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

@Override
protected void init() {
    inflate(getContext(), R.layout.colorpicker_layout_preset_picker, this);

    adapter = new PresetColorAdapter(DEFAULT_PRESETS).withListener(this);

    RecyclerView recycler = findViewById(R.id.recycler);
    recycler.setHasFixedSize(true);

    RecyclerView.ItemAnimator animator = recycler.getItemAnimator();
    if (animator instanceof SimpleItemAnimator)
        ((SimpleItemAnimator) animator).setSupportsChangeAnimations(false);

    recycler.setLayoutManager(new GridLayoutManager(getContext(), 4));
    recycler.setAdapter(adapter);
}
 

@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;
}
 

/**
 * Process a change event.
 * @param debug: string for debug usually the source of the call
 * @param checkItemAnimator: true if it need to check if ItemAnimator is running
 */
private void processChangeEvent(String debug, boolean checkItemAnimator) {
  final RecyclerView recyclerView = attachedRecyclerView;
  if (recyclerView != null) {
    final ItemAnimator itemAnimator = recyclerView.getItemAnimator();
    if (checkItemAnimator && itemAnimator != null) {
      // `itemAnimatorFinishedListener.onAnimationsFinished` will process visibility check
      // - If the animations are running `onAnimationsFinished` will be invoked on animations end.
      // - If the animations are not running `onAnimationsFinished` will be invoked right away.
      if (itemAnimator.isRunning(itemAnimatorFinishedListener)) {
        // If running process visibility now as `onAnimationsFinished` was not yet called
        processChangeEventWithDetachedView(null, debug);
      }
    } else {
      processChangeEventWithDetachedView(null, debug);
    }
  }
}
 

@Override
protected void onCreate(@Nullable final Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_scanner);
    ButterKnife.bind(this);

    final MaterialToolbar toolbar = findViewById(R.id.toolbar);
    toolbar.setTitle(R.string.app_name);
    setSupportActionBar(toolbar);

    // Create view model containing utility methods for scanning
    scannerViewModel = new ViewModelProvider(this).get(ScannerViewModel.class);
    scannerViewModel.getScannerState().observe(this, this::startScan);

    // Configure the recycler view
    final RecyclerView recyclerView = findViewById(R.id.recycler_view_ble_devices);
    recyclerView.setLayoutManager(new LinearLayoutManager(this));
    recyclerView.addItemDecoration(new DividerItemDecoration(this, DividerItemDecoration.VERTICAL));
    final RecyclerView.ItemAnimator animator = recyclerView.getItemAnimator();
    if (animator instanceof SimpleItemAnimator) {
        ((SimpleItemAnimator) animator).setSupportsChangeAnimations(false);
    }
    final DevicesAdapter adapter = new DevicesAdapter(this, scannerViewModel.getDevices());
    adapter.setOnItemClickListener(this);
    recyclerView.setAdapter(adapter);
}
 

/**
 * Disables all the {@link RecyclerView} animations.
 */
public static void disableAnimations(@NonNull RecyclerView recyclerView) {
    Preconditions.nonNull(recyclerView);

    if(recyclerView.getItemAnimator() != null) {
        recyclerView.setItemAnimator(null);
    }
}
 

@Override
protected void onCreate(@Nullable final Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_scanner);
    ButterKnife.bind(this);

    // Create view model containing utility methods for scanning
    mViewModel = new ViewModelProvider(this, mViewModelFactory).get(ScannerViewModel.class);

    final Toolbar toolbar = findViewById(R.id.toolbar);
    toolbar.setTitle(R.string.title_scanner);
    setSupportActionBar(toolbar);
    //noinspection ConstantConditions
    getSupportActionBar().setDisplayHomeAsUpEnabled(true);

    if (getIntent() != null) {
        mScanWithProxyService = getIntent().getBooleanExtra(Utils.EXTRA_DATA_PROVISIONING_SERVICE, true);
        if (mScanWithProxyService) {
            getSupportActionBar().setSubtitle(R.string.sub_title_scanning_nodes);
        } else {
            getSupportActionBar().setSubtitle(R.string.sub_title_scanning_proxy_node);
        }
    }

