|
// 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:
// DocumentSequenceTextView implements TextView for DocumentSequence
// to support text editing (e.g Selection).
//
namespace System.Windows.Documents
{
using MS.Internal.Documents;
using MS.Internal;
using MS.Utility;
using System;
using System.Collections;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Diagnostics;
using System.Windows;
using System.Windows.Media;
using System.Windows.Shapes;
/// <summary>
/// DocumentSequenceTextView implements TextView for DocumentSequence
/// to support text editing (e.g Selection).
/// </summary>
internal sealed class DocumentSequenceTextView : TextViewBase
{
//------------------------------------------------------
//
// Constructors
//
//------------------------------------------------------
#region Constructors
/// <summary>
/// Constructor.
/// </summary>
internal DocumentSequenceTextView(FixedDocumentSequenceDocumentPage docPage)
{
_docPage = docPage;
}
#endregion Constructors
//------------------------------------------------------
//
// Internal Methods
//
//------------------------------------------------------
#region Internal Methods
/// <summary>
/// Retrieves a position matching a point.
/// </summary>
/// <param name="point">
/// Point in pixel coordinates to test.
/// </param>
/// <param name="snapToText">
/// If true, this method must always return a positioned text position
/// (the closest position as calculated by the control's heuristics).
/// If false, this method should return null position, if the test
/// point does not fall within any character bounding box.
/// </param>
/// <returns>
/// A text position and its orientation matching or closest to the point.
/// </returns>
/// <exception cref="System.InvalidOperationException">
/// Throws InvalidOperationException if IsValid is false.
/// If IsValid returns false, Validate method must be called before
/// calling this method.
/// </exception>
internal override ITextPointer GetTextPositionFromPoint(Point point, bool snapToText)
{
DocumentsTrace.FixedDocumentSequence.TextOM.Trace($"GetTextPositionFromPoint {point}-{snapToText}");
DocumentSequenceTextPointer tp = null;
LogicalDirection edge = LogicalDirection.Forward;
if (ChildTextView != null)
{
ITextPointer childOTP = ChildTextView.GetTextPositionFromPoint(point, snapToText);
if (childOTP != null)
{
tp = new DocumentSequenceTextPointer(ChildBlock, childOTP);
edge = childOTP.LogicalDirection;
}
}
// When snapToText is true, ChildTextView.GetTextPositionFromPoint will guranttee to
// return a non-null position.
// In current code, ChildTextView can't be null.
return tp == null ? null : DocumentSequenceTextPointer.CreatePointer(tp, edge);
}
/// <summary>
/// Retrieves the height and offset, in pixels, of the edge of
/// the object/character represented by position.
/// </summary>
/// <param name="position">
/// Position of an object/character.
/// </param>
/// <param name="transform">
/// Transform to be applied to returned rect
/// </param>
/// <returns>
/// The height, in pixels, of the edge of the object/character
/// represented by position.
/// </returns>
/// <exception cref="System.InvalidOperationException">
/// Throws InvalidOperationException if IsValid is false.
/// If IsValid returns false, Validate method must be called before
/// calling this method.
/// </exception>
/// <remarks>
/// Rect.Width is always 0.
///
/// If the document is empty, then this method returns the expected
/// height of a character, if placed at the specified position.
/// </remarks>
internal override Rect GetRawRectangleFromTextPosition(ITextPointer position, out Transform transform)
{
DocumentsTrace.FixedDocumentSequence.TextOM.Trace($"GetRawRectangleFromTextPosition {position} {position.LogicalDirection}");
DocumentSequenceTextPointer tp = null;
// Initialize transform to identity
transform = Transform.Identity;
if (position != null)
{
tp = _docPage.FixedDocumentSequence.TextContainer.VerifyPosition(position);
}
if (tp != null)
{
if (ChildTextView != null)
{
if (ChildTextView.TextContainer == tp.ChildBlock.ChildContainer)
{
return ChildTextView.GetRawRectangleFromTextPosition(tp.ChildPointer.CreatePointer(position.LogicalDirection), out transform);
}
}
}
return Rect.Empty;
}
/// <summary>
/// <see cref="TextViewBase.GetTightBoundingGeometryFromTextPositions"/>
/// </summary>
internal override Geometry GetTightBoundingGeometryFromTextPositions(ITextPointer startPosition, ITextPointer endPosition)
{
if (startPosition != null && endPosition != null && ChildTextView != null)
{
DocumentSequenceTextPointer startTp = null;
DocumentSequenceTextPointer endTp = null;
startTp = _docPage.FixedDocumentSequence.TextContainer.VerifyPosition(startPosition);
endTp = _docPage.FixedDocumentSequence.TextContainer.VerifyPosition(endPosition);
if (startTp != null && endTp != null)
{
return ChildTextView.GetTightBoundingGeometryFromTextPositions(startTp.ChildPointer, endTp.ChildPointer);
}
}
return (new PathGeometry());;
}
/// <summary>
/// Retrieves an oriented text position matching position advanced by
/// a number of lines from its initial position.
