直播平台源代码，Android自定义View实现呼吸灯效果

直播平台源代码，Android自定义View实现呼吸灯效果

自定义View

自定义 BreathView 的Kotlin代码如下：

import android.animation.ValueAnimator
import android.animation.ValueAnimator.AnimatorUpdateListener
import android.content.Context
import android.graphics.Canvas
import android.graphics.Color
import android.graphics.Paint
import android.util.AttributeSet
import android.view.View
import android.view.animation.Animation
import android.view.animation.LinearInterpolator
class BreathView @JvmOverloads constructor(
    context: Context,
    attrs: AttributeSet? = null,
    defStyleAttr: Int = 0
) : View(context, attrs, defStyleAttr), AnimatorUpdateListener {
    private val mCenterCircleRadius: Float
    private var mMaxCircleRadius: Float
    private val mCirclePaint: Paint
    private var mAlphaValue = 0
    init {
        val a = context.obtainStyledAttributes(attrs, R.styleable.BreathView)
        mCenterCircleRadius = a.getDimension(R.styleable.BreathView_centerCircleRadius, 5f)
        mMaxCircleRadius = a.getDimension(R.styleable.BreathView_maxCircleRadius, 10f)
        if (mCenterCircleRadius >= mMaxCircleRadius) {
            mMaxCircleRadius = mCenterCircleRadius * 2
        }
        val circleColor = a.getColor(R.styleable.BreathView_circleColor, Color.GREEN)
        a.recycle()
        mCirclePaint = Paint()
        mCirclePaint.isAntiAlias = true
        mCirclePaint.style = Paint.Style.FILL
        mCirclePaint.color = circleColor
        val circleAlphaValueAnimator = ValueAnimator.ofInt(0, 255)
        circleAlphaValueAnimator.duration = BREATH_TIME
        circleAlphaValueAnimator.repeatCount = Animation.INFINITE
        circleAlphaValueAnimator.repeatMode = ValueAnimator.REVERSE
        circleAlphaValueAnimator.interpolator = LinearInterpolator()
        circleAlphaValueAnimator.addUpdateListener(this)
        circleAlphaValueAnimator.start()
    }
    override fun onMeasure(widthMeasureSpec: Int, heightMeasureSpec: Int) {
        super.onMeasure(widthMeasureSpec, heightMeasureSpec)
        var width = MeasureSpec.getSize(widthMeasureSpec)
        var height = MeasureSpec.getSize(heightMeasureSpec)
        val widthMode = MeasureSpec.getMode(widthMeasureSpec)
        val heightMode = MeasureSpec.getMode(widthMeasureSpec)
        if (widthMode == MeasureSpec.AT_MOST || widthMode == MeasureSpec.UNSPECIFIED) {
            width = Math.max(width.toFloat(), mMaxCircleRadius * 2).toInt()
        }
        if (heightMode == MeasureSpec.AT_MOST || heightMode == MeasureSpec.UNSPECIFIED) {
            height = Math.max(width.toFloat(), mMaxCircleRadius * 2).toInt()
        }
        setMeasuredDimension(width, height)
    }
    override fun draw(canvas: Canvas) {
        super.draw(canvas)
        val centerX = width / 2.0f
        val centerY = height / 2.0f
        mCirclePaint.alpha = 255
        canvas.drawCircle(centerX, centerY, mCenterCircleRadius, mCirclePaint)
        mCirclePaint.alpha = mAlphaValue
        canvas.drawCircle(centerX, centerY, mMaxCircleRadius, mCirclePaint)
    }
    override fun onAnimationUpdate(valueAnimator: ValueAnimator) {
        mAlphaValue = valueAnimator.animatedValue as Int
        invalidate()
    }
    companion object {
        private const val BREATH_TIME: Long = 1000 //动画执行时间/呼吸速率
    }
} 

​

自定义 BreathView 的Java代码如下：

import android.animation.ValueAnimator;
import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.util.AttributeSet;
import android.view.View;
import android.view.animation.Animation;
import android.view.animation.LinearInterpolator;
public class BreathView extends View implements ValueAnimator.AnimatorUpdateListener {
private static final long BREATH_TIME = 1000; //动画执行时间/呼吸速率
private final float mCenterCircleRadius;
private float mMaxCircleRadius;
private final Paint mCirclePaint;
private int mAlphaValue;
public BreathView(Context context) {
this(context, null);
}
public BreathView(Context context, AttributeSet attrs) {
this(context, attrs, 0);
}
public BreathView(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
final TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.BreathView);
mCenterCircleRadius = a.getDimension(R.styleable.BreathView_centerCircleRadius, 5f);
mMaxCircleRadius = a.getDimension(R.styleable.BreathView_maxCircleRadius, 10f);
if (mCenterCircleRadius >= mMaxCircleRadius) {
mMaxCircleRadius = mCenterCircleRadius * 2;
}
int circleColor = a.getColor(R.styleable.BreathView_circleColor, Color.GREEN);
a.recycle();
mCirclePaint = new Paint();
mCirclePaint.setAntiAlias(true);
mCirclePaint.setStyle(Paint.Style.FILL);
mCirclePaint.setColor(circleColor);
ValueAnimator circleAlphaValueAnimator = ValueAnimator.ofInt(0, 255);
circleAlphaValueAnimator.setDuration(BREATH_TIME);
circleAlphaValueAnimator.setRepeatCount(Animation.INFINITE);
circleAlphaValueAnimator.setRepeatMode(ValueAnimator.REVERSE);
circleAlphaValueAnimator.setInterpolator(new LinearInterpolator());
circleAlphaValueAnimator.addUpdateListener(this);
circleAlphaValueAnimator.start();
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
int width = MeasureSpec.getSize(widthMeasureSpec);
int height = MeasureSpec.getSize(heightMeasureSpec);
int widthMode = MeasureSpec.getMode(widthMeasureSpec);
int heightMode = MeasureSpec.getMode(widthMeasureSpec);
if(widthMode == MeasureSpec.AT_MOST || widthMode == MeasureSpec.UNSPECIFIED) {
width = (int) Math.max(width, mMaxCircleRadius * 2);
}
if(heightMode == MeasureSpec.AT_MOST || heightMode == MeasureSpec.UNSPECIFIED) {
            height = (int) Math.max(width, mMaxCircleRadius * 2);
        }
setMeasuredDimension(width, height);
}
@Override
public void draw(Canvas canvas) {
        super.draw(canvas);
float centerX = getWidth() / 2.0f;
float centerY = getHeight() / 2.0f;
mCirclePaint.setAlpha(255);
canvas.drawCircle(centerX, centerY, mCenterCircleRadius, mCirclePaint);
mCirclePaint.setAlpha(mAlphaValue);
canvas.drawCircle(centerX, centerY, mMaxCircleRadius, mCirclePaint);
}
@Override
public void onAnimationUpdate(ValueAnimator valueAnimator) {
mAlphaValue = (int) valueAnimator.getAnimatedValue();
invalidate();
}
}

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