DefaultTextStore.cs source code in C# .NET

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/ DotNET / DotNET / 8.0 / untmp / WIN_WINDOWS / lh_tools_devdiv_wpf / Windows / wcp / Core / System / Windows / Input / DefaultTextStore.cs / 1 / DefaultTextStore.cs

                            //---------------------------------------------------------------------------- 
//
// 
//    Copyright (C) Microsoft Corporation.  All rights reserved.
//  
//
// Description: the default text store that allows default TSF enabling. 
// 
// History:
//  11/17/2003 : [....] 
//
//---------------------------------------------------------------------------

using System; 
using System.Runtime.InteropServices;
using System.Windows; 
using System.Windows.Threading; 
using System.Threading;
using System.Diagnostics; 
using System.Security;
using MS.Internal;
using MS.Internal.PresentationCore;                        // SecurityHelper
using System.Security.Permissions; 
using MS.Win32;
 
namespace System.Windows.Input 
{
    // This class has the default text store implementation. 
    // DefaultTextStore is a TextStore to be shared by any element of the Dispatcher.
    // When the keyboard focus is on the element, Cicero input goes into this by default.
    // This DefaultTextStore will be used unless an Element (such as TextBox) set
    // the focus on the document manager for its own TextStore. 
    internal class DefaultTextStore :  UnsafeNativeMethods.ITfContextOwner,
                                       UnsafeNativeMethods.ITfContextOwnerCompositionSink, 
                                       UnsafeNativeMethods.ITfTransitoryExtensionSink 
    {
        //----------------------------------------------------- 
        //
        //  Constructors
        //
        //----------------------------------------------------- 

        #region Constructors 
 
        // Creates a DefaultTextStore instance.
        internal DefaultTextStore(Dispatcher dispatcher) 
        {
            // Save the target Dispatcher.
            _dispatcher = dispatcher;
 
            _editCookie = UnsafeNativeMethods.TF_INVALID_COOKIE;
            _transitoryExtensionSinkCookie = UnsafeNativeMethods.TF_INVALID_COOKIE; 
        } 

        #endregion Constructors 

        //------------------------------------------------------
        //
        //  Public Methods - ITfContextOwner 
        //
        //----------------------------------------------------- 
 
        #region ITfContextOwner
 

        //
        //  ITfContextOwner implementation for Cicero's default text store.
        // 

        public void GetACPFromPoint(ref UnsafeNativeMethods.POINT point, UnsafeNativeMethods.GetPositionFromPointFlags flags, out int position) 
        { 
            position = 0;
        } 

        public void GetTextExt(int start, int end, out UnsafeNativeMethods.RECT rect, out bool clipped)
        {
            rect = new UnsafeNativeMethods.RECT(); 
            clipped = false;
        } 
 
        public void GetScreenExt(out UnsafeNativeMethods.RECT rect)
        { 
            rect = new UnsafeNativeMethods.RECT();
        }

        public void GetStatus(out UnsafeNativeMethods.TS_STATUS status) 
        {
            status = new UnsafeNativeMethods.TS_STATUS(); 
        } 

        public void GetWnd(out IntPtr hwnd) 
        {
            hwnd = IntPtr.Zero;
        }
 
        public void GetValue(ref Guid guidAttribute, out object varValue)
        { 
            varValue = null; 
        }
 
        #endregion ITfContextOwner


        //------------------------------------------------------ 
        //
        //  Public Methods - ITfContextOwnerCompositionSink 
        // 
        //------------------------------------------------------
 
        #region ITfContextOwnerCompositionSink

        public void OnStartComposition(UnsafeNativeMethods.ITfCompositionView view, out bool ok)
        { 
            // Return true in ok to start the composition.
            ok = true; 
        } 

        public void OnUpdateComposition(UnsafeNativeMethods.ITfCompositionView view, UnsafeNativeMethods.ITfRange rangeNew) 
        {
        }

        public void OnEndComposition(UnsafeNativeMethods.ITfCompositionView view) 
        {
        } 
 
        #endregion ITfContextOwnerCompositionSink
 
        //-----------------------------------------------------
        //
        //  Public Methods - ITfTransitoryExtensionSink
        // 
        //------------------------------------------------------
 
