Android仿豆瓣笑脸进度加载

龙旋

共 16069字,需浏览 33分钟

 · 2021-05-01

最近看到豆瓣的笑脸loading很有意思,看一张效果图:



下面分析一下如何实现这样的效果:


1、默认状态是一张笑脸的状态(一个嘴巴,两个眼睛,默认状态)

2、开始旋转,嘴巴追上眼睛(合并状态)

3、追上以后自转一周(自转状态)

4、然后逐渐释放眼睛(分离状态)

5、回到初始笑脸状态(默认状态)


一、默认状态


首先需要确定好嘴巴和眼睛的初始位置,我这里的初始化嘴巴是一个半圆,在横轴下方。眼睛分别与横轴夹角60度,如下图:



这两部分可以使用pathMeasure,我这里使用最简单的两个api:canvas.drawArc()和canvas.drawPoint()。


1、画嘴巴
 //画起始笑脸canvas.drawArc(-radius, -radius, radius, radius, startAngle, swipeAngle, false,facePaint);


这里的startAngle初始值为0,swiperAngle为180,半径radius为40。


2、画眼睛

(1)初始化眼睛坐标

   /**     * 初始化眼睛坐标     */    private void initEyes() {        //默认两个眼睛坐标位置 角度转弧度        leftEyeX = (float) (-radius * Math.cos(eyeStartAngle * Math.PI / 180));        leftEyeY = (float) (-radius * Math.sin(eyeStartAngle * Math.PI / 180));        rightEyeX = (float) (radius * Math.cos(eyeStartAngle * Math.PI / 180));        rightEyeY = (float) (-radius * Math.sin(eyeStartAngle * Math.PI / 180));    }


注意:需要将角度转弧度


(2)开始画眼睛

   //画起始眼睛  canvas.drawPoint(leftEyeX, leftEyeY, eyePaint);  canvas.drawPoint(rightEyeX, rightEyeY, eyePaint);


二、合并状态

这个状态可以分为两部分

  1. 嘴巴的旋转

  2. 眼睛的旋转

1、嘴巴的旋转

开启动画

     faceLoadingAnimator = ValueAnimator.ofFloat(0, 1).setDuration(1000);     faceLoadingAnimator.setInterpolator(new AccelerateDecelerateInterpolator());     faceLoadingAnimator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {            @Override            public void onAnimationUpdate(ValueAnimator animation) {                faceValue = (float) animation.getAnimatedValue();                invalidate();            }        });        //动画延迟500ms启动        faceLoadingAnimator.setStartDelay(200);
faceLoadingAnimator.addListener(new Animator.AnimatorListener() { @Override public void onAnimationStart(Animator animation) {
}
@Override public void onAnimationEnd(Animator animation) { //恢复起始状态 currentStatus = smileStatus; }
@Override public void onAnimationCancel(Animator animation) {
}
@Override public void onAnimationRepeat(Animator animation) {
} });


动画执行时间1s,记录动画当前执行进度值,存放在faceValue中。当动画执行结束的时候,需要将状态恢复到默认状态,调用invalidate的时候,进入onDraw()方法,开始重新绘制嘴巴。

                //记录时刻的旋转角度                startAngle = faceValue * 360;

//追上右边眼睛 if (startAngle >= 120 + startAngle / 2) {
canvas.drawArc(-radius, -radius, radius, radius, startAngle, swipeAngle, false, facePaint);
//开始自转一圈 mHandler.sendEmptyMessage(2);
//此时记录自转一圈起始的角度 circleStartAngle = 120 + startAngle / 2;
} else {
//追眼睛的过程 canvas.drawArc(-radius, -radius, radius, radius, startAngle, swipeAngle, false, facePaint);
}


这里的每次旋转角度为startAngle。当完全追赶上右侧眼睛的时候,开始执行自转一周,并停止当前动画。

2、眼睛的旋转

眼睛的开始旋转速度明显是慢于嘴巴的旋转速度,所以每次的旋转速度可以设置为嘴巴的一半

  //画左边眼睛 ,旋转的角度设置为笑脸旋转角度的一半,这样笑脸才能追上眼睛  leftEyeX = (float) (-radius * Math.cos((60 + startAngle / 2) * Math.PI / 180));  leftEyeY = (float) (-radius * Math.sin((60 + startAngle / 2) * Math.PI / 180));  canvas.drawPoint(leftEyeX, leftEyeY, eyePaint);
//画右边眼睛 ,旋转的角度设置为笑脸旋转角度的一半,这样笑脸才能追上眼睛 rightEyeX = (float) (radius * Math.cos((60 - startAngle / 2) * Math.PI / 180)); rightEyeY = (float) (-radius * Math.sin((60 - startAngle / 2) * Math.PI / 180)); canvas.drawPoint(rightEyeX, rightEyeY, eyePaint);


