@Override
public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
RecyclerView.LayoutManager layoutManager = recyclerView.getLayoutManager();
StaggeredGridLayoutManager staggeredGridLayoutManager =
(StaggeredGridLayoutManager) layoutManager;
if (lastPositions == null) {
lastPositions = new int[staggeredGridLayoutManager.getSpanCount()];
}
staggeredGridLayoutManager.findLastVisibleItemPositions(lastPositions);
lastVisibleItemPosition = findMax(lastPositions);
}
/** 获取最后一条展示的位置 */
private int getLastVisiblePosition() {
int position;
if (getLayoutManager() instanceof LinearLayoutManager) {
position = ((LinearLayoutManager) getLayoutManager()).findLastVisibleItemPosition();
} else if (getLayoutManager() instanceof GridLayoutManager) {
position = ((GridLayoutManager) getLayoutManager()).findLastVisibleItemPosition();
} else if (getLayoutManager() instanceof StaggeredGridLayoutManager) {
StaggeredGridLayoutManager layoutManager = (StaggeredGridLayoutManager) getLayoutManager();
int[] lastPositions =
layoutManager.findLastVisibleItemPositions(new int[layoutManager.getSpanCount()]);
position = getMaxPosition(lastPositions);
} else {
position = getLayoutManager().getItemCount() - 1;
}
return position;
}
@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 onScrolled(RecyclerView recyclerView, int dx, int dy) {
super.onScrolled(recyclerView, dx, dy);
RecyclerView.LayoutManager layoutManager = recyclerView.getLayoutManager();
// int lastVisibleItemPosition = -1;
if (layoutManagerType == null) {
if (layoutManager instanceof LinearLayoutManager) {
layoutManagerType = LAYOUT_MANAGER_TYPE.LINEAR;
} else if (layoutManager instanceof GridLayoutManager) {
layoutManagerType = LAYOUT_MANAGER_TYPE.GRID;
} else if (layoutManager instanceof StaggeredGridLayoutManager) {
layoutManagerType = LAYOUT_MANAGER_TYPE.STAGGERED_GRID;
} else {
throw new RuntimeException(
"Unsupported LayoutManager used. Valid ones are LinearLayoutManager, GridLayoutManager and StaggeredGridLayoutManager");
}
}
switch (layoutManagerType) {
case LINEAR:
lastVisibleItemPosition =
((LinearLayoutManager) layoutManager).findLastVisibleItemPosition();
break;
case GRID:
lastVisibleItemPosition = ((GridLayoutManager) layoutManager).findLastVisibleItemPosition();
break;
case STAGGERED_GRID:
StaggeredGridLayoutManager staggeredGridLayoutManager =
(StaggeredGridLayoutManager) layoutManager;
if (lastPositions == null) {
lastPositions = new int[staggeredGridLayoutManager.getSpanCount()];
}
staggeredGridLayoutManager.findLastVisibleItemPositions(lastPositions);
lastVisibleItemPosition = findMax(lastPositions);
break;
}
}
/**
* 检查是否需要执行Loadmore
*
* @param recycler RecyclerView
* @param listener 加载更多监听
*/
private static void checkLoadmore(RecyclerView recycler, OnLoadmoreListener listener) {
RecyclerView.LayoutManager layoutManager = recycler.getLayoutManager();
if (layoutManager instanceof LinearLayoutManager) {
int lastVisibleItem = ((LinearLayoutManager) layoutManager).findLastVisibleItemPosition();
int totalItemCount = recycler.getAdapter().getItemCount();
if (lastVisibleItem >= totalItemCount - 1) {
listener.onLoadmore();
}
} else if (layoutManager instanceof StaggeredGridLayoutManager) {
StaggeredGridLayoutManager gridLayoutManager = (StaggeredGridLayoutManager) layoutManager;
int last[] = new int[gridLayoutManager.getSpanCount()];
gridLayoutManager.findLastVisibleItemPositions(last);
int totalItemCount = recycler.getAdapter().getItemCount();
for (int i = 0; i < last.length; i++) {
int lastVisibleItem = last[i];
if (lastVisibleItem >= totalItemCount - 1) {
listener.onLoadmore();
break;
}
}
}
}
private int calculateLastVisiblePosition(LayoutManager layoutManager) {
if (layoutManager instanceof LinearLayoutManager) {
LinearLayoutManager linearLayoutManager = (LinearLayoutManager) layoutManager;
return linearLayoutManager.findLastVisibleItemPosition();
}
if (layoutManager instanceof StaggeredGridLayoutManager) {
StaggeredGridLayoutManager staggeredGridLayoutManager =
(StaggeredGridLayoutManager) layoutManager;
int[] lastVisibleItemPositions =
staggeredGridLayoutManager.findLastVisibleItemPositions(null);
int max = -1;
for (int i = 0; i < lastVisibleItemPositions.length; i++) {
max = Math.max(max, lastVisibleItemPositions[i]);
Log.e(TAG, "lastVisibleItemPositions" + i + lastVisibleItemPositions[i]);
}
return max;
}
return -1;
}
