Use this library

[polo2169]

Hi, I'm a beginner in java and I would like to use this library but I don't understand how to use it. The example is half explained, for example I don't understand what are the parent and child layouts. If you have just a working example it would help me a lot! Thanks

[AmrDeveloper]

Hello @polo2169,

First welcome to java and TreeView😄

I don't understand what are the parent and child layouts.

The tree is represented as roots and subnodes for example

- directory 1
  - file 1
  - directory 2
    - file 2 

Directory 1 node is a parent and has 2 children (file 1, directory 2) and directory 2 is also a parent of one child who is file 2, so to create this in java after creating 4 nodes you need to set the relation between them, so add file 2 node as a child in directory 2, and then add file 1 and directory 2 as children in directory 2

TreeNode directory1 = new TreeNode("Directory 1", R.layout.directory);
TreeNode directory2 = new TreeNode("Directory 2", R.layout.directory);
TreeNode file1 = new TreeNode("File 1", R.layout.file);
TreeNode file2 = new TreeNode("File 2", R.layout.file);

directory2.addChild(file2);
directory1.addChild(file1);
directory1.addChild(directory2);

This is how to use TreeView basically, if you have any problem with any example we can discuss it.

Thanks Amr Hesham

[polo2169]

Hi @AmrDeveloper, Thanks for your answer, unfortunately it doesn't work any better. The editor says "add String to first parameter to the constructor". I think I defined some things wrong but I followed the example.

[AmrDeveloper]

It weird @polo2169,

Make sure you used this import

import com.amrdeveloper.treeview.TreeNode;

Can you please write the error message in this line

treeViewAdapter.updateTreeNodes(roots);

[polo2169]

you are right I had the wrong import :/ I don't have any more errors! However, nothing is displayed during my test... I don't understand what I have to put in the layout R.layout.list_item_one I'm sorry I don't understand ahah

package fr.pdego.treeview2;

import androidx.appcompat.app.AppCompatActivity;
import androidx.recyclerview.widget.RecyclerView;

import android.os.Bundle;

import com.amrdeveloper.treeview.TreeNode;
import com.amrdeveloper.treeview.TreeViewAdapter;
import com.amrdeveloper.treeview.TreeViewHolderFactory;

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

public class MainActivity extends AppCompatActivity {
RecyclerView recyclerView;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        recyclerView=findViewById(R.id.recycler_view);
        TreeViewHolderFactory factory = (v, layout) -> {
            if (layout == R.layout.directory) return new CustomViewHolderOne(v);
            else if (layout == R.layout.file) return new CustomViewHolderTwo(v);
            else return new CustomViewHolderThree(v);
        };
        TreeViewAdapter treeViewAdapter = new TreeViewAdapter(factory);
        recyclerView.setAdapter(treeViewAdapter);
        TreeNode root1 = new TreeNode("Root1", R.layout.directory);
        root1.addChild(new TreeNode("Child1", R.layout.file));
        root1.addChild(new TreeNode("Child2", R.layout.file));

        List<TreeNode> roots = new ArrayList<>();
        roots.add(root1);

        treeViewAdapter.updateTreeNodes(roots);
    }
}

My view Holder

package fr.pdego.treeview2;

import android.view.View;

import androidx.annotation.NonNull;

import com.amrdeveloper.treeview.TreeNode;
import com.amrdeveloper.treeview.TreeViewHolder;

public class CustomViewHolderOne extends TreeViewHolder {

    public CustomViewHolderOne(@NonNull View itemView) {
        super(itemView);
    }

    @Override
    public void bindTreeNode(TreeNode node) {
        super.bindTreeNode(node);
        // Here you can bind your node and check if it selected or not
    }
}

My layouts

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_centerVertical="true"
    android:paddingLeft="10dp"
    android:paddingRight="10dp"
    android:paddingTop="10dp"
    android:paddingBottom="10dp">

    <ImageView
        android:id="@+id/image"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:src="@drawable/ic_folder" />

    <TextView
        android:id="@+id/text"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginLeft="10dp"
        android:layout_toRightOf="@id/image"
        android:text="List Item"
        android:textAppearance="@style/Base.TextAppearance.AppCompat.Small"
        android:textStyle="bold" />
</RelativeLayout>

Thank you for all your help!

[AmrDeveloper]

First of all roots should add to the roots list so if you want to show Directories 1 and 2 add them to the list

roots.add(directory1);
roots.add(directory2);

Then in your view holder, you should update the text view to show the value for example, think of it as an adapter

package fr.pdego.treeview2;

import android.view.View;

import androidx.annotation.NonNull;

import com.amrdeveloper.treeview.TreeNode;
import com.amrdeveloper.treeview.TreeViewHolder;

public class CustomViewHolderOne extends TreeViewHolder {

    private TextView text;

    public CustomViewHolderOne(@NonNull View itemView) {
        super(itemView);
        text = itemView.findViewById(R.id.text);
    }

    @Override
    public void bindTreeNode(TreeNode node) {
        super.bindTreeNode(node);
        text.setText(node.getValue().toString());
    }
}

After your first example work well, I suggest to run the example app and play with it to see the features, and if you have any question please feel free to ask

[polo2169]

I did it! Thank you so much for your help and for this really nice project!

[AmrDeveloper]

@polo2169 You're most welcome :D, enjoy using it