/// </summary>
/// <param name="position">
/// Initial text position of an object/character.
/// </param>
/// <param name="suggestedX">
/// The suggested X offset, in pixels, of text position on the destination
/// line. If suggestedX is set to Double.NaN it will be ignored, otherwise
/// the method will try to find a position on the destination line closest
/// to suggestedX.
/// </param>
/// <param name="count">
/// Number of lines to advance. Negative means move backwards.
/// </param>
/// <param name="newSuggestedX">
/// newSuggestedX is the offset at the position moved (useful when moving
/// between columns or pages).
/// </param>
/// <param name="linesMoved">
/// linesMoved indicates the number of lines moved, which may be less
/// than count if there is no more content.
/// </param>
/// <returns>
/// A TextPointer and its orientation matching suggestedX on the
/// destination line.
/// </returns>
/// <exception cref="System.InvalidOperationException">
/// Throws InvalidOperationException if IsValid is false.
/// If IsValid returns false, Validate method must be called before
/// calling this method.
/// </exception>
internal override ITextPointer GetPositionAtNextLine(ITextPointer position, double suggestedX, int count, out double newSuggestedX, out int linesMoved)
{
newSuggestedX = suggestedX;
linesMoved = count;
DocumentsTrace.FixedDocumentSequence.TextOM.Trace($"GetPositionAtNextLine {position} {position.LogicalDirection} {suggestedX} {count} ");
DocumentSequenceTextPointer newTp = null;
LogicalDirection newEdge = LogicalDirection.Forward;
DocumentSequenceTextPointer tp = null;
if (position != null)
{
tp = _docPage.FixedDocumentSequence.TextContainer.VerifyPosition(position);
}
// Note we do not handle cross page navigation
if (tp != null)
{
if (ChildTextView != null)
{
if (ChildTextView.TextContainer == tp.ChildBlock.ChildContainer)
{
ITextPointer childOTP = ChildTextView.GetPositionAtNextLine(tp.ChildPointer.CreatePointer(position.LogicalDirection), suggestedX, count, out newSuggestedX, out linesMoved);
if (childOTP != null)
{
newTp = new DocumentSequenceTextPointer(ChildBlock, childOTP);
newEdge = childOTP.LogicalDirection;
}
}
}
}
return DocumentSequenceTextPointer.CreatePointer(newTp, newEdge);
}
/// <summary>
/// Determines if a position is located between two caret units.
/// </summary>
/// <param name="position">
/// Position to test.
/// </param>
/// <returns>
/// Returns true if the specified position precedes or follows
/// the first or last code point of a caret unit, respectively.
/// </returns>
/// <exception cref="System.InvalidOperationException">
/// Throws InvalidOperationException if IsValid is false.
/// If IsValid returns false, Validate method must be called before
/// calling this method.
/// </exception>
/// <remarks>
/// In the context of this method, "caret unit" refers to a group
/// of one or more Unicode code points that map to a single rendered
/// glyph.
/// </remarks>
internal override bool IsAtCaretUnitBoundary(ITextPointer position)
{
Invariant.Assert(position != null);
ArgumentNullException.ThrowIfNull(position);
//Verify the position and propagate the call to the child text view
Invariant.Assert(ChildTextView != null);
DocumentSequenceTextPointer ftp = this.DocumentSequenceTextContainer.VerifyPosition(position);
return this.ChildTextView.IsAtCaretUnitBoundary(ftp.ChildPointer);
}
/// <summary>
/// Finds the next position at the edge of a caret unit in
/// specified direction.
/// </summary>
/// <param name="position">
/// Initial text position of an object/character.
/// </param>
/// <param name="direction">
/// If Forward, this method returns the "caret unit" position following
/// the initial position.
/// If Backward, this method returns the caret unit" position preceding
/// the initial position.
/// </param>
/// <returns>
/// The next caret unit break position in specified direction.
/// </returns>
/// <exception cref="System.InvalidOperationException">
/// Throws InvalidOperationException if IsValid is false.
/// If IsValid returns false, Validate method must be called before
/// calling this method.
/// </exception>
/// <remarks>
/// In the context of this method, "caret unit" refers to a group of one
/// or more Unicode code points that map to a single rendered glyph.
///
/// If position is located between two caret units, this method returns
/// a new position located at the opposite edge of the caret unit in
/// the indicated direction.
