UnitControl.cs source code in C# .NET

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                         / DotNET / DotNET / 8.0 / untmp / whidbey / REDBITS / ndp / fx / src / Designer / WebForms / System / Web / UI / Design / Util / UnitControl.cs / 1 / UnitControl.cs
                        
                        
                            //------------------------------------------------------------------------------ 
// 
//     Copyright (c) Microsoft Corporation.  All rights reserved.
// 
//----------------------------------------------------------------------------- 

// UnitControl.cs 
// 
// 12/22/98: Created: [....]
// 

namespace System.Web.UI.Design.Util {
    using System.Runtime.Serialization.Formatters;
 
    using System.Diagnostics;
    using System.Design; 
    using System.Globalization; 
    using System;
    using System.ComponentModel; 
    using System.Windows.Forms;
    using System.Drawing;

    using Microsoft.Win32; 

    ///  
    ///  
    ///     UnitControl
    ///     Provides a UI to edit a unit, i.e., its value and type. 
    ///     Additionally allows placing restrictions on the types of units that
    ///     that can be entered.
    /// 
    ///  
    [System.Security.Permissions.SecurityPermission(System.Security.Permissions.SecurityAction.Demand, Flags=System.Security.Permissions.SecurityPermissionFlag.UnmanagedCode)]
    internal sealed class UnitControl : Panel { 
        /////////////////////////////////////////////////////////////////////////// 
        // Constants
 
        // UI Layout constants
        private const int EDIT_X_SIZE = 44;
        private const int COMBO_X_SIZE = 40;
        private const int SEPARATOR_X_SIZE = 4; 
        private const int CTL_Y_SIZE = 21;
 
        // Units 
        public const int UNIT_PX = 0;
        public const int UNIT_PT = 1; 
        public const int UNIT_PC = 2;
        public const int UNIT_MM = 3;
        public const int UNIT_CM = 4;
        public const int UNIT_IN = 5; 
        public const int UNIT_EM = 6;
        public const int UNIT_EX = 7; 
        public const int UNIT_PERCENT = 8; 
        public const int UNIT_NONE = 9;
 
        private static readonly string[] UNIT_VALUES = new string[] {
            "px", "pt", "pc", "mm", "cm", "in", "em", "ex", "%", ""
        };
 

        /////////////////////////////////////////////////////////////////////////// 
        // Members 

        private NumberEdit valueEdit; 
        private ComboBox unitCombo;

        private bool allowPercent = true;
        private bool allowNonUnit = false; 

        private int defaultUnit = UNIT_PT; 
        private int minValue = 0; 
        private int maxValue = 0xFFFF;
        private bool validateMinMax = false; 

        private EventHandler onChangedHandler = null;

        private bool initMode = false; 
        private bool internalChange = false;
        private bool valueChanged = false; 
 

        /////////////////////////////////////////////////////////////////////////// 
        // Constructor

        /// 
        ///  
        ///     Createa a new UnitControl.
        ///  
        public UnitControl() { 
            initMode = true;
 
            Size = new Size((EDIT_X_SIZE + COMBO_X_SIZE + SEPARATOR_X_SIZE),
                             CTL_Y_SIZE);
            InitControl();
            InitUI(); 

            initMode = false; 
        } 

        /////////////////////////////////////////////////////////////////////////// 
        // Properties

        /// 
        ///  
        ///     Controls whether the unit value can be negative
        ///  
        public bool AllowNegativeValues { 
            get {
                return valueEdit.AllowNegative; 
            }
            set {
                valueEdit.AllowNegative = value;
            } 
        }
 
        ///  
        /// 
        ///     Controls whether the unit value can be a unit-less 
        /// 
        public bool AllowNonUnitValues {
            get {
                return allowNonUnit; 
            }
            set { 
                if (value == allowNonUnit) 
                    return;
 
                if (value && !allowPercent) {
                    Debug.Fail("AllowPercentValues must be set to true first");
                    throw new Exception();
                } 

                allowNonUnit = value; 
                if (allowNonUnit) 
                    unitCombo.Items.Add(UNIT_VALUES[UNIT_NONE]);
                else 
                    unitCombo.Items.Remove(UNIT_VALUES[UNIT_NONE]);
            }
        }
 
        /// 
        ///  
        ///     Controls whether the unit value can be a percent value 
        /// 
        public bool AllowPercentValues { 
            get {
                return allowPercent;
            }
            set { 
                if (value == allowPercent)
                    return; 
 
                if (!value && allowNonUnit) {
                    Debug.Fail("AllowNonUnitValues must be set to false first"); 
                    throw new Exception();
                }

                allowPercent = value; 
                if (allowPercent)
                    unitCombo.Items.Add(UNIT_VALUES[UNIT_PERCENT]); 
                else 
                    unitCombo.Items.Remove(UNIT_VALUES[UNIT_PERCENT]);
            } 
        }

