gui-cs.Terminal.Gui/UICatalog/Scenarios/CsvEditor.cs

using System;
using System.Collections.Generic;
using System.Data;
using Terminal.Gui;
using Terminal.Gui.Trees;
using System.Linq;
using System.Globalization;
using System.IO;
using System.Text;
using NStack;

namespace UICatalog.Scenarios {

	[ScenarioMetadata (Name: "Csv Editor", Description: "Open and edit simple CSV files")]
	[ScenarioCategory ("Controls")]
	[ScenarioCategory ("Dialogs")]
	[ScenarioCategory ("Text")]
	[ScenarioCategory ("Dialogs")]
	[ScenarioCategory ("TopLevel")]
	public class CsvEditor : Scenario 
	{
		TableView tableView;
		private string currentFile;
		private MenuItem miLeft;
		private MenuItem miRight;
		private MenuItem miCentered;
		private Label selectedCellLabel;

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

			this.tableView = new TableView () {
				X = 0,
				Y = 0,
				Width = Dim.Fill (),
				Height = Dim.Fill (1),
			};

			var menu = new MenuBar (new MenuBarItem [] {
				new MenuBarItem ("_File", new MenuItem [] {
					new MenuItem ("_Open CSV", "", () => Open()),
					new MenuItem ("_Save", "", () => Save()),
					new MenuItem ("_Quit", "", () => Quit()),
				}),
				new MenuBarItem ("_Edit", new MenuItem [] {
					new MenuItem ("_New Column", "", () => AddColumn()),
					new MenuItem ("_New Row", "", () => AddRow()),
					new MenuItem ("_Rename Column", "", () => RenameColumn()),
					new MenuItem ("_Delete Column", "", () => DeleteColum()),
					new MenuItem ("_Move Column", "", () => MoveColumn()),
					new MenuItem ("_Move Row", "", () => MoveRow()),
					new MenuItem ("_Sort Asc", "", () => Sort(true)),
					new MenuItem ("_Sort Desc", "", () => Sort(false)),
				}),
				new MenuBarItem ("_View", new MenuItem [] {
					miLeft = new MenuItem ("_Align Left", "", () => Align(TextAlignment.Left)),
					miRight = new MenuItem ("_Align Right", "", () => Align(TextAlignment.Right)),
					miCentered = new MenuItem ("_Align Centered", "", () => Align(TextAlignment.Centered)),
					
					// Format requires hard typed data table, when we read a CSV everything is untyped (string) so this only works for new columns in this demo
					miCentered = new MenuItem ("_Set Format Pattern", "", () => SetFormat()),
				})
			});
			Top.Add (menu);

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

			Win.Add (tableView);

			selectedCellLabel = new Label(){
				X = 0,
				Y = Pos.Bottom(tableView),
				Text = "0,0",
				Width = Dim.Fill(),
				TextAlignment = TextAlignment.Right
				
			};

			Win.Add(selectedCellLabel);

			tableView.SelectedCellChanged += OnSelectedCellChanged;
			tableView.CellActivated += EditCurrentCell;
			tableView.KeyPress += TableViewKeyPress;

			SetupScrollBar();
		}


		private void OnSelectedCellChanged (TableView.SelectedCellChangedEventArgs e)
		{
			selectedCellLabel.Text = $"{tableView.SelectedRow},{tableView.SelectedColumn}";
			
			if(tableView.Table == null || tableView.SelectedColumn == -1)
				return;

			var col = tableView.Table.Columns[tableView.SelectedColumn];

			var style = tableView.Style.GetColumnStyleIfAny(col);
			
			miLeft.Checked = style?.Alignment == TextAlignment.Left;
			miRight.Checked = style?.Alignment == TextAlignment.Right;
			miCentered.Checked = style?.Alignment == TextAlignment.Centered;			
		}

