|
//---------------------------------------------------------------------------
//
// <copyright file="TextLineResult.cs" company="Microsoft">
// Copyright (C) Microsoft Corporation. All rights reserved.
// </copyright>
//
// Description: Access to calculated information of a line of text created
// by TextBlock.
//
// History:
// 04/25/2003 : Microsoft - Moving from Avalon branch.
// 06/25/2004 : Microsoft - 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
{
/// <summary>
/// Provides access to calculated information of a line of text created
/// by TextBlock.
/// </summary>
internal sealed class TextLineResult : LineResult
{
//-------------------------------------------------------------------
//
// LineResult Methods
//
//-------------------------------------------------------------------
#region LineResult Methods
/// <summary>
/// Retrieves a position matching distance within the line.
/// </summary>
/// <param name="distance">Distance within the line.</param>
/// <returns>
/// A text position and its orientation matching or closest to the distance.
/// </returns>
internal override ITextPointer GetTextPositionFromDistance(double distance)
{
return _owner.GetTextPositionFromDistance(_dcp, distance, _layoutBox.Top, _index);
}
/// <summary>
///
/// </summary>
/// <param name="position"></param>
/// <returns></returns>
internal override bool IsAtCaretUnitBoundary(ITextPointer position)
{
Debug.Assert(false);
return false;
}
/// <summary>
///
/// </summary>
/// <param name="position"></param>
/// <param name="direction"></param>
/// <returns></returns>
internal override ITextPointer GetNextCaretUnitPosition(ITextPointer position, LogicalDirection direction)
{
Debug.Assert(false);
return null;
}
/// <summary>
///
/// </summary>
/// <param name="position"></param>
/// <returns></returns>
internal override ITextPointer GetBackspaceCaretUnitPosition(ITextPointer position)
{
Debug.Assert(false);
return null;
}
/// <summary>
///
/// </summary>
/// <param name="start"></param>
/// <param name="end"></param>
/// <returns></returns>
internal override ReadOnlyCollection<GlyphRun> GetGlyphRuns(ITextPointer start, ITextPointer end)
{
Debug.Assert(false);
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 ITextPointer GetContentEndPosition()
{
EnsureComplexData();
return _owner.TextContainer.CreatePointerAtOffset(_dcp + _cchContent, LogicalDirection.Backward);
}
/// <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 ITextPointer GetEllipsesPosition()
{
EnsureComplexData();
if (_cchEllipses != 0)
{
return _owner.TextContainer.CreatePointerAtOffset(_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.TextContainer.CreatePointerAtOffset(_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.TextContainer.CreatePointerAtOffset(_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; } }
/// <summary>
/// Character position representing the end of the Line's contents.
/// </summary>
internal override int EndPositionCP { get { return _dcp + _cch; } }
/// <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>
/// <param name="index">Index of the line within the text block</param>
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
/// <summary>
/// Owner of the line.
/// </summary>
private readonly System.Windows.Controls.TextBlock _owner;
/// <summary>
/// Index of the first character in the line.
/// </summary>
private readonly int _dcp;
/// <summary>
/// Number of all characters in the line.
/// </summary>
private readonly int _cch;
/// <summary>
/// Rectangle of the line within a text paragraph.
/// </summary>
private readonly Rect _layoutBox;
/// <summary>
/// Index of the line within the TextBlock
/// </summary>
private int _index;
/// <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
}
}
|