Creating Arc shaped progress bars (http://i.imgur.com/WNFX38Z.png)

ArcProgressBar.java

package me.rishabhmhjn.droid.widgets;

import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.PorterDuff;
import android.graphics.PorterDuffXfermode;
import android.graphics.RectF;
import android.support.annotation.NonNull;
import android.util.AttributeSet;
import android.widget.ProgressBar;

import me.rishabhmhjn.droid.R;

public class ArcProgressBar extends ProgressBar {

    private RectF mRect;
    private RectF mProgressRect;
    private RectF mEmptyRect;

    private Bitmap mTransparentBm;

    private Paint mPaint;
    private Paint mBackgroundPaint;
    private Paint mTransparentPaint;
    private Canvas mTempCanvas;

    private float mBorderWidth = 20;
    private int mProgressColor = 0xFFFF0000;
    private int mBackgroundColor = 0xFFFF00FF;
    private int mDrawDirection = 0;
    private int mStartAngle = -90;

    public ArcProgressBar(Context context, AttributeSet attrs) {
        this(context, attrs, 0);
    }

    public ArcProgressBar(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
        init(attrs, defStyle);
    }

    private void init(AttributeSet attrs, int defStyle) {

        final TypedArray a = getContext()
            .obtainStyledAttributes(attrs, R.styleable.ArcProgressBar, defStyle, 0);
        mBorderWidth = a.getDimension(R.styleable.ArcProgressBar_borderWidth, mBorderWidth);
        mBackgroundColor = a.getColor(R.styleable.ArcProgressBar_backgroundColor, mBackgroundColor);
        mProgressColor = a.getColor(R.styleable.ArcProgressBar_progressColor, mProgressColor);
        mDrawDirection = a.getInteger(R.styleable.ArcProgressBar_drawDirection, mDrawDirection);
        mStartAngle = a.getInteger(R.styleable.ArcProgressBar_startAngle, mStartAngle);
        a.recycle();

        mRect = new RectF();
        mProgressRect = new RectF();
        mEmptyRect = new RectF();

        mPaint = new Paint();
        mPaint.setColor(mProgressColor);
        mPaint.setAntiAlias(true);
        mPaint.setStrokeWidth(mBorderWidth);
        mPaint.setStrokeCap(Paint.Cap.ROUND);
        mPaint.setStyle(Paint.Style.STROKE);

        mBackgroundPaint = new Paint(mPaint);
        mBackgroundPaint.setColor(mBackgroundColor);

        mTransparentPaint = new Paint();
        mTransparentPaint.setColor(getResources().getColor(android.R.color.transparent));
        mTransparentPaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.CLEAR));
        mTransparentPaint.setAntiAlias(true);
    }

    @Override
    protected synchronized void onDraw(@NonNull Canvas canvas) {
        super.onDraw(canvas);

        mTempCanvas.drawArc(mRect, 0, 360, true, mBackgroundPaint);

        if (getProgress() > 0) {
            float angle = 360 * (float) getProgress() / getMax();
            angle = mDrawDirection == 0 ? -angle : angle;
            mTempCanvas.drawArc(mProgressRect, mStartAngle, angle, true, mPaint);
        }
        mTempCanvas.drawOval(mEmptyRect, mTransparentPaint);

        canvas.drawBitmap(mTransparentBm, 0, 0, null);
    }

    @Override
    protected void onSizeChanged(int w, int h, int oldw, int oldh) {
        super.onSizeChanged(w, h, oldw, oldh);
        float offset = mBorderWidth / 2;
        mRect.set(offset, offset, w - offset, h - offset);
        mProgressRect.set(offset, offset, w - offset, h - offset);
        mEmptyRect.set(mBorderWidth, mBorderWidth, w - mBorderWidth, h - mBorderWidth);

        mTransparentBm = Bitmap.createBitmap(getWidth(), getHeight(), Bitmap.Config.ARGB_8888);
        mTransparentBm.eraseColor(Color.TRANSPARENT);
        mTempCanvas = new Canvas(mTransparentBm);
    }
}

attrs.xml

<resources>
    <declare-styleable name="ArcProgressBar">
        <attr name="borderWidth" format="dimension"/>
        <attr name="backgroundColor" format="color"/>
        <attr name="progressColor" format="color"/>
        <attr name="startAngle" format="integer"/>
        <attr name="drawDirection" format="enum">
            <enum name="anti_clockwise" value="0"/>
            <enum name="clockwise" value="1"/>
        </attr>
    </declare-styleable>
</resources>

main_layout.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <me.rishabhmhjn.droid.widgets.ArcProgressBar
        android:layout_height="300dp"
        android:layout_width="300dp"
        android:max="360"
        android:progress="20"
        app:borderWidth="10dp"/>

</LinearLayout>