		private void RenameColumn ()
		{
			if(NoTableLoaded()) {
				return;
			}

			var currentCol = tableView.Table.Columns[tableView.SelectedColumn];

			if(GetText("Rename Column","Name:",currentCol.ColumnName,out string newName)) {
				currentCol.ColumnName = newName;
				tableView.Update();
			}
		}

		private void DeleteColum()
		{
			if(NoTableLoaded()) {
				return;
			}

			if(tableView.SelectedColumn == -1) {
				
				MessageBox.ErrorQuery("No Column","No column selected", "Ok");
				return;
			}


			try {
				tableView.Table.Columns.RemoveAt(tableView.SelectedColumn);
				tableView.Update();

			} catch (Exception ex) {
				MessageBox.ErrorQuery("Could not remove column",ex.Message, "Ok");
			}
		}

		private void MoveColumn ()
		{
			if(NoTableLoaded()) {
				return;
			}

			if(tableView.SelectedColumn == -1) {
				
				MessageBox.ErrorQuery("No Column","No column selected", "Ok");
				return;
			}
			
			try{

				var currentCol = tableView.Table.Columns[tableView.SelectedColumn];

				if(GetText("Move Column","New Index:",currentCol.Ordinal.ToString(),out string newOrdinal)) {

					var newIdx = Math.Min(Math.Max(0,int.Parse(newOrdinal)),tableView.Table.Columns.Count-1);

					currentCol.SetOrdinal(newIdx);

					tableView.SetSelection(newIdx,tableView.SelectedRow,false);
					tableView.EnsureSelectedCellIsVisible();
					tableView.SetNeedsDisplay();
				}

			}catch(Exception ex)
			{
				MessageBox.ErrorQuery("Error moving column",ex.Message, "Ok");
			}
		}
		private void Sort (bool asc)
		{

			if(NoTableLoaded()) {
				return;
			}

			if(tableView.SelectedColumn == -1) {
				
				MessageBox.ErrorQuery("No Column","No column selected", "Ok");
				return;
			}

			var colName = tableView.Table.Columns[tableView.SelectedColumn].ColumnName;

			tableView.Table.DefaultView.Sort = colName + (asc ? " asc" : " desc");
			tableView.Table = tableView.Table.DefaultView.ToTable();
		}

		private void MoveRow ()
		{
			if(NoTableLoaded()) {
				return;
			}

			if(tableView.SelectedRow == -1) {
				
				MessageBox.ErrorQuery("No Rows","No row selected", "Ok");
				return;
			}
			
			try{

				int oldIdx = tableView.SelectedRow;

				var currentRow = tableView.Table.Rows[oldIdx];

				if(GetText("Move Row","New Row:",oldIdx.ToString(),out string newOrdinal)) {

					var newIdx = Math.Min(Math.Max(0,int.Parse(newOrdinal)),tableView.Table.Rows.Count-1);


					if(newIdx == oldIdx)
						return;

					var arrayItems = currentRow.ItemArray;
					tableView.Table.Rows.Remove(currentRow);

					// Removing and Inserting the same DataRow seems to result in it loosing its values so we have to create a new instance
					var newRow = tableView.Table.NewRow();
					newRow.ItemArray = arrayItems;
					
					tableView.Table.Rows.InsertAt(newRow,newIdx);
					
					tableView.SetSelection(tableView.SelectedColumn,newIdx,false);
					tableView.EnsureSelectedCellIsVisible();
					tableView.SetNeedsDisplay();
				}

