import</span> android.graphics.Color;
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">import</span> android.graphics.ColorFilter;
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">import</span> android.graphics.Matrix;
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">import</span> android.graphics.Paint;
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">import</span> android.graphics.RectF;
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">import</span> android.graphics.Shader;
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">import</span> android.graphics.drawable.BitmapDrawable;
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">import</span> android.graphics.drawable.ColorDrawable;
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">import</span> android.graphics.drawable.Drawable;
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">import</span> android.net.Uri;
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">import</span> android.support.annotation.ColorRes;
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">import</span> android.support.annotation.DrawableRes;
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">import</span> android.util.AttributeSet;
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">import</span> android.widget.ImageView;
<span class="hljs-javadoc" style="color: rgb(136, 0, 0); box-sizing: border-box;">/**
* 流程控制的比较严谨，比如setup函数的使用
* updateShaderMatrix保证图片损失度最小和始终绘制图片正中央的那部分
* 作者思路是画圆用渲染器位图填充，而不是把Bitmap重绘切割成一个圆形图片。
*/</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);">CircleImageView</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);">ImageView</span> {</span>
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//缩放类型</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;">static</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">final</span> ScaleType SCALE_TYPE = ScaleType.CENTER_CROP;
<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> Bitmap.Config BITMAP_CONFIG = Bitmap.Config.ARGB_8888;
<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> COLORDRAWABLE_DIMENSION = <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>;
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">// 默认边界宽度</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;">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> DEFAULT_BORDER_WIDTH = <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>;
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">// 默认边界颜色</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;">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> DEFAULT_BORDER_COLOR = Color.BLACK;
<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;">boolean</span> DEFAULT_BORDER_OVERLAY = <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">false</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;">final</span> RectF mDrawableRect = <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> RectF();
<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;">final</span> RectF mBorderRect = <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> RectF();
<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;">final</span> Matrix mShaderMatrix = <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> Matrix();
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//这个画笔最重要的是关联了mBitmapShader 使canvas在执行的时候可以切割原图片(mBitmapShader是关联了原图的bitmap的)</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;">final</span> Paint mBitmapPaint = <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> Paint();
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//这个描边，则与本身的原图bitmap没有任何关联，</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;">final</span> Paint mBorderPaint = <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> Paint();
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//这里定义了 圆形边缘的默认宽度和颜色</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;">int</span> mBorderColor = DEFAULT_BORDER_COLOR;
<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;">int</span> mBorderWidth = DEFAULT_BORDER_WIDTH;
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">private</span> Bitmap mBitmap;
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">private</span> BitmapShader mBitmapShader; <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">// 位图渲染</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;">int</span> mBitmapWidth; <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">// 位图宽度</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;">int</span> mBitmapHeight; <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">// 位图高度</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;">float</span> mDrawableRadius;<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">// 图片半径</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;">float</span> mBorderRadius;<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">// 带边框的的图片半径</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">private</span> ColorFilter mColorFilter;
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//初始false</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> mReady;
<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> mSetupPending;
<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> mBorderOverlay;
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//构造函数</span>
<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;">CircleImageView</span>(Context context) {
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">super</span>(context);
init();
}
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//构造函数</span>
<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;">CircleImageView</span>(Context context, AttributeSet attrs) {
