Android Open Source - Amazing-Listview--Multiheader-Listview- Amazing Adapter

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License

The source code is released under:

Apache License

Java Source Code

package com.foound.widget;
//ww w. j a v  a  2  s  . c o m
import android.view.*;
import android.widget.*;
import android.widget.AbsListView.OnScrollListener;

public abstract class AmazingAdapter extends BaseAdapter implements SectionIndexer, OnScrollListener {
  public static final String TAG = AmazingAdapter.class.getSimpleName();

  public interface HasMorePagesListener {
    void noMorePages();
    void mayHaveMorePages();
  }

  /**
   * The <em>current</em> page, not the page that is going to be loaded.
   */
  int page = 1;
  int initialPage = 1;
  boolean automaticNextPageLoading = false;
  HasMorePagesListener hasMorePagesListener;
  
  void setHasMorePagesListener(HasMorePagesListener hasMorePagesListener) {
    this.hasMorePagesListener = hasMorePagesListener;
  }
  
    /**
     * Pinned header state: don't show the header.
     */
    public static final int PINNED_HEADER_GONE = 0;

    /**
     * Pinned header state: show the header at the top of the list.
     */
    public static final int PINNED_HEADER_VISIBLE = 1;

    /**
     * Pinned header state: show the header. If the header extends beyond
     * the bottom of the first shown element, push it up and clip.
     */
    public static final int PINNED_HEADER_PUSHED_UP = 2;

    /**
     * Computes the desired state of the pinned header for the given
     * position of the first visible list item. Allowed return values are
     * {@link #PINNED_HEADER_GONE}, {@link #PINNED_HEADER_VISIBLE} or
     * {@link #PINNED_HEADER_PUSHED_UP}.
     */
    public int getPinnedHeaderState(int position) {
      if (position < 0 || getCount() == 0) {
        return PINNED_HEADER_GONE;
      }
      
      // The header should get pushed up if the top item shown
      // is the last item in a section for a particular letter.
      int section = getSectionForPosition(position);
      int nextSectionPosition = getPositionForSection(section + 1);
      if (nextSectionPosition != -1 && position == nextSectionPosition - 1) {
        return PINNED_HEADER_PUSHED_UP;
      }
      
      return PINNED_HEADER_VISIBLE;
    }
    
    /**
     * Sets the initial page when {@link #resetPage()} is called.
     * Default is 1 (for APIs with 1-based page number).
     */
    public void setInitialPage(int initialPage) {
    this.initialPage = initialPage;
  }
    
    /**
     * Resets the current page to the page specified in {@link #setInitialPage(int)}.
     */
    public void resetPage() {
      this.page = this.initialPage;
    }
    
    /**
     * Increases the current page number.
     */
    public void nextPage() {
      this.page++;
    }
    
  @Override
  public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) {
    if (view instanceof AmazingListView) {
      ((AmazingListView) view).configureHeaderView(firstVisibleItem);
    }
  }

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

  @Override
  public final View getView(int position, View convertView, ViewGroup parent) {
    View res = getAmazingView(position, convertView, parent);
    
    if (position == getCount() - 1 && automaticNextPageLoading) {
      onNextPageRequested(page + 1);
    }
    
    final int section = getSectionForPosition(position);
    boolean displaySectionHeaders = (getPositionForSection(section) == position);
    
    bindSectionHeader(res, position, displaySectionHeaders);
    
    return res;
  }
    
  public void notifyNoMorePages() {
    automaticNextPageLoading = false;
    if (hasMorePagesListener != null) hasMorePagesListener.noMorePages();
  }
  
  public void notifyMayHaveMorePages() {
    automaticNextPageLoading = true;
    if (hasMorePagesListener != null) hasMorePagesListener.mayHaveMorePages();
  }
  
  /**
   * The last item on the list is requested to be seen, so do the request 
   * and call {@link AmazingListView#tellNoMoreData()} if there is no more pages.
   * 
   * @param page the page number to load.
   */
  protected abstract void onNextPageRequested(int page);

  /**
   * Configure the view (a listview item) to display headers or not based on displaySectionHeader 
   * (e.g. if displaySectionHeader header.setVisibility(VISIBLE) else header.setVisibility(GONE)).
   */
  protected abstract void bindSectionHeader(View view, int position, boolean displaySectionHeader);
  
  /**
   * read: get view too
   */
  public abstract View getAmazingView(int position, View convertView, ViewGroup parent);

    /**
     * Configures the pinned header view to match the first visible list item.
     *
     * @param header pinned header view.
     * @param position position of the first visible list item.
     * @param alpha fading of the header view, between 0 and 255.
     */
    public abstract void configurePinnedHeader(View header, int position, int alpha);

  @Override
  public abstract int getPositionForSection(int section);

  @Override
  public abstract int getSectionForPosition(int position);

  @Override
  public abstract Object[] getSections();
}

Java Source Code List

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