Android TreeView using ListViews

TreeElement.java

public interface TreeElement extends Serializable {
public void addChild(TreeElement child);

public String getId();

public void setId(String id);

public String getOutlineTitle();

public void setOutlineTitle(String outlineTitle);

public boolean isHasParent();

public void setHasParent(boolean hasParent);

public boolean isHasChild();

public void setHasChild(boolean hasChild);

public int getLevel();

public void setLevel(int level);

public boolean isExpanded();

public void setExpanded(boolean expanded);

public ArrayList<TreeElement> getChildList();

public TreeElement getParent();

public void setParent(TreeElement parent);
}

TreeElementImpl.java

import java.util.ArrayList;

public class TreeElementImpl implements TreeElement {
private String id;
private String outlineTitle;
private boolean hasParent;
private boolean hasChild;
private TreeElement parent;
private int level;
private final List<TreeElement> childList = new ArrayList<>();
private boolean expanded;

public TreeElementImpl(final String id, final String outlineTitle) {
	super();
	this.id = id;
	this.outlineTitle = outlineTitle;
	this.level = 0;
	this.hasParent = true;
	this.hasChild = false;
	this.parent = null;
}

public TreeElementImpl(final String id, final String outlineTitle, final boolean hasParent, final boolean hasChild, final TreeElement parent, final int level, final boolean expanded) {
	super();
	this.id = id;
	this.outlineTitle = outlineTitle;
	this.hasParent = hasParent;
	this.hasChild = hasChild;
	this.parent = parent;
	if (parent != null)
		this.parent.getChildList().add(this);
	this.level = level;
	this.expanded = expanded;
}

@Override
public void addChild(final TreeElement child) {
	this.getChildList().add(child);
	this.setHasParent(false);
	this.setHasChild(true);
	child.setParent(this);
	child.setLevel(this.getLevel() + 1);
}

@Override
public String getId() {
	return this.id;
}

@Override
public void setId(final String id) {
	this.id = id;
}

@Override
public String getOutlineTitle() {
	return this.outlineTitle;
}

@Override
public void setOutlineTitle(final String outlineTitle) {
	this.outlineTitle = outlineTitle;
}

@Override
public boolean isHasParent() {
	return this.hasParent;
}

@Override
public void setHasParent(final boolean hasParent) {
	this.hasParent = hasParent;
}

@Override
public boolean isHasChild() {
	return this.hasChild;
}

@Override
public void setHasChild(final boolean hasChild) {
	this.hasChild = hasChild;
}

@Override
public int getLevel() {
	return this.level;
}

@Override
public void setLevel(final int level) {
	this.level = level;
}

@Override
public boolean isExpanded() {
	return this.expanded;
}

@Override
public void setExpanded(final boolean expanded) {
	this.expanded = expanded;
}

@Override
public ArrayList<TreeElement> getChildList() {
	return this.childList;
}

@Override
public TreeElement getParent() {
	return this.parent;
}

@Override
public void setParent(final TreeElement parent) {
	this.parent = parent;
}
}

TreeViewClassifAdapter.java

import android.widget.ListView;

public class TreeViewClassifAdapter extends BaseAdapter {
private static final int TREE_ELEMENT_PADDING_VAL = 25;
private List<TreeElement> fileList;
private Context context;
private Bitmap iconCollapse;
private Bitmap iconExpand;
private Dialog dialog;
private EditText textLabel;
private ListView treeView;

public TreeViewClassifAdapter(final Context context, final List<TreeElement> fileList, final Dialog dialog, final EditText textLabel, final ListView treeView) {
	this.context = context;
	this.fileList = fileList;
	this.dialog = dialog;
	this.textLabel = textLabel;
	this.treeView = treeView;
	iconCollapse = BitmapFactory.decodeResource(context.getResources(), R.drawable.x_treeview_outline_list_collapse);
	iconExpand = BitmapFactory.decodeResource(context.getResources(), R.drawable.x_treeview_outline_list_expand);
}

public List<TreeElement> getListData() {
	return this.fileList;
}

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

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

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

@Override
public View getView(int position, View convertView, ViewGroup parent) {
	ViewHolder holder;

	convertView = View.inflate(context, R.layout.x_treeview_classif_list_item, null);
	holder = new ViewHolder();
	holder.setTextView((TextView) convertView.findViewById(R.id.text));
	holder.setImageView((ImageView) convertView.findViewById(R.id.icon));
	convertView.setTag(holder);

	final TreeElement elem = (TreeElement) getItem(position);

	int level = elem.getLevel();
	holder.getIcon().setPadding(TREE_ELEMENT_PADDING_VAL * (level + 1), holder.icon.getPaddingTop(), 0, holder.icon.getPaddingBottom());
	holder.getText().setText(elem.getOutlineTitle());
	if (elem.isHasChild() && (elem.isExpanded() == false))
		holder.getIcon().setImageBitmap(iconCollapse);
	else if (elem.isHasChild() && (elem.isExpanded() == true))
		holder.getIcon().setImageBitmap(iconExpand);
	else if (!elem.isHasChild()) {
		holder.getIcon().setImageBitmap(iconCollapse);
		holder.getIcon().setVisibility(View.INVISIBLE);
	}

	IconClickListener iconListener = new IconClickListener(this, position);
	TextClickListener txtListener = new TextClickListener((ArrayList<TreeElement>) this.getListData(), position);
	holder.getIcon().setOnClickListener(iconListener);
	holder.getText().setOnClickListener(txtListener);
	return convertView;
}

private class ViewHolder {
	ImageView icon;
	TextView text;

	public TextView getText() {
		return this.text;
	}

	public void setTextView(TextView text) {
		this.text = text;
	}

	public ImageView getIcon() {
		return this.icon;
	}

	public void setImageView(ImageView icon) {
		this.icon = icon;
	}
}

/**
 * Listener For TreeElement Text Click
 */
private class TextClickListener implements View.OnClickListener {
	private ArrayList<TreeElement> list;
	private int position;

	public TextClickListener(ArrayList<TreeElement> list, int position) {
		this.list = list;
		this.position = position;
	}

	@Override
	public void onClick(View v) {
		treeView.setXValue(String.valueOf(list.get(position).getId()));
		dialog.dismiss();
	}
}

/**
 * Listener for TreeElement "Expand" button Click
 */
private class IconClickListener implements View.OnClickListener {
	private ArrayList<TreeElement> list;
	private TreeViewClassifAdapter adapter;
	private int position;

	public IconClickListener(TreeViewClassifAdapter adapter, int position) {
		this.list = (ArrayList<TreeElement>) adapter.getListData();
		this.adapter = adapter;
		this.position = position;
	}

	@Override
	public void onClick(View v) {
		if (!list.get(position).isHasChild())
			return;

		if (list.get(position).isExpanded()) {
			list.get(position).setExpanded(false);
			TreeElement element = list.get(position);
			ArrayList<TreeElement> temp = new ArrayList<TreeElement>();
			for (int i = position + 1; i < list.size(); i++) {
				if (element.getLevel() >= list.get(i).getLevel())
					break;
				temp.add(list.get(i));
			}
			list.removeAll(temp);
			adapter.notifyDataSetChanged();
		} else {
			TreeElement obj = list.get(position);
			obj.setExpanded(true);
			int level = obj.getLevel();
			int nextLevel = level + 1;

			for (TreeElement element : obj.getChildList()) {
				element.setLevel(nextLevel);
				element.setExpanded(false);
				list.add(position + 1, element);
			}
			adapter.notifyDataSetChanged();
		}
	}
}
}