SectionedAdapter.java

/***
Copyright (c) 2008-2010 CommonsWare, LLC
portions Copyright (c) 2008-10 Jeffrey Sharkey

This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/ 

package at.madexperts.logmynight;

import java.util.ArrayList;
import java.util.List;

import android.view.View;
import android.view.ViewGroup;
import android.widget.Adapter;
import android.widget.BaseAdapter;

abstract class SectionedAdapter extends BaseAdapter {
	abstract protected View getHeaderView(String caption, int index, View convertView, ViewGroup parent);
	
	private List<Section> sections=new ArrayList<Section>();
	private int TYPE_SECTION_HEADER=0;

	public SectionedAdapter() {
		super();
	}

	public void addSection(String caption, Adapter adapter) {
		sections.add(new Section(caption, adapter));
	}

	public Object getItem(int position) {
		for (Section section : this.sections) {
			if (position==0) {
				return(section);
			}
			
			int size=section.adapter.getCount()+1;

			if (position<size) {
				return(section.adapter.getItem(position-1));
			}

			position-=size;
		}
		
		return(null);
	}

	public int getCount() {
		int total=0;
		
		for (Section section : this.sections) {
			total+=section.adapter.getCount()+1; // add one for header
		}
		
		return(total);
	}

	public int getViewTypeCount() {
		int total=1;	// one for the header, plus those from sections
		
		for (Section section : this.sections) {
			total+=section.adapter.getViewTypeCount();
		}
		
		return(total);
	}

	public int getItemViewType(int position) {
		int typeOffset=TYPE_SECTION_HEADER+1;	// start counting from here
		
		for (Section section : this.sections) {
			if (position==0) {
				return(TYPE_SECTION_HEADER);
			}
			
			int size=section.adapter.getCount()+1;

			if (position<size) {
				return(typeOffset+section.adapter.getItemViewType(position-1));
			}

			position-=size;
			typeOffset+=section.adapter.getViewTypeCount();
		}
		
		return(-1);
	}

	public boolean areAllItemsSelectable() {
		return(false);
	}

	public boolean isEnabled(int position) {
		return(getItemViewType(position)!=TYPE_SECTION_HEADER);
	}
	
	public View getView(int position, View convertView, ViewGroup parent) {
		
		int sectionIndex=0;
		
		for (Section section : this.sections) {
			if (position==0) {
				return(getHeaderView(section.caption, sectionIndex, convertView, parent));
			}

			int size=section.adapter.getCount()+1;

			if (position<size) {
				return(section.adapter.getView(position-1, convertView, parent));
			}
			position-=size;
			sectionIndex++;
		}
		
		return(null);
	}


	public long getItemId(int position) {
		for (Section section : this.sections) {
			if (position==0) {
				return -1; 
			}
			int size=section.adapter.getCount()+1;
			
			if (position<size) {
				return(section.adapter.getItemId(position-1));
			}
			position-=size;
		}
		return -1;
	}



	class Section {
		String caption;
		Adapter adapter;
	
		Section(String caption, Adapter adapter) {
			this.caption=caption;
			this.adapter=adapter;
		}
	}
}