Represents a simple context used to extend the default brace completion behaviors to include language-specific behaviors such as parsing and formatting.
상속: IBraceCompletionContext
        /// <summary>
        /// Creates an <see cref="IBraceCompletionContext"/> to handle
        /// language-specific actions such as parsing and formatting.
        /// </summary>
        /// <remarks>
        /// Opening points within strings and comments are usually invalid points to start
        /// an <see cref="IBraceCompletionSession"/> and will return false.
        /// </remarks>
        /// <param name="textView">View containing the <paramref name="openingPoint"/>.</param>
        /// <param name="openingPoint">Insertion point of the <paramref name="openingBrace"/>.</param>
        /// <param name="openingBrace">Opening brace that has been typed by the user.</param>
        /// <param name="closingBrace">Closing brace character</param>
        /// <param name="context">Brace completion context if created.</param>
        /// <returns>Returns true if the <paramref name="openingPoint"/>
        /// was a valid point in the buffer to start a <see cref="IBraceCompletionSession"/>.
        /// </returns>
        public bool TryCreateContext(ITextView textView, SnapshotPoint openingPoint, char openingBrace, char closingBrace, out IBraceCompletionContext context)
        {
            IREditorDocument document = REditorDocument.TryFromTextBuffer(openingPoint.Snapshot.TextBuffer);

            if (document != null)
            {
                var ast = document.EditorTree.AstRoot;

                // We don't want to complete inside strings
                if (ast.IsPositionInsideString(openingPoint.Position))
                {
                    context = null;
                    return(false);
                }

                // We don't want to complete inside comments
                int index = ast.Comments.GetItemContaining(openingPoint.Position);
                if (index >= 0)
                {
                    context = null;
                    return(false);
                }
            }
            context = new BraceCompletionContext();
            return(true);
        }
        /// <summary>
        /// Creates an <see cref="IBraceCompletionContext"/> to handle 
        /// language-specific actions such as parsing and formatting.
        /// </summary>
        /// <remarks>
        /// Opening points within strings and comments are usually invalid points to start 
        /// an <see cref="IBraceCompletionSession"/> and will return false.
        /// </remarks>
        /// <param name="textView">View containing the <paramref name="openingPoint"/>.</param>
        /// <param name="openingPoint">Insertion point of the <paramref name="openingBrace"/>.</param>
        /// <param name="openingBrace">Opening brace that has been typed by the user.</param>
        /// <param name="closingBrace">Closing brace character</param>
        /// <param name="context">Brace completion context if created.</param>
        /// <returns>Returns true if the <paramref name="openingPoint"/> 
        /// was a valid point in the buffer to start a <see cref="IBraceCompletionSession"/>.
        /// </returns>
        public bool TryCreateContext(ITextView textView, SnapshotPoint openingPoint, char openingBrace, char closingBrace, out IBraceCompletionContext context) {
            IREditorDocument document = REditorDocument.TryFromTextBuffer(openingPoint.Snapshot.TextBuffer);
            if (document != null) {
                var ast = document.EditorTree.AstRoot;

                // We don't want to complete inside strings
                if (ast.IsPositionInsideString(openingPoint.Position)) {
                    context = null;
                    return false;
                }

                // We don't want to complete inside comments
                if (document.IsPositionInComment(openingPoint.Position)) {
                    context = null;
                    return false;
                }
            }
            context = new BraceCompletionContext(_shell);
            return true;
        }
        /// <summary>
        /// Creates an <see cref="IBraceCompletionContext"/> to handle 
        /// language-specific actions such as parsing and formatting.
        /// </summary>
        /// <remarks>
        /// Opening points within strings and comments are usually invalid points to start 
        /// an <see cref="IBraceCompletionSession"/> and will return false.
        /// </remarks>
        /// <param name="textView">View containing the <paramref name="openingPoint"/>.</param>
        /// <param name="openingPoint">Insertion point of the <paramref name="openingBrace"/>.</param>
        /// <param name="openingBrace">Opening brace that has been typed by the user.</param>
        /// <param name="closingBrace">Closing brace character</param>
        /// <param name="context">Brace completion context if created.</param>
        /// <returns>Returns true if the <paramref name="openingPoint"/> 
        /// was a valid point in the buffer to start a <see cref="IBraceCompletionSession"/>.
        /// </returns>
        public bool TryCreateContext(ITextView textView, SnapshotPoint openingPoint, char openingBrace, char closingBrace, out IBraceCompletionContext context) {
            IREditorDocument document = REditorDocument.TryFromTextBuffer(openingPoint.Snapshot.TextBuffer);
            if (document != null) {
                IEditorTree tree = document.EditorTree;
                tree.EnsureTreeReady();

                // We don't want to complete inside strings
                if (tree.AstRoot.IsPositionInsideString(openingPoint.Position)) {
                    context = null;
                    return false;
                }

                // We don't want to complete inside comments
                int index = tree.AstRoot.Comments.GetItemContaining(openingPoint.Position);
                if (index >= 0) {
                    context = null;
                    return false;
                }
            }
            context = new BraceCompletionContext();
            return true;
        }