    // Configure the recycler view
    final RecyclerView recyclerViewDevices = findViewById(R.id.recycler_view_ble_devices);
    recyclerViewDevices.setLayoutManager(new LinearLayoutManager(this));
    final DividerItemDecoration dividerItemDecoration = new DividerItemDecoration(recyclerViewDevices.getContext(), DividerItemDecoration.VERTICAL);
    recyclerViewDevices.addItemDecoration(dividerItemDecoration);

    final SimpleItemAnimator itemAnimator = (SimpleItemAnimator) recyclerViewDevices.getItemAnimator();
    if (itemAnimator != null) itemAnimator.setSupportsChangeAnimations(false);

    final DevicesAdapter adapter = new DevicesAdapter(this, mViewModel.getScannerRepository().getScannerResults());
    adapter.setOnItemClickListener(this);
    recyclerViewDevices.setAdapter(adapter);

    mViewModel.getScannerRepository().getScannerState().observe(this, this::startScan);
}
 

public long getAnimationDuration(@NonNull RecyclerView recyclerView, int animationType,
    float animateDx, float animateDy) {
  final RecyclerView.ItemAnimator itemAnimator = recyclerView.getItemAnimator();
  if (itemAnimator == null) {
    return DEFAULT_SWIPE_ANIMATION_DURATION;
  } else {
    return itemAnimator.getMoveDuration();
  }
}
 

protected void initRecyclerView(RecyclerView view){
    view.addItemDecoration(new BoxItemDividerDecoration(getResources()));
    view.addItemDecoration(new FooterDecoration(getResources()));
    view.setLayoutManager(new LinearLayoutManager(getActivity()));
    if (view.getItemAnimator() instanceof SimpleItemAnimator) {
        ((SimpleItemAnimator) view.getItemAnimator()).setSupportsChangeAnimations(false);
    }
}
 

protected void initRecyclerView(RecyclerView view){
    int numColumns = (getResources().getConfiguration().orientation == Configuration.ORIENTATION_LANDSCAPE) ? 5 : 3;
    view.setLayoutManager(new GridLayoutManager(getActivity(),numColumns));
    view.addItemDecoration(new SpacesItemDecoration(8));
    if (view.getItemAnimator() instanceof SimpleItemAnimator) {
        ((SimpleItemAnimator) view.getItemAnimator()).setSupportsChangeAnimations(false);
    }
}
 

/**
 * Disables the animations of the specified {@link RecyclerView}.
 *
 * @param recyclerView The recycler view to disable animations of
 */
public static void disableRecyclerViewAnimations(RecyclerView recyclerView) {
    if((recyclerView != null) && (recyclerView.getItemAnimator() != null)) {
        recyclerView.setItemAnimator(null);
    }
}
 

/**
 * Called by the WeSwipeHelper when user action finished on a ViewHolder and now the View
 * will be animated to its final position.
 * <p>
 * Default implementation uses ItemAnimator's duration values. If
 * <code>animationType</code> is {@link #ANIMATION_TYPE_DRAG}, it returns
 * {@link RecyclerView.ItemAnimator#getMoveDuration()}, otherwise, it returns
 * {@link RecyclerView.ItemAnimator#getRemoveDuration()}. If RecyclerView does not have
 * any {@link RecyclerView.ItemAnimator} attached, this method returns
 * {@code DEFAULT_DRAG_ANIMATION_DURATION} or {@code DEFAULT_SWIPE_ANIMATION_DURATION}
 * depending on the animation type.
 *
 * @param recyclerView  The RecyclerView to which the WeSwipeHelper is attached to.
 * @param animationType The type of animation. Is one of {@link #ANIMATION_TYPE_DRAG},
 *                      {@link #ANIMATION_TYPE_SWIPE_CANCEL} or
 *                      {@link #ANIMATION_TYPE_SWIPE_SUCCESS}.
 * @param animateDx     The horizontal distance that the animation will offset
 * @param animateDy     The vertical distance that the animation will offset
 * @return The duration for the animation
 */
public long getAnimationDuration(RecyclerView recyclerView, int animationType,
                                 float animateDx, float animateDy) {
    final RecyclerView.ItemAnimator itemAnimator = recyclerView.getItemAnimator();
    if (itemAnimator == null) {
        return animationType == ANIMATION_TYPE_DRAG ? DEFAULT_DRAG_ANIMATION_DURATION
                : DEFAULT_SWIPE_ANIMATION_DURATION;
    } else {
        return animationType == ANIMATION_TYPE_DRAG ? itemAnimator.getMoveDuration()
                : itemAnimator.getRemoveDuration();
    }
}
 