三、自转状态

1、开启动画
        circleAnimator = ValueAnimator.ofFloat(0, 1).setDuration(1000);
circleAnimator.setInterpolator(new LinearInterpolator());
circleAnimator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() { @Override public void onAnimationUpdate(ValueAnimator animation) { circleValue = (float) animation.getAnimatedValue(); invalidate(); } });
circleAnimator.addListener(new Animator.AnimatorListener() { @Override public void onAnimationStart(Animator animation) { }
@Override public void onAnimationEnd(Animator animation) { mHandler.sendEmptyMessage(3); }
@Override public void onAnimationCancel(Animator animation) {
}
@Override public void onAnimationRepeat(Animator animation) {
} });


2、重新绘制
 canvas.drawArc(-radius, -radius, radius, radius,                        circleStartAngle + circleValue * 360,                        swipeAngle, false, facePaint);


四、分离状态

主要的注意点就是眼睛的旋转角度设置为嘴巴旋转角度的2倍,这样才会达到眼睛超过嘴巴的效果,主要的旋转代码如下:

                startAngle = faceValue * 360;                //判断当前笑脸的起点是否已经走过260度 (吐出眼睛的角度,角度可以任意设置)                if (startAngle >= splitAngle) {
//画左边眼睛 ,旋转的角度设置为笑脸旋转角度的2倍,这样眼睛才能快于笑脸旋转速度 leftEyeX = (float) (-radius * Math.cos((eyeStartAngle + startAngle * 2) * Math.PI / 180)); leftEyeY = (float) (-radius * Math.sin((eyeStartAngle + startAngle * 2) * Math.PI / 180)); canvas.drawPoint(leftEyeX, leftEyeY, eyePaint);
//画右边眼睛 ,旋转的角度设置为笑脸旋转角度的2倍,这样眼睛才能快于笑脸旋转速度 rightEyeX = (float) (radius * Math.cos((eyeStartAngle - startAngle * 2) * Math.PI / 180)); rightEyeY = (float) (-radius * Math.sin((eyeStartAngle - startAngle * 2) * Math.PI / 180)); canvas.drawPoint(rightEyeX, rightEyeY, eyePaint);
} //画笑脸 canvas.drawArc(-radius, -radius, radius, radius, startAngle, swipeAngle, false, facePaint);


