@Override
public void run() {
/**
* Only set mStartTime if this is the first time we're starting, else actually calculate the Y
* delta
*/
if (mStartTime == -1) {
mStartTime = System.currentTimeMillis();
} else {
/**
* We do do all calculations in long to reduce software float calculations. We use 1000 as
* it gives us good accuracy and small rounding errors
*/
long normalizedTime = (1000 * (System.currentTimeMillis() - mStartTime)) / mDuration;
normalizedTime = Math.max(Math.min(normalizedTime, 1000), 0);
final int deltaY =
Math.round(
(mScrollFromY - mScrollToY)
* mInterpolator.getInterpolation(normalizedTime / 1000f));
mCurrentY = mScrollFromY - deltaY;
setHeaderScroll(mCurrentY);
}
// If we're not at the target Y, keep going...
if (mContinueRunning && mScrollToY != mCurrentY) {
ViewCompat.postOnAnimation(PullToRefreshBase.this, this);
} else {
if (null != mListener) {
mListener.onSmoothScrollFinished();
}
}
}
/**
* Helper method which just calls scrollTo() in the correct scrolling direction.
*
* @param value - New Scroll value
*/
protected final void setHeaderScroll(int value) {
if (DEBUG) {
Log.d(LOG_TAG, "setHeaderScroll: " + value);
}
// Clamp value to with pull scroll range
final int maximumPullScroll = getMaximumPullScroll();
value = Math.min(maximumPullScroll, Math.max(-maximumPullScroll, value));
if (mLayoutVisibilityChangesEnabled) {
if (value < 0) {
mHeaderLayout.setVisibility(View.VISIBLE);
} else if (value > 0) {
mFooterLayout.setVisibility(View.VISIBLE);
} else {
mHeaderLayout.setVisibility(View.INVISIBLE);
mFooterLayout.setVisibility(View.INVISIBLE);
}
}
if (USE_HW_LAYERS) {
/**
* Use a Hardware Layer on the Refreshable View if we've scrolled at all. We don't use them on
* the Header/Footer Views as they change often, which would negate any HW layer performance
* boost.
*/
ViewCompat.setLayerType(
mRefreshableViewWrapper, value != 0 ? 2 /*
* View.
* LAYER_TYPE_HARDWARE
*/ : 0 /* View.LAYER_TYPE_NONE */);
}
switch (getPullToRefreshScrollDirection()) {
case VERTICAL:
scrollTo(0, value);
break;
case HORIZONTAL:
scrollTo(value, 0);
break;
}
}
public final void setHeaderBackground(Drawable backgroundDrawable) {
ViewCompat.setBackground(mHeaderLayout, backgroundDrawable);
}