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// 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.
//
// Description: Access to calculated information of a line of text created
// by TextParagraph.
//
using System;
using System.Diagnostics;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Windows.Documents;
using System.Windows;
using System.Windows.Media;
using MS.Internal.Documents;
namespace MS.Internal.PtsHost
{
/// <summary>
/// Provides access to calculated information of a line of text created
/// by TextParagraph
/// </summary>
internal sealed class TextParaLineResult : LineResult
{
//-------------------------------------------------------------------
//
// LineResult Methods
//
//-------------------------------------------------------------------
#region LineResult Methods
/// <summary>
/// Get text position corresponding to given distance from start of line
/// </summary>
/// <param name="distance">
/// Distance from start of line.
/// </param>
internal override ITextPointer GetTextPositionFromDistance(double distance)
{
return _owner.GetTextPositionFromDistance(_dcp, distance);
}
/// <summary>
/// Returns true if given position is at a caret unit boundary and false if not.
/// Not presently implemented.
/// </summary>
/// <param name="position">
/// TextPointer representing position to check for unit boundary
/// </param>
internal override bool IsAtCaretUnitBoundary(ITextPointer position)
{
Debug.Assert(false);
return false;
}
/// <summary>
/// Return next caret unit position from the specified position in the given direction.
/// Not presently implemented.
/// </summary>
/// <param name="position">
/// TextPointer for the current position
/// </param>
/// <param name="direction">
/// LogicalDirection in which next caret unit position is desired
/// </param>
internal override ITextPointer GetNextCaretUnitPosition(ITextPointer position, LogicalDirection direction)
{
Debug.Assert(false);
return null;
}
/// <summary>
/// Return next caret unit position from the specified position.
/// Not presently implemented.
/// </summary>
/// <param name="position">
/// TextPointer for the current position
/// </param>
internal override ITextPointer GetBackspaceCaretUnitPosition(ITextPointer position)
{
Debug.Assert(false);
return null;
}
/// <summary>
/// Return GlyphRun collection for the specified range of positions.
/// Not presently implemented.
/// </summary>
/// <param name="start">
/// ITextPointer marking start of range.
/// </param>
/// <param name="end">
/// ITextPointer marking end of range
/// </param>
internal override ReadOnlyCollection<GlyphRun> GetGlyphRuns(ITextPointer start, ITextPointer end)
{
Debug.Assert(false);
return null;
}
/// <summary>
/// Returns the position after last content character of the line,
/// not including any line breaks.
/// </summary>
internal override ITextPointer GetContentEndPosition()
{
EnsureComplexData();
return _owner.GetTextPosition(_dcp + _cchContent, LogicalDirection.Backward);
}
/// <summary>
/// Returns the position in the line pointing to the beginning of content
/// hidden by ellipses.
/// </summary>
internal override ITextPointer GetEllipsesPosition()
{
EnsureComplexData();
if (_cchEllipses != 0)
{
return _owner.GetTextPosition(_dcp + _cch - _cchEllipses, LogicalDirection.Forward);
}
return null;
}
/// <summary>
/// Retrieves the position after last content character of the line,
/// not including any line breaks.
/// </summary>
/// <returns>
/// The position after last content character of the line,
/// not including any line breaks.
/// </returns>
internal override int GetContentEndPositionCP()
{
EnsureComplexData();
return _dcp + _cchContent;
}
/// <summary>
/// Retrieves the position in the line pointing to the beginning of content
/// hidden by ellipses.
/// </summary>
/// <returns>
/// The position in the line pointing to the beginning of content
/// hidden by ellipses.
/// </returns>
internal override int GetEllipsesPositionCP()
{
EnsureComplexData();
return _dcp + _cch - _cchEllipses;
}
#endregion LineResult Methods
//-------------------------------------------------------------------
//
// LineResult Properties
//
//-------------------------------------------------------------------
#region LineResult Properties
/// <summary>
/// ITextPointer representing the beginning of the Line's contents.
