Redisplaying Squiggles

using System;

namespace StatNeth.Blaise.IDE.SourceEditorWPF.Language {


    public class IncludeSquiggleTagger : TaggerBase<ISquiggleTag> {

        private IEditorView view;
        private IEnumerable<ActiproSoftware.Text.Parsing.IParseError> errors = null;

        public IncludeSquiggleTagger(IEditorView view)
            : base("IncludeSquiggleTagger",
                new Ordering[] { new Ordering(TaggerKeys.Token, OrderPlacement.Before) }, view.SyntaxEditor.Document) {

            this.view = view;
            IDE.ProjectManagement.CachedParsingData.Instance.NotifyFileErrorsRefresh += new Shared.FileNameEventHandler(Instance_NotifyFileErrorsRefresh);
            ActivateTagging();

        }

        void Instance_NotifyFileErrorsRefresh(object sender, Shared.FileNameEventArgs e) {
            if (String.Compare(e.FileName, view.SyntaxEditor.Document.FileName) == 0)
                ActivateTagging();
        }

        public void ActivateTagging() {
            try {
                string fn = view.SyntaxEditor.Document.FileName;
                this.errors = from ActiproSoftware.Text.Parsing.IParseError pe in ProjectManagement.CachedParsingData.Instance.GetFileMessages(fn)
                              where BlaiseParseErrorProvider.IsValidSquiggle(pe, fn)
                              select pe;
            } catch {
                this.errors = null;
            }
            // Notify that tags changed
            this.OnTagsChanged(new TagsChangedEventArgs(new TextSnapshotRange(view.SyntaxEditor.Document.CurrentSnapshot, view.SyntaxEditor.Document.CurrentSnapshot.TextRange)));

        }


        public override IEnumerable<TagSnapshotRange<ISquiggleTag>> GetTags(NormalizedTextSnapshotRangeCollection snapshotRanges, object parameter) {
            if (this.errors != null) {
                foreach (ActiproSoftware.Text.Parsing.IParseError error in this.errors) {
                    TextRange tr = new TextRange(view.SyntaxEditor.Document.CurrentSnapshot.PositionToOffset(error.PositionRange.StartPosition),
                        view.SyntaxEditor.Document.CurrentSnapshot.PositionToOffset(error.PositionRange.LastPosition));

                    foreach (TextSnapshotRange range in snapshotRanges) {
                        if (range.IntersectsWith(tr)) {
                            SquiggleTag tag = new SquiggleTag();
                            tag.ClassificationType = error.ClassificationType;
                            // Yield the tag
                            yield return new TagSnapshotRange<ISquiggleTag>(
                                new TextSnapshotRange(view.SyntaxEditor.Document.CurrentSnapshot, tr), tag);
                        }
                    }

                }
            }
        }

    } // class
}