			}catch(Exception ex)
			{
				MessageBox.ErrorQuery("Error moving column",ex.Message, "Ok");
			}
		}

		private void Align (TextAlignment newAlignment)
		{
			if (NoTableLoaded ()) {
				return;
			}

			var col = tableView.Table.Columns[tableView.SelectedColumn];

			var style = tableView.Style.GetOrCreateColumnStyle(col);
			style.Alignment = newAlignment;

			miLeft.Checked = style.Alignment == TextAlignment.Left;
			miRight.Checked = style.Alignment == TextAlignment.Right;
			miCentered.Checked = style.Alignment == TextAlignment.Centered;	
			
			tableView.Update();
		}
		
		private void SetFormat()
		{
			if (NoTableLoaded ()) {
				return;
			}

			var col = tableView.Table.Columns[tableView.SelectedColumn];

			if(col.DataType == typeof(string)) {
				MessageBox.ErrorQuery("Cannot Format Column","String columns cannot be Formatted, try adding a new column to the table with a date/numerical Type","Ok");
				return;
			}

			var style = tableView.Style.GetOrCreateColumnStyle(col);

			if(GetText("Format","Pattern:",style.Format ?? "",out string newPattern)) {
				style.Format = newPattern;
				tableView.Update();
			}
		}

		private bool NoTableLoaded ()
		{
			if(tableView.Table == null) {
				MessageBox.ErrorQuery("No Table Loaded","No table has currently be opened","Ok");
				return true;
			}

			return false;
		}

		private void AddRow ()
		{
			if(NoTableLoaded()) {
				return;
			}

			var newRow = tableView.Table.NewRow();

			var newRowIdx = Math.Min(Math.Max(0,tableView.SelectedRow+1),tableView.Table.Rows.Count);

			tableView.Table.Rows.InsertAt(newRow,newRowIdx);
			tableView.Update();
		}

		private void AddColumn ()
		{
			if(NoTableLoaded()) {
				return;
			}

			if(GetText("Enter column name","Name:","",out string colName)) {

				var col = new DataColumn(colName);

				var newColIdx = Math.Min(Math.Max(0,tableView.SelectedColumn + 1),tableView.Table.Columns.Count);
				
				int result = MessageBox.Query(40,15,"Column Type","Pick a data type for the column",new ustring[]{"Date","Integer","Double","Text","Cancel"});

				if(result <= -1 || result >= 4)
					return;
				switch(result) {
					case 0: col.DataType = typeof(DateTime);
						break;
					case 1: col.DataType = typeof(int);
						break;
					case 2: col.DataType = typeof(double);
						break;
					case 3: col.DataType = typeof(string);
						break;
				}

				tableView.Table.Columns.Add(col);
				col.SetOrdinal(newColIdx);
				tableView.Update();
			}

			
				
		}

		private void Save()
		{
			if(tableView.Table == null || string.IsNullOrWhiteSpace(currentFile)) {
				MessageBox.ErrorQuery("No file loaded","No file is currently loaded","Ok");
				return;
			}

			var sb = new StringBuilder();

			sb.AppendLine(string.Join(",",tableView.Table.Columns.Cast<DataColumn>().Select(c=>c.ColumnName)));

			foreach(DataRow row in tableView.Table.Rows) {
				sb.AppendLine(string.Join(",",row.ItemArray));
			}
			
			File.WriteAllText(currentFile,sb.ToString());
		}

		private void Open()
		{
			var ofd = new FileDialog("Select File","Open","File","Select a CSV file to open (does not support newlines, escaping etc)");
			ofd.AllowedFileTypes = new string[]{".csv" };

			Application.Run(ofd);
			
			if(!ofd.Canceled && !string.IsNullOrWhiteSpace(ofd.FilePath?.ToString()))
			{
				Open(ofd.FilePath.ToString());
			}
		}
		
		private void Open(string filename)
		{
			
			int lineNumber = 0;
			currentFile = null;

			try {
				var dt = new DataTable();
				var lines = File.ReadAllLines(filename);
			
				foreach(var h in lines[0].Split(',')){
					dt.Columns.Add(h);
				}
				

				foreach(var line in lines.Skip(1)) {
					lineNumber++;
					dt.Rows.Add(line.Split(','));
				}
				
				tableView.Table = dt;
				
