blessed-contrib/lib/widget/tree.js

Build dashboards (or any other application) using ascii/ansi art and javascript.

'use strict';
var blessed = require('blessed'),
  Node = blessed.Node,
  Box = blessed.Box;

function Tree(options) {
  if (!(this instanceof Node)) {
    return new Tree(options);
  }

  var self = this;
  options = options || {};
  options.bold = true;
  this.options = options;
  this.data = {};
  this.nodeLines = [];
  this.lineNbr = 0;
  Box.call(this, options);

  options.extended = options.extended || false;
  options.keys = options.keys || ['+', 'space', 'enter'];

  options.template = options.template || {};
  options.template.extend = options.template.extend || ' [+]';
  options.template.retract = options.template.retract || ' [-]';
  options.template.lines = options.template.lines || false;

  // Do not set height, since this create a bug where the first line is not always displayed
  this.rows = blessed.list({
    top: 1,
    width: 0,
    left: 1,
    style: options.style,
    padding: options.padding,
    keys: true,
    tags: options.tags,
    input: options.input,
    vi: options.vi,
    ignoreKeys: options.ignoreKeys,
    scrollable: options.scrollable,
    mouse: options.mouse,
    selectedBg: options.selectedBg || 'blue',
    selectedFg: options.selectedFg || 'black',
  });

  this.append(this.rows);

  this.rows.key(options.keys, function() {
    var selectedNode = self.nodeLines[this.getItemIndex(this.selected)];
    if (selectedNode.children) {
      selectedNode.extended = !selectedNode.extended;
      self.setData(self.data);
      self.screen.render();
    }

    self.emit('select', selectedNode, this.getItemIndex(this.selected));
  });

}

Tree.prototype = Object.create(Box.prototype);

Tree.prototype.walk = function(node, treeDepth) {

  var lines = [];

  if (!node.parent) {
    // root level
    this.lineNbr = 0;
    this.nodeLines.length = 0;
    node.parent = null;
  }

  if (treeDepth === '' && node.name) {
    this.lineNbr = 0;
    this.nodeLines[this.lineNbr++] = node;
    lines.push(node.name);
    treeDepth = ' ';
  }

  node.depth = treeDepth.length - 1;

  if (node.children && node.extended) {

    var i = 0;

    if (typeof node.children === 'function')
      node.childrenContent = node.children(node);

    if (!node.childrenContent)
      node.childrenContent = node.children;

    for (var child in node.childrenContent) {

      if (!node.childrenContent[child].name)
        node.childrenContent[child].name = child;

      child = node.childrenContent[child];
      child.parent = node;
      child.position = i++;

      if (typeof child.extended === 'undefined')
        child.extended = this.options.extended;

      if (typeof child.children === 'function')
        child.childrenContent = child.children(child);
      else
        child.childrenContent = child.children;

      var isLastChild = child.position === Object.keys(child.parent.childrenContent).length - 1;
      var treePrefix;
      var suffix = '';
      if (isLastChild)
        treePrefix = '└';
      else
        treePrefix = '├';

      if (!child.childrenContent || Object.keys(child.childrenContent).length === 0) {
        treePrefix += '─';
      } else if (child.extended) {
        treePrefix += '┬';
        suffix = this.options.template.retract;
      } else {
        treePrefix += '─';
        suffix = this.options.template.extend;
      }

      if (!this.options.template.lines) treePrefix = '|-';
      if (this.options.template.spaces) treePrefix = ' ';

      lines.push(treeDepth + treePrefix + child.name + suffix);

      this.nodeLines[this.lineNbr++] = child;

      var parentTree;
      if (isLastChild || !this.options.template.lines)
        parentTree = treeDepth + ' ';
      else
        parentTree = treeDepth + '│';

      lines = lines.concat(this.walk(child, parentTree));
    }
  }
  return lines;
};

Tree.prototype.focus = function() {
  this.rows.focus();
};

Tree.prototype.render = function() {
  if (this.screen.focused === this.rows) this.rows.focus();

  this.rows.width = this.width - 3;
  this.rows.height = this.height - 3;
  Box.prototype.render.call(this);
};

Tree.prototype.setData = function(nodes) {
  this.data = nodes;
  this.rows.setItems(this.walk(nodes, ''));
};

Tree.prototype.type = 'tree';

module.exports = Tree;