androidx.recyclerview.widget.RecyclerView#setAlpha ( )源码实例Demo

@Nullable
@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
    View rootView = inflater.inflate(R.layout.mal_material_about_content, container, false);

    recyclerView = (RecyclerView) rootView.findViewById(R.id.mal_recyclerview);
    adapter = new MaterialAboutListAdapter(getViewTypeManager());
    recyclerView.setLayoutManager(new LinearLayoutManager(getActivity()));
    recyclerView.setAdapter(adapter);

    RecyclerView.ItemAnimator animator = recyclerView.getItemAnimator();
    if (animator instanceof SimpleItemAnimator) {
        ((SimpleItemAnimator) animator).setSupportsChangeAnimations(false);
    }

    recyclerView.setAlpha(0f);
    recyclerView.setTranslationY(20);

    new ListTask(this).execute();

    return rootView;
}
 

public static void manipulateVisibility(AppCompatActivity activity, float slideOffset, View arrow_up,
                                        RecyclerView instantRecyclerView, RecyclerView recyclerView,
                                        View status_bar_bg, View topbar, View clickme, View sendButton, boolean longSelection) {
    instantRecyclerView.setAlpha(1 - slideOffset);
    arrow_up.setAlpha(1 - slideOffset);
    clickme.setAlpha(1 - slideOffset);
    if (longSelection) {
        sendButton.setAlpha(1 - slideOffset);
    }
    topbar.setAlpha(slideOffset);
    recyclerView.setAlpha(slideOffset);
    if ((1 - slideOffset) == 0 && instantRecyclerView.getVisibility() == View.VISIBLE) {
        instantRecyclerView.setVisibility(View.GONE);
        arrow_up.setVisibility(View.GONE);
        clickme.setVisibility(View.GONE);
    } else if (instantRecyclerView.getVisibility() == View.GONE && (1 - slideOffset) > 0) {
        instantRecyclerView.setVisibility(View.VISIBLE);
        arrow_up.setVisibility(View.VISIBLE);
        clickme.setVisibility(View.VISIBLE);
        if (longSelection) {
            sendButton.clearAnimation();
            sendButton.setVisibility(View.VISIBLE);
        }
    }
    if ((slideOffset) > 0 && recyclerView.getVisibility() == View.INVISIBLE) {
        recyclerView.setVisibility(View.VISIBLE);
        status_bar_bg.animate().translationY(0).setDuration(200).start();
        topbar.setVisibility(View.VISIBLE);
        Utility.showStatusBar(activity);
    } else if (recyclerView.getVisibility() == View.VISIBLE && (slideOffset) == 0) {
        Utility.hideStatusBar(activity);
        recyclerView.setVisibility(View.INVISIBLE);
        topbar.setVisibility(View.GONE);
        status_bar_bg.animate().translationY(-(status_bar_bg.getHeight())).setDuration(550).start();
    }
}
 

private void assignViews() {
    recyclerView = (RecyclerView) findViewById(R.id.mal_recyclerview);
    recyclerView.setAlpha(0f);
    recyclerView.setTranslationY(20);
}