Android自定义view实现进度条动画、按钮渐变及录制状态控制

不得不说自定义view绘制各种图形及它们的动画是令人有成就感的事情。该篇来分享之前项目中写的一个视频录制按钮的自定义view，该view有录制、暂停（结束）等状态的控制，各种状态转变的动画，以及录制进度展示。先看效果（圆圈的小白色段是最小录制时长的标记点）：
录制效果
代码的内容其实主要就是绘制进度条、录制按钮的切换动画（圆角正方形—>圆—>圆角正方形）。还是那句话，计算好每个组件的坐标（半径）事情就完成了一半，所以关键在于计算，这里的图形都简单计算并不复杂，只是要稍微细心点。注释都写得比较详细，就不一一解释了，具体看代码：
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.LinearGradient;
import android.graphics.Paint;
import android.graphics.RectF;
import android.graphics.Shader;
import android.util.AttributeSet;
import android.view.View;
import androidx.annotation.Nullable;
import com.robot.common.frame.BaseApp;
import com.robot.common.utils.PixelUtil;

/**
 * 视频录制控制、进度
 *
 * @author ly
 * date 2020/3/3 11:02
 */
public class RecordProgressView extends View implements View.OnClickListener {

    private static final float changeRatio = 5f;
    //最小录制时长标记的弧长
    private static final int minPAngle = 2;

    private OnRecordStatusListener onRecordStatusListener;
    private Paint paint;
    //内圈录制、暂停按钮颜色
    private int circleInsideColor;
    //进度圈颜色
    private int circleOutsideColor;
    //进度颜色
    private int circleProgressColor;
    private float progressW;
    //进度条圆圈半径
    private float circleProgressR;
    //内实心圆圈半径
    private float circleInsideR;
    //录制按钮宽高
    private float pauseRectW;

    //动态变量内圈半径（逐渐变小或变大）
    private float curCircleInsideR;

    private State state = State.READY;
    //暂停按钮rect
    private RectF pauseRect;
    private int pauseRadius;
    private RectF progressRect;
    private float progress;
    private float minProgress = 90;
    private float minCircleR;
    private LinearGradient linearGradientCircle;
    private LinearGradient linearGradientRect;

    public enum State {
        READY, RECORDING, PAUSE, FINISH
    }

    public RecordProgressView(Context context) {
        super(context);
        init();
    }

    public RecordProgressView(Context context, @Nullable AttributeSet attrs) {
        super(context, attrs);
        init();
    }

    public RecordProgressView(Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        init();
    }

    private void init() {
        circleInsideColor = 0xffE9B763;
        circleOutsideColor = 0x55ffffff;
        circleProgressColor = 0xffffffff;
        paint = new Paint();
        paint.setAntiAlias(true);//抗锯齿
        pauseRadius = PixelUtil.dp2px(5);

        setOnClickListener();
    }

    public float getProgress() {
        return progress;
    }

    /**
     * @param progress 已录制时长/最大时长
     * @author ly on 2020/3/3 16:41
     */
    public void setProgress(float progress) {
        this.progress = progress * 360;
        if (this.progress >= 360) {//表示录制达到最大时长，自动结束
            this.progress = 360;
            state = State.FINISH;
            if (onRecordStatusListener != null)
                onRecordStatusListener.onFinish();
        }
        invalidate();
    }

    /**
     * @param minProgress 最小录制时长/最大时长
     * @author ly on 2020/3/3 16:41
     */
    public void setMinProgress(float minProgress) {
        this.minProgress = minProgress * 360;
    }

    @Override
    protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
        super.onLayout(changed, left, top, right, bottom);
        if (circleProgressR == 0) {
            int w = getWidth();
            progressW = w * 0.061f;
            circleProgressR = (w - progressW) / 2f;
            circleInsideR = (w * 0.83f) / 2;
            pauseRectW = w * 0.37f;
            curCircleInsideR = circleInsideR;
            //矩形对角线的一半
//            minCircleR = (float) (Math.sqrt(Math.pow(pauseRectW, 2) * 2) / 2f);
            minCircleR = pauseRectW / 2;

            pauseRect = new RectF(w / 2f - pauseRectW / 2
                    , w / 2f - pauseRectW / 2
                    , w / 2f + pauseRectW / 2
                    , w / 2f + pauseRectW / 2);
            progressRect = new RectF(0 + progressW / 2, 0 + progressW / 2, w - progressW / 2, w - progressW / 2);

            float offsetX = (float) Math.sqrt(Math.pow(curCircleInsideR, 2) / 2);

