Terminal.Gui/UICatalog/Scenarios/DynamicStatusBar.cs

using System.Text;
using System;
using System.Collections;
using System.Collections.Generic;
using System.ComponentModel;
using System.Reflection;
using System.Runtime.CompilerServices;
using Terminal.Gui;

namespace UICatalog.Scenarios;
[ScenarioMetadata (Name: "Dynamic StatusBar", Description: "Demonstrates how to add and remove a StatusBar and change items dynamically.")]
[ScenarioCategory ("Top Level Windows")]
public class DynamicStatusBar : Scenario {
	public override void Init ()
	{
		Application.Init ();
		Application.Top.Add (new DynamicStatusBarSample () { Title = $"{Application.QuitKey} to Quit - Scenario: {GetName ()}" });
	}

	public class DynamicStatusItemList {
		public string Title { get; set; }
		public StatusItem StatusItem { get; set; }

		public DynamicStatusItemList () { }

		public DynamicStatusItemList (string title, StatusItem statusItem)
		{
			Title = title;
			StatusItem = statusItem;
		}

		public override string ToString () => $"{Title}, {StatusItem}";
	}

	public class DynamicStatusItem {
		public string title = "New";
		public string action = "";
		public string shortcut;

		public DynamicStatusItem () { }

		public DynamicStatusItem (string title)
		{
			this.title = title;
		}

		public DynamicStatusItem (string title, string action, string shortcut = null)
		{
			this.title = title;
			this.action = action;
			this.shortcut = shortcut;
		}
	}

	public class DynamicStatusBarSample : Window {
		StatusBar _statusBar;
		StatusItem _currentStatusItem;
		int _currentSelectedStatusBar = -1;
		StatusItem _currentEditStatusItem;
		ListView _lstItems;

		public DynamicStatusItemModel DataContext { get; set; }

		public DynamicStatusBarSample () : base ()
		{
			DataContext = new DynamicStatusItemModel ();

			var _frmDelimiter = new FrameView ("Shortcut Delimiter:") {
				X = Pos.Center (),
				Y = 0,
				Width = 25,
				Height = 4
			};

			var _txtDelimiter = new TextField ($"{StatusBar.ShortcutDelimiter}") {
				X = Pos.Center (),
				Width = 2,
			};
			_txtDelimiter.TextChanged += (s, _) => StatusBar.ShortcutDelimiter = _txtDelimiter.Text.ToRunes () [0];
			_frmDelimiter.Add (_txtDelimiter);

			Add (_frmDelimiter);

			var _frmStatusBar = new FrameView ("Items:") {
				Y = 5,
				Width = Dim.Percent (50),
				Height = Dim.Fill (2)
			};

			var _btnAddStatusBar = new Button ("Add a StatusBar") {
				Y = 1,
			};
			_frmStatusBar.Add (_btnAddStatusBar);

			var _btnRemoveStatusBar = new Button ("Remove a StatusBar") {
				Y = 1
			};
			_btnRemoveStatusBar.X = Pos.AnchorEnd () - (Pos.Right (_btnRemoveStatusBar) - Pos.Left (_btnRemoveStatusBar));
			_frmStatusBar.Add (_btnRemoveStatusBar);

			var _btnAdd = new Button (" Add  ") {
				Y = Pos.Top (_btnRemoveStatusBar) + 2,
			};
			_btnAdd.X = Pos.AnchorEnd () - (Pos.Right (_btnAdd) - Pos.Left (_btnAdd));
			_frmStatusBar.Add (_btnAdd);

			_lstItems = new ListView (new List<DynamicStatusItemList> ()) {
				ColorScheme = Colors.Dialog,
				Y = Pos.Top (_btnAddStatusBar) + 2,
				Width = Dim.Fill () - Dim.Width (_btnAdd) - 1,
				Height = Dim.Fill (),
			};
			_frmStatusBar.Add (_lstItems);

			var _btnRemove = new Button ("Remove") {
				X = Pos.Left (_btnAdd),
				Y = Pos.Top (_btnAdd) + 1
			};
			_frmStatusBar.Add (_btnRemove);

			var _btnUp = new Button ("^") {
				X = Pos.Right (_lstItems) + 2,
				Y = Pos.Top (_btnRemove) + 2
			};
			_frmStatusBar.Add (_btnUp);

			var _btnDown = new Button ("v") {
				X = Pos.Right (_lstItems) + 2,
				Y = Pos.Top (_btnUp) + 1
			};
			_frmStatusBar.Add (_btnDown);