        /// 
        ///  
        ///     The default unit to be used
        ///  
        public int DefaultUnit { 
            get {
                return defaultUnit; 
            }
            set {
                Debug.Assert((value >= UNIT_PX) &&
                             (value <= UNIT_NONE) && 
                             (allowNonUnit || (value != UNIT_NONE)) ||
                             (allowPercent || (value != UNIT_PERCENT)), 
                             "Invalid default unit"); 

                defaultUnit = value; 
            }
        }

        public int MaxValue { 
            get {
                return maxValue; 
            } 
            set {
                maxValue = value; 
            }
        }

        public int MinValue { 
            get {
                return minValue; 
            } 
            set {
                minValue = value; 
            }
        }

        protected override void OnEnabledChanged(EventArgs e) { 
            base.OnEnabledChanged(e);
 
            valueEdit.Enabled = Enabled; 
            unitCombo.Enabled = Enabled;
        } 

        public bool ValidateMinMax {
            get {
                return validateMinMax; 
            }
            set { 
                validateMinMax = value; 
            }
        } 

        /// 
        /// 
        ///     The unit reflecting the value and unit type within the UI. 
        ///     Returns null if no unit is selected.
        ///  
        public string Value { 
            get {
                string value = GetValidatedValue(); 

                if (value == null) {
                    value = valueEdit.Text;
                } 
                else {
                    valueEdit.Text = value; 
                    OnValueTextChanged(valueEdit, EventArgs.Empty); 
                }
 
                int unit = unitCombo.SelectedIndex;

                if ((value.Length == 0) || (unit == -1))
                    return null; 

                return value + UNIT_VALUES[unit]; 
            } 
            set {
                initMode = true; 

                InitUI();
                if (value != null) {
                    string temp = value.Trim().ToLower(CultureInfo.InvariantCulture); 
                    int len = temp.Length;
 
                    int unit = -1; 
                    int iLastDigit = -1;
                    char ch; 

                    // find the end of the number part
                    for (int i = 0; i < len; i++) {
                        ch = temp[i]; 
                        if (!(((ch >= '0') && (ch <= '9')) ||
                              (NumberFormatInfo.CurrentInfo.NumberDecimalSeparator.Contains(ch.ToString(CultureInfo.CurrentCulture))) || 
                              (NumberFormatInfo.CurrentInfo.NegativeSign.Contains(ch.ToString(CultureInfo.CurrentCulture))) && (valueEdit.AllowNegative))) 
                            break;
                        else 
                            iLastDigit = i;
                    }
                    if (iLastDigit != -1) {
                        // detect the type of unit 
                        if ((iLastDigit + 1) < len) {
                            int maxUnit = allowPercent ? UNIT_PERCENT : UNIT_EX; 
                            string unitString = temp.Substring(iLastDigit+1); 
                            for (int i = 0; i <= maxUnit; i++) {
                                if (UNIT_VALUES[i].Equals(unitString)) { 
                                    unit = i;
                                    break;
                                }
                            } 
                        } else if (allowNonUnit)
                            unit = UNIT_NONE; 
 
                        if (unit != -1) {
                            valueEdit.Text = temp.Substring(0, iLastDigit+1); 
                            unitCombo.SelectedIndex = unit;
                        }
                    }
                } 
                initMode = false;
            } 
        } 

        public string UnitAccessibleName { 
            get {
                if (unitCombo != null) {
                    return unitCombo.AccessibleName;
                } 
                return String.Empty;
            } 
            set { 
                if (unitCombo != null) {
                    unitCombo.AccessibleName = value; 
                }
            }
        }
 
        public string UnitAccessibleDescription {
            get { 
                if (unitCombo != null) { 
                    return unitCombo.AccessibleDescription;
                } 
                return String.Empty;
            }
            set {
                if (unitCombo != null) { 
                    unitCombo.AccessibleDescription = value;
                } 
            } 
        }
 
        public string ValueAccessibleName {
            get {
                if (valueEdit != null) {
                    return valueEdit.AccessibleName; 
                }
                return String.Empty; 
            } 
            set {
                if (valueEdit != null) { 
                    valueEdit.AccessibleName = value;
                }
            }
        } 

        public string ValueAccessibleDescription { 
            get { 
                if (valueEdit != null) {
                    return valueEdit.AccessibleDescription; 
                }
                return String.Empty;
            }
            set { 
                if (valueEdit != null) {
                    valueEdit.AccessibleDescription = value; 
                } 
            }
        } 

        ///////////////////////////////////////////////////////////////////////////
        // Events
 
        public event EventHandler Changed {
            add { 
                onChangedHandler += value; 
            }
            remove { 
                onChangedHandler -= value;
            }
        }
 

        /////////////////////////////////////////////////////////////////////////// 
        // Implementation 

