Back to project page KangarooImageSearch.
The source code is released under:
MIT License
If you think the Android project KangarooImageSearch listed in this page is inappropriate, such as containing malicious code/tools or violating the copyright, please email info at java2s dot com, thanks.
package com.nickrasband.kangarooimagesearchv2; /*from w w w. j a va2 s .c o m*/ import android.widget.AbsListView; import android.widget.AbsListView.OnScrollListener; public abstract class EndlessScrollListener implements OnScrollListener { // The minimum amount of items to have below your current scroll position // before loading more. private int visibleThreshold = 5; // The current offset index of data you have loaded private int currentPage = 0; // The total number of items in the dataset after the last load private int previousTotalItemCount = 0; // True if we are still waiting for the last set of data to load. private boolean loading = true; // Sets the starting page index private int startingPageIndex = 0; public EndlessScrollListener() { } public EndlessScrollListener(int visibleThreshold) { this.visibleThreshold = visibleThreshold; } public EndlessScrollListener(int visibleThreshold, int startPage) { this.visibleThreshold = visibleThreshold; this.startingPageIndex = startPage; this.currentPage = startPage; } // This happens many times a second during a scroll, so be wary of the code you place here. // We are given a few useful parameters to help us work out if we need to load some more data, // but first we check if we are waiting for the previous load to finish. @Override public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) { // If the total item count is zero and the previous isn't, assume the // list is invalidated and should be reset back to initial state // If there are no items in the list, assume that initial items are loading if (!loading && (totalItemCount < previousTotalItemCount)) { this.currentPage = this.startingPageIndex; this.previousTotalItemCount = totalItemCount; if (totalItemCount == 0) { this.loading = true; } } // If it?s still loading, we check to see if the dataset count has // changed, if so we conclude it has finished loading and update the current page // number and total item count. if (loading) { if (totalItemCount > previousTotalItemCount) { loading = false; previousTotalItemCount = totalItemCount; currentPage++; } } // If it isn?t currently loading, we check to see if we have breached // the visibleThreshold and need to reload more data. // If we do need to reload some more data, we execute onLoadMore to fetch the data. if (!loading && (totalItemCount - visibleItemCount) <= (firstVisibleItem + visibleThreshold)) { onLoadMore(currentPage + 1, totalItemCount); loading = true; } } // Defines the process for actually loading more data based on page public abstract void onLoadMore(int page, int totalItemsCount); @Override public void onScrollStateChanged(AbsListView view, int scrollState) { // Don't take any action on changed } }