			Add (_frmStatusBar);

			var _frmStatusBarDetails = new DynamicStatusBarDetails ("StatusBar Item Details:") {
				X = Pos.Right (_frmStatusBar),
				Y = Pos.Top (_frmStatusBar),
				Width = Dim.Fill (),
				Height = Dim.Fill (4)
			};
			Add (_frmStatusBarDetails);

			_btnUp.Clicked += (s, e) => {
				var i = _lstItems.SelectedItem;
				var statusItem = DataContext.Items.Count > 0 ? DataContext.Items [i].StatusItem : null;
				if (statusItem != null) {
					var items = _statusBar.Items;
					if (i > 0) {
						items [i] = items [i - 1];
						items [i - 1] = statusItem;
						DataContext.Items [i] = DataContext.Items [i - 1];
						DataContext.Items [i - 1] = new DynamicStatusItemList (statusItem.Title, statusItem);
						_lstItems.SelectedItem = i - 1;
						_statusBar.SetNeedsDisplay ();
					}
				}
			};

			_btnDown.Clicked += (s, e) => {
				var i = _lstItems.SelectedItem;
				var statusItem = DataContext.Items.Count > 0 ? DataContext.Items [i].StatusItem : null;
				if (statusItem != null) {
					var items = _statusBar.Items;
					if (i < items.Length - 1) {
						items [i] = items [i + 1];
						items [i + 1] = statusItem;
						DataContext.Items [i] = DataContext.Items [i + 1];
						DataContext.Items [i + 1] = new DynamicStatusItemList (statusItem.Title, statusItem);
						_lstItems.SelectedItem = i + 1;
						_statusBar.SetNeedsDisplay ();
					}
				}
			};

			var _btnOk = new Button ("Ok") {
				X = Pos.Right (_frmStatusBar) + 20,
				Y = Pos.Bottom (_frmStatusBarDetails),
			};
			Add (_btnOk);

			var _btnCancel = new Button ("Cancel") {
				X = Pos.Right (_btnOk) + 3,
				Y = Pos.Top (_btnOk),
			};
			_btnCancel.Clicked += (s, e) => {
				SetFrameDetails (_currentEditStatusItem);
			};
			Add (_btnCancel);

			_lstItems.SelectedItemChanged += (s, e) => {
				SetFrameDetails ();
			};

			_btnOk.Clicked += (s, e) => {
				if (string.IsNullOrEmpty (_frmStatusBarDetails._txtTitle.Text) && _currentEditStatusItem != null) {
					MessageBox.ErrorQuery ("Invalid title", "Must enter a valid title!.", "Ok");
				} else if (_currentEditStatusItem != null) {
					_frmStatusBarDetails._txtTitle.Text = SetTitleText (
						_frmStatusBarDetails._txtTitle.Text, _frmStatusBarDetails._txtShortcut.Text);
					var statusItem = new DynamicStatusItem (_frmStatusBarDetails._txtTitle.Text,
						_frmStatusBarDetails._txtAction.Text,
						_frmStatusBarDetails._txtShortcut.Text);
					UpdateStatusItem (_currentEditStatusItem, statusItem, _lstItems.SelectedItem);
				}
			};

			_btnAdd.Clicked += (s, e) => {
				if (StatusBar == null) {
					MessageBox.ErrorQuery ("StatusBar Bar Error", "Must add a StatusBar first!", "Ok");
					_btnAddStatusBar.SetFocus ();
					return;
				}

				var frameDetails = new DynamicStatusBarDetails ();
				var item = frameDetails.EnterStatusItem ();
				if (item == null) {
					return;
				}

				StatusItem newStatusItem = CreateNewStatusBar (item);
				_currentSelectedStatusBar++;
				_statusBar.AddItemAt (_currentSelectedStatusBar, newStatusItem);
				DataContext.Items.Add (new DynamicStatusItemList (newStatusItem.Title, newStatusItem));
				_lstItems.MoveDown ();
				SetFrameDetails ();
			};

			_btnRemove.Clicked += (s, e) => {
				var statusItem = DataContext.Items.Count > 0 ? DataContext.Items [_lstItems.SelectedItem].StatusItem : null;
				if (statusItem != null) {
					_statusBar.RemoveItem (_currentSelectedStatusBar);
					DataContext.Items.RemoveAt (_lstItems.SelectedItem);
					if (_lstItems.Source.Count > 0 && _lstItems.SelectedItem > _lstItems.Source.Count - 1) {
						_lstItems.SelectedItem = _lstItems.Source.Count - 1;
					}
					_lstItems.SetNeedsDisplay ();
					SetFrameDetails ();
				}
			};

