boolean smoothSlideTo(float slideOffset, int velocity) {
        if (!isEnabled() || mSlideableView == null) {
            // Nothing to do.
            return false;
        }

        int panelTop = computePanelTopPosition(slideOffset);

        if (mDragHelper.smoothSlideViewTo(mSlideableView, mSlideableView.getLeft(), panelTop)) {
            setAllChildrenVisible();
            ViewCompat.postInvalidateOnAnimation(this);
            return true;
        }
        return false;
    }
Smoothly animate mDraggingPane to the target X position within its range.

@param slideOffset position to animate to
@param velocity    initial velocity in case of fling, or 0.
app/src/main/java/home/smart/fly/animations/widget/slidepanel/SlidingUpPanelLayout.java