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LibreHardwareMonitor-0.9.4/Aga.Controls/NumericTextBox.cs

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+using System;
+using System.ComponentModel;
+using System.Windows.Forms;
+using System.Globalization;
+
+
+namespace Aga.Controls
+{
+	/// <summary>
+	/// Restricts the entry of characters to digits, the negative sign,
+	/// the decimal point, and editing keystrokes (backspace).
+	/// It does not handle the AltGr key so any keys that can be created in any
+	/// combination with AltGr these are not filtered
+	/// </summary>
+	public class NumericTextBox : TextBox
+	{
+		private const int WM_PASTE = 0x302;
+		private NumberStyles numberStyle = NumberStyles.AllowDecimalPoint | NumberStyles.AllowLeadingSign;
+
+		/// <summary>
+		/// Restricts the entry of characters to digits, the negative sign,
+		/// the decimal point, and editing keystrokes (backspace).
+		/// It does not handle the AltGr key
+		/// </summary>
+		/// <param name="e"></param>
+		protected override void OnKeyPress(KeyPressEventArgs e)
+		{
+			base.OnKeyPress(e);
+
+			e.Handled = invalidNumeric(e.KeyChar);
+		}
+
+
+		/// <summary>
+		/// Main method for verifying allowed keypresses.
+		/// This does not catch cut paste copy ... operations.
+		/// </summary>
+		/// <param name="key"></param>
+		/// <returns></returns>
+		private bool invalidNumeric(char key)
+		{
+			bool handled = false;
+
+			NumberFormatInfo numberFormatInfo = CultureInfo.CurrentCulture.NumberFormat;
+			string decimalSeparator = numberFormatInfo.NumberDecimalSeparator;
+			string negativeSign = numberFormatInfo.NegativeSign;
+
+			string keyString = key.ToString();
+
+			if (Char.IsDigit(key))
+			{
+				// Digits are OK
+			}
+			else if (AllowDecimalSeparator && keyString.Equals(decimalSeparator))
+			{
+				if (Text.IndexOf(decimalSeparator) >= 0)
+				{
+					handled = true;
+				}
+			}
+			else if (AllowNegativeSign && keyString.Equals(negativeSign))
+			{
+				if (Text.IndexOf(negativeSign) >= 0)
+				{
+					handled = true;
+				}
+			}
+			else if (key == '\b')
+			{
+				// Backspace key is OK
+			}
+			else if ((ModifierKeys & (Keys.Control)) != 0)
+			{
+				// Let the edit control handle control and alt key combinations
+			}
+			else
+			{
+				// Swallow this invalid key and beep
+				handled = true;
+			}
+			return handled;
+		}
+
+
+		/// <summary>
+		/// Method invoked when Windows sends a message.
+		/// </summary>
+		/// <param name="m">Message from Windows.</param>
+		/// <remarks>
+		/// This is over-ridden so that the user can not use
+		/// cut or paste operations to bypass the TextChanging event.
+		/// This catches ContextMenu Paste, Shift+Insert, Ctrl+V,
+		/// While it is generally frowned upon to override WndProc, no
+		/// other simple mechanism was apparent to simultaneously and
+		/// transparently intercept so many different operations.
+		/// </remarks>
+		protected override void WndProc(ref Message m)
+		{
+			// Switch to handle message...
+			switch (m.Msg)
+			{
+				case WM_PASTE:
+					{
+						// Get clipboard object to paste
+						IDataObject clipboardData = Clipboard.GetDataObject();
+
+						// Get text from clipboard data
+						string pasteText = (string)clipboardData.GetData(
+								DataFormats.UnicodeText);
+
+						// Get the number of characters to replace
+						int selectionLength = SelectionLength;
+
+						// If no replacement or insertion, we are done
+						if (pasteText.Length == 0)
+						{
+							break;
+						}
+						else if (selectionLength != 0)
+						{
+							base.Text = base.Text.Remove(SelectionStart, selectionLength);
+						}
+
+						bool containsInvalidChars = false;
+						foreach (char c in pasteText)
+						{
+							if (containsInvalidChars)
+							{
+								break;
+							}
+							else if (invalidNumeric(c))
+							{
+								containsInvalidChars = true;
+							}
+						}
+
+						if (!containsInvalidChars)
+						{
+							base.Text = base.Text.Insert(SelectionStart, pasteText);
+						}
+
+						return;
+					}
+
+			}
+			base.WndProc(ref m);
+		}
+
+
+		public int IntValue
+		{
+			get
+			{
+				int intValue;
+				Int32.TryParse(this.Text, numberStyle, CultureInfo.CurrentCulture.NumberFormat, out intValue);
+				return intValue;
+			}
+		}
+
+		public decimal DecimalValue
+		{
+			get
+			{
+				decimal decimalValue;
+				Decimal.TryParse(this.Text, numberStyle, CultureInfo.CurrentCulture.NumberFormat, out decimalValue);
+				return decimalValue;
+			}
+		}
+
+
+		private bool allowNegativeSign;
+		[DefaultValue(true)]
+		public bool AllowNegativeSign
+		{
+			get { return allowNegativeSign; }
+			set { allowNegativeSign = value; }
+		}
+
+		private bool allowDecimalSeparator;
+		[DefaultValue(true)]
+		public bool AllowDecimalSeparator
+		{
+			get { return allowDecimalSeparator; }
+			set { allowDecimalSeparator = value; }
+		}
+
+	}
+
+}