        #region ITfTransitoryExtensionSink 

        // Transitory Document has been updated. 
        // This is the notification of the changes of the result string and the composition string.
        ///
        ///     Critical: This code acceses critical data in the form of TextCompositionManager
        ///     TreatAsSafe: There exists a demand for unmanaged code. 
        ///
        [SecurityCritical,SecurityTreatAsSafe] 
        public void OnTransitoryExtensionUpdated(UnsafeNativeMethods.ITfContext context, int ecReadOnly, UnsafeNativeMethods.ITfRange rangeResult, UnsafeNativeMethods.ITfRange rangeComposition, out bool fDeleteResultRange) 
        {
            SecurityHelper.DemandUnmanagedCode(); 

            fDeleteResultRange = true;

            TextCompositionManager compmgr = InputManager.Current.PrimaryKeyboardDevice.TextCompositionManager; 

            if (rangeResult != null) 
            { 
                string result = StringFromITfRange(rangeResult, ecReadOnly);
                if (result.Length > 0) 
                {
                    if (_composition == null)
                    {
 
                        // We don't have the composition now and we got the result string.
                        // The result text is result and automatic termination is true. 
                        _composition = new DefaultTextStoreTextComposition(InputManager.Current, Keyboard.FocusedElement, result, TextCompositionAutoComplete.On); 
                        TextCompositionManager.StartComposition(_composition);
 
                        // relese composition.
                        _composition = null;
                        }
                    else 
                    {
                        // Finalize the composition. 
                        _composition.SetCompositionText(""); 
                        _composition.SetText(result);
 
                        // We don't call _composition.Complete() here. We just want to generate
                        // TextInput events.
                        TextCompositionManager.CompleteComposition(_composition);
 
                        // relese composition.
                        _composition = null; 
                    } 
                }
            } 

            if (rangeComposition != null)
            {
                string comp = StringFromITfRange(rangeComposition, ecReadOnly); 
                if (comp.Length > 0)
                { 
                if (_composition == null) 
                    {
 
                        // Start the new composition.
                        _composition = new DefaultTextStoreTextComposition(InputManager.Current, Keyboard.FocusedElement, "", TextCompositionAutoComplete.Off);
                        _composition.SetCompositionText(comp);
                        TextCompositionManager.StartComposition(_composition); 
                    }
                    else 
                    { 
                        // Update the current composition.
                        _composition.SetCompositionText(comp); 
                        _composition.SetText("");
                        TextCompositionManager.UpdateComposition(_composition);
                    }
                } 
            }
        } 
 
        #endregion ITfTransitoryExtensionSink
 
        //-----------------------------------------------------
        //
        //  Public Properties
        // 
        //-----------------------------------------------------
 
        //----------------------------------------------------- 
        //
        //  Public Events 
        //
        //------------------------------------------------------

        //----------------------------------------------------- 
        //
        //  Protected Methods 
        // 
        //------------------------------------------------------
 
        //------------------------------------------------------
        //
        //  Internal Methods
        // 
        //-----------------------------------------------------
 
        // Return the text services host associated with the current Dispatcher. 
        internal static DefaultTextStore Current
        { 
            get
            {
                // DefaultTextStore is per Dispatcher and the cached referrence is stored in InputMethod class.
                DefaultTextStore defaulttextstore = InputMethod.Current.DefaultTextStore; 

                if(defaulttextstore == null) 
                { 
                    defaulttextstore = new DefaultTextStore(Dispatcher.CurrentDispatcher);
                    InputMethod.Current.DefaultTextStore = defaulttextstore; 

                    defaulttextstore.Register();
                }
                return defaulttextstore; 
            }
        } 
 
        //------------------------------------------------------
        // 
        //  Internal Properties
        //
        //-----------------------------------------------------
 
        // Pointer to ITfDocumentMgr interface.
        ///  
        ///     Critical: This exposes ITfDocumentMgr that has methods with SuppressUnmanagedCodeSecurity. 
        /// 
        internal UnsafeNativeMethods.ITfDocumentMgr DocumentManager 
        {
            [SecurityCritical]
            get { return _doc.Value;}
            set { _doc = new SecurityCriticalData(value); } 
        }
 
