package test.com.treedemo;
import java.util.ArrayList;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.ImageView;
import android.widget.TextView;
import test.com.edittextdemo.R;
/**
* TreeViewAdapter
*
* @author carrey
*/
public class TreeViewAdapter extends BaseAdapter {
private ArrayList<Element> elementsData;
/**
* 树中元素
*/
private ArrayList<Element> elements;
/**
* LayoutInflater
*/
private LayoutInflater inflater;
/**
* item的行首缩进基数
*/
private int indentionBase;
public TreeViewAdapter(ArrayList<Element> elements, ArrayList<Element> elementsData, LayoutInflater inflater) {
this.elements = elements;
this.elementsData = elementsData;
this.inflater = inflater;
indentionBase = 50;
}
public ArrayList<Element> getElements() {
return elements;
}
public ArrayList<Element> getElementsData() {
return elementsData;
}
@Override
public int getCount() {
return elements.size();
}
@Override
public Object getItem(int position) {
return elements.get(position);
}
@Override
public long getItemId(int position) {
return position;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
ViewHolder holder = null;
if (convertView == null) {
holder = new ViewHolder();
convertView = inflater.inflate(R.layout.treeview_item, null);
holder.disclosureImg = convertView.findViewById(R.id.disclosureImg);
holder.contentText = convertView.findViewById(R.id.contentText);
convertView.setTag(holder);
} else {
holder = (ViewHolder) convertView.getTag();
}
Element element = elements.get(position);
int level = element.getLevel();
holder.disclosureImg.setPadding(
indentionBase * (level + 1),
holder.disclosureImg.getPaddingTop(),
holder.disclosureImg.getPaddingRight(),
holder.disclosureImg.getPaddingBottom());
holder.contentText.setText(element.getContentText());
if (element.isHasChildren() && !element.isExpanded()) {
holder.disclosureImg.setImageResource(R.drawable.close);
//这里要主动设置一下icon可见，因为convertView有可能是重用了"设置了不可见"的view，下同。
holder.disclosureImg.setVisibility(View.VISIBLE);
} else if (element.isHasChildren() && element.isExpanded()) {
holder.disclosureImg.setImageResource(R.drawable.open);
holder.disclosureImg.setVisibility(View.VISIBLE);
} else if (!element.isHasChildren()) {
holder.disclosureImg.setImageResource(R.drawable.close);
holder.disclosureImg.setVisibility(View.INVISIBLE);
}
return convertView;
}
/**
* 优化Holder
*
* @author carrey
*/
static class ViewHolder {
ImageView disclosureImg;
TextView contentText;
}
}
