TreeView implementation in Android.Now available on Jitpack:tada:

中文版

You can also see a more simple example.

• TreeView extends from ListView.

• DFS travel the expandable tree node, and convert it to List which adapt with TreeAdapter.

• Use SimpleTreeAdapter ot set different indentation on nodes of different depths.

• Use LinkedList to store node's children, see DefaultTreeNode.

1. Add it in your root build.gradle at the end of repositories:

	allprojects {
		repositories {
			...
			maven { url 'https://jitpack.io' }
		}
	}

2. Add the dependency

	dependencies {
	        implementation 'com.github.LeeReindeer:Tree2View:v0.1.2'
	}

1. Add in your xml:

Feel free to use it as ListView.

    <moe.leer.tree2view.TreeView
        android:id="@+id/tree_view"
        android:layout_marginTop="16dp"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:divider="#ffffff"
        android:dividerHeight="1px">

    </moe.leer.tree2view.TreeView>

2. Add children in Kotlin code(Java is similar whit it)

  var root :DefaultTreeNode? = DefaultTreeNode("Root")
  tree_view.root = root
  val child1 = DefaultTreeNode("Child1")
  val child2 = DefaultTreeNode("Child2")
  // After create a node your should immediately add it.
  root.addChild(child1)
  root.addChild(child2)
  val child3 = DefaultTreeNode("Child3")
  child1.addChild(child3)
  //whether the root's children is expanded by default
  tree_view.isRootVisible = true
  //animation
  tree_view.isDefaultAnimation = true

3. Add click listener and select listener

Tree2View has a default click listener, but it's ok to add your own.You can refer to here.

4. If you want to use customized item view, you should implement TreeAapater, like this:

public class FileTreeAdapter extends TreeAdapter<FileItem> {
  //resourceId is your customized view resourceId, please use RelativeLayout, and let view neighbour.
  public FileTreeAdapter(Context context, DefaultTreeNode root, int resourceId) {
    super(context, root, resourceId);
  }
  
    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
     //your code here
     //...
     //call padding for a better UI
     setPadding(holder.arrowIcon, depth, -1);
     //toggle your view's status here
     toggle(node, holder);
    }
    
    @Override
     public void toggle(Object... objects) {
     }

Then simply add:

  val adapter = FileTreeAdapter(this@MainActivity, root, R.layout.layout_file_tree_item)
  treeView.treeAdapter = adapter

Apache 2.0