public boolean shouldHandleRecyclerViewLoadingMore(RecyclerView recyclerView) {
if (mIsLoadingMore
|| mCurrentRefreshStatus == RefreshStatus.REFRESHING
|| mLoadMoreFooterView == null
|| mDelegate == null
|| recyclerView.getAdapter() == null
|| recyclerView.getAdapter().getItemCount() == 0) {
return false;
}
RecyclerView.LayoutManager manager = recyclerView.getLayoutManager();
if (manager == null || manager.getItemCount() == 0) {
return false;
}
if (manager instanceof LinearLayoutManager) {
LinearLayoutManager layoutManager = (LinearLayoutManager) manager;
if (layoutManager.findLastCompletelyVisibleItemPosition()
== recyclerView.getAdapter().getItemCount() - 1) {
return true;
}
} else if (manager instanceof StaggeredGridLayoutManager) {
StaggeredGridLayoutManager layoutManager = (StaggeredGridLayoutManager) manager;
int[] out = layoutManager.findLastCompletelyVisibleItemPositions(null);
int lastPosition = layoutManager.getItemCount() - 1;
for (int position : out) {
if (position == lastPosition) {
return true;
}
}
}
return false;
}
View findOneVisibleChild(
int fromIndex, int toIndex, boolean completelyVisible, boolean acceptPartiallyVisible) {
OrientationHelper helper;
if (layoutManager.canScrollVertically()) {
helper = OrientationHelper.createVerticalHelper(layoutManager);
} else {
helper = OrientationHelper.createHorizontalHelper(layoutManager);
}
final int start = helper.getStartAfterPadding();
final int end = helper.getEndAfterPadding();
final int next = toIndex > fromIndex ? 1 : -1;
View partiallyVisible = null;
for (int i = fromIndex; i != toIndex; i += next) {
final View child = layoutManager.getChildAt(i);
final int childStart = helper.getDecoratedStart(child);
final int childEnd = helper.getDecoratedEnd(child);
if (childStart < end && childEnd > start) {
if (completelyVisible) {
if (childStart >= start && childEnd <= end) {
return child;
} else if (acceptPartiallyVisible && partiallyVisible == null) {
partiallyVisible = child;
}
} else {
return child;
}
}
}
return partiallyVisible;
}
public HeaderItemDecoration(RecyclerView.LayoutManager layoutManager, int height) {
if (layoutManager.getClass() == LinearLayoutManager.class) {
mNumberOfChildren = 1;
} else if (layoutManager.getClass() == GridLayoutManager.class) {
mNumberOfChildren = ((GridLayoutManager) layoutManager).getSpanCount();
} else if (layoutManager instanceof StaggeredGridLayoutManager) {
mNumberOfChildren = ((StaggeredGridLayoutManager) layoutManager).getSpanCount();
}
mHeaderHeight = height;
}
@Override
public void onScrollStateChanged(RecyclerView recyclerView, int newState) {
currentScrollState = newState;
RecyclerView.LayoutManager layoutManager = recyclerView.getLayoutManager();
int visibleItemCount = layoutManager.getChildCount();
int totalItemCount = layoutManager.getItemCount();
if ((visibleItemCount > 0
&& currentScrollState == RecyclerView.SCROLL_STATE_IDLE
&& (lastVisibleItemPosition) >= totalItemCount - 1)) {
onBottom(); // Scroll to bottom
}
}
private void handleIntent(Intent intent) {
if (intent == null) return;
final FollowState followState =
intent.getParcelableExtra(WearUIActivity.EXTRA_VEHICLE_FOLLOW_STATE);
if (followState != null) {
RecyclerView.LayoutManager layoutMgr = followTypesView.getLayoutManager();
if (layoutMgr != null) {
layoutMgr.scrollToPosition(adapter.getItemPosition(followState.getMode()));
}
}
}
@Override
public void onSaveInstanceState(Bundle outState) {
// save list view position
mListState = mLayoutManager.onSaveInstanceState();
outState.putParcelable(TransistorKeys.INSTANCE_LIST_STATE, mListState);
super.onSaveInstanceState(outState);
}
