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//---------------------------------------------------------------------------
//
// File: ITextSelection.cs
//
// Copyright (C) Microsoft Corporation. All rights reserved.
//
// Description:
// A part of TextOM abstraction layer.
// Contains an extension of ITextRange.
//
//---------------------------------------------------------------------------
namespace System.Windows.Documents
{
using System.Diagnostics;
using System.Collections.Generic;
using System.Globalization;
using System.Windows.Input;
using System.Threading;
using MS.Internal.Documents;
using MS.Win32;
/// <summary>
/// The TextSelection class encapsulates selection state for the TextEditor
/// class. It has no public constructor, but is exposed via a public property
/// on RichTextBox.
/// </summary>
internal interface ITextSelection : ITextRange
{
//------------------------------------------------------
//
// Internal Methods
//
//------------------------------------------------------
#region Internal Methods
//......................................................
//
// Extending via movingEnd movements
//
//......................................................
/// <summary>
/// Creates empty selection - corresponding to a caret position.
/// </summary>
/// <param name="caretPosition">
/// Position to which the caret is set.
/// </param>
/// <param name="direction">
/// Used for normalizing a position, and for its gravity in the following
/// behavior when content change happens around.
/// The direction can be ignored though if there is a space
/// in that direction, or if the position happens to be at line wrapping.
/// In case of a space caret chooses a direction opposite to a space;
/// in case of line wrapping, Forward direction is taken to set caret
/// to the beginning of a next line.
/// Both exceptions can be controlled by boolean parameters:
/// allowStopAtLineEnd and allowStopNearSpace
/// </param>
/// <param name="allowStopAtLineEnd">
/// True allows Backward normalization even when the caretPsotion is at
/// line wrapping, so that visually it will appear at the end of a first
/// of wrapped lines
/// </param>
/// <param name="allowStopNearSpace">
/// True allows normalization towards a space, event when the caretPosition is
/// at formatting switching position.
/// </param>
void SetCaretToPosition(ITextPointer caretPosition, LogicalDirection direction, bool allowStopAtLineEnd, bool allowStopNearSpace);
/// <summary>
/// Selects a content starting from a previous anchorPosition to the given
/// textPosition.
/// Sets visual orientation of a position to textPosition.LogicalDirection.
/// </summary>
void ExtendToPosition(ITextPointer textPosition);
/// <summary>
/// </summary>
bool ExtendToNextInsertionPosition(LogicalDirection direction);
// Returns true if the text matching a pixel position falls within
// the selection.
bool Contains(Point point);
//......................................................
//
// Interaction with Selection host
//
//......................................................
// TODO: This section must go away when TextEditor merged with TextSelection)
// Called by TextEditor.OnDetach, when the behavior is shut down.
void OnDetach();
// Called by Got/LostKeyboardFocus and LostFocusedElement handlers
void UpdateCaretAndHighlight();
// ITextView.Updated event listener.
// Called by the TextEditor.
void OnTextViewUpdated();
// Perform any cleanup necessary when removing the current UiScope
// from the visual tree (eg, during a template change).
void DetachFromVisualTree();
void RefreshCaret();
void OnInterimSelectionChanged(bool interimSelection);
//......................................................
//
// Selection Heuristics
//
//......................................................
// Moves the selection to the mouse cursor position.
// Extends the active end if extend == true, otherwise the selection
// is collapsed to a caret.
void SetSelectionByMouse(ITextPointer cursorPosition, Point cursorMousePoint);
// Extends the selection to the mouse cursor position.
void ExtendSelectionByMouse(ITextPointer cursorPosition, bool forceWordSelection, bool forceParagraphSelection);
//......................................................
//
// Table Selection
//
//......................................................
/// <summary>
/// Extends table selection by one row in a given direction
/// </summary>
/// <param name="direction">
/// LogicalDirection.Forward means moving active cell one row down,
/// LogicalDirection.Backward - one row up.
/// </param>
bool ExtendToNextTableRow(LogicalDirection direction);
// Called after a caret navigation, to signal that the next caret
// scroll-into-view should include hueristics to include following
// text.
void OnCaretNavigation();
// Forces a synchronous layout validation, up to the selection moving position.
void ValidateLayout();
#endregion Internal Methods
//------------------------------------------------------
//
// Internal Properties
//
//------------------------------------------------------
#region Internal Properties
TextEditor TextEditor { get; }
ITextView TextView { get; }
// True if the current seleciton is for interim character.
// Korean Interim character is now invisilbe selection (no highlight) and the controls needs to
// have the block caret to indicate the interim character.
// This should be updated by TextStore.
bool IsInterimSelection { get; }
/// <summary>
/// Static end of a selection.
/// LogicalDirection of this pointer is an orientation of a visual caret
/// </summary>
/// <returns></returns>
ITextPointer AnchorPosition { get; }
/// <summary>
/// Active end of a selection.
/// LogicalDirection of this pointer is an orientation of a visual caret
/// </summary>
/// <returns></returns>
ITextPointer MovingPosition { get; }
// Caret associated with this TextSelection.
CaretElement CaretElement { get; }
// Returns true iff there are no additional insertion positions are either
// end of the selection.
bool CoversEntireContent { get; }
#endregion Internal Properties
}
}
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