TextLineResult.cs source code in C# .NET

                        Code:
                         / 4.0 / 4.0 / untmp / DEVDIV_TFS / Dev10 / Releases / RTMRel / wpf / src / Framework / MS / Internal / Text / TextLineResult.cs / 1305600 / TextLineResult.cs
                        
                        
                            //---------------------------------------------------------------------------- 
//
// 
//    Copyright (C) Microsoft Corporation.  All rights reserved.
//  
//
// Description: Access to calculated information of a line of text created 
//              by TextBlock. 
//
// History: 
//  04/25/2003 : [....] - Moving from Avalon branch.
//  06/25/2004 : [....] - Performance work.
//
//--------------------------------------------------------------------------- 

using System; 
using System.Diagnostics; 
using System.Collections.Generic;
using System.Collections.ObjectModel; 
using System.Windows;
using System.Windows.Controls;
using System.Windows.Documents;
using System.Windows.Media; 
using MS.Internal.Documents;
 
namespace MS.Internal.Text 
{
    ///  
    /// Provides access to calculated information of a line of text created
    /// by TextBlock.
    /// 
    internal sealed class TextLineResult : LineResult 
    {
        //------------------------------------------------------------------- 
        // 
        //  LineResult Methods
        // 
        //-------------------------------------------------------------------

        #region LineResult Methods
 
        /// 
        /// Retrieves a position matching distance within the line. 
        ///  
        /// Distance within the line.
        ///  
        /// A text position and its orientation matching or closest to the distance.
        /// 
        internal override ITextPointer GetTextPositionFromDistance(double distance)
        { 
            return _owner.GetTextPositionFromDistance(_dcp, distance, _layoutBox.Top, _index);
        } 
 
        /// 
        /// 
        /// 
        /// 
        /// 
        internal override bool IsAtCaretUnitBoundary(ITextPointer position) 
        {
            Debug.Assert(false); 
            return false; 
        }
 
        /// 
        ///
        /// 
        ///  
        /// 
        ///  
        internal override ITextPointer GetNextCaretUnitPosition(ITextPointer position, LogicalDirection direction) 
        {
            Debug.Assert(false); 
            return null;
        }

        ///  
        ///
        ///  
        ///  
        /// 
        internal override ITextPointer GetBackspaceCaretUnitPosition(ITextPointer position) 
        {
            Debug.Assert(false);
            return null;
        } 

        ///  
        /// 
        /// 
        ///  
        /// 
        /// 
         internal override ReadOnlyCollection GetGlyphRuns(ITextPointer start, ITextPointer end)
        { 
            Debug.Assert(false);
            return null; 
        } 

        ///  
        /// Retrieves the position after last content character of the line,
        /// not including any line breaks.
        /// 
        ///  
        /// The position after last content character of the line,
        /// not including any line breaks. 
        ///  
        internal override ITextPointer GetContentEndPosition()
        { 
            EnsureComplexData();
            return _owner.TextContainer.CreatePointerAtOffset(_dcp + _cchContent, LogicalDirection.Backward);
        }
 
        /// 
        /// Retrieves the position in the line pointing to the beginning of content 
        /// hidden by ellipses. 
        /// 
        ///  
        /// The position in the line pointing to the beginning of content
        /// hidden by ellipses.
        /// 
        internal override ITextPointer GetEllipsesPosition() 
        {
            EnsureComplexData(); 
            if (_cchEllipses != 0) 
            {
                return _owner.TextContainer.CreatePointerAtOffset(_dcp + _cch - _cchEllipses, LogicalDirection.Forward); 
            }
            return null;
        }
 
        /// 
        /// Retrieves the position after last content character of the line, 
        /// not including any line breaks. 
        /// 
        ///  
        /// The position after last content character of the line,
        /// not including any line breaks.
        /// 
        internal override int GetContentEndPositionCP() 
        {
            EnsureComplexData(); 
            return _dcp + _cchContent; 
        }
 
        /// 
        /// Retrieves the position in the line pointing to the beginning of content
        /// hidden by ellipses.
        ///  
        /// 
        /// The position in the line pointing to the beginning of content 
        /// hidden by ellipses. 
        /// 
        internal override int GetEllipsesPositionCP() 
        {
            EnsureComplexData();
            return _dcp + _cch - _cchEllipses;
        } 