private void initDiscountCardsRecyclerView() {
cardsRecyclerView.setHasFixedSize(true);
layoutManager = new LinearLayoutManager(getActivity());
cardsRecyclerView.setLayoutManager(layoutManager);
Customer customer = new Select().from(Customer.class).executeSingle();
List<DiscountCard> records = customer.discountCards();
adapter = new DiscountCardsListAdapter(records);
cardsRecyclerView.setAdapter(adapter);
cardsRecyclerView.setItemAnimator(cardsRecyclerView.getItemAnimator());
cardsRecyclerView.addItemDecoration(
new HorizontalDividerItemDecoration.Builder(getContext()).build());
cardsRecyclerView.setItemAnimator(new FadeInAnimator());
cardsRecyclerView.getItemAnimator().setRemoveDuration(1000);
cardsRecyclerView.setDefaultOnRefreshListener(
() ->
new Handler()
.postDelayed(
() -> {
// insert things to adapter
cardsRecyclerView.setRefreshing(false);
layoutManager.scrollToPosition(0);
},
1000));
}
@Override
public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
super.onScrolled(recyclerView, dx, dy);
int lastVisibleItem = 0;
int firstVisibleItem = 0;
RecyclerView.LayoutManager layoutManager = recyclerView.getLayoutManager();
int totalItemCount = layoutManager.getItemCount();
if (layoutManager instanceof LinearLayoutManager) {
LinearLayoutManager linearLayoutManager = ((LinearLayoutManager) layoutManager);
lastVisibleItem = linearLayoutManager.findLastVisibleItemPosition();
firstVisibleItem = linearLayoutManager.findFirstCompletelyVisibleItemPosition();
} else if (layoutManager instanceof GridLayoutManager) {
GridLayoutManager gridLayoutManager = ((GridLayoutManager) layoutManager);
// 通过LayoutManager找到当前显示的最后的item的position
lastVisibleItem = gridLayoutManager.findLastVisibleItemPosition();
firstVisibleItem = gridLayoutManager.findFirstCompletelyVisibleItemPosition();
} else if (layoutManager instanceof StaggeredGridLayoutManager) {
StaggeredGridLayoutManager staggeredGridLayoutManager =
((StaggeredGridLayoutManager) layoutManager);
// 因为StaggeredGridLayoutManager的特殊性可能导致最后显示的item存在多个，所以这里取到的是一个数组
// 得到这个数组后再取到数组中position值最大的那个就是最后显示的position值了
int[] lastPositions = new int[((StaggeredGridLayoutManager) layoutManager).getSpanCount()];
staggeredGridLayoutManager.findLastVisibleItemPositions(lastPositions);
lastVisibleItem = findMax(lastPositions);
firstVisibleItem = staggeredGridLayoutManager.findFirstVisibleItemPositions(lastPositions)[0];
}
if (firstVisibleItem == 0) {
if (!mPullLoadMoreRecyclerView.isLoadMore()) {
mPullLoadMoreRecyclerView.setPullRefreshEnable(true);
}
} else {
mPullLoadMoreRecyclerView.setPullRefreshEnable(false);
}
/** 无论水平还是垂直 */
if (!mPullLoadMoreRecyclerView.isRefresh()
&& mPullLoadMoreRecyclerView.isHasMore()
&& (lastVisibleItem >= totalItemCount - 1)
&& !mPullLoadMoreRecyclerView.isLoadMore()
&& (dx > 0 || dy > 0)) {
mPullLoadMoreRecyclerView.setIsLoadMore(true);
mPullLoadMoreRecyclerView.loadMore();
}
}
@Override
public void onViewStateRestored(Bundle savedInstanceState) {
super.onViewStateRestored(savedInstanceState);
Log.d(TAG, "onViewStateRestored()");
if (savedInstanceState != null) {
Parcelable savedRecyclerLayoutState = savedInstanceState.getParcelable(KEY_LAYOUT_MANAGER);
mLayoutManager.onRestoreInstanceState(savedRecyclerLayoutState);
mAdapter.notifyDataSetChanged();
}
}
private void validateRecycler(RecyclerView recycler, boolean headerAlreadyAligned) {
RecyclerView.LayoutManager layoutManager = recycler.getLayoutManager();
if (layoutManager == null) {
throw new IllegalStateException(
"Be sure to call RecyclerViewHeader constructor after setting your RecyclerView's LayoutManager.");
} else if (layoutManager.getClass()
