package com.lcjian.lib.recyclerview;
|
|
import android.os.Handler;
|
import android.os.Looper;
|
import android.view.View;
|
|
import androidx.annotation.NonNull;
|
import androidx.recyclerview.widget.RecyclerView;
|
|
public class LoadMoreAdapter extends AdvanceAdapter {
|
|
public static final int STATE_DEFAULT = 0;
|
public static final int STATE_LOADING = 1;
|
public static final int STATE_ERROR = 2;
|
public static final int STATE_END = 3;
|
|
private boolean mEnabled = true;
|
|
private View mLoadingView;
|
|
private View mErrorView;
|
|
private View mEndView;
|
|
private int mState = STATE_DEFAULT;
|
|
private OnLoadMoreListener mOnLoadMoreListener;
|
|
private final EndlessRecyclerOnScrollListener mOnScrollListener;
|
|
private final Handler mHandler;
|
|
private final Runnable mStateSetter;
|
|
public LoadMoreAdapter(RecyclerView.Adapter<? extends RecyclerView.ViewHolder> adapter) {
|
super(adapter);
|
this.mOnScrollListener = new EndlessRecyclerOnScrollListener() {
|
@Override
|
public void onLoadMore() {
|
if (mOnLoadMoreListener != null) {
|
mOnLoadMoreListener.onLoadMore();
|
}
|
}
|
};
|
this.mHandler = new Handler(Looper.getMainLooper());
|
this.mStateSetter = () -> {
|
switch (mState) {
|
case STATE_DEFAULT:
|
removeFooter(mLoadingView);
|
removeFooter(mErrorView);
|
removeFooter(mEndView);
|
break;
|
case STATE_LOADING:
|
removeFooter(mErrorView);
|
removeFooter(mEndView);
|
addFooter(mLoadingView);
|
break;
|
case STATE_ERROR:
|
removeFooter(mLoadingView);
|
removeFooter(mEndView);
|
addFooter(mErrorView);
|
break;
|
case STATE_END:
|
removeFooter(mLoadingView);
|
removeFooter(mErrorView);
|
addFooter(mEndView);
|
break;
|
default:
|
break;
|
}
|
};
|
}
|
|
@Override
|
public void onAttachedToRecyclerView(@NonNull RecyclerView recyclerView) {
|
super.onAttachedToRecyclerView(recyclerView);
|
recyclerView.addOnScrollListener(mOnScrollListener);
|
}
|
|
@Override
|
public void onDetachedFromRecyclerView(@NonNull RecyclerView recyclerView) {
|
super.onDetachedFromRecyclerView(recyclerView);
|
recyclerView.removeOnScrollListener(mOnScrollListener);
|
}
|
|
public LoadMoreAdapter setLoadingView(View loadingView) {
|
if (mLoadingView != null) {
|
removeFooter(mLoadingView);
|
}
|
mLoadingView = loadingView;
|
return this;
|
}
|
|
public LoadMoreAdapter setErrorView(View errorView) {
|
if (mErrorView != null) {
|
removeFooter(mErrorView);
|
}
|
mErrorView = errorView;
|
return this;
|
}
|
|
public LoadMoreAdapter setEndView(View endView) {
|
if (mEndView != null) {
|
removeFooter(mEndView);
|
}
|
mEndView = endView;
|
return this;
|
}
|
|
public LoadMoreAdapter setEnabled(boolean enabled) {
|
mEnabled = enabled;
|
return this;
|
}
|
|
public LoadMoreAdapter setThreshold(int visibleThreshold) {
|
mOnScrollListener.setThreshold(visibleThreshold);
|
return this;
|
}
|
|
public LoadMoreAdapter setOnLoadMoreListener(OnLoadMoreListener onLoadmoreListener) {
|
this.mOnLoadMoreListener = onLoadmoreListener;
|
return this;
|
}
|
|
public void setState(int state) {
|
mState = state;
|
mHandler.post(mStateSetter);
|
}
|
|
public interface OnLoadMoreListener {
|
void onLoadMore();
|
}
|
|
/**
|
* Custom Scroll listener for RecyclerView.
|
* Based on implementation https://gist.github.com/ssinss/e06f12ef66c51252563e
|
*/
|
private abstract class EndlessRecyclerOnScrollListener extends RecyclerView.OnScrollListener {
|
|
private int mVisibleThreshold = 5; // The minimum amount of items to have below your current scroll position before mLoading more.
|
|
@Override
|
public void onScrolled(@NonNull RecyclerView recyclerView, int dx, int dy) {
|
super.onScrolled(recyclerView, dx, dy);
|
RecyclerViewPositionHelper recyclerViewHelper = RecyclerViewPositionHelper.createHelper(recyclerView);
|
int visibleItemCount = recyclerView.getChildCount();
|
int totalItemCount = recyclerViewHelper.getItemCount();
|
int firstVisibleItem = recyclerViewHelper.findFirstVisibleItemPosition();
|
|
if (mEnabled && mState == STATE_DEFAULT && (totalItemCount - visibleItemCount) <= (firstVisibleItem + mVisibleThreshold)) {
|
// End has been reached
|
// Do something
|
onLoadMore();
|
}
|
}
|
|
private void setThreshold(int visibleThreshold) {
|
this.mVisibleThreshold = visibleThreshold;
|
}
|
|
public abstract void onLoadMore();
|
}
|
}
|
