A circular drawable to display minutes.

import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.ColorFilter;
import android.graphics.Paint;
import android.graphics.Rect;
import android.graphics.RectF;
import android.graphics.drawable.Drawable;
import android.support.annotation.ColorInt;
import android.support.annotation.NonNull;

public class TimerDrawable extends Drawable {

    private static final int MINUTES_PER_HOUR = 60;
    private static final int DEGREES_PER_MINUTE = 6;
    private static final int START_ANGLE = -90;
    public static final int DEFAULT_STROKE_WIDTH= -1;
    private static final float DEFAULT_STROKE_DIVIDER = 0.08f;
    public static final int FULL_CIRCLE = 360;

    @NonNull private final Paint mPaint;

    private int mSweep = 20 * DEGREES_PER_MINUTE;
    private float mStrokeWidth = DEFAULT_STROKE_WIDTH;

    private float mSize = 200f;
    private boolean mSkipArc = false;
    private float mCenter = mSize / 2;
    private float mRadius = mSize / 2;
    private RectF mBounds = new RectF(0, 0, mSize, mSize);

    public TimerDrawable() {
        mPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
        mPaint.setColor(Color.BLACK);
        mPaint.setStyle(Paint.Style.STROKE);
        mPaint.setStrokeWidth(DEFAULT_STROKE_WIDTH);
        setBounds(0, 0, (int) mSize, (int) mSize);
    }


    @Override
    protected void onBoundsChange(Rect bounds) {
        super.onBoundsChange(bounds);
        resize();
    }

    private void resize() {
        Rect bounds = getBounds();
        mSize = Math.min(bounds.right - bounds.left, bounds.bottom - bounds.top);
        mCenter = mSize / 2;
        float padding = resolveAppliedStrokeWith() / 2;
        mRadius = (mSize / 2) - padding;
        mBounds = new RectF(padding, padding, mSize - padding, mSize - padding);
    }

    private float resolveAppliedStrokeWith() {
        float appliedStrokeWidth;
        if (mStrokeWidth == DEFAULT_STROKE_WIDTH) {
            appliedStrokeWidth = mSize * DEFAULT_STROKE_DIVIDER;
        } else {
            appliedStrokeWidth = mStrokeWidth;
        }
        mPaint.setStrokeWidth(appliedStrokeWidth);
        return appliedStrokeWidth;
    }

    @Override
    public void draw(Canvas canvas) {
        mPaint.setStyle(Paint.Style.STROKE);
        canvas.drawCircle(mCenter, mCenter, mRadius, mPaint);
        if (!mSkipArc) {
            mPaint.setStyle(Paint.Style.FILL);
            canvas.drawArc(mBounds, START_ANGLE, mSweep, true, mPaint);
        }
    }

    @Override
    public void setAlpha(int alpha) {
        mPaint.setAlpha(alpha);
    }

    @Override
    public void setColorFilter(ColorFilter colorFilter) {
        // Not needed
    }

    @Override
    public int getOpacity() {
        // Not needed
        return 0;
    }

    public void setMinutes(int minutes) {
        mSweep = (minutes % MINUTES_PER_HOUR) * DEGREES_PER_MINUTE;
        mSkipArc = minutes == 0;
        if (!mSkipArc && mSweep == 0) {
            mSweep = FULL_CIRCLE;
        }
        invalidateSelf();
    }

    public void setStrokeWidth(int width) {
        mStrokeWidth = width;
        resize();
        invalidateSelf();
    }

    public void setTint(@ColorInt int color) {
        mPaint.setColor(color);
        invalidateSelf();
    }

}