Slide calculations.java

// To evaluate value between x and y base on fraction(0 - 1)
private IntEvaluator mIntEvaluator = new IntEvaluator();
// Interpolator just for curvy animations.
private Interpolator mInterpolator = new AccelerateDecelerateInterpolator();
public void invalidateSlider(MenuViewHolder holder) {
SliderImageView imageCard = holder.imageCard;
    // top defines the pixel position of the item in the screen
    float top = holder.itemView.getTop() + holder.itemView.getMeasuredHeight();

    float height = App.getInstance().getResources().getDisplayMetrics().heightPixels
            + holder.itemView.getMeasuredHeight();
    float containerFraction = 0; // Defines the value from 0 - 1 according to the
                                 // item position on screen
    if (top > height / 2) { // Apply's value only if the view is above half of screen
        containerFraction = mInterpolator.getInterpolation((top - height / 2)
                / (height / 2));
    }

    // These two variables are the start and end distance of the views in item.
    // Direction of movement is based on the views(Image moves right and Card
    // moves left while scrolling down).
    int end = App.getInstance()
            .getResources().getDimensionPixelSize(R.dimen.dp_25);
    int start = (holder.itemView.getMeasuredWidth() / 2)
            - (imageCard.getMeasuredWidth() / 2);

    // This will move the content textView from center to left based on containerFraction
    holder.contentView.setX(mIntEvaluator.evaluate(1f - containerFraction, start, end));
    // The imageCard have to move opposite to the content but not out of the item,
    // so having some calculations to move opposite to content
   imageCard.setX(mIntEvaluator.evaluate(1f - containerFraction, start,
            holder.itemView.getMeasuredWidth() - imageCard.getMeasuredWidth() - end));
   // Pass the animation factor variable here to make the image slide, But the
   // interesting part is that the image will slide backwards since we provided
    // the fraction inversely(1 - fraction)
   imageCard.setAnimationFactor(1f - containerFraction);
}