			_lstItems.Enter += (s, e) => {
				var statusItem = DataContext.Items.Count > 0 ? DataContext.Items [_lstItems.SelectedItem].StatusItem : null;
				SetFrameDetails (statusItem);
			};

			_btnAddStatusBar.Clicked += (s, e) => {
				if (_statusBar != null) {
					return;
				}

				_statusBar = new StatusBar ();
				Add (_statusBar);
			};

			_btnRemoveStatusBar.Clicked += (s, e) => {
				if (_statusBar == null) {
					return;
				}

				Remove (_statusBar);
				_statusBar = null;
				DataContext.Items = new List<DynamicStatusItemList> ();
				_currentStatusItem = null;
				_currentSelectedStatusBar = -1;
				SetListViewSource (_currentStatusItem, true);
				SetFrameDetails (null);
			};

			SetFrameDetails ();

			var ustringConverter = new UStringValueConverter ();
			var listWrapperConverter = new ListWrapperConverter ();

			var lstItems = new Binding (this, "Items", _lstItems, "Source", listWrapperConverter);

			void SetFrameDetails (StatusItem statusItem = null)
			{
				StatusItem newStatusItem;

				if (statusItem == null) {
					newStatusItem = DataContext.Items.Count > 0 ? DataContext.Items [_lstItems.SelectedItem].StatusItem : null;
				} else {
					newStatusItem = statusItem;
				}

				_currentEditStatusItem = newStatusItem;
				_frmStatusBarDetails.EditStatusItem (newStatusItem);
				var f = _btnOk.Enabled == _frmStatusBarDetails.Enabled;
				if (!f) {
					_btnOk.Enabled = _frmStatusBarDetails.Enabled;
					_btnCancel.Enabled = _frmStatusBarDetails.Enabled;
				}
			}

			void SetListViewSource (StatusItem _currentStatusItem, bool fill = false)
			{
				DataContext.Items = new List<DynamicStatusItemList> ();
				var statusItem = _currentStatusItem;
				if (!fill) {
					return;
				}
				if (statusItem != null) {
					foreach (var si in _statusBar.Items) {
						DataContext.Items.Add (new DynamicStatusItemList (si.Title, si));
					}
				}
			}

			StatusItem CreateNewStatusBar (DynamicStatusItem item)
			{
				var newStatusItem = new StatusItem (ShortcutHelper.GetShortcutFromTag (
					item.shortcut, StatusBar.ShortcutDelimiter),
					item.title, _frmStatusBarDetails.CreateAction (item));

				return newStatusItem;
			}

			void UpdateStatusItem (StatusItem _currentEditStatusItem, DynamicStatusItem statusItem, int index)
			{
				_currentEditStatusItem = CreateNewStatusBar (statusItem);
				_statusBar.Items [index] = _currentEditStatusItem;
				if (DataContext.Items.Count == 0) {
					DataContext.Items.Add (new DynamicStatusItemList (_currentEditStatusItem.Title, _currentEditStatusItem));
				}
				DataContext.Items [index] = new DynamicStatusItemList (_currentEditStatusItem.Title, _currentEditStatusItem);
				SetFrameDetails (_currentEditStatusItem);
			}

			//_frmStatusBarDetails.Initialized += (s, e) => _frmStatusBarDetails.Enabled = false;
		}

		public static string SetTitleText (string title, string shortcut)
		{
			var txt = title;
			var split = title.Split ('~');
			if (split.Length > 1) {
				txt = split [2].Trim (); ;
			}
			if (string.IsNullOrEmpty (shortcut)) {
				return txt;
			}

			return $"~{shortcut}~ {txt}";
		}
	}

	public class DynamicStatusBarDetails : FrameView {
		public StatusItem _statusItem;
		public TextField _txtTitle;
		public TextView _txtAction;
		public TextField _txtShortcut;

		public DynamicStatusBarDetails (StatusItem statusItem = null) : this (statusItem == null ? "Adding New StatusBar Item." : "Editing StatusBar Item.")
		{
			_statusItem = statusItem;
		}

		public DynamicStatusBarDetails (string title) : base (title)
		{
			var _lblTitle = new Label ("Title:") {
				Y = 1
			};
			Add (_lblTitle);