        // EditCookie for ITfContext. 
        internal int EditCookie
        { 
            // get { return _editCookie; }
            set { _editCookie = value; }
        }
 
        internal int TransitoryExtensionSinkCookie
        { 
            get { return _transitoryExtensionSinkCookie; } 
            set { _transitoryExtensionSinkCookie = value; }
        } 

        //
        // Get Transitory's DocumentMgr from GUID_COMPARTMENT_TRANSITORYEXTENSION_DOCUMENTMANAGER.
        // 
        /// 
        ///     Critical: This code acceses ITfDocumentMgr, ItfCompartment and ITfCompartmentMgr 
        ///     TreatAsSafe: There exists a demand for unmanaged code 
        /// 
        internal UnsafeNativeMethods.ITfDocumentMgr TransitoryDocumentManager 
        {
            [SecurityCritical,SecurityTreatAsSafe]
            get
            { 
                SecurityHelper.DemandUnmanagedCode();
 
                UnsafeNativeMethods.ITfDocumentMgr doc; 
                UnsafeNativeMethods.ITfCompartmentMgr compartmentMgr;
                UnsafeNativeMethods.ITfCompartment compartment; 

                // get compartment manager of the parent doc.
                compartmentMgr = (UnsafeNativeMethods.ITfCompartmentMgr)DocumentManager;
 
                // get compartment.
                Guid guid = UnsafeNativeMethods.GUID_COMPARTMENT_TRANSITORYEXTENSION_DOCUMENTMANAGER; 
                compartmentMgr.GetCompartment(ref guid, out compartment); 

                // get value of the compartment. 
                object obj;
                compartment.GetValue(out obj);
                doc = obj as UnsafeNativeMethods.ITfDocumentMgr;
 
                Marshal.ReleaseComObject(compartment);
                return doc; 
            } 
        }
 

        //-----------------------------------------------------
        //
        //  Internal Events 
        //
        //----------------------------------------------------- 
 
        //------------------------------------------------------
        // 
        //  Private Methods
        //
        //-----------------------------------------------------
 
        // get the text from ITfRange.
        ///  
        /// Critical - calls unmanaged code (GetExtent) 
        /// 
        [SecurityCritical] 
        private string StringFromITfRange(UnsafeNativeMethods.ITfRange range, int ecReadOnly)
        {
            // Transitory Document uses ther TextStore, which is ACP base.
            UnsafeNativeMethods.ITfRangeACP rangeacp = (UnsafeNativeMethods.ITfRangeACP)range; 
            int start;
            int count; 
            int countRet; 
            rangeacp.GetExtent(out start, out count);
            char[] text = new char[count]; 
            rangeacp.GetText(ecReadOnly, 0, text, count, out countRet);
            return new string(text);
        }
 
        // This function calls TextServicesContext to create TSF document and start transitory extension.
        ///  
        /// Critical - directly access the text store 
        /// TreatAsSafe - registers "this" as a text store (safe operation)
        ///  
        [SecurityCritical, SecurityTreatAsSafe]
        private void Register()
        {
            // Create TSF document and advise the sink to it. 
            TextServicesContext.DispatcherCurrent.RegisterTextStore(this);
        } 
 
        //------------------------------------------------------
        // 
        //  Private Properties
        //
        //------------------------------------------------------
 
        //-----------------------------------------------------
        // 
        //  Private Fields 
        //
        //------------------------------------------------------ 

        // Dispatcher for this text store
        private readonly Dispatcher _dispatcher;
 
        // The current active composition.
        private TextComposition _composition; 
 
        // The TSF document object.  This is a native resource.
        ///  
        ///     Critical: UnsafeNativeMethods.ITfDocumentMgr has methods with SuppressUnmanagedCodeSecurity.
        /// 
        private SecurityCriticalData _doc;
 
        // The edit cookie TSF returns from CreateContext.
        private int _editCookie; 
 
        // The transitory extension sink cookie.
        private int _transitoryExtensionSinkCookie; 
    }
}

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


                        

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