!= LinearLayoutManager.class // not using instanceof on purpose
&& layoutManager.getClass() != GridLayoutManager.class
&& !(layoutManager instanceof StaggeredGridLayoutManager)) {
throw new IllegalArgumentException(
"Currently RecyclerViewHeader supports only LinearLayoutManager, GridLayoutManager and StaggeredGridLayoutManager.");
}
if (layoutManager instanceof LinearLayoutManager) {
if (((LinearLayoutManager) layoutManager).getOrientation() != LinearLayoutManager.VERTICAL) {
throw new IllegalArgumentException(
"Currently RecyclerViewHeader supports only VERTICAL orientation LayoutManagers.");
}
} else if (layoutManager instanceof StaggeredGridLayoutManager) {
if (((StaggeredGridLayoutManager) layoutManager).getOrientation()
!= StaggeredGridLayoutManager.VERTICAL) {
throw new IllegalArgumentException(
"Currently RecyclerViewHeader supports only VERTICAL orientation StaggeredGridLayoutManagers.");
}
}
if (!headerAlreadyAligned) {
ViewParent parent = recycler.getParent();
if (parent != null
&& !(parent instanceof LinearLayout)
&& !(parent instanceof FrameLayout)
&& !(parent instanceof RelativeLayout)) {
throw new IllegalStateException(
"Currently, NOT already aligned RecyclerViewHeader "
+ "can only be used for RecyclerView with a parent of one of types: LinearLayout, FrameLayout, RelativeLayout.");
}
}
}
private void maybeFireLoadMore() {
if (hasLoadMoreFired) {
return;
}
if (!showShowLoadMore) {
return;
}
final RecyclerView.LayoutManager layoutManager = recyclerView.getLayoutManager();
int visibleItemCount = layoutManager.getChildCount();
int totalItemCount = layoutManager.getItemCount();
int firstVisibleItemPosition = findFirstVisibleItemPosition();
if (totalItemCount == 0) {
return;
}
if (firstVisibleItemPosition + visibleItemCount + bufferItems > totalItemCount) {
if (onLoadMoreListener != null) {
hasLoadMoreFired = true;
onLoadMoreListener.onLoadMore(adapter.getLastItem());
}
}
}
private int findPartlyVisiblePosition() {
int positionView = 1;
RecyclerView.LayoutManager layoutManager = videoList.getLayoutManager();
int start = layoutManager.getPaddingStart();
int end = layoutManager.getHeight() + start;
int next = isScrolledUp ? 1 : -1;
int fromIndex = isScrolledUp ? 0 : layoutManager.getChildCount() - 1;
int toIndex = isScrolledUp ? layoutManager.getChildCount() : -1;
for (int i = fromIndex; i != toIndex; i += next) {
View child = layoutManager.getChildAt(i);
View childTex = child.findViewById(R.id.iv_feed_center_video);
int[] texLocation = new int[2];
childTex.getLocationInWindow(texLocation);
int childStart = texLocation[VIEW_TOP_LOCATION_INDEX] - actionbarSize;
int childEnd = childStart + childTex.getHeight();
if (childStart <= end && childEnd >= start) {
positionView = layoutManager.getPosition(child);
break;
}
}
return positionView;
}
/* Handles adding, deleting and renaming of station */
private void handleCollectionChanges(Intent intent) {
// load app state
loadAppState(mActivity);
int newStationPosition;
switch (intent.getIntExtra(TransistorKeys.EXTRA_COLLECTION_CHANGE, 1)) {
// CASE: station was added
case TransistorKeys.STATION_ADDED:
if (intent.hasExtra(TransistorKeys.EXTRA_STATION)) {
// get station from intent
Station station = intent.getParcelableExtra(TransistorKeys.EXTRA_STATION);
// add station to adapter, scroll to new position and update adapter
newStationPosition = mCollectionAdapter.add(station);
if (mCollectionAdapter.getItemCount() > 0) {
toggleActionCall();
}
mLayoutManager.scrollToPosition(newStationPosition);
mCollectionAdapter.setStationIDSelected(newStationPosition, mPlayback, false);
mCollectionAdapter.notifyDataSetChanged(); // TODO Remove?