            //圆的左上到右下方向渐变
            linearGradientCircle = new LinearGradient(
                    curCircleInsideR - offsetX, curCircleInsideR - offsetX, w - offsetX, w - offsetX,
                    0xff7360FF, 0xff9663F3,
                    Shader.TileMode.MIRROR);

            linearGradientRect = new LinearGradient(
                    pauseRect.left, pauseRect.top, pauseRect.right, pauseRect.bottom,
                    0xff7360FF, 0xff9663F3,
                    Shader.TileMode.MIRROR);
        }
    }

    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);
        //画外圈进度圈、进度
        paint.setShader(null);
        paint.setStyle(Paint.Style.STROKE);
        paint.setColor(circleOutsideColor);
        paint.setStrokeWidth(progressW);//设置画笔粗细
        canvas.drawCircle(getWidth() / 2f, getHeight() / 2f, circleProgressR, paint);

        if (minProgress - minPAngle > 0 && BaseApp.get().isDebug()) {
            paint.setColor(circleProgressColor);
            canvas.drawArc(progressRect, minProgress - 90, minPAngle, false, paint);
        }

        if (state != State.READY) {
            //进度就是圆弧
            //时钟3点的方向为0度，顺时钟方向为正，-90是圆弧的开始点，即12点位置开始，
            //sweepAngle扫过的角度，调整该值即可实现进度顺时针加载(0-360)
            paint.setColor(circleProgressColor);
            canvas.drawArc(progressRect, -90, progress, false, paint);
        }

        //画内部圆/暂停按钮
        paint.setColor(circleInsideColor);
        paint.setStyle(Paint.Style.FILL);
        paint.setShader(linearGradientCircle);
        if (state == State.RECORDING) {//录制中画矩形和进度
            if (curCircleInsideR > minCircleR) {
                canvas.drawCircle(getWidth() / 2f, getHeight() / 2f, curCircleInsideR, paint);
                changeCircleR(false);
            } else {
                paint.setShader(linearGradientRect);
                canvas.drawRoundRect(pauseRect, pauseRadius, pauseRadius, paint);
            }
        } else {
            canvas.drawCircle(getWidth() / 2f, getHeight() / 2f, curCircleInsideR, paint);
            if (curCircleInsideR < circleInsideR)
                changeCircleR(true);
        }
    }


    public void resetState() {
        state = State.READY;
        progress = 0;
        invalidate();
    }

    public void setState(State state) {
        this.state = state;
        invalidate();
    }

    public void setOnClickListener() {
        setOnClickListener(this);
    }

    @Override
    public void onClick(View v) {
        switch (state) {
            //由开始状态变为录制状态，点击后由圆变为矩形
            case READY:
            case PAUSE:
                state = State.RECORDING;
                if (onRecordStatusListener != null)
                    onRecordStatusListener.onRecording();

                invalidate();
                break;
            //录制中，点击后由矩形变为圆
            case RECORDING:
                if (progress < minProgress) {
                    state = State.PAUSE;
                    if (onRecordStatusListener != null)
                        onRecordStatusListener.onPause();
                } else {
                    state = State.FINISH;
                    if (onRecordStatusListener != null)
                        onRecordStatusListener.onFinish();

                }
                invalidate();
                break;
            default:

                break;
        }
    }

    private void changeCircleR(boolean is2Big) {
        if (is2Big) {//变大
            curCircleInsideR += changeRatio;
            if (curCircleInsideR >= circleInsideR)
                curCircleInsideR = circleInsideR;
        } else {//变小
            curCircleInsideR -= changeRatio;
            if (curCircleInsideR <= minCircleR)
                curCircleInsideR = minCircleR;
        }
        invalidate();
    }

    public void setOnRecordStatusListener(OnRecordStatusListener onRecordStatusListener) {
        this.onRecordStatusListener = onRecordStatusListener;
    }

    public interface OnRecordStatusListener {
        void onRecording();

        void onPause();

        void onFinish();
    }
}
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