			_txtTitle = new TextField () {
				X = Pos.Right (_lblTitle) + 4,
				Y = Pos.Top (_lblTitle),
				Width = Dim.Fill ()
			};
			Add (_txtTitle);

			var _lblAction = new Label ("Action:") {
				X = Pos.Left (_lblTitle),
				Y = Pos.Bottom (_lblTitle) + 1
			};
			Add (_lblAction);

			_txtAction = new TextView () {
				X = Pos.Left (_txtTitle),
				Y = Pos.Top (_lblAction),
				Width = Dim.Fill (),
				Height = 5
			};
			Add (_txtAction);

			var _lblShortcut = new Label ("Shortcut:") {
				X = Pos.Left (_lblTitle),
				Y = Pos.Bottom (_txtAction) + 1
			};
			Add (_lblShortcut);

			_txtShortcut = new TextField () {
				X = Pos.X (_txtAction),
				Y = Pos.Y (_lblShortcut),
				Width = Dim.Fill (),
				ReadOnly = true
			};
			_txtShortcut.KeyDown += (s, e) => {
				if (!ProcessKey (e)) {
					return;
				}

				if (CheckShortcut (e.KeyCode, true)) {
					e.Handled = true;
				}
			};

			bool ProcessKey (Key ev)
			{
				switch (ev.KeyCode) {
				case KeyCode.CursorUp:
				case KeyCode.CursorDown:
				case KeyCode.Tab:
				case KeyCode.Tab | KeyCode.ShiftMask:
					return false;
				}

				return true;
			}

			bool CheckShortcut (KeyCode k, bool pre)
			{
				var m = _statusItem != null ? _statusItem : new StatusItem (k, "", null);
				if (pre && !ShortcutHelper.PreShortcutValidation (k)) {
					_txtShortcut.Text = "";
					return false;
				}
				if (!pre) {
					if (!ShortcutHelper.PostShortcutValidation (ShortcutHelper.GetShortcutFromTag (
						_txtShortcut.Text, StatusBar.ShortcutDelimiter))) {
						_txtShortcut.Text = "";
						return false;
					}
					return true;
				}
				_txtShortcut.Text = Key.ToString (k, StatusBar.ShortcutDelimiter);//ShortcutHelper.GetShortcutTag (k, StatusBar.ShortcutDelimiter);

				return true;
			}

			_txtShortcut.KeyUp += (s, e) => {
				if (CheckShortcut (e.KeyCode, true)) {
					e.Handled = true;
				}
			};
			Add (_txtShortcut);

			var _btnShortcut = new Button ("Clear Shortcut") {
				X = Pos.X (_lblShortcut),
				Y = Pos.Bottom (_txtShortcut) + 1
			};
			_btnShortcut.Clicked += (s, e) => {
				_txtShortcut.Text = "";
			};
			Add (_btnShortcut);
		}

		public DynamicStatusItem EnterStatusItem ()
		{
			var valid = false;

			if (_statusItem == null) {
				var m = new DynamicStatusItem ();
				_txtTitle.Text = m.title;
				_txtAction.Text = m.action;
			} else {
				EditStatusItem (_statusItem);
			}

			var _btnOk = new Button ("Ok") {
				IsDefault = true,
			};
			_btnOk.Clicked += (s, e) => {
				if (string.IsNullOrEmpty (_txtTitle.Text)) {
					MessageBox.ErrorQuery ("Invalid title", "Must enter a valid title!.", "Ok");
				} else {
					if (!string.IsNullOrEmpty (_txtShortcut.Text)) {
						_txtTitle.Text = DynamicStatusBarSample.SetTitleText (
							_txtTitle.Text, _txtShortcut.Text);
					}
					valid = true;
					Application.RequestStop ();
				}
			};
			var _btnCancel = new Button ("Cancel");
			_btnCancel.Clicked += (s, e) => {
				_txtTitle.Text = string.Empty;
				Application.RequestStop ();
			};
			var _dialog = new Dialog (_btnOk, _btnCancel) { Title = "Enter the menu details." };

