PagerIndicator.java

public class PagerIndicator extends View {
    // Constructors and auxiliars
    
    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        desiredRadius = getContext().getResources().getDimensionPixelSize(R.dimen.pager_indicator_radius);

        int desiredWidth = 2 * desiredRadius + getPaddingLeft() + getPaddingRight();
        int desiredHeight = 2 * desiredRadius + getPaddingTop() + getPaddingBottom();

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

        int width;
        int height;

        //Measure Width
        if (widthMode == MeasureSpec.EXACTLY) {
            //Must be this size
            width = widthSize;
        } else if (widthMode == MeasureSpec.AT_MOST) {
            //Can't be bigger than...
            width = Math.min(desiredWidth, widthSize);
        } else {
            //Be whatever you want
            width = desiredWidth;
        }

        //Measure Height
        if (heightMode == MeasureSpec.EXACTLY) {
            //Must be this size
            height = heightSize;
        } else if (heightMode == MeasureSpec.AT_MOST) {
            //Can't be bigger than...
            height = Math.min(desiredHeight, heightSize);
        } else {
            //Be whatever you want
            height = desiredHeight;
        }

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


    private void drawDots(Canvas canvas, int total, int currentPage) {
        canvas.getClipBounds(bounds);
        float centerX = bounds.centerX();
        float centerY = bounds.centerY();

        float totalWidth = total * desiredRadius + (total - 1) * desiredRadius;

        float x = centerX - totalWidth + desiredRadius;
        for (int i = 0; i < total; i++) {
            canvas.drawCircle(x, centerY, desiredRadius, i == currentPage ? currentPaint : paint);
            x += desiredRadius * 4;
        }
    }
}