/// If position is located within a group of Unicode code points that map
/// to a single caret unit, this method returns a new position at
/// the indicated edge of the containing caret unit.
/// If position is located at the beginning of end of content -- there is
/// no content in the indicated direction -- then this method returns
/// a position located at the same location as initial position.
/// </remarks>
internal override ITextPointer GetNextCaretUnitPosition(ITextPointer position, LogicalDirection direction)
{
Invariant.Assert(position != null);
ArgumentNullException.ThrowIfNull(position);
//Verify the position and propagate the call to the child text view
Invariant.Assert(ChildTextView != null);
DocumentSequenceTextPointer ftp = this.DocumentSequenceTextContainer.VerifyPosition(position);
return this.ChildTextView.GetNextCaretUnitPosition(ftp.ChildPointer, direction);
}
/// <summary>
/// Finds the previous position at the edge of a caret after backspacing.
/// </summary>
/// <param name="position">
/// Initial text position of an object/character.
/// </param>
/// <returns>
/// The previous caret unit break position after backspacing.
/// </returns>
/// <exception cref="System.InvalidOperationException">
/// Throws InvalidOperationException if IsValid is false.
/// If IsValid returns false, Validate method must be called before
/// calling this method.
/// </exception>
internal override ITextPointer GetBackspaceCaretUnitPosition(ITextPointer position)
{
Invariant.Assert(position != null);
ArgumentNullException.ThrowIfNull(position);
//Verify the position and propagate the call to the child text view
Invariant.Assert(ChildTextView != null);
DocumentSequenceTextPointer ftp = this.DocumentSequenceTextContainer.VerifyPosition(position);
return this.ChildTextView.GetBackspaceCaretUnitPosition(ftp.ChildPointer);
}
/// <summary>
/// Returns a TextSegment that spans the line on which position is located.
/// </summary>
/// <param name="position">
/// Any oriented text position on the line.
/// </param>
/// <returns>
/// TextSegment that spans the line on which position is located.
/// </returns>
/// <exception cref="System.InvalidOperationException">
/// Throws InvalidOperationException if IsValid is false.
/// If IsValid returns false, Validate method must be called before
/// calling this method.
/// </exception>
internal override TextSegment GetLineRange(ITextPointer position)
{
DocumentsTrace.FixedDocumentSequence.TextOM.Trace($"GetLineRange {position} {position.LogicalDirection}");
DocumentSequenceTextPointer tpStart = null;
DocumentSequenceTextPointer tpEnd = null;
DocumentSequenceTextPointer tpLine = null;
if (position != null)
{
if (ChildTextView != null)
{
tpLine = _docPage.FixedDocumentSequence.TextContainer.VerifyPosition(position);
if (ChildTextView.TextContainer == tpLine.ChildBlock.ChildContainer)
{
TextSegment childTR = ChildTextView.GetLineRange(tpLine.ChildPointer.CreatePointer(position.LogicalDirection));
if (!childTR.IsNull)
{
tpStart = new DocumentSequenceTextPointer(ChildBlock, childTR.Start);
tpEnd = new DocumentSequenceTextPointer(ChildBlock, childTR.End);
return new TextSegment(tpStart, tpEnd, true);
}
}
}
}
return TextSegment.Null;
}
/// <summary>
/// Provides a collection of glyph properties corresponding to runs
/// of Unicode code points.
/// </summary>
/// <param name="start">
/// A position preceding the first code point to examine.
/// </param>
/// <param name="end">
/// A position following the last code point to examine.
/// </param>
/// <returns>
/// A collection of glyph property runs.
/// </returns>
/// <exception cref="System.InvalidOperationException">
/// Throws InvalidOperationException if IsValid is false.
/// If IsValid returns false, Validate method must be called before
/// calling this method.
/// </exception>
/// <remarks>
/// A "glyph" in this context is the lowest level rendered representation
/// of text. Each entry in the output array describes a constant run of
/// properties on the glyphs corresponding to a range of Unicode code points.
/// With this array, it's possible to enumerate the glpyh properties for
/// each code point in the specified text run.
/// </remarks>
internal override ReadOnlyCollection<GlyphRun> GetGlyphRuns(ITextPointer start, ITextPointer end)
{
throw new NotImplementedException();
}
/// <summary>
/// Determines whenever TextView contains specified position.
/// </summary>
/// <param name="position">
/// A position to test.
/// </param>
/// <returns>
/// True if TextView contains specified text position.
/// Otherwise returns false.
/// </returns>
/// <exception cref="System.InvalidOperationException">
/// Throws InvalidOperationException if IsValid is false.