最后附上完整代码

public class FaceView2 extends View {

//圆弧半径 private int radius = 40;
//圆弧画笔宽度 private float paintWidth = 15;
//笑脸状态(一个脸,两个眼睛) private final int smileStatus = 0;
//加载状态 合并眼睛,旋转 private final int loadingStatus = 1;
//合并完成 转一圈 private final int circleStatus = 2;
//转圈完成 吐出眼睛 private final int splitStatus = 3;
//当前状态 private int currentStatus = smileStatus;
//笑脸画笔 private Paint facePaint; //眼睛画笔 private Paint eyePaint;
//笑脸开始角度 private float startAngle; //笑脸弧度 private float swipeAngle;
//左侧眼睛起点x轴坐标 private float leftEyeX = 0; //左侧眼睛起点y轴坐标 private float leftEyeY = 0;
//右侧眼睛起点x轴坐标 private float rightEyeX; //右侧眼睛起点y轴坐标 private float rightEyeY;
//一开始默认状态笑脸转圈动画 private ValueAnimator faceLoadingAnimator;
//吞并完成后,自转一圈动画 private ValueAnimator circleAnimator;
//faceLoadingAnimator动画进度值 private float faceValue;
//circleAnimator动画进度值 private float circleValue;
//记录开始自转一圈的起始角度 private float circleStartAngle;
//吐出眼睛的角度 private float splitAngle;
private float initStartAngle;
//眼睛起始角度 private float eyeStartAngle = 60;
public FaceView2(Context context) { this(context, null); }
public FaceView2(Context context, AttributeSet attrs) { this(context, attrs, 0); }
public FaceView2(Context context, AttributeSet attrs, int defStyleAttr) { super(context, attrs, defStyleAttr);
//自定义属性 TypedArray typedArray = context.obtainStyledAttributes(attrs, R.styleable.FaceView2, defStyleAttr, 0);
initStartAngle = typedArray.getFloat(R.styleable.FaceView2_startAngle, 0); swipeAngle = typedArray.getFloat(R.styleable.FaceView2_swipeAngle, 180); splitAngle = typedArray.getFloat(R.styleable.FaceView2_splitAngle, 260);
typedArray.recycle();
startAngle = initStartAngle; eyeStartAngle += startAngle;
initEyes();
initPaint();
//开始默认动画 initAnimator();
}
/** * 初始化画笔 */ private void initPaint() { //初始化画笔 facePaint = new Paint(); facePaint.setStrokeWidth(paintWidth); facePaint.setColor(Color.RED); facePaint.setAntiAlias(true); facePaint.setStyle(Paint.Style.STROKE); facePaint.setStrokeCap(Paint.Cap.ROUND);
eyePaint = new Paint(); eyePaint.setStrokeWidth(paintWidth); eyePaint.setColor(Color.RED); eyePaint.setAntiAlias(true); eyePaint.setStyle(Paint.Style.STROKE); eyePaint.setStrokeCap(Paint.Cap.ROUND);
}
/** * 初始化眼睛坐标 */ private void initEyes() { //默认两个眼睛坐标位置 角度转弧度 leftEyeX = (float) (-radius * Math.cos(eyeStartAngle * Math.PI / 180)); leftEyeY = (float) (-radius * Math.sin(eyeStartAngle * Math.PI / 180)); rightEyeX = (float) (radius * Math.cos(eyeStartAngle * Math.PI / 180)); rightEyeY = (float) (-radius * Math.sin(eyeStartAngle * Math.PI / 180));
}
private Handler mHandler = new Handler(new Handler.Callback() { @RequiresApi(api = Build.VERSION_CODES.KITKAT) @Override public boolean handleMessage(Message msg) { switch (msg.what) { case 1: //启动一开始笑脸转圈动画,并且开始合并眼睛 currentStatus = loadingStatus; faceLoadingAnimator.start(); break;
case 2: //暂停眼睛和笑脸动画 currentStatus = circleStatus; faceLoadingAnimator.pause(); //启动笑脸自转一圈动画 circleAnimator.start(); break; case 3: //恢复笑脸转圈动画,并且开始分离眼睛 currentStatus = splitStatus; circleAnimator.cancel(); faceLoadingAnimator.resume(); invalidate();
break; } return false; } });
@RequiresApi(api = Build.VERSION_CODES.LOLLIPOP) @Override protected void onDraw(Canvas canvas) { super.onDraw(canvas); //画布移到中间 canvas.translate(getWidth() / 2, getHeight() / 2);
switch (currentStatus) { //起始状态 case smileStatus: //起始角度为0 startAngle = initStartAngle;
//画起始笑脸 canvas.drawArc(-radius, -radius, radius, radius, startAngle, swipeAngle, false, facePaint);
//重置起始眼睛坐标 initEyes();
//画起始眼睛 canvas.drawPoint(leftEyeX, leftEyeY, eyePaint); canvas.drawPoint(rightEyeX, rightEyeY, eyePaint);
//更改状态,进行笑脸合并眼睛 mHandler.sendEmptyMessage(1); break;
//合并状态 case loadingStatus:
//记录时刻的旋转角度 startAngle = faceValue * 360;