        ///  
        /// 
        /// 
        private string GetValidatedValue() {
            string validValue = null; 
            if (validateMinMax) {
                string value = valueEdit.Text; 
 
                if (value.Length != 0) {
                    try { 
                        if (!value.Contains(NumberFormatInfo.CurrentInfo.NumberDecimalSeparator)) {
                            int valueNum = Int32.Parse(value, CultureInfo.CurrentCulture);
                            if (valueNum < minValue)
                                validValue = minValue.ToString(NumberFormatInfo.CurrentInfo); 
                            else if (valueNum > maxValue)
                                validValue = maxValue.ToString(NumberFormatInfo.CurrentInfo); 
                        } 
                        else {
                            float valueNum = Single.Parse(value, CultureInfo.CurrentCulture); 

                            if (valueNum < (float)minValue)
                                validValue = minValue.ToString(NumberFormatInfo.CurrentInfo);
                            else if (valueNum > (float)maxValue) 
                                validValue = maxValue.ToString(NumberFormatInfo.CurrentInfo);
                        } 
                    } catch { 
                        validValue = maxValue.ToString(NumberFormatInfo.CurrentInfo);
                    } 
                }
            }
            return validValue;
        } 

        ///  
        ///  
        ///     Create the contained controls and initialize their settings
        ///  
        private void InitControl() {
            int editWidth = this.Width - (COMBO_X_SIZE + SEPARATOR_X_SIZE);
            if (editWidth < 0)
                editWidth = 0; 

            valueEdit = new NumberEdit(); 
            valueEdit.Location = new Point(0, 0); 
            valueEdit.Size = new Size(editWidth, CTL_Y_SIZE);
            valueEdit.TabIndex = 0; 
            valueEdit.MaxLength = 10;
            valueEdit.TextChanged += new EventHandler(this.OnValueTextChanged);
            valueEdit.LostFocus += new EventHandler(this.OnValueLostFocus);
 
            unitCombo = new ComboBox();
            unitCombo.DropDownStyle = ComboBoxStyle.DropDownList; 
            unitCombo.Location = new Point(editWidth + SEPARATOR_X_SIZE, 0); 
            unitCombo.Size = new Size(COMBO_X_SIZE, CTL_Y_SIZE);
            unitCombo.TabIndex = 1; 
            unitCombo.MaxDropDownItems = 9;
            unitCombo.SelectedIndexChanged += new EventHandler(this.OnUnitSelectedIndexChanged);

            this.Controls.Clear(); 
            this.Controls.AddRange(new Control[] {
                                        unitCombo, 
                                        valueEdit}); 

            for (int i = UNIT_PX; i <= UNIT_EX; i++) 
                unitCombo.Items.Add(UNIT_VALUES[i]);
            if (allowPercent)
                unitCombo.Items.Add(UNIT_VALUES[UNIT_PERCENT]);
            if (allowNonUnit) 
                unitCombo.Items.Add(UNIT_VALUES[UNIT_NONE]);
        } 
 
        /// 
        ///  
        ///     Initialize the controls to their default state
        /// 
        private void InitUI() {
            valueEdit.Text = String.Empty; 
            unitCombo.SelectedIndex = -1;
        } 
 
        /// 
        ///  
        ///     Fires the "changed" event.
        /// 
        private void OnChanged(EventArgs e) {
            if (onChangedHandler != null) 
                onChangedHandler(this, e);
        } 
 

        /////////////////////////////////////////////////////////////////////////// 
        // Event Handlers

        protected override void OnGotFocus(EventArgs e) {
            valueEdit.Focus(); 
        }
 
        ///  
        /// 
        ///     Handles changes in the value edit control. 
        ///     If there is no unit selected, and a value is entered, the default unit is
        ///     selected.  If the value is cleared, the unit is also deselected.
        /// 
        private void OnValueTextChanged(object source, EventArgs e) { 
            if (initMode)
                return; 
 
            string text = valueEdit.Text;
            if (text.Length == 0) { 
                internalChange = true;
                unitCombo.SelectedIndex = -1;
                internalChange = false;
            } 
            else {
                if (unitCombo.SelectedIndex == -1) { 
                    internalChange = true; 
                    unitCombo.SelectedIndex = defaultUnit;
                    internalChange = false; 
                }
            }
            valueChanged = true;
            OnChanged(null); 
        }
 
        private void OnValueLostFocus(object source, EventArgs e) { 
            if (valueChanged) {
                string value = GetValidatedValue(); 
                if (value != null) {
                    valueEdit.Text = value;
                    OnValueTextChanged(valueEdit, EventArgs.Empty);
                } 

                valueChanged = false; 
                OnChanged(EventArgs.Empty); 
            }
        } 

        /// 
        /// 
        ///     Handles the event when the unit combobox selection changes. 
        ///     Fires a changed event.
        ///  
        private void OnUnitSelectedIndexChanged(object source, EventArgs e) { 
            if (initMode || internalChange)
                return; 

            OnChanged(EventArgs.Empty);
        }
    } 
}
 

// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
// Copyright (c) Microsoft Corporation. All rights reserved.
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