project_files/Android-build/SDL-android-project/src/org/hedgewars/hedgeroid/netplay/ChatlogAdapter.java
author Medo <smaxein@googlemail.com>
Mon, 06 Aug 2012 22:39:36 +0200
changeset 7476 2fb781bbdd51
parent 7349 12fdfd2038d4
permissions -rw-r--r--
Hedgeroid: Start using the frontlib for more operations

package org.hedgewars.hedgeroid.netplay;

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

import org.hedgewars.hedgeroid.netplay.MessageLog.Observer;

import android.content.Context;
import android.text.method.LinkMovementMethod;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AbsListView.LayoutParams;
import android.widget.BaseAdapter;
import android.widget.TextView;

/**
 * Optimization: ListView is smart enough to try re-using the same view for an item
 * with the same ID, but it still calls getView for those items when the list changes.
 * Since lines with a given ID never change in our chatlog, we can avoid the effort
 * of TextView.setText in many cases by checking if the view is already set up for the
 * line with the right ID - but to do that, the view needs to remember the ID it's
 * holding the text for. That's what the LoglineView does. 
 */
class LoglineView extends TextView {
	long chatlogId = -1;
	
	public LoglineView(Context context) {
		super(context);
	}
}

public class ChatlogAdapter extends BaseAdapter implements Observer {
	long idOffset = 0;
	private List<CharSequence> log = new ArrayList<CharSequence>();
	private Context context;
	
	public ChatlogAdapter(Context context) {
		this.context = context;
	}
	
	public int getCount() {
		return log.size();
	}

	public Object getItem(int position) {
		return log.get(position);
	}

	public long getItemId(int position) {
		return position+idOffset;
	}

	public boolean hasStableIds() {
		return true;
	}

	public void clear() {
		idOffset += log.size();
		log.clear();
		notifyDataSetChanged();
	}
	
	public void lineAdded(CharSequence text) {
		log.add(text);
		notifyDataSetChanged();
	}
	
	public void lineRemoved() {
		log.remove(0);
		idOffset += 1;
		notifyDataSetChanged();
	}
	
	public void setLog(Collection<CharSequence> log) {
		idOffset += log.size();
		this.log = new ArrayList<CharSequence>(log);
		notifyDataSetChanged();
	}
	
	public View getView(int position, View convertView, ViewGroup parent) {
		LoglineView v = (LoglineView)convertView;
		if (v == null) {
			v = new LoglineView(context);
			v.setLayoutParams(new LayoutParams(LayoutParams.FILL_PARENT, LayoutParams.WRAP_CONTENT));
			v.setMovementMethod(LinkMovementMethod.getInstance());
		}
		long id = getItemId(position);
		if(id != v.chatlogId) {
			v.setText(log.get(position));
			v.chatlogId = id;
		}
		return v;
	}
}