DataListView.java

/*******************************************************************************
 * Copyright 2012 momock.com
 * 
 * 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 com.momock.data;

import java.util.Arrays;
import java.util.Comparator;

import com.momock.event.IEventHandler;

public class DataListView<T> extends DataViewBase<T> implements IEventHandler<DataChangedEventArgs>{
	IDataList<T> source;
	public DataListView(){
		
	}
	public DataListView(IDataList<T> source){	
		this(source, null);
	}
	public DataListView(IDataList<T> source, IFilter<T> filter) {
		this(source, filter, null);
	}

	public DataListView(IDataList<T> source, IFilter<T> filter, IOrder<T> order) {
		setFilter(filter);
		setOrder(order);
		setSource(source);
	}
	@SuppressWarnings("unchecked")
	@Override
	public void onRefresh() {		
		store.removeAllItems();
		if (source == null) return;
		for (int i = 0; i < source.getItemCount(); i++) {
			T obj = source.getItem(i);
			if (filter == null || filter.check(obj)) {
				store.addItem(obj);
			}
		}
		int count = store.getItemCount();
		Object[] objs = new Object[count];
		for (int i = 0; i < count; i++) {
			objs[i] = store.getItem(i);
		}
		if (store.getItemCount() > 0 && order != null) {
			Arrays.sort(objs, new Comparator<Object>() {
				@Override
				public int compare(Object lhs, Object rhs) {
					return order.compare((T)lhs, (T)rhs);
				}
			});
		}
		if (limit > 0){
			store.removeAllItems();
			for (int i = 0; i < limit; i++) {	
				if (offset + i < count)
					store.addItem((T)objs[offset + i]);
				else 
					break;
			}
		} else {
			for (int i = 0; i < count; i++) {
				store.setItem(i, (T)objs[i]);
			}
		}
	}
	public IDataList<T> getSource() {
		return source;
	}
	public void setSource(IDataList<T> source) {
		if (this.source != null && this.source instanceof IDataChangedAware) 
			((IDataChangedAware)this.source).removeDataChangedHandler(this);
		this.source = source;
		this.needRefreshData = true;
		if (this.source != null && this.source instanceof IDataChangedAware) 
			((IDataChangedAware)this.source).addDataChangedHandler(this);
	}
	@Override
	public void process(Object sender, DataChangedEventArgs args) {
		this.needRefreshData = true;
		refresh();
	}

}