mirror of https://codeberg.org/gitnex/GitNex.git
93 lines
3.3 KiB
Java
93 lines
3.3 KiB
Java
/*
|
|
* Copyright (C) 2016 Piotr Wittchen
|
|
*
|
|
* Licensed under the Apache License, Version 2.0 (the "License");
|
|
* you may not use this file except in compliance with the License.
|
|
* You may obtain a copy of the License at
|
|
*
|
|
* http://www.apache.org/licenses/LICENSE-2.0
|
|
*
|
|
* Unless required by applicable law or agreed to in writing, software
|
|
* distributed under the License is distributed on an "AS IS" BASIS,
|
|
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
* See the License for the specific language governing permissions and
|
|
* limitations under the License.
|
|
*/
|
|
package org.mian.gitnex.helpers;
|
|
|
|
import androidx.annotation.NonNull;
|
|
import androidx.recyclerview.widget.LinearLayoutManager;
|
|
import androidx.recyclerview.widget.RecyclerView;
|
|
|
|
/**
|
|
* InfiniteScrollListener, which can be added to RecyclerView with addOnScrollListener
|
|
* to detect moment when RecyclerView was scrolled to the end.
|
|
*/
|
|
public abstract class InfiniteScrollListener extends RecyclerView.OnScrollListener {
|
|
private final int maxItemsPerRequest;
|
|
private final LinearLayoutManager layoutManager;
|
|
|
|
/**
|
|
* Initializes InfiniteScrollListener, which can be added
|
|
* to RecyclerView with addOnScrollListener method
|
|
*
|
|
* @param maxItemsPerRequest Max items to be loaded in a single request.
|
|
* @param layoutManager LinearLayoutManager created in the Activity.
|
|
*/
|
|
public InfiniteScrollListener(int maxItemsPerRequest, LinearLayoutManager layoutManager) {
|
|
assert maxItemsPerRequest > 0;
|
|
assert layoutManager != null;
|
|
|
|
this.maxItemsPerRequest = maxItemsPerRequest;
|
|
this.layoutManager = layoutManager;
|
|
}
|
|
|
|
/**
|
|
* Callback method to be invoked when the RecyclerView has been scrolled
|
|
*
|
|
* @param recyclerView The RecyclerView which scrolled.
|
|
* @param dx The amount of horizontal scroll.
|
|
* @param dy The amount of vertical scroll.
|
|
*/
|
|
@Override public void onScrolled(@NonNull RecyclerView recyclerView, int dx, int dy) {
|
|
super.onScrolled(recyclerView, dx, dy);
|
|
if (canLoadMoreItems()) {
|
|
onScrolledToEnd(layoutManager.findFirstVisibleItemPosition());
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Refreshes RecyclerView by setting new adapter,
|
|
* calling invalidate method and scrolling to given position
|
|
*
|
|
* @param view RecyclerView to be refreshed
|
|
* @param adapter adapter with new list of items to be loaded
|
|
* @param position position to which RecyclerView will be scrolled
|
|
*/
|
|
protected void refreshView(RecyclerView view, RecyclerView.Adapter adapter, int position) {
|
|
view.setAdapter(adapter);
|
|
view.invalidate();
|
|
view.scrollToPosition(position);
|
|
}
|
|
|
|
/**
|
|
* Checks if more items can be loaded to the RecyclerView
|
|
*
|
|
* @return boolean Returns true if can load more items or false if not.
|
|
*/
|
|
protected boolean canLoadMoreItems() {
|
|
final int visibleItemsCount = layoutManager.getChildCount();
|
|
final int totalItemsCount = layoutManager.getItemCount();
|
|
final int pastVisibleItemsCount = layoutManager.findFirstVisibleItemPosition();
|
|
final boolean lastItemShown = visibleItemsCount + pastVisibleItemsCount >= totalItemsCount;
|
|
return lastItemShown && totalItemsCount >= maxItemsPerRequest;
|
|
}
|
|
|
|
/**
|
|
* Callback method to be invoked when the RecyclerView has been scrolled to the end
|
|
*
|
|
* @param firstVisibleItemPosition Id of the first visible item on the list.
|
|
*/
|
|
public abstract void onScrolledToEnd(final int firstVisibleItemPosition);
|
|
}
|