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">this</span>(context, attrs, <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>);
}
<span class="hljs-javadoc" style="color: rgb(136, 0, 0); box-sizing: border-box;">/**
* 构造函数
*/</span>
<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;">CircleImageView</span>(Context context, AttributeSet attrs, <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span> defStyle) {
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">super</span>(context, attrs, defStyle);
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//通过obtainStyledAttributes 获得一组值赋给 TypedArray（数组） , 这一组值来自于res/values/attrs.xml中的name="CircleImageView"的declare-styleable中。</span>
TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.CircleImageView, defStyle, <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>);
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//通过TypedArray提供的一系列方法getXXXX取得我们在xml里定义的参数值；</span>
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">// 获取边界的宽度</span>
mBorderWidth = a.getDimensionPixelSize(R.styleable.CircleImageView_border_width, DEFAULT_BORDER_WIDTH);
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">// 获取边界的颜色</span>
mBorderColor = a.getColor(R.styleable.CircleImageView_border_color, DEFAULT_BORDER_COLOR);
mBorderOverlay = a.getBoolean(R.styleable.CircleImageView_border_overlay, DEFAULT_BORDER_OVERLAY);
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//调用 recycle() 回收TypedArray,以便后面重用</span>
a.recycle();
System.out.println(<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"CircleImageView -- 构造函数"</span>);
init();
}
<span class="hljs-javadoc" style="color: rgb(136, 0, 0); box-sizing: border-box;">/**
* 作用就是保证第一次执行setup函数里下面代码要在构造函数执行完毕时调用
*/</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;">init</span>() {
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//在这里ScaleType被强制设定为CENTER_CROP，就是将图片水平垂直居中，进行缩放。</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">super</span>.setScaleType(SCALE_TYPE);
mReady = <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">true</span>;
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (mSetupPending) {
setup();
mSetupPending = <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">false</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> ScaleType <span class="hljs-title" style="box-sizing: border-box;">getScaleType</span>() {
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">return</span> SCALE_TYPE;
}
<span class="hljs-javadoc" style="color: rgb(136, 0, 0); box-sizing: border-box;">/**
* 这里明确指出 此种imageview 只支持CENTER_CROP 这一种属性
*
*<span class="hljs-javadoctag" style="color: rgb(102, 0, 102); box-sizing: border-box;"> @param</span> scaleType
*/</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;">setScaleType</span>(ScaleType scaleType) {
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (scaleType != SCALE_TYPE) {
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">throw</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> IllegalArgumentException(String.format(<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"ScaleType %s not supported."</span>, scaleType));
}
}
<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;">setAdjustViewBounds</span>(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">boolean</span> adjustViewBounds) {
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (adjustViewBounds) {
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">throw</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> IllegalArgumentException(<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"adjustViewBounds not supported."</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;">protected</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;">onDraw</span>(Canvas canvas) {
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//如果图片不存在就不画</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (getDrawable() == <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-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//绘制内圆形 图片 画笔为mBitmapPaint</span>
canvas.drawCircle(getWidth() / <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>, getHeight() / <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>, mDrawableRadius, mBitmapPaint);
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//如果圆形边缘的宽度不为0 我们还要绘制带边界的外圆形 边界画笔为mBorderPaint</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (mBorderWidth != <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>) {
canvas.drawCircle(getWidth() / <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>, getHeight() / <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>, mBorderRadius, mBorderPaint);
}
}
<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;">protected</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;">onSizeChanged</span>(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span> w, <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span> h, <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span> oldw, <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span> oldh) {
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">super</span>.onSizeChanged(w, h, oldw, oldh);
setup();
}
<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;">getBorderColor</span>() {
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">return</span> mBorderColor;
}
<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;">setBorderColor</span>(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span> borderColor) {
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (borderColor == mBorderColor) {
