简介及效果

Tree View; Mind map; Think map; tree map; 树状图；思维导图；

目前没发现比较好的Android树状图开源控件，于是决定自己写一个开源控件，对比了一下市面上关于思维导图或者树状图显示（如xMind，mind master等）的app，本文开源框架并不逊色。本控件实现了丝滑的放缩、移动、自动动画回归屏幕中心、子节点布局自定义等优点。
在我的另相关一篇文章介绍原理

github连接: https://github.com/guaishouN/android-tree-view.git

### 使用步骤：

下面说明中Animal类是仅仅用于举例的bean

public class Animal {
    public int headId;
    public String name;
}

按照以下四个步骤使用该开源控件

1 通过继承 TreeViewAdapter实现节点数据与节点视图的绑定

public class AnimalTreeViewAdapter extends TreeViewAdapter<Animal> {
    private DashLine dashLine =  new DashLine(Color.parseColor("#F06292"),6);
    @Override
    public TreeViewHolder<Animal> onCreateViewHolder(@NonNull ViewGroup viewGroup, NodeModel<Animal> node) {
        //TODO in inflate item view
        NodeBaseLayoutBinding nodeBinding = NodeBaseLayoutBinding.inflate(LayoutInflater.from(viewGroup.getContext()),viewGroup,false);
        return new TreeViewHolder<>(nodeBinding.getRoot(),node);
    }

    @Override
    public void onBindViewHolder(@NonNull TreeViewHolder<Animal> holder) {
        //TODO get view and node from holder, and then control your item view
        View itemView = holder.getView();
        NodeModel<Animal> node = holder.getNode();
		...
    }

    @Override
    public Baseline onDrawLine(DrawInfo drawInfo) {
        // TODO If you return an BaseLine, line will be draw by the return one instead of TreeViewLayoutManager's
		// if(...){
        //   ...
        // 	 return dashLine;
   		// }
        return null;
    }
}

2 配置LayoutManager。主要设置布局风格（向右展开或垂直向下展开）、父节点与子节点的间隙、子节点间的间隙、节点间的连线（已经实现了直线、光滑曲线、虚线、根状线，也可通过BaseLine实现你自己的连线）

int space_50dp = 50;
int space_20dp = 20;
//choose a demo line or a customs line. StraightLine, PointedLine, DashLine, SmoothLine are available.
Baseline line =  new DashLine(Color.parseColor("#4DB6AC"),8);
//choose layoout manager. VerticalTreeLayoutManager,RightTreeLayoutManager are available.
TreeLayoutManager treeLayoutManager = new RightTreeLayoutManager(this,space_50dp,space_20dp,line);

3 把Adapter和LayoutManager设置到你的树状图

...
treeView = findViewById(R.id.tree_view);   
TreeViewAdapter adapter = new AnimlTreeViewAdapter();
treeView.setAdapter(adapter);
treeView.setTreeLayoutManager(treeLayoutManager);
...

4 设置节点数据

//Create a TreeModel by using a root node.
NodeModel<Animal> node0 = new NodeModel<>(new Animal(R.drawable.ic_01,"root"));
TreeModel<Animal> treeModel = new TreeModel<>(root);

//Other nodes.
NodeModel<Animal> node1 = new NodeModel<>(new Animal(R.drawable.ic_02,"sub0"));
NodeModel<Animal> node2 = new NodeModel<>(new Animal(R.drawable.ic_03,"sub1"));
NodeModel<Animal> node3 = new NodeModel<>(new Animal(R.drawable.ic_04,"sub2"));
NodeModel<Animal> node4 = new NodeModel<>(new Animal(R.drawable.ic_05,"sub3"));
NodeModel<Animal> node5 = new NodeModel<>(new Animal(R.drawable.ic_06,"sub4"));


//Build the relationship between parent node and childs,like:
//treeModel.add(parent, child1, child2, ...., childN);
treeModel.add(node0, node1, node2);
treeModel.add(node1, node3, node4);
treeModel.add(node2, node5);

//finally set this treeModel to the adapter
adapter.setTreeModel(treeModel);

写在最后

目前只写了垂直向下布局及向右展开布局，其他的还得花时间。对于线的实现只是实现了几种，也还得丰富。在自定义自己的BaseLine线时，Android初学者注意因为画线动作是在View的onDraw(canvas)中的，所以在里面不要new对象，不要任何耗时操作。

这个项目如果有人用就会持续更新下去。喜欢点个赞，谢谢。