/**
 * Called by the ItemTouchHelper when user action finished on a ViewHolder and now the View
 * will be animated to its final position.
 * <p>
 * Default implementation uses ItemAnimator's duration values. If
 * <code>animationType</code> is {@link #ANIMATION_TYPE_DRAG}, it returns
 * {@link RecyclerView.ItemAnimator#getMoveDuration()}, otherwise, it returns
 * {@link RecyclerView.ItemAnimator#getRemoveDuration()}. If RecyclerView does not have
 * any {@link RecyclerView.ItemAnimator} attached, this method returns
 * {@code DEFAULT_DRAG_ANIMATION_DURATION} or {@code DEFAULT_SWIPE_ANIMATION_DURATION}
 * depending on the animation type.
 *
 * @param recyclerView  The RecyclerView to which the ItemTouchHelper is attached to.
 * @param animationType The type of animation. Is one of {@link #ANIMATION_TYPE_DRAG},
 *                      {@link #ANIMATION_TYPE_SWIPE_CANCEL} or
 *                      {@link #ANIMATION_TYPE_SWIPE_SUCCESS}.
 * @param animateDx     The horizontal distance that the animation will offset
 * @param animateDy     The vertical distance that the animation will offset
 * @return The duration for the animation
 */
public long getAnimationDuration(RecyclerView recyclerView, int animationType,
                                 float animateDx, float animateDy) {
    final RecyclerView.ItemAnimator itemAnimator = recyclerView.getItemAnimator();
    if (itemAnimator == null) {
        return animationType == ANIMATION_TYPE_DRAG ? DEFAULT_DRAG_ANIMATION_DURATION
                : DEFAULT_SWIPE_ANIMATION_DURATION;
    } else {
        return animationType == ANIMATION_TYPE_DRAG ? itemAnimator.getMoveDuration()
                : itemAnimator.getRemoveDuration();
    }
}
 

/**
 * Called by the ItemTouchHelper when user action finished on a ViewHolder and now the View
 * will be animated to its final position.
 * <p>
 * Default implementation uses ItemAnimator's duration values. If
 * <code>animationType</code> is {@link #ANIMATION_TYPE_DRAG}, it returns
 * {@link RecyclerView.ItemAnimator#getMoveDuration()}, otherwise, it returns {@link
 * RecyclerView.ItemAnimator#getRemoveDuration()}. If RecyclerView does not have any {@link
 * RecyclerView.ItemAnimator} attached, this method returns {@code
 * DEFAULT_DRAG_ANIMATION_DURATION} or {@code DEFAULT_SWIPE_ANIMATION_DURATION} depending on
 * the animation type.
 *
 * @param recyclerView  The RecyclerView to which the ItemTouchHelper is attached to.
 * @param animationType The type of animation. Is one of {@link #ANIMATION_TYPE_DRAG},
 *                      {@link #ANIMATION_TYPE_SWIPE_CANCEL} or {@link
 *                      #ANIMATION_TYPE_SWIPE_SUCCESS}.
 * @param animateDx     The horizontal distance that the animation will offset
 * @param animateDy     The vertical distance that the animation will offset
 * @return The duration for the animation
 */
public long getAnimationDuration(RecyclerView recyclerView, int animationType,
                                 float animateDx, float animateDy) {
    final RecyclerView.ItemAnimator itemAnimator = recyclerView.getItemAnimator();
    if (itemAnimator == null) {
        return animationType == ANIMATION_TYPE_DRAG ? DEFAULT_DRAG_ANIMATION_DURATION
                : DEFAULT_SWIPE_ANIMATION_DURATION;
    } else {
        return animationType == ANIMATION_TYPE_DRAG ? itemAnimator.getMoveDuration()
                : itemAnimator.getRemoveDuration();
    }
}