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">return</span>;
}
mBorderColor = borderColor;
mBorderPaint.setColor(mBorderColor);
invalidate();
}
<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;">setBorderColorResource</span>(@ColorRes <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span> borderColorRes) {
setBorderColor(getContext().getResources().getColor(borderColorRes));
}
<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;">getBorderWidth</span>() {
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">return</span> mBorderWidth;
}
<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;">setBorderWidth</span>(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span> borderWidth) {
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (borderWidth == mBorderWidth) {
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">return</span>;
}
mBorderWidth = borderWidth;
setup();
}
<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;">isBorderOverlay</span>() {
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">return</span> mBorderOverlay;
}
<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;">setBorderOverlay</span>(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">boolean</span> borderOverlay) {
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (borderOverlay == mBorderOverlay) {
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">return</span>;
}
mBorderOverlay = borderOverlay;
setup();
}
<span class="hljs-javadoc" style="color: rgb(136, 0, 0); box-sizing: border-box;">/**
* 以下四个函数都是
* 复写ImageView的setImageXxx()方法
* 注意这个函数先于构造函数调用之前调用
*<span class="hljs-javadoctag" style="color: rgb(102, 0, 102); box-sizing: border-box;"> @param</span> bm
*/</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;">setImageBitmap</span>(Bitmap bm) {
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">super</span>.setImageBitmap(bm);
mBitmap = bm;
setup();
}
<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;">setImageDrawable</span>(Drawable drawable) {
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">super</span>.setImageDrawable(drawable);
mBitmap = getBitmapFromDrawable(drawable);
System.out.println(<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"setImageDrawable -- setup"</span>);
setup();
}
<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;">setImageResource</span>(@DrawableRes <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span> resId) {
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">super</span>.setImageResource(resId);
mBitmap = getBitmapFromDrawable(getDrawable());
setup();
}
<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;">setImageURI</span>(Uri uri) {
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">super</span>.setImageURI(uri);
mBitmap = getBitmapFromDrawable(getDrawable());
setup();
}
<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;">setColorFilter</span>(ColorFilter cf) {
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (cf == mColorFilter) {
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">return</span>;
}
mColorFilter = cf;
mBitmapPaint.setColorFilter(mColorFilter);
invalidate();
}
<span class="hljs-javadoc" style="color: rgb(136, 0, 0); box-sizing: border-box;">/**
* Drawable转Bitmap
*<span class="hljs-javadoctag" style="color: rgb(102, 0, 102); box-sizing: border-box;"> @param</span> drawable
*<span class="hljs-javadoctag" style="color: rgb(102, 0, 102); box-sizing: border-box;"> @return</span>
*/</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">private</span> Bitmap <span class="hljs-title" style="box-sizing: border-box;">getBitmapFromDrawable</span>(Drawable drawable) {
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (drawable == <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;">null</span>;
}
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (drawable <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">instanceof</span> BitmapDrawable) {
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//通常来说 我们的代码就是执行到这里就返回了。返回的就是我们最原始的bitmap</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">return</span> ((BitmapDrawable) drawable).getBitmap();
}
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">try</span> {
Bitmap bitmap;
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (drawable <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">instanceof</span> ColorDrawable) {
bitmap = Bitmap.createBitmap(COLORDRAWABLE_DIMENSION, COLORDRAWABLE_DIMENSION, BITMAP_CONFIG);
} <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">else</span> {
bitmap = Bitmap.createBitmap(drawable.getIntrinsicWidth(), drawable.getIntrinsicHeight(), BITMAP_CONFIG);
}
Canvas canvas = <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> Canvas(bitmap);
drawable.setBounds(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>, <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>, canvas.getWidth(), canvas.getHeight());
drawable.draw(canvas);
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">return</span> bitmap;
} <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">catch</span> (OutOfMemoryError e) {
<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>;
}
}
<span class="hljs-javadoc" style="color: rgb(136, 0, 0); box-sizing: border-box;">/**
* 这个函数很关键，进行图片画笔边界画笔(Paint)一些重绘参数初始化：
* 构建渲染器BitmapShader用Bitmap来填充绘制区域,设置样式以及内外圆半径计算等，
* 以及调用updateShaderMatrix()函数和 invalidate()函数；
*/</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;">setup</span>() {
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//因为mReady默认值为false,所以第一次进这个函数的时候if语句为真进入括号体内</span>
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//设置mSetupPending为true然后直接返回，后面的代码并没有执行。</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (!mReady) {