}
break;
// CASE: station was renamed
case TransistorKeys.STATION_RENAMED:
if (intent.hasExtra(TransistorKeys.EXTRA_STATION_NEW_NAME)
&& intent.hasExtra(TransistorKeys.EXTRA_STATION)
&& intent.hasExtra(TransistorKeys.EXTRA_STATION_ID)) {
// get new name, station and station ID from intent
String newStationName = intent.getStringExtra(TransistorKeys.EXTRA_STATION_NEW_NAME);
Station station = intent.getParcelableExtra(TransistorKeys.EXTRA_STATION);
int stationID = intent.getIntExtra(TransistorKeys.EXTRA_STATION_ID, 0);
// update notification
if (station.getPlaybackState()) {
NotificationHelper.update(station, stationID, null, null);
}
// change station within in adapter, scroll to new position and update adapter
newStationPosition = mCollectionAdapter.rename(newStationName, station, stationID);
mLayoutManager.scrollToPosition(newStationPosition);
mCollectionAdapter.setStationIDSelected(newStationPosition, mPlayback, false);
mCollectionAdapter.notifyDataSetChanged(); // TODO Remove?
}
break;
// CASE: station was deleted
case TransistorKeys.STATION_DELETED:
if (intent.hasExtra(TransistorKeys.EXTRA_STATION)
&& intent.hasExtra(TransistorKeys.EXTRA_STATION_ID)) {
// get station and station ID from intent
Station station = intent.getParcelableExtra(TransistorKeys.EXTRA_STATION);
int stationID = intent.getIntExtra(TransistorKeys.EXTRA_STATION_ID, 0);
// dismiss notification
NotificationHelper.stop();
if (station.getPlaybackState()) {
// stop player service and notification using intent
Intent i = new Intent(mActivity, PlayerService.class);
i.setAction(TransistorKeys.ACTION_DISMISS);
mActivity.startService(i);
LogHelper.v(LOG_TAG, "Stopping player service.");
}
// remove station from adapter and update
newStationPosition = mCollectionAdapter.delete(station, stationID);
if (newStationPosition == -1 || mCollectionAdapter.getItemCount() == 0) {
// show call to action
toggleActionCall();
} else {
// scroll to new position
mCollectionAdapter.setStationIDSelected(newStationPosition, mPlayback, false);
mLayoutManager.scrollToPosition(newStationPosition);
}
mCollectionAdapter.notifyDataSetChanged(); // TODO Remove?
}
break;
}
}
@Override
public void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
outState.putParcelable(KEY_LAYOUT_MANAGER, mLayoutManager.onSaveInstanceState());
super.onSaveInstanceState(outState);
}
/**
* Returns the adapter item count.
*
* @return The total number on items in a layout manager
*/
public int getItemCount() {
return layoutManager == null ? 0 : layoutManager.getItemCount();
}
/**
* Returns the adapter position of the first visible view. This position does not include adapter
* changes that were dispatched after the last layout pass.
*
* @return The adapter position of the first visible item or {@link RecyclerView#NO_POSITION} if
* there aren't any visible items.
*/
public int findFirstVisibleItemPosition() {
final View child = findOneVisibleChild(0, layoutManager.getChildCount(), false, true);
return child == null ? RecyclerView.NO_POSITION : recyclerView.getChildAdapterPosition(child);
}
/**
* Returns the adapter position of the last fully visible view. This position does not include
* adapter changes that were dispatched after the last layout pass.
*
* @return The adapter position of the last fully visible view or {@link RecyclerView#NO_POSITION}
* if there aren't any visible items.
*/
public int findLastCompletelyVisibleItemPosition() {
final View child = findOneVisibleChild(layoutManager.getChildCount() - 1, -1, true, false);
return child == null ? RecyclerView.NO_POSITION : recyclerView.getChildAdapterPosition(child);
}
private float getHeaderY(View item, RecyclerView.LayoutManager lm) {
return headerStore.isSticky() && lm.getDecoratedTop(item) < 0 ? 0 : lm.getDecoratedTop(item);
}