DonutChart.java

package com.hmkcode.views;


import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.BlurMaskFilter;
import android.graphics.Canvas;

import android.graphics.Paint;
import android.graphics.Path;
import android.graphics.RadialGradient;
import android.graphics.RectF;
import android.graphics.Shader.TileMode;
import android.util.AttributeSet;
import android.view.View;

public class DonutChart extends View {

	
	 private float radius;
	
	 Paint paint;
	 Paint shadowPaint;
	 
	 Path myPath;
	 Path shadowPath;
	 
	 RectF outterCircle;
	 RectF innerCircle;
	 RectF shadowRectF;
	 
	public DonutChart(Context context, AttributeSet attrs) {
		super(context, attrs);
		
		TypedArray a = context.getTheme().obtainStyledAttributes(
                attrs,
                R.styleable.DonutChart,
                0, 0
        );
		
		try {
            radius = a.getDimension(R.styleable.DonutChart_radius, 20.0f);
        } finally {
            a.recycle();
        }
		
		paint = new Paint();
		paint.setDither(true);       
		paint.setStyle(Paint.Style.FILL); 
		paint.setStrokeJoin(Paint.Join.ROUND); 
		paint.setStrokeCap(Paint.Cap.ROUND);     
		paint.setAntiAlias(true); 
		paint.setStrokeWidth(radius / 14.0f);
		
		shadowPaint = new Paint();
	    shadowPaint.setColor(0xf0000000);
	    shadowPaint.setStyle(Paint.Style.STROKE); 
	    shadowPaint.setAntiAlias(true);
	    shadowPaint.setStrokeWidth(6.0f);
	    shadowPaint.setMaskFilter(new BlurMaskFilter(4, BlurMaskFilter.Blur.SOLID));


		myPath = new Path();
		shadowPath = new Path();


		outterCircle = new RectF();
		innerCircle = new RectF();
		shadowRectF = new RectF();

		float adjust = (.019f*radius);
		shadowRectF.set(adjust, adjust, radius*2-adjust, radius*2-adjust);
		
		adjust = .038f * radius;
		outterCircle.set(adjust, adjust, radius*2-adjust, radius*2-adjust);
		
		adjust = .276f * radius;
		innerCircle.set(adjust, adjust, radius*2-adjust, radius*2-adjust);

	}

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

		// draw shadow
		paint.setShader(null);
		float adjust = (.0095f*radius);
		paint.setShadowLayer(8, adjust, -adjust, 0xaa000000);
		drawDonut(canvas,paint, 0,359.9f);
		
		
		// green	
		setGradient(0xff84BC3D,0xff5B8829); 
		drawDonut(canvas,paint, 0,60);		
		
		//red
		setGradient(0xffe04a2f,0xffB7161B); 
		drawDonut(canvas,paint, 60,60);
		
		// blue
		setGradient(0xff4AB6C1,0xff2182AD);
		drawDonut(canvas,paint, 120,60);
		
		// yellow
		setGradient(0xffFFFF00,0xfffed325);
		drawDonut(canvas,paint, 180,180);
	

		
	}
	
	public void drawDonut(Canvas canvas, Paint paint, float start,float sweep){

		myPath.reset();
		myPath.arcTo(outterCircle, start, sweep, false);
		myPath.arcTo(innerCircle, start+sweep, -sweep, false);
		myPath.close();
		canvas.drawPath(myPath, paint);
	}
	
	public void setGradient(int sColor, int eColor){
		paint.setShader(new RadialGradient(radius, radius, radius-5, 
				new int[]{sColor,eColor}, 
				new float[]{.6f,.95f},TileMode.CLAMP) );
	}
	
	@Override
	protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
		super.onMeasure(widthMeasureSpec, heightMeasureSpec);
		
	    int desiredWidth = (int) radius*2;
	    int desiredHeight = (int) radius*2;

	    int widthMode = MeasureSpec.getMode(widthMeasureSpec);
	    int widthSize = MeasureSpec.getSize(widthMeasureSpec);
	    int heightMode = MeasureSpec.getMode(heightMeasureSpec);
	    int heightSize = MeasureSpec.getSize(heightMeasureSpec);

	    int width;
	    int height;

	    //70dp exact
	    if (widthMode == MeasureSpec.EXACTLY) {
	        width = widthSize;
	    }else if (widthMode == MeasureSpec.AT_MOST) {
		    //wrap content
	        width = Math.min(desiredWidth, widthSize);
	    } else {
	        width = desiredWidth;
	    }

	    //Measure Height
	    if (heightMode == MeasureSpec.EXACTLY) {
	        height = heightSize;
	    } else if (heightMode == MeasureSpec.AT_MOST) {
	        height = Math.min(desiredHeight, heightSize);
	    } else {
	        height = desiredHeight;
	    }

	    //MUST CALL THIS
	    setMeasuredDimension(width, height);
	}
	
	
}