DataSetAdapter.java

package org.robobinding.widget.adapterview;

import org.robobinding.BindableView;
import org.robobinding.itempresentationmodel.ItemContext;
import org.robobinding.itempresentationmodel.RefreshableItemPresentationModel;
import org.robobinding.presentationmodel.AbstractPresentationModelObject;
import org.robobinding.property.DataSetValueModel;
import org.robobinding.viewattribute.ViewTag;
import org.robobinding.viewattribute.ViewTags;

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

/**
 * 
 * @since 1.0
 * @author Cheng Wei
 * @author Robert Taylor
 */
public class DataSetAdapter extends BaseAdapter {
	private enum DisplayType {
		ITEM_LAYOUT, DROPDOWN_LAYOUT
	}

	private final DataSetValueModel dataSetValueModel;

	private final ItemLayoutBinder itemLayoutBinder;
	private final ItemLayoutBinder dropdownLayoutBinder;
	private final ItemLayoutSelector itemLayoutSelector;
	private final int dropdownLayoutId;
	private final ViewTags<RefreshableItemPresentationModel> viewTags;

	private final boolean preInitializeViews;

	public DataSetAdapter(DataSetValueModel dataSetValueModel, 
			ItemLayoutBinder itemLayoutBinder, ItemLayoutBinder dropdownLayoutBinder, 
			ItemLayoutSelector itemLayoutSelector, int dropdownLayoutId,
			ViewTags<RefreshableItemPresentationModel> viewTags, boolean preInitializeViews) {
		this.preInitializeViews = preInitializeViews;
		
		this.dataSetValueModel = dataSetValueModel;
		this.itemLayoutBinder = itemLayoutBinder;
		this.dropdownLayoutBinder = dropdownLayoutBinder;
		this.itemLayoutSelector = itemLayoutSelector;
		this.dropdownLayoutId = dropdownLayoutId;
		this.viewTags = viewTags;
	}

	@Override
	public int getCount() {
		return dataSetValueModel.size();
	}

	@Override
	public Object getItem(int position) {
		return dataSetValueModel.get(position);
	}

	@Override
	public long getItemId(int position) {
		return position;
	}

	@Override
	public View getView(int position, View convertView, ViewGroup parent) {
		return createViewFromResource(position, convertView, parent, DisplayType.ITEM_LAYOUT);
	}

	@Override
	public View getDropDownView(int position, View convertView, ViewGroup parent) {
		return createViewFromResource(position, convertView, parent, DisplayType.DROPDOWN_LAYOUT);
	}

	private View createViewFromResource(int position, View convertView, ViewGroup parent, DisplayType displayType) {
		if (convertView == null) {
			return newView(position, parent, displayType);
		} else {
			updateItemPresentationModel(convertView, position);
			return convertView;
		}
	}

	private View newView(int position, ViewGroup parent, DisplayType displayType) {
		BindableView bindableView;
		Object item = getItem(position);
		if (displayType == DisplayType.ITEM_LAYOUT) {
			int layoutId = itemLayoutSelector.selectLayout(getItemViewType(position));
			bindableView = itemLayoutBinder.inflate(parent, layoutId);
		} else {
			bindableView = dropdownLayoutBinder.inflate(parent, dropdownLayoutId);
		}
		
		View view = bindableView.getRootView();
		RefreshableItemPresentationModel itemPresentationModel = dataSetValueModel.newRefreshableItemPresentationModel(
				getItemViewType(position));
		itemPresentationModel.updateData(item, new ItemContext(view, position));
		bindableView.bindTo((AbstractPresentationModelObject)itemPresentationModel);

		ViewTag<RefreshableItemPresentationModel> viewTag = viewTags.tagFor(view);
		viewTag.set(itemPresentationModel);
		return view;
	}

	private void updateItemPresentationModel(View view, int position) {
		ViewTag<RefreshableItemPresentationModel> viewTag = viewTags.tagFor(view);
		RefreshableItemPresentationModel itemPresentationModel = viewTag.get();
		itemPresentationModel.updateData(getItem(position), new ItemContext(view, position));
		refreshIfRequired(itemPresentationModel);
	}
	
	private void refreshIfRequired(RefreshableItemPresentationModel itemPresentationModel) {
		if(preInitializeViews) {
			itemPresentationModel.refresh();
		}
	}
	
	@Override
	public int getViewTypeCount() {
		return itemLayoutSelector.getViewTypeCount();
	}
	
	@Override
	public int getItemViewType(int position) {
		return itemLayoutSelector.getItemViewType(getItem(position), position);
	}
}