//追上右边眼睛 if (startAngle >= 120 + startAngle / 2) {
canvas.drawArc(-radius, -radius, radius, radius, startAngle, swipeAngle, false, facePaint);
//开始自转一圈 mHandler.sendEmptyMessage(2);
//此时记录自转一圈起始的角度 circleStartAngle = 120 + startAngle / 2;
} else {
//追眼睛的过程 canvas.drawArc(-radius, -radius, radius, radius, startAngle, swipeAngle, false, facePaint);
}
//画左边眼睛 ,旋转的角度设置为笑脸旋转角度的一半,这样笑脸才能追上眼睛 leftEyeX = (float) (-radius * Math.cos((60 + startAngle / 2) * Math.PI / 180)); leftEyeY = (float) (-radius * Math.sin((60 + startAngle / 2) * Math.PI / 180)); canvas.drawPoint(leftEyeX, leftEyeY, eyePaint);
//画右边眼睛 ,旋转的角度设置为笑脸旋转角度的一半,这样笑脸才能追上眼睛 rightEyeX = (float) (radius * Math.cos((60 - startAngle / 2) * Math.PI / 180)); rightEyeY = (float) (-radius * Math.sin((60 - startAngle / 2) * Math.PI / 180)); canvas.drawPoint(rightEyeX, rightEyeY, eyePaint); break;
//自转一圈状态 circleValue * 360 为旋转角度 case circleStatus: canvas.drawArc(-radius, -radius, radius, radius, circleStartAngle + circleValue * 360, swipeAngle, false, facePaint); break;
//笑脸眼睛分离状态 case splitStatus:
startAngle = faceValue * 360; //判断当前笑脸的起点是否已经走过260度 (吐出眼睛的角度,角度可以任意设置) if (startAngle >= splitAngle) {
//画左边眼睛 ,旋转的角度设置为笑脸旋转角度的2倍,这样眼睛才能快于笑脸旋转速度 leftEyeX = (float) (-radius * Math.cos((eyeStartAngle + startAngle * 2) * Math.PI / 180)); leftEyeY = (float) (-radius * Math.sin((eyeStartAngle + startAngle * 2) * Math.PI / 180)); canvas.drawPoint(leftEyeX, leftEyeY, eyePaint);
//画右边眼睛 ,旋转的角度设置为笑脸旋转角度的2倍,这样眼睛才能快于笑脸旋转速度 rightEyeX = (float) (radius * Math.cos((eyeStartAngle - startAngle * 2) * Math.PI / 180)); rightEyeY = (float) (-radius * Math.sin((eyeStartAngle - startAngle * 2) * Math.PI / 180)); canvas.drawPoint(rightEyeX, rightEyeY, eyePaint);
} //画笑脸 canvas.drawArc(-radius, -radius, radius, radius, startAngle, swipeAngle, false, facePaint);
break;
} }
/** * 初始化动画 */ private void initAnimator() {

faceLoadingAnimator = ValueAnimator.ofFloat(0, 1).setDuration(1000); faceLoadingAnimator.setInterpolator(new AccelerateDecelerateInterpolator()); faceLoadingAnimator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() { @Override public void onAnimationUpdate(ValueAnimator animation) { faceValue = (float) animation.getAnimatedValue(); invalidate(); } }); //动画延迟500ms启动 faceLoadingAnimator.setStartDelay(200);
faceLoadingAnimator.addListener(new Animator.AnimatorListener() { @Override public void onAnimationStart(Animator animation) {
}
@Override public void onAnimationEnd(Animator animation) { //恢复起始状态 currentStatus = smileStatus; }
@Override public void onAnimationCancel(Animator animation) {
}
@Override public void onAnimationRepeat(Animator animation) {
} });

circleAnimator = ValueAnimator.ofFloat(0, 1).setDuration(1000);
circleAnimator.setInterpolator(new LinearInterpolator());
circleAnimator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() { @Override public void onAnimationUpdate(ValueAnimator animation) { circleValue = (float) animation.getAnimatedValue(); invalidate(); } });
circleAnimator.addListener(new Animator.AnimatorListener() { @Override public void onAnimationStart(Animator animation) { }
@Override public void onAnimationEnd(Animator animation) { mHandler.sendEmptyMessage(3); }
@Override public void onAnimationCancel(Animator animation) {
}
@Override public void onAnimationRepeat(Animator animation) {
} });    }}


自定义属性

<declare-styleable name="FaceView2">        <attr name="startAngle" format="dimension" />        <attr name="swipeAngle" format="dimension" />        <attr name="splitAngle" format="dimension" /></declare-styleable>


布局文件中使用

<com.example.viewdemo.FaceView2     android:layout_width="match_parent"     android:layout_height="match_parent"/>


完整代码都在上面啦.


到这里就结束啦.


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