/// If IsValid returns false, Validate method must be called before
/// calling this method.
/// </exception>
internal override bool Contains(ITextPointer position)
{
DocumentsTrace.FixedDocumentSequence.TextOM.Trace($"Contains {position} {position.LogicalDirection}");
DocumentSequenceTextPointer tp = null;
if (position != null)
{
tp = _docPage.FixedDocumentSequence.TextContainer.VerifyPosition(position);
}
// Note we do not handle cross page navigation
if (tp != null)
{
if (ChildTextView != null)
{
if (ChildTextView.TextContainer == tp.ChildBlock.ChildContainer)
{
return ChildTextView.Contains(tp.ChildPointer.CreatePointer(position.LogicalDirection));
}
}
}
return false;
}
/// <summary>
/// Makes sure that TextView is in a clean layout state and it is
/// possible to retrieve layout related data.
/// </summary>
/// <remarks>
/// If IsValid returns false, it is required to call this method
/// before calling any other method on TextView.
/// Validate method might be very expensive, because it may lead
/// to full layout update.
/// </remarks>
internal override bool Validate()
{
if (ChildTextView != null)
{
ChildTextView.Validate();
}
return ((ITextView)this).IsValid;
}
/// <see cref="ITextView.Validate(Point)"/>
internal override bool Validate(Point point)
{
if (ChildTextView != null)
{
ChildTextView.Validate(point);
}
return ((ITextView)this).IsValid;
}
#endregion Internal Methods
//------------------------------------------------------
//
// Internal Properties
//
//------------------------------------------------------
#region Internal Properties
/// <summary>
/// </summary>
internal override UIElement RenderScope
{
get
{
Visual visual = _docPage.Visual;
while (visual != null && !(visual is UIElement))
{
visual = VisualTreeHelper.GetParent(visual) as Visual;
}
return visual as UIElement;
}
}
/// <summary>
/// TextContainer that stores content.
/// </summary>
internal override ITextContainer TextContainer
{
get
{
return this._docPage.FixedDocumentSequence.TextContainer;
}
}
/// <summary>
/// Determines whenever layout is in clean state and it is possible
/// to retrieve layout related data.
/// </summary>
internal override bool IsValid
{
get
{
if (ChildTextView != null)
{
return ChildTextView.IsValid;
}
return true;
}
}
/// <summary>
/// <see cref="ITextView.RendersOwnSelection"/>
/// </summary>
internal override bool RendersOwnSelection
{
get
{
return true;
}
}
/// <summary>
/// Collection of TextSegments representing content of the TextView.
/// </summary>
internal override ReadOnlyCollection<TextSegment> TextSegments
{
get
{
if (_textSegments == null)
{
ReadOnlyCollection<TextSegment> childSegments = ChildTextView.TextSegments;
if (childSegments != null)
{
List<TextSegment> parentSegments = new List<TextSegment>(childSegments.Count);
foreach (TextSegment segment in childSegments)
{
DocumentSequenceTextPointer ptpStart, ptpEnd;
ptpStart = this._docPage.FixedDocumentSequence.TextContainer.MapChildPositionToParent(segment.Start);
ptpEnd = this._docPage.FixedDocumentSequence.TextContainer.MapChildPositionToParent(segment.End);
parentSegments.Add(new TextSegment(ptpStart, ptpEnd,true));
}
_textSegments = new ReadOnlyCollection<TextSegment>(parentSegments);
}
}
return _textSegments;
}
}
#endregion Internal Properties
//------------------------------------------------------
//
// Private Properties
//
//------------------------------------------------------
#region Private Properties
private ITextView ChildTextView
{
get
{
if (_childTextView == null)
{
IServiceProvider isp = _docPage.ChildDocumentPage as IServiceProvider;
if (isp != null)
{
_childTextView = (ITextView)isp.GetService(typeof(ITextView));
}
}
return _childTextView;
}
}
private ChildDocumentBlock ChildBlock
{
get
{
if (_childBlock == null)
{
_childBlock = _docPage.FixedDocumentSequence.TextContainer.FindChildBlock(_docPage.ChildDocumentReference);
}
return _childBlock;
}
}
private DocumentSequenceTextContainer DocumentSequenceTextContainer
{
get
{
return _docPage.FixedDocumentSequence.TextContainer;
}
}
#endregion Private Properties
//------------------------------------------------------
//
// Private Fields
//
//------------------------------------------------------
// The FixedDocumentSequenceDocumentPage for this TextView
private readonly FixedDocumentSequenceDocumentPage _docPage;
private ITextView _childTextView;
private ReadOnlyCollection<TextSegment> _textSegments;
private ChildDocumentBlock _childBlock;
}
}
|