Terminal.Gui/UICatalog/Scenarios/TreeUseCases.cs

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using Terminal.Gui;
using Terminal.Gui.Trees;

namespace UICatalog.Scenarios {
	[ScenarioMetadata (Name: "Tree View", Description: "Simple tree view examples.")]
	[ScenarioCategory ("Controls"), ScenarioCategory ("TreeView")]
	public class TreeUseCases : Scenario {

		View currentTree;

		public override void Setup ()
		{
			Win.Title = this.GetName ();
			Win.Y = 1; // menu
			Win.Height = Dim.Fill (1); // status bar
			Application.Top.LayoutSubviews ();

			var menu = new MenuBar (new MenuBarItem [] {
				new MenuBarItem ("_File", new MenuItem [] {
					new MenuItem ("_Quit", "", () => Quit()),
				}),
				new MenuBarItem ("_Scenarios", new MenuItem [] {
					new MenuItem ("_Simple Nodes", "", () => LoadSimpleNodes()),
					new MenuItem ("_Rooms", "", () => LoadRooms()),
					new MenuItem ("_Armies With Builder", "", () => LoadArmies(false)),
					new MenuItem ("_Armies With Delegate", "", () => LoadArmies(true)),
				}),
			});

			Application.Top.Add (menu);

			var statusBar = new StatusBar (new StatusItem [] {
				new StatusItem(Key.CtrlMask | Key.Q, "~^Q~ Quit", () => Quit()),
			});

			Application.Top.Add (statusBar);

			// Start with the most basic use case
			LoadSimpleNodes ();
		}

		// Your data class
		private class House : TreeNode {

			// Your properties
			public string Address { get; set; }
			public List<Room> Rooms { get; set; }

			// ITreeNode member:
			public override IList<ITreeNode> Children => Rooms.Cast<ITreeNode> ().ToList ();

			public override string Text { get => Address; set => Address = value; }
		}
		private class Room : TreeNode {

			public string Name { get; set; }

			public override string Text { get => Name; set { Name = value; } }
		}

		private void LoadRooms ()
		{
			var myHouse = new House () {
				Address = "23 Nowhere Street",
				Rooms = new List<Room>{
		    new Room(){Name = "Ballroom"},
		    new Room(){Name = "Bedroom 1"},
		    new Room(){Name = "Bedroom 2"}
		}
			};

			if (currentTree != null) {
				Win.Remove (currentTree);
				currentTree.Dispose ();
			}


			var tree = new TreeView () {
				X = 0,
				Y = 0,
				Width = 40,
				Height = 20
			};

			Win.Add (tree);

			tree.AddObject (myHouse);

			currentTree = tree;
		}



		private abstract class GameObject {

		}
		private class Army : GameObject {
			public string Designation { get; set; }
			public List<Unit> Units { get; set; }


			public override string ToString ()
			{
				return Designation;
			}
		}

		private class Unit : GameObject {
			public string Name { get; set; }
			public override string ToString ()
			{
				return Name;
			}
		}

		private class GameObjectTreeBuilder : ITreeBuilder<GameObject> {
			public bool SupportsCanExpand => true;

			public bool CanExpand (GameObject model)
			{
				return model is Army;
			}

			public IEnumerable<GameObject> GetChildren (GameObject model)
			{
				if (model is Army a) {
					return a.Units;
				}

				return Enumerable.Empty<GameObject> ();
			}
		}


		private void LoadArmies (bool useDelegate)
		{
			var army1 = new Army () {
				Designation = "3rd Infantry",
				Units = new List<Unit>{
		    new Unit(){Name = "Orc"},
		    new Unit(){Name = "Troll"},
		    new Unit(){Name = "Goblin"},
		}
			};

			if (currentTree != null) {
				Win.Remove (currentTree);
				currentTree.Dispose ();
			}


			var tree = new TreeView<GameObject> () {
				X = 0,
				Y = 0,
				Width = 40,
				Height = 20
			};

			if (useDelegate) {
				tree.TreeBuilder = new DelegateTreeBuilder<GameObject> ((o) => o is Army a ? a.Units : Enumerable.Empty<GameObject> ());
			} else {
				tree.TreeBuilder = new GameObjectTreeBuilder ();
			}

			Win.Add (tree);

			tree.AddObject (army1);

			currentTree = tree;
		}

		private void Quit ()
		{
			Application.RequestStop ();
		}

		private void LoadSimpleNodes ()
		{
			if (currentTree != null) {
				Win.Remove (currentTree);
				currentTree.Dispose ();
			}


			var tree = new TreeView () {
				X = 0,
				Y = 0,
				Width = 40,
				Height = 20
			};

			Win.Add (tree);

			var root1 = new TreeNode ("Root1");
			root1.Children.Add (new TreeNode ("Child1.1"));
			root1.Children.Add (new TreeNode ("Child1.2"));

			var root2 = new TreeNode ("Root2");
			root2.Children.Add (new TreeNode ("Child2.1"));
			root2.Children.Add (new TreeNode ("Child2.2"));

			tree.AddObject (root1);
			tree.AddObject (root2);

			currentTree = tree;

		}
	}
}