        #endregion LineResult Methods 
 
        //--------------------------------------------------------------------
        // 
        //  LineResult Properties
        //
        //-------------------------------------------------------------------
 
        #region LineResult Properties
 
        ///  
        /// ITextPointer representing the beginning of the Line's contents.
        ///  
        internal override ITextPointer StartPosition
        {
            get
            { 
                if (_startPosition == null)
                { 
                    _startPosition = _owner.TextContainer.CreatePointerAtOffset(_dcp, LogicalDirection.Forward); 
                }
                return _startPosition; 
            }
        }

        ///  
        /// ITextPointer representing the end of the Line's contents.
        ///  
        internal override ITextPointer EndPosition 
        {
            get 
            {
                if (_endPosition == null)
                {
                    _endPosition = _owner.TextContainer.CreatePointerAtOffset(_dcp + _cch, LogicalDirection.Backward); 
                }
                return _endPosition; 
            } 
        }
 
        /// 
        /// Character position representing the beginning of the Line's contents.
        /// 
        internal override int StartPositionCP { get { return _dcp; } } 

        ///  
        /// Character position representing the end of the Line's contents. 
        /// 
        internal override int EndPositionCP { get { return _dcp + _cch; } } 

        /// 
        /// The bounding rectangle of the line.
        ///  
        internal override Rect LayoutBox { get { return _layoutBox; } }
 
        ///  
        /// The dominant baseline of the line.
        /// Distance from the top of the line to the baseline. 
        /// 
        internal override double Baseline { get { return _baseline; } }

        #endregion LineResult Properties 

        //-------------------------------------------------------------------- 
        // 
        //  Constructors
        // 
        //--------------------------------------------------------------------

        #region Constructors
 
        /// 
        /// Constructor. 
        ///  
        /// Owner of the line.
        /// Index of the first character in the line. 
        /// Number of all characters in the line.
        /// Rectangle of the line within a text paragraph.
        /// Distance from the top of the line to the baseline.
        /// Index of the line within the text block 
        internal TextLineResult(System.Windows.Controls.TextBlock owner, int dcp, int cch, Rect layoutBox, double baseline, int index)
        { 
            _owner = owner; 
            _dcp = dcp;
            _cch = cch; 
            _layoutBox = layoutBox;
            _baseline = baseline;
            _index = index;
            _cchContent = _cchEllipses = -1; 
        }
 
        #endregion Constructors 

        //------------------------------------------------------------------- 
        //
        //  Private Methods
        //
        //-------------------------------------------------------------------- 

        #region Private Methods 
 
        private void EnsureComplexData()
        { 
            if (_cchContent == -1)
            {
                _owner.GetLineDetails(_dcp, _index, _layoutBox.Top, out _cchContent, out _cchEllipses);
            } 
        }
 
        #endregion Private Methods 

        //------------------------------------------------------------------- 
        //
        //  Private Fields
        //
        //------------------------------------------------------------------- 

        #region Private Fields 
 
        /// 
        /// Owner of the line. 
        /// 
        private readonly System.Windows.Controls.TextBlock _owner;

        ///  
        /// Index of the first character in the line.
        ///  
        private readonly int _dcp; 

        ///  
        /// Number of all characters in the line.
        /// 
        private readonly int _cch;
 
        /// 
        /// Rectangle of the line within a text paragraph. 
        ///  
        private readonly Rect _layoutBox;
 
        /// 
        /// Index of the line within the TextBlock
        /// 
        private int _index; 

        ///  
        /// The dominant baseline of the line. Distance from the top of the 
        /// line to the baseline.
        ///  
        private readonly double _baseline;

        /// 
        /// ITextPointer representing the beginning of the Line's contents. 
        /// 
        private ITextPointer _startPosition; 
 
        /// 
        /// ITextPointer representing the end of the Line's contents. 
        /// 
        private ITextPointer _endPosition;

        ///  
        /// Number of characters of content of the line, not including any line breaks.
        ///  
        private int _cchContent; 

        ///  
        /// Number of characters hidden by ellipses.
        /// 
        private int _cchEllipses;
 
        #endregion Private Fields
    } 
} 

// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
// Copyright (c) Microsoft Corporation. All rights reserved.
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TextLineResult.cs source code in C# .NET

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