			Width = Dim.Fill ();
			Height = Dim.Fill () - 1;
			_dialog.Add (this);
			_txtTitle.SetFocus ();
			_txtTitle.CursorPosition = _txtTitle.Text.Length;
			Application.Run (_dialog);

			if (valid) {
				return new DynamicStatusItem (_txtTitle.Text, _txtAction.Text, _txtShortcut.Text);
			} else {
				return null;
			}
		}

		public void EditStatusItem (StatusItem statusItem)
		{
			if (statusItem == null) {
				Enabled = false;
				CleanEditStatusItem ();
				return;
			} else {
				Enabled = true;
			}
			_statusItem = statusItem;
			_txtTitle.Text = statusItem?.Title ?? "";
			_txtAction.Text = statusItem != null && statusItem.Action != null ? GetTargetAction (statusItem.Action) : string.Empty;
			_txtShortcut.Text = Key.ToString ((KeyCode)statusItem.Shortcut, StatusBar.ShortcutDelimiter);//ShortcutHelper.GetShortcutTag (statusItem.Shortcut, StatusBar.ShortcutDelimiter) ?? "";
		}

		void CleanEditStatusItem ()
		{
			_txtTitle.Text = "";
			_txtAction.Text = "";
			_txtShortcut.Text = "";
		}

		string GetTargetAction (Action action)
		{
			var me = action.Target;

			if (me == null) {
				throw new ArgumentException ();
			}
			object v = new object ();
			foreach (var field in me.GetType ().GetFields ()) {
				if (field.Name == "item") {
					v = field.GetValue (me);
				}
			}
			return v == null || !(v is DynamicStatusItem item) ? string.Empty : item.action;
		}

		public Action CreateAction (DynamicStatusItem item)
		{
			return new Action (() => MessageBox.ErrorQuery (item.title, item.action, "Ok"));
		}
	}

	public class DynamicStatusItemModel : INotifyPropertyChanged {
		public event PropertyChangedEventHandler PropertyChanged;

		private string statusBar;
		private List<DynamicStatusItemList> items;

		public string StatusBar {
			get => statusBar;
			set {
				if (value != statusBar) {
					statusBar = value;
					PropertyChanged?.Invoke (this, new PropertyChangedEventArgs (GetPropertyName ()));
				}
			}
		}

		public List<DynamicStatusItemList> Items {
			get => items;
			set {
				if (value != items) {
					items = value;
					PropertyChanged?.Invoke (this, new PropertyChangedEventArgs (GetPropertyName ()));
				}
			}
		}

		public DynamicStatusItemModel ()
		{
			Items = new List<DynamicStatusItemList> ();
		}

		public string GetPropertyName ([CallerMemberName] string propertyName = null)
		{
			return propertyName;
		}
	}

	public interface IValueConverter {
		object Convert (object value, object parameter = null);
	}

	public class Binding {
		public View Target { get; private set; }
		public View Source { get; private set; }

		public string SourcePropertyName { get; private set; }
		public string TargetPropertyName { get; private set; }

		private object sourceDataContext;
		private PropertyInfo sourceBindingProperty;
		private IValueConverter valueConverter;

		public Binding (View source, string sourcePropertyName, View target, string targetPropertyName, IValueConverter valueConverter = null)
		{
			Target = target;
			Source = source;
			SourcePropertyName = sourcePropertyName;
			TargetPropertyName = targetPropertyName;
			sourceDataContext = Source.GetType ().GetProperty ("DataContext").GetValue (Source);
			sourceBindingProperty = sourceDataContext.GetType ().GetProperty (SourcePropertyName);
			this.valueConverter = valueConverter;
			UpdateTarget ();

			var notifier = ((INotifyPropertyChanged)sourceDataContext);
			if (notifier != null) {
				notifier.PropertyChanged += (s, e) => {
					if (e.PropertyName == SourcePropertyName) {
						UpdateTarget ();
					}
				};
			}
		}

		private void UpdateTarget ()
		{
			try {
				var sourceValue = sourceBindingProperty.GetValue (sourceDataContext);
				if (sourceValue == null) {
					return;
				}

				var finalValue = valueConverter?.Convert (sourceValue) ?? sourceValue;

				var targetProperty = Target.GetType ().GetProperty (TargetPropertyName);
				targetProperty.SetValue (Target, finalValue);
			} catch (Exception ex) {
				MessageBox.ErrorQuery ("Binding Error", $"Binding failed: {ex}.", "Ok");
			}
		}
	}

	public class ListWrapperConverter : IValueConverter {
		public object Convert (object value, object parameter = null)
		{
			return new ListWrapper ((IList)value);
		}
	}

	public class UStringValueConverter : IValueConverter {
		public object Convert (object value, object parameter = null)
		{
			var data = Encoding.ASCII.GetBytes (value.ToString ());
			return StringExtensions.ToString (data);
		}
	}
}