private void bounceBackHeader() {
int yTranslate =
state == State.REFRESHING
? header.getHeight() - headerContainer.getHeight()
: -headerContainer.getHeight() - headerContainer.getTop();
TranslateAnimation bounceAnimation =
new TranslateAnimation(
TranslateAnimation.ABSOLUTE,
0,
TranslateAnimation.ABSOLUTE,
0,
TranslateAnimation.ABSOLUTE,
0,
TranslateAnimation.ABSOLUTE,
yTranslate);
bounceAnimation.setDuration(BOUNCE_ANIMATION_DURATION);
bounceAnimation.setFillEnabled(true);
bounceAnimation.setFillAfter(false);
bounceAnimation.setFillBefore(true);
bounceAnimation.setInterpolator(new OvershootInterpolator(BOUNCE_OVERSHOOT_TENSION));
bounceAnimation.setAnimationListener(new HeaderAnimationListener(yTranslate));
startAnimation(bounceAnimation);
}
private void resetHeader() {
if (getFirstVisiblePosition() > 0) {
setHeaderPadding(-header.getHeight());
setState(State.PULL_TO_REFRESH);
return;
}
if (getAnimation() != null && !getAnimation().hasEnded()) {
bounceBackHeader = true;
} else {
bounceBackHeader();
}
}
@Override
public boolean onTouchEvent(MotionEvent event) {
if (lockScrollWhileRefreshing
&& (state == State.REFRESHING || getAnimation() != null && !getAnimation().hasEnded())) {
return true;
}
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
if (getFirstVisiblePosition() == 0) previousY = event.getY();
else previousY = -1;
break;
case MotionEvent.ACTION_UP:
if (previousY != -1
&& (state == State.RELEASE_TO_REFRESH || getFirstVisiblePosition() == 0)) {
switch (state) {
case RELEASE_TO_REFRESH:
setState(State.REFRESHING);
bounceBackHeader();
break;
case PULL_TO_REFRESH:
resetHeader();
break;
default:
break;
}
}
break;
case MotionEvent.ACTION_MOVE:
if (previousY != -1) {
float y = event.getY();
float diff = y - previousY;
if (diff > 0) diff /= PULL_RESISTANCE;
previousY = y;
int newHeaderPadding = Math.max(Math.round(headerPadding + diff), -header.getHeight());
if (newHeaderPadding != headerPadding && state != State.REFRESHING) {
setHeaderPadding(newHeaderPadding);
if (state == State.PULL_TO_REFRESH && headerPadding > 0) {
setState(State.RELEASE_TO_REFRESH);
image.clearAnimation();
image.startAnimation(flipAnimation);
} else if (state == State.RELEASE_TO_REFRESH && headerPadding < 0) {
setState(State.PULL_TO_REFRESH);
image.clearAnimation();
image.startAnimation(reverseFlipAnimation);
}
return true;
}
}
break;
}
return super.onTouchEvent(event);
}