1 files changed, 226 insertions, 0 deletions
diff --git a/grapher/Models/Fields/Field.cs b/grapher/Models/Fields/Field.cs
new file mode 100644
index 0000000..8d75172
--- /dev/null
+++ b/grapher/Models/Fields/Field.cs
@@ -0,0 +1,226 @@
+using System;
+using System.Collections.Generic;
+using System.Drawing;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using System.Windows.Forms;
+
+namespace grapher
+{
+    public class Field
+    {
+        #region Constants
+
+        public const string DefaultFormatString = "0.#########";
+
+        #endregion Constants
+
+        #region Enums
+
+        public enum FieldState
+        {
+            Undefined,
+            Default,
+            Typing,
+            Entered,
+            Unavailable,
+        }
+
+        #endregion Enums
+
+
+        #region Constructors
+
+        public Field(TextBox box, Form containingForm, double defaultData)
+        {
+            DefaultText = DecimalString(defaultData);
+            Box = box;
+            Data = defaultData;
+            DefaultData = defaultData;
+            State = FieldState.Undefined;
+            ContainingForm = containingForm;
+            FormatString = DefaultFormatString;
+            box.KeyDown += new System.Windows.Forms.KeyEventHandler(KeyDown);
+            box.Leave += new System.EventHandler(FocusLeave);
+
+            SetToDefault();
+        }
+
+        #endregion Constructors
+
+        #region Properties
+
+        public TextBox Box { get; }
+
+        private Form ContainingForm { get; }
+
+        public double Data { get; private set; }
+
+        public string FormatString { get; set; }
+
+        public string DefaultText { get; }
+
+        public FieldState State { get; private set; }
+
+        public FieldState PreviousState { get; private set; }
+
+        private double DefaultData { get; }
+
+        #endregion Properties
+
+        #region Methods
+
+        public void SetToDefault()
+        {
+            if (State != FieldState.Default)
+            {
+                Box.BackColor = Color.White;
+                Box.ForeColor = Color.Gray;
+                State = FieldState.Default;
+                PreviousState = FieldState.Default;
+            }
+
+            Data = DefaultData;
+            Box.Text = DefaultText;
+            ContainingForm.ActiveControl = null;
+        }
+
+        public void SetToTyping()
+        {
+            if (State != FieldState.Typing)
+            {
+                Box.BackColor = Color.White;
+                Box.ForeColor = Color.Black;
+
+                PreviousState = State;
+                State = FieldState.Typing;
+            }
+
+            Box.Text = string.Empty;
+        }
+
+        public void SetToEntered()
+        {
+            if (State != FieldState.Entered)
+            {
+                Box.BackColor = Color.AntiqueWhite;
+                Box.ForeColor = Color.DarkGray;
+
+                PreviousState = State;
+                State = FieldState.Entered;
+            }
+
+            ContainingForm.ActiveControl = null;
+        }
+
+        public void SetToEntered(double value)
+        {
+            SetToEntered();
+
+            Data = value;
+            Box.Text = DecimalString(Data);
+        }
+
+        public void SetToUnavailable()
+        {
+            if (State != FieldState.Unavailable)
+            {
+                Box.BackColor = Color.LightGray;
+                Box.ForeColor = Color.LightGray;
+                Box.Text = string.Empty;
+
+                PreviousState = State;
+                State = FieldState.Unavailable;
+            }
+        }
+
+        public void KeyDown(object sender, KeyEventArgs e)
+        {
+            switch(State)
+            {
+                case FieldState.Default:
+                    if (e.KeyCode == Keys.Enter)
+                    {
+                        SetToDefault();
+                    }
+                    else
+                    {
+                        SetToTyping();
+                    }
+                    break;
+
+                case FieldState.Entered:
+                    if (e.KeyCode != Keys.Enter)
+                    {
+                        SetToTyping();
+                    }
+                    break;
+                case FieldState.Typing:
+                    HandleTyping(sender, e);
+                    break;
+                case FieldState.Unavailable:
+                    Box.Text = string.Empty;
+                    ContainingForm.ActiveControl = null;
+                    break;
+                default:
+                    break;
+            }
+        }
+
+        private void FocusLeave(object sender, EventArgs e)
+        {
+            if (State == FieldState.Typing)
+            {
+                TextToData();
+            }
+        }
+
+        private void HandleTyping(object sender, KeyEventArgs e)
+        {
+            if (e.KeyCode == Keys.Enter)
+            {
+                TextToData();
+
+                e.Handled = true;
+                e.SuppressKeyPress = true;
+            }
+            else if (e.KeyCode == Keys.Escape)
+            {
+                ContainingForm.ActiveControl = null;
+                e.Handled = true;
+                e.SuppressKeyPress = true;
+            }
+        }
+
+        private void TextToData()
+        {
+            try
+            {
+                Data = Convert.ToDouble(Box.Text);
+            }
+            catch
+            {
+            }
+
+            Box.Text = DecimalString(Data);
+            
+            if (string.Equals(Box.Text, DefaultText))
+            {
+                SetToDefault();
+            }
+            else
+            {
+                SetToEntered();
+            }
+        }
+
+        private string DecimalString(double value)
+        {
+            return value.ToString(FormatString);
+        }
+
+
+        #endregion Methods
+    }
+}