/src/Core/UnitsComboBoxHandler.cs

/////////////////////////////////////////////////////////////////////////////////

// Paint.NET                                                                   //

// Copyright (C) dotPDN LLC, Rick Brewster, Tom Jackson, and contributors.     //

// Portions Copyright (C) Microsoft Corporation. All Rights Reserved.          //

// See src/Resources/Files/License.txt for full licensing and attribution      //

// details.                                                                    //

// .                                                                           //

/////////////////////////////////////////////////////////////////////////////////



using System;

using System.Collections;

using System.ComponentModel;

using System.Windows.Forms;



namespace PaintDotNet

{

    public sealed class UnitsComboBoxHandler

        : IUnitsComboBox

    {

        private readonly ComboBox _comboBox;



        [Browsable(false)]

        public ComboBox ComboBox

        {

            get

            {

                return _comboBox;

            }

        }



        public UnitsComboBoxHandler(ComboBox comboBox)

        {

            _comboBox = comboBox;

            _comboBox.DropDownStyle = ComboBoxStyle.DropDownList;

            _comboBox.SelectedIndexChanged += ComboBoxSelectedIndexChanged;

            ReloadItems();

        }



        private bool _lowercase = true;



        private Hashtable _unitsToString;

        private Hashtable _stringToUnits;



        // maps from MeasurementUnit->bool for whether that item should be in the list or not

        private Hashtable _measurementItems;



        private UnitsDisplayType _unitsDisplayType = UnitsDisplayType.Plural;



        [DefaultValue(UnitsDisplayType.Plural)]

        public UnitsDisplayType UnitsDisplayType

        {

            get

            {

                return _unitsDisplayType;

            }



            set

            {

                if (_unitsDisplayType == value) return;

                _unitsDisplayType = value;

                ReloadItems();

            }

        }



        [DefaultValue(true)]

        public bool LowercaseStrings

        {

            get

            {

                return _lowercase;

            }



            set

            {

                if (_lowercase == value) return;

                _lowercase = value;

                ReloadItems();

            }

        }



        [DefaultValue(MeasurementUnit.Pixel)]

        public MeasurementUnit Units

        {

            get

            {

                object selected = _stringToUnits[ComboBox.SelectedItem];

                return (MeasurementUnit)selected;

            }



            set

            {

                object selectMe = _unitsToString[value];

                ComboBox.SelectedItem = selectMe;

            }

        }



        [Browsable(false)]

        public string UnitsText

        {

            get

            {

                if (ComboBox.SelectedItem == null)

                {

                    return string.Empty;

                }

                return (string)ComboBox.SelectedItem;

            }

        }



        [DefaultValue(true)]

        public bool PixelsAvailable

        {

            get

            {

                return (bool)_measurementItems[MeasurementUnit.Pixel];

            }



            set

            {

                if (value == PixelsAvailable) return;

                if (value)

                {

                    AddUnit(MeasurementUnit.Pixel);

                }

                else

                {

                    if (Units == MeasurementUnit.Pixel)

                    {

                        if (InchesAvailable)

                        {

                            Units = MeasurementUnit.Inch;

                        }

                        else if (CentimetersAvailable)

                        {

                            Units = MeasurementUnit.Centimeter;

                        }

                    }



                    RemoveUnit(MeasurementUnit.Pixel);

                }

            }

        }



        [DefaultValue(true)]

        public bool InchesAvailable

        {

            get

            {

                return (bool)_measurementItems[MeasurementUnit.Inch];

            }

        }



        [DefaultValue(true)]

        public bool CentimetersAvailable

        {

            get

            {

                return (bool)_measurementItems[MeasurementUnit.Centimeter];

            }

        }



        public void RemoveUnit(MeasurementUnit removeMe)

        {

            InitMeasurementItems();

            _measurementItems[removeMe] = false;

            ReloadItems();

        }



        public void AddUnit(MeasurementUnit addMe)

        {

            InitMeasurementItems();

            _measurementItems[addMe] = true;

            ReloadItems();

        }



        private void InitMeasurementItems()

        {

            if (_measurementItems == null)

            {

                _measurementItems = new Hashtable

                                        {

                                            {MeasurementUnit.Pixel, true},

                                            {MeasurementUnit.Centimeter, true},

                                            {MeasurementUnit.Inch, true}

                                        };

            }

        }



        private void ReloadItems()

        {

            string suffix;



            switch (_unitsDisplayType)

            {

                case UnitsDisplayType.Plural:

                    suffix = ".Plural";

                    break;



                case UnitsDisplayType.Singular:

                    suffix = string.Empty;

                    break;



                case UnitsDisplayType.Ratio:

                    suffix = ".Ratio";

                    break;



                default:

                    throw new InvalidEnumArgumentException("UnitsDisplayType");

            }



            InitMeasurementItems();



            MeasurementUnit oldUnits = _unitsToString == null ? MeasurementUnit.Pixel : Units;



            ComboBox.Items.Clear();



            string pixelsString = PdnResources.GetString("MeasurementUnit.Pixel" + suffix);

            string inchesString = PdnResources.GetString("MeasurementUnit.Inch" + suffix);

            string centimetersString = PdnResources.GetString("MeasurementUnit.Centimeter" + suffix);



            if (_lowercase)

            {

                // TODO: we shouldn't really be using ToLower() here, these should be separately localizable strings



                pixelsString = pixelsString.ToLower();

                inchesString = inchesString.ToLower();

                centimetersString = centimetersString.ToLower();

            }



            _unitsToString = new Hashtable

                                 {

                                     {MeasurementUnit.Pixel, pixelsString},

                                     {MeasurementUnit.Inch, inchesString},

                                     {MeasurementUnit.Centimeter, centimetersString}

                                 };



            _stringToUnits = new Hashtable();



            if ((bool)_measurementItems[MeasurementUnit.Pixel])

            {

                _stringToUnits.Add(pixelsString, MeasurementUnit.Pixel);

                ComboBox.Items.Add(pixelsString);

            }



            if ((bool)_measurementItems[MeasurementUnit.Inch])

            {

                _stringToUnits.Add(inchesString, MeasurementUnit.Inch);

                ComboBox.Items.Add(inchesString);

            }



            if ((bool)_measurementItems[MeasurementUnit.Centimeter])

            {

                _stringToUnits.Add(centimetersString, MeasurementUnit.Centimeter);

                ComboBox.Items.Add(centimetersString);

            }



            if (!(bool)_measurementItems[oldUnits])

            {

                if (ComboBox.Items.Count == 0)

                {

                    ComboBox.SelectedItem = null;

                }

                else

                {

                    ComboBox.SelectedIndex = 0;

                }

            }

            else

            {

                Units = oldUnits;

            }

        }



        public event EventHandler UnitsChanged;



        private void OnUnitsChanged()

        {

            if (UnitsChanged != null)

            {

                UnitsChanged(this, EventArgs.Empty);

            }

        }



        private void ComboBoxSelectedIndexChanged(object sender, EventArgs e)

        {

            OnUnitsChanged();

        }

    }

}