55 lines
2.0 KiB
Java
55 lines
2.0 KiB
Java
/* Copyright 2017 Andrew Dawson
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*
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* This file is a part of Tusky.
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*
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* This program is free software; you can redistribute it and/or modify it under the terms of the
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* GNU General Public License as published by the Free Software Foundation; either version 3 of the
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* License, or (at your option) any later version.
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*
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* Tusky is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even
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* the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
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* Public License for more details.
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*
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* You should have received a copy of the GNU General Public License along with Tusky; if not,
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* see <http://www.gnu.org/licenses>. */
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package com.keylesspalace.tusky.view;
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import androidx.annotation.NonNull;
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import androidx.recyclerview.widget.LinearLayoutManager;
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import androidx.recyclerview.widget.RecyclerView;
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public abstract class EndlessOnScrollListener extends RecyclerView.OnScrollListener {
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private static final int VISIBLE_THRESHOLD = 15;
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private int previousTotalItemCount;
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private LinearLayoutManager layoutManager;
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public EndlessOnScrollListener(LinearLayoutManager layoutManager) {
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this.layoutManager = layoutManager;
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previousTotalItemCount = 0;
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}
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@Override
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public void onScrolled(@NonNull RecyclerView view, int dx, int dy) {
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int totalItemCount = layoutManager.getItemCount();
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int lastVisibleItemPosition = layoutManager.findLastVisibleItemPosition();
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if (totalItemCount < previousTotalItemCount) {
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previousTotalItemCount = totalItemCount;
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}
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if (totalItemCount != previousTotalItemCount) {
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previousTotalItemCount = totalItemCount;
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}
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if (lastVisibleItemPosition + VISIBLE_THRESHOLD > totalItemCount) {
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onLoadMore(totalItemCount, view);
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}
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}
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public void reset() {
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previousTotalItemCount = 0;
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}
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public abstract void onLoadMore(int totalItemsCount, RecyclerView view);
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}
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