				// Only set the current filename if we succesfully loaded the entire file
				currentFile = filename;
			}
			catch(Exception ex) {
				MessageBox.ErrorQuery("Open Failed",$"Error on line {lineNumber}{Environment.NewLine}{ex.Message}","Ok");
			}
		}
		private void SetupScrollBar ()
		{
			var _scrollBar = new ScrollBarView (tableView, true);

			_scrollBar.ChangedPosition += () => {
				tableView.RowOffset = _scrollBar.Position;
				if (tableView.RowOffset != _scrollBar.Position) {
					_scrollBar.Position = tableView.RowOffset;
				}
				tableView.SetNeedsDisplay ();
			};
			/*
			_scrollBar.OtherScrollBarView.ChangedPosition += () => {
				_listView.LeftItem = _scrollBar.OtherScrollBarView.Position;
				if (_listView.LeftItem != _scrollBar.OtherScrollBarView.Position) {
					_scrollBar.OtherScrollBarView.Position = _listView.LeftItem;
				}
				_listView.SetNeedsDisplay ();
			};*/

			tableView.DrawContent += (e) => {
				_scrollBar.Size = tableView.Table?.Rows?.Count ??0;
				_scrollBar.Position = tableView.RowOffset;
			//	_scrollBar.OtherScrollBarView.Size = _listView.Maxlength - 1;
			//	_scrollBar.OtherScrollBarView.Position = _listView.LeftItem;
				_scrollBar.Refresh ();
			};
		
		}

		private void TableViewKeyPress (View.KeyEventEventArgs e)
		{
			if(e.KeyEvent.Key == Key.DeleteChar){

				if(tableView.FullRowSelect)
				{
					// Delete button deletes all rows when in full row mode
					foreach(int toRemove in tableView.GetAllSelectedCells().Select(p=>p.Y).Distinct().OrderByDescending(i=>i))
						tableView.Table.Rows.RemoveAt(toRemove);
				}
				else{

					// otherwise set all selected cells to null
					foreach(var pt in tableView.GetAllSelectedCells())
					{
						tableView.Table.Rows[pt.Y][pt.X] = DBNull.Value;
					}
				}

				tableView.Update();
				e.Handled = true;
			}
		}

		private void ClearColumnStyles ()
		{
			tableView.Style.ColumnStyles.Clear();
			tableView.Update();
		}
			

		private void CloseExample ()
		{
			tableView.Table = null;
		}

		private void Quit ()
		{
			Application.RequestStop ();
		}
		private bool GetText(string title, string label, string initialText, out string enteredText)
		{
			bool okPressed = false;

			var ok = new Button ("Ok", is_default: true);
			ok.Clicked += () => { okPressed = true; Application.RequestStop (); };
			var cancel = new Button ("Cancel");
			cancel.Clicked += () => { Application.RequestStop (); };
			var d = new Dialog (title, 60, 20, ok, cancel);

			var lbl = new Label() {
				X = 0,
				Y = 1,
				Text = label
			};

			var tf = new TextField()
				{
					Text = initialText,
					X = 0,
					Y = 2,
					Width = Dim.Fill()
				};
			
			d.Add (lbl,tf);
			tf.SetFocus();

			Application.Run (d);

			enteredText = okPressed? tf.Text.ToString() : null;
			return okPressed;
		}
		private void EditCurrentCell (TableView.CellActivatedEventArgs e)
		{
			if(e.Table == null)
				return;

			var oldValue = e.Table.Rows[e.Row][e.Col].ToString();

			if(GetText("Enter new value",e.Table.Columns[e.Col].ColumnName,oldValue, out string newText)) {
				try {
					e.Table.Rows[e.Row][e.Col] = string.IsNullOrWhiteSpace(newText) ? DBNull.Value : (object)newText;
				}
				catch(Exception ex) {
					MessageBox.ErrorQuery(60,20,"Failed to set text", ex.Message,"Ok");
				}
				
				tableView.Update();
			}
		}
	}
}