http://www.jcodecraeer.com/a/anzhuokaifa/androidkaifa/2016/0619/4362.html
public abstract class AppBarStateChangeListener implements AppBarLayout.OnOffsetChangedListener {
public enum State {
EXPANDED,
COLLAPSED,
IDLE
}
private State mCurrentState = State.IDLE;
@Override
public final void onOffsetChanged(AppBarLayout appBarLayout, int i) {
if (i == 0) {
if (mCurrentState != State.EXPANDED) {
onStateChanged(appBarLayout, State.EXPANDED);
}
mCurrentState = State.EXPANDED;
} else if (Math.abs(i) >= appBarLayout.getTotalScrollRange()) {
if (mCurrentState != State.COLLAPSED) {
onStateChanged(appBarLayout, State.COLLAPSED);
}
mCurrentState = State.COLLAPSED;
} else {
if (mCurrentState != State.IDLE) {
onStateChanged(appBarLayout, State.IDLE);
}
mCurrentState = State.IDLE;
}
}
public abstract void onStateChanged(AppBarLayout appBarLayout, State state);
}
appBarLayout.addOnOffsetChangedListener(new AppBarStateChangeListener() {
@Override
public void onStateChanged(AppBarLayout appBarLayout, State state) {
if( state == State.EXPANDED ) {
//展开状态
tvTitle.setVisibility(View.GONE);
ivBack.setColorFilter(Color.WHITE);
}else if(state == State.COLLAPSED){
//折叠状态
tvTitle.setVisibility(View.VISIBLE);
ivBack.setColorFilter(null);
}else {
//中间状态
}
}
});
