android 进度条两边半圆

如下该类实现了两边半圆形状进度条:

public class SemiCircleDrawable extends Drawable {
    private Paint paint;
    private int arcWidth;
    private int color;
 
    public SemiCircleDrawable(int arcWidth, int color) {
        this.arcWidth = arcWidth;
        this.color = color;
        paint = new Paint(Paint.ANTI_ALIAS_FLAG);
        paint.setColor(color);
        paint.setStyle(Paint.Style.FILL);
    }
 
    @Override
    public void draw(@NonNull Canvas canvas) {
        Rect bounds = getBounds();
        float right = bounds.right;
        float left = right - arcWidth;
        float top = bounds.top;
        float bottom = bounds.bottom;
 
        // 画左半圆
        canvas.drawArc(new RectF(left, top, right, bottom), -90, 180, true, paint);
    }
 
    @Override
    public void setAlpha(int alpha) {
        paint.setAlpha(alpha);
    }
 
    @Override
    public void setColorFilter(@Nullable ColorFilter colorFilter) {
        paint.setColorFilter(colorFilter);
    }
 
    @Override
    public int getOpacity() {
        return PixelFormat.TRANSLUCENT;
    }
 
    @Override
    public int getIntrinsicWidth() {
        return arcWidth;
    }
 
    @Override
    public int getIntrinsicHeight() {
        return arcWidth;
    }
}

可以采用如下代码来使用该类:

SemiCircleDrawable leftDrawable = new SemiCircleDrawable(50, Color.BLUE); // 半圆的宽度为50px，颜色为蓝色
SemiCircleDrawable rightDrawable = new SemiCircleDrawable(50, Color.RED); // 半圆的宽度为50px，颜色为红色
 
ProgressBar progressBar = findViewById(R.id.progressBar);
progressBar.setProgressDrawable(new LayerDrawable(new Drawable[]{leftDrawable, rightDrawable}));