mSetupPending = <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">true</span>;
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">return</span>;
}
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//防止空指针异常</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (mBitmap == <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-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">// 构建渲染器，用mBitmap位图来填充绘制区域 ，参数值代表如果图片太小的话 就直接拉伸</span>
mBitmapShader = <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> BitmapShader(mBitmap, Shader.TileMode.CLAMP, Shader.TileMode.CLAMP);
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">// 设置图片画笔反锯齿</span>
mBitmapPaint.setAntiAlias(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">true</span>);
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">// 设置图片画笔渲染器</span>
mBitmapPaint.setShader(mBitmapShader);
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">// 设置边界画笔样式</span>
mBorderPaint.setStyle(Paint.Style.STROKE);<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//设画笔为空心</span>
mBorderPaint.setAntiAlias(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">true</span>);
mBorderPaint.setColor(mBorderColor); <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//画笔颜色</span>
mBorderPaint.setStrokeWidth(mBorderWidth);<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//画笔边界宽度</span>
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//这个地方是取的原图片的宽高</span>
mBitmapHeight = mBitmap.getHeight();
mBitmapWidth = mBitmap.getWidth();
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">// 设置含边界显示区域，取的是CircleImageView的布局实际大小，为方形，查看xml也就是160dp(240px) getWidth得到是某个view的实际尺寸</span>
mBorderRect.set(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>, <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>, getWidth(), getHeight());
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//计算 圆形带边界部分（外圆）的最小半径，取mBorderRect的宽高减去一个边缘大小的一半的较小值（这个地方我比较纳闷为什么求外圆半径需要先减去一个边缘大小）</span>
mBorderRadius = Math.min((mBorderRect.height() - mBorderWidth) / <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>, (mBorderRect.width() - mBorderWidth) / <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>);
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">// 初始图片显示区域为mBorderRect（CircleImageView的布局实际大小）</span>
mDrawableRect.set(mBorderRect);
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (!mBorderOverlay) {
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//demo里始终执行</span>
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//通过inset方法 使得图片显示的区域从mBorderRect大小上下左右内移边界的宽度形成区域，查看xml边界宽度为2dp（3px）,所以方形边长为就是160-4=156dp(234px)</span>
mDrawableRect.inset(mBorderWidth, mBorderWidth);
}
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//这里计算的是内圆的最小半径，也即去除边界宽度的半径</span>
mDrawableRadius = Math.min(mDrawableRect.height() / <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>, mDrawableRect.width() / <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>);
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//设置渲染器的变换矩阵也即是mBitmap用何种缩放形式填充</span>
updateShaderMatrix();
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//手动触发ondraw()函数 完成最终的绘制</span>
invalidate();
}
<span class="hljs-javadoc" style="color: rgb(136, 0, 0); box-sizing: border-box;">/**
* 这个函数为设置BitmapShader的Matrix参数，设置最小缩放比例，平移参数。
* 作用：保证图片损失度最小和始终绘制图片正中央的那部分
*/</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;">updateShaderMatrix</span>() {
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span> scale;
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span> dx = <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>;
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span> dy = <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>;
mShaderMatrix.set(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">null</span>);
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">// 这里不好理解 这个不等式也就是(mBitmapWidth / mDrawableRect.width()) > (mBitmapHeight / mDrawableRect.height())</span>
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//取最小的缩放比例</span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (mBitmapWidth * mDrawableRect.height() > mDrawableRect.width() * mBitmapHeight) {
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//y轴缩放 x轴平移 使得图片的y轴方向的边的尺寸缩放到图片显示区域（mDrawableRect）一样）</span>
scale = mDrawableRect.height() / (<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span>) mBitmapHeight;
dx = (mDrawableRect.width() - mBitmapWidth * scale) * <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0.5</span>f;
} <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">else</span> {
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//x轴缩放 y轴平移 使得图片的x轴方向的边的尺寸缩放到图片显示区域（mDrawableRect）一样）</span>
scale = mDrawableRect.width() / (<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">float</span>) mBitmapWidth;
dy = (mDrawableRect.height() - mBitmapHeight * scale) * <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0.5</span>f;
}
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">// shaeder的变换矩阵，我们这里主要用于放大或者缩小。</span>
mShaderMatrix.setScale(scale, scale);
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">// 平移</span>
mShaderMatrix.postTranslate((<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span>) (dx + <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0.5</span>f) + mDrawableRect.left, (<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span>) (dy + <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0.5</span>f) + mDrawableRect.top);
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">// 设置变换矩阵</span>
mBitmapShader.setLocalMatrix(mShaderMatrix);
}
}</code>