File: System\Windows\Input\Stylus\Wisp\WispStylusTouchDevice.cs
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Project: src\src\Microsoft.DotNet.Wpf\src\PresentationCore\PresentationCore.csproj (PresentationCore)
// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
// See the LICENSE file in the project root for more information.
 
//
//
 
using MS.Internal;
 
namespace System.Windows.Input.StylusWisp
{
    /// <summary>
    ///     The implementation of a TouchDevice specific to StylusDevice.
    /// </summary>
    internal sealed class WispStylusTouchDevice : StylusTouchDeviceBase
    {
        #region TouchDevice Implementation
 
        internal WispStylusTouchDevice(StylusDeviceBase stylusDevice)
            : base(stylusDevice)
        {
            _stylusLogic = StylusLogic.GetCurrentStylusLogicAs<WispLogic>();
            PromotingToOther = true;
        }
 
        /// <summary>
        /// Get the width or height of the stylus point's bounding box.
        /// </summary>
        /// <param name="stylusPoint">The point for which the width or height is being calculated</param>
        /// <param name="isWidth">True if this should calculate width, false for height</param>
        /// <returns>The width or height of the stylus poing</returns>
        /// <remarks>
        /// Note that this is not DPI aware.  This implementation has never been aware of DPI changes and
        /// changing that now could cause issues with people who depended on this to be based on 96 DPI.
        /// </remarks>
        protected override double GetStylusPointWidthOrHeight(StylusPoint stylusPoint, bool isWidth)
        {
            double pixelsPerInch = DpiUtil.DefaultPixelsPerInch;
 
            StylusPointProperty property = (isWidth ? StylusPointProperties.Width : StylusPointProperties.Height);
 
            double value = 0d;
 
            if (stylusPoint.HasProperty(property))
            {
                // Get the property value in the corresponding units
                value = (double)stylusPoint.GetPropertyValue(property);
 
                StylusPointPropertyInfo propertyInfo = stylusPoint.Description.GetPropertyInfo(property);
 
                if (!DoubleUtil.AreClose(propertyInfo.Resolution, 0d))
                {
                    value /= propertyInfo.Resolution;
                }
                else
                {
                    value = 0;
                }
 
                // Convert the value to Inches
                if (propertyInfo.Unit == StylusPointPropertyUnit.Centimeters)
                {
                    value /= CentimetersPerInch;
                }
 
                // Convert the value to pixels
                value *= pixelsPerInch;
            }
 
            return value;
        }
 
        #endregion
 
        #region StylusLogic Related
 
        protected override void OnManipulationStarted()
        {
            base.OnManipulationStarted();
            PromotingToOther = false;
        }
 
        protected override void OnManipulationEnded(bool cancel)
        {
            base.OnManipulationEnded(cancel);
            if (cancel)
            {
                // Set PromotingToOther to true because the
                // the manipulation has been canceled and hence
                // we want the promotions to happen.
                PromotingToOther = true;
                _stylusLogic.PromoteStoredItemsToMouse(this);
            }
            else
            {
                // Set PromotingToOther to false because we
                // dont want any mouse promotions to happen for
                // rest of this touch cycle.
                PromotingToOther = false;
            }
            if (_storedStagingAreaItems != null)
            {
                _storedStagingAreaItems.Clear();
            }
        }
 
        /// <summary>
        ///     Stored items that occurred during the time before we knew where to promote to.
        /// </summary>
        internal WispLogic.StagingAreaInputItemList StoredStagingAreaItems
        {
            get
            {
                if (_storedStagingAreaItems == null)
                {
                    _storedStagingAreaItems = new WispLogic.StagingAreaInputItemList();
                }
                return _storedStagingAreaItems;
            }
        }
 
        protected override void OnActivateImpl()
        {
            if (ActiveDeviceCount == 1)
            {
                _stylusLogic.CurrentMousePromotionStylusDevice = StylusDevice;
            }
        }
 
        protected override void OnDeactivateImpl()
        {
            if (_storedStagingAreaItems != null)
            {
                _storedStagingAreaItems.Clear();
            }
 
            if (ActiveDeviceCount == 0)
            {
                _stylusLogic.CurrentMousePromotionStylusDevice = null;
            }
            else if (IsPrimary)
            {
                _stylusLogic.CurrentMousePromotionStylusDevice = NoMousePromotionStylusDevice;
            }
        }
 
        #endregion
 
        #region Data
 
        private WispLogic _stylusLogic;
 
        private WispLogic.StagingAreaInputItemList _storedStagingAreaItems;
 
        private static object NoMousePromotionStylusDevice = new object();
 
        #endregion
    }
}