/// </summary>
internal override ITextPointer StartPosition
{
get
{
if (_startPosition == null)
{
_startPosition = _owner.GetTextPosition(_dcp, LogicalDirection.Forward);
}
return _startPosition;
}
}
/// <summary>
/// ITextPointer representing the end of the Line's contents.
/// </summary>
internal override ITextPointer EndPosition
{
get
{
if (_endPosition == null)
{
_endPosition = _owner.GetTextPosition(_dcp + _cch, LogicalDirection.Backward);
}
return _endPosition;
}
}
/// <summary>
/// Character position representing the beginning of the Line's contents.
/// </summary>
internal override int StartPositionCP
{
get
{
return _dcp + _owner.Paragraph.ParagraphStartCharacterPosition;
}
}
/// <summary>
/// Character position representing the end of the Line's contents.
/// </summary>
internal override int EndPositionCP
{
get
{
return _dcp + _cch + _owner.Paragraph.ParagraphStartCharacterPosition;
}
}
/// <summary>
/// The bounding rectangle of the line.
/// </summary>
internal override Rect LayoutBox
{
get
{
return _layoutBox;
}
}
/// <summary>
/// The dominant baseline of the line.
/// Distance from the top of the line to the baseline.
/// </summary>
internal override double Baseline
{
get
{
return _baseline;
}
}
#endregion LineResult Properties
//-------------------------------------------------------------------
//
// Constructors
//
//-------------------------------------------------------------------
#region Constructors
/// <summary>
/// Constructor.
/// </summary>
/// <param name="owner">Owner of the line.</param>
/// <param name="dcp">Index of the first character in the line.</param>
/// <param name="cch">Number of all characters in the line.</param>
/// <param name="layoutBox">Rectangle of the line within a text paragraph.</param>
/// <param name="baseline">Distance from the top of the line to the baseline.</param>
internal TextParaLineResult(TextParaClient owner, int dcp, int cch, Rect layoutBox, double baseline)
{
_owner = owner;
_dcp = dcp;
_cch = cch;
_layoutBox = layoutBox;
_baseline = baseline;
_cchContent = _cchEllipses = -1;
}
#endregion Constructors
//-------------------------------------------------------------------
//
// Internal Properties
//
//-------------------------------------------------------------------
#region Internal Properties
/// <summary>
/// Last character index in the line.
/// </summary>
internal int DcpLast
{
get
{
return _dcp + _cch;
}
set
{
_cch = value - _dcp;
}
}
#endregion Internal Properties
//-------------------------------------------------------------------
//
// Private Methods
//
//-------------------------------------------------------------------
#region Private Methods
/// <summary>
/// Ensure complex data in line
/// </summary>
private void EnsureComplexData()
{
if (_cchContent == -1)
{
_owner.GetLineDetails(_dcp, out _cchContent, out _cchEllipses);
}
}
#endregion Private Methods
//-------------------------------------------------------------------
//
// Private Fields
//
//-------------------------------------------------------------------
#region Private Fields
/// <summary>
/// Owner of the line.
/// </summary>
private readonly TextParaClient _owner;
/// <summary>
/// Index of the first character in the line.
/// </summary>
private int _dcp;
/// <summary>
/// Number of all characters in the line.
/// </summary>
private int _cch;
/// <summary>
/// Rectangle of the line within a text paragraph.
/// </summary>
private readonly Rect _layoutBox;
/// <summary>
/// The dominant baseline of the line. Distance from the top of the
/// line to the baseline.
/// </summary>
private readonly double _baseline;
/// <summary>
/// ITextPointer representing the beginning of the Line's contents.
/// </summary>
private ITextPointer _startPosition;
/// <summary>
/// ITextPointer representing the end of the Line's contents.
/// </summary>
private ITextPointer _endPosition;
/// <summary>
/// Number of characters of content of the line, not including any line breaks.
/// </summary>
private int _cchContent;
/// <summary>
/// Number of characters hidden by ellipses.
/// </summary>
private int _cchEllipses;
#endregion Private Fields
}
}
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