SimpleWaveform
[说明：以前画过波形图，最近又需要画，略不同，但还得重复写。在网上搜了一下，只找到一个复杂的框架，而我们往往只需要画简单的波形或柱状图。所以我整理提取了过去的代码，有了这个简洁的波形及柱状图控件。实现上很简单，关键在于，怎样简单，又可灵活定制来适用于通常的应用场景。比如在画图之外增加了进度条及触碰反馈功能，就可适用于录音及播音的场景]
SimpleWaveform 显示一串数据为波形图，或者条状图
SimpleWaveform 可以高度定制:
(1)可以显示原始的正负数据，也可以取绝对值来显示数据的幅度
(2)数据可以直接对应像素，也可以是满幅的百分比。控件会自动检测自己的宽度及高度像素
(3)可以选择显示：柱状条 /峰值轮廓 /x 轴
(4)可以选择怎样连接峰值来画出轮廓
(5)其 x 轴可以放在控件的顶部 /中间 /底部
(6)可以设定柱状条的宽度与间隔
(7)可以设定所有的笔，包括柱条 /轮廓 /x 轴 /背景，前两者是两支笔
(8)用两支笔来画前后两部分，这样就有不同的颜色来标识进度
(9)波形图可以从左边或右边开始
(10)如果你手指碰触视图，监听器可以返回碰触的柱条位置
常见用法
(1)当你录音时可以用 SimpleWaveform 来显示声波，请参考 advance demo1
(2)嵌入为 recycler view 的元素，通过左右滑动来显示很长的波形图，请参考 advance demo2
demo1: 显示正负数据
demo2: 柱状图
demo3: 显示振幅绝对值
demo4: 显示声波
advance demo1: 显示录音得到音频输入
advance demo2: 嵌入到横向的 recycler view 中显示很长时间的录音
控件用法:
(1)直接拷贝 SimpleWaveform.java 到项目. 目前我还不懂得怎么制作一个 gradle 模块.
(2)查看及拷贝 demo1~4 及 advance demo1~2 代码，位于文件 SimpleWaveformDemo.java 中. 使用非常的直观简单，并且有缺省设置，只要添加数据链表，然后可以省略后续设置并直接显示.
这里是例子 demo3 ，看一下注释即可:
private void demo3() {
//restore default setting, you can omit all following setting and goto the final refresh() show
simpleWaveform.init();
LinkedList ampList = new LinkedList<>();
//generate random data
for (int i = 0; i < 80; i++) {
ampList.add(randomInt(-50, 50));
}
simpleWaveform.setDataList(ampList);//input data to show
//define bar gap
simpleWaveform.barGap = 30;
//define x-axis direction
simpleWaveform.modeDirection = SimpleWaveform.MODE_DIRECTION_LEFT_RIGHT;
//define if draw opposite pole when show bars
simpleWaveform.modeAmp = SimpleWaveform.MODE_AMP_ABSOLUTE;
//define if the unit is px or percent of the view's height
simpleWaveform.modeHeight = SimpleWaveform.MODE_HEIGHT_PERCENT;
//define where is the x-axis in y-axis
simpleWaveform.modeZero = SimpleWaveform.MODE_ZERO_CENTER;
//if show bars?
simpleWaveform.showBar = true;
//define how to show peaks outline
simpleWaveform.modePeak = SimpleWaveform.MODE_PEAK_PARALLEL;
//if show peaks outline?
simpleWaveform.showPeak = true;
//show x-axis
simpleWaveform.showXAxis = true;
xAxisPencil.setStrokeWidth(1);
xAxisPencil.setColor(0x88ffffff);//the first 0x88 is transparency, the next 0xffffff is color
simpleWaveform.xAxisPencil = xAxisPencil;
//define pencil to draw bar
barPencilFirst.setStrokeWidth(15);
barPencilFirst.setColor(0xff1dcf0f);
simpleWaveform.barPencilFirst = barPencilFirst;
barPencilSecond.setStrokeWidth(15);
barPencilSecond.setColor(0xff1dcfcf);
simpleWaveform.barPencilSecond = barPencilSecond;
//define pencil to draw peaks outline
peakPencilFirst.setStrokeWidth(5);
peakPencilFirst.setColor(0xfffe2f3f);
simpleWaveform.peakPencilFirst = peakPencilFirst;
peakPencilSecond.setStrokeWidth(5);
peakPencilSecond.setColor(0xfffeef3f);
simpleWaveform.peakPencilSecond = peakPencilSecond;
//the first part will be draw by PencilFirst
simpleWaveform.firstPartNum = 20;//first 20 bars will be draw by first pencil
//define how to clear screen
simpleWaveform.clearScreenListener = new SimpleWaveform.ClearScreenListener() {
@Override
public void clearScreen(Canvas canvas) {
canvas.drawColor(Color.TRANSPARENT, PorterDuff.Mode.CLEAR);
}
};
// set touch listener
simpleWaveform.progressTouch = new SimpleWaveform.ProgressTouch() {
@Override
public void progressTouch(int progress, MotionEvent event) {
Log.d("", "you touch at: " + progress);
simpleWaveform.firstPartNum = progress;//set touch position back to its progress
simpleWaveform.refresh();
}
};
//show...
simpleWaveform.refresh();
demo_introduce.setText("demo3: amplitude bar");
}
android:id="@+id/simplewaveform"
android:layout_width="match_parent"
android:layout_height="300dp"
android:layout_margin="10dp" />
