Android Open Source - Android-Infinite-Scroll-Listview Infinite Scroll List Adapter

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License

The source code is released under:

Apache License

Java Source Code

/**
 */*from   w w  w  .ja  v a2s  .  com*/
 * Copyright 2013 Wei Xiao
 *
 * 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 ca.weixiao.widget;

import android.view.View;
import android.view.ViewGroup;
import android.widget.AbsListView;
import android.widget.AbsListView.OnScrollListener;
import android.widget.BaseAdapter;
import ca.weixiao.widget.InfiniteScrollListView.LoadingMode;
import ca.weixiao.widget.InfiniteScrollListView.StopPosition;

/**
 * A customized list adapter to work with infinite scroll list view
 */
public abstract class InfiniteScrollListAdapter extends BaseAdapter implements OnScrollListener {

  public static final String TAG = InfiniteScrollListAdapter.class.getSimpleName();

  // A lock to prevent another scrolling event to be triggered if one is already in session
  protected boolean canScroll = false;
  // A flag to enable/disable row clicks
  protected boolean rowEnabled = true;
  protected LoadingMode loadingMode;
  protected StopPosition stopPosition;
  protected InfiniteScrollListPageListener infiniteListPageListener;

  protected abstract void onScrollNext();
  public abstract View getInfiniteScrollListView(int position, View convertView, ViewGroup parent);
  
  public void setInfiniteListPageListener(InfiniteScrollListPageListener infiniteListPageListener) {
    this.infiniteListPageListener = infiniteListPageListener;
  }

  public void lock() {
    canScroll = false;
  }  
  public void unlock() {
    canScroll = true;
  }

    @Override
    public boolean isEnabled(int position) {
      return rowEnabled; 
    }
  public void setRowEnabled(boolean rowEabled) {
    this.rowEnabled = rowEabled;
  }
  
  public void setLoadingMode(LoadingMode loadingMode) {
    this.loadingMode = loadingMode;
  }
  
  public StopPosition getStopPosition() {
    return stopPosition;
  }
  public void setStopPosition(StopPosition stopPosition) {
    this.stopPosition = stopPosition;
  }

  @Override
  public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) {
    if (view instanceof InfiniteScrollListView) {
      // In scroll-to-top-to-load mode, when the list view scrolls to the first visible position it reaches the top
      if (loadingMode == LoadingMode.SCROLL_TO_TOP && firstVisibleItem == 0 && canScroll) {
        onScrollNext();
      }
      // In scroll-to-bottom-to-load mode, when the sum of first visible position and visible count equals the total number
      // of items in the adapter it reaches the bottom
      if (loadingMode == LoadingMode.SCROLL_TO_BOTTOM && firstVisibleItem + visibleItemCount - 1 == getCount() && canScroll) {
        onScrollNext();
      }
    }
  }

  @Override
  public void onScrollStateChanged(AbsListView view, int scrollState) {}

  @Override
  public final View getView(int position, View convertView, ViewGroup parent) {
    return getInfiniteScrollListView(position, convertView, parent);
  }

  public void notifyEndOfList() {
    // When there is no more to load use the lock to prevent loading from happening
    lock();
    // More actions when there is no more to load
    if (infiniteListPageListener != null) {
      infiniteListPageListener.endOfList();
    }
  }

  public void notifyHasMore() {
    // Release the lock when there might be more to load
    unlock();
    // More actions when it might have more to load
    if (infiniteListPageListener != null) {
      infiniteListPageListener.hasMore();
    }
  }

}

Java Source Code List

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