MERGE

1 files changed, 213 insertions, 0 deletions

diff --git a/Software/Visual_Studio/Scripting/Tango.Scripting.Editors/Snippets/SnippetReplaceableTextElement.cs b/Software/Visual_Studio/Scripting/Tango.Scripting.Editors/Snippets/SnippetReplaceableTextElement.cs
new file mode 100644
index 000000000..9bf872f11
--- /dev/null
+++ b/Software/Visual_Studio/Scripting/Tango.Scripting.Editors/Snippets/SnippetReplaceableTextElement.cs
@@ -0,0 +1,213 @@
+// Copyright (c) AlphaSierraPapa for the SharpDevelop Team (for details please see \doc\copyright.txt)
+// This code is distributed under the GNU LGPL (for details please see \doc\license.txt)
+
+using System;
+using System.Linq;
+using System.Windows;
+using System.Windows.Documents;
+using System.Windows.Media;
+using System.Windows.Threading;
+
+using Tango.Scripting.Editors.Document;
+using Tango.Scripting.Editors.Rendering;
+
+namespace Tango.Scripting.Editors.Snippets
+{
+	/// <summary>
+	/// Text element that is supposed to be replaced by the user.
+	/// Will register an <see cref="IReplaceableActiveElement"/>.
+	/// </summary>
+	[Serializable]
+	public class SnippetReplaceableTextElement : SnippetTextElement
+	{
+		/// <inheritdoc/>
+		public override void Insert(InsertionContext context)
+		{
+			int start = context.InsertionPosition;
+			base.Insert(context);
+			int end = context.InsertionPosition;
+			context.RegisterActiveElement(this, new ReplaceableActiveElement(context, start, end));
+		}
+		
+		/// <inheritdoc/>
+		public override Inline ToTextRun()
+		{
+			return new Italic(base.ToTextRun());
+		}
+	}
+	
+	/// <summary>
+	/// Interface for active element registered by <see cref="SnippetReplaceableTextElement"/>.
+	/// </summary>
+	public interface IReplaceableActiveElement : IActiveElement
+	{
+		/// <summary>
+		/// Gets the current text inside the element.
+		/// </summary>
+		string Text { get; }
+		
+		/// <summary>
+		/// Occurs when the text inside the element changes.
+		/// </summary>
+		event EventHandler TextChanged;
+	}
+	
+	sealed class ReplaceableActiveElement : IReplaceableActiveElement, IWeakEventListener
+	{
+		readonly InsertionContext context;
+		readonly int startOffset, endOffset;
+		TextAnchor start, end;
+		
+		public ReplaceableActiveElement(InsertionContext context, int startOffset, int endOffset)
+		{
+			this.context = context;
+			this.startOffset = startOffset;
+			this.endOffset = endOffset;
+		}
+		
+		void AnchorDeleted(object sender, EventArgs e)
+		{
+			context.Deactivate(new SnippetEventArgs(DeactivateReason.Deleted));
+		}
+		
+		public void OnInsertionCompleted()
+		{
+			// anchors must be created in OnInsertionCompleted because they should move only
+			// due to user insertions, not due to insertions of other snippet parts
+			start = context.Document.CreateAnchor(startOffset);
+			start.MovementType = AnchorMovementType.BeforeInsertion;
+			end = context.Document.CreateAnchor(endOffset);
+			end.MovementType = AnchorMovementType.AfterInsertion;
+			start.Deleted += AnchorDeleted;
+			end.Deleted += AnchorDeleted;
+			
+			// Be careful with references from the document to the editing/snippet layer - use weak events
+			// to prevent memory leaks when the text area control gets dropped from the UI while the snippet is active.
+			// The InsertionContext will keep us alive as long as the snippet is in interactive mode.
+			TextDocumentWeakEventManager.TextChanged.AddListener(context.Document, this);
+			
+			background = new Renderer { Layer = KnownLayer.Background, element = this };
+			foreground = new Renderer { Layer = KnownLayer.Text, element = this };
+			context.TextArea.TextView.BackgroundRenderers.Add(background);
+			context.TextArea.TextView.BackgroundRenderers.Add(foreground);
+			context.TextArea.Caret.PositionChanged += Caret_PositionChanged;
+			Caret_PositionChanged(null, null);
+			
+			this.Text = GetText();
+		}
+
+		public void Deactivate(SnippetEventArgs e)
+		{
+			TextDocumentWeakEventManager.TextChanged.RemoveListener(context.Document, this);
+			context.TextArea.TextView.BackgroundRenderers.Remove(background);
+			context.TextArea.TextView.BackgroundRenderers.Remove(foreground);
+			context.TextArea.Caret.PositionChanged -= Caret_PositionChanged;
+		}
+		
+		bool isCaretInside;
+		
+		void Caret_PositionChanged(object sender, EventArgs e)
+		{
+			ISegment s = this.Segment;
+			if (s != null) {
+				bool newIsCaretInside = s.Contains(context.TextArea.Caret.Offset);
+				if (newIsCaretInside != isCaretInside) {
+					isCaretInside = newIsCaretInside;
+					context.TextArea.TextView.InvalidateLayer(foreground.Layer);
+				}
+			}
+		}
+		
+		Renderer background, foreground;
+		
+		public string Text { get; private set; }
+		
+		string GetText()
+		{
+			if (start.IsDeleted || end.IsDeleted)
+				return string.Empty;
+			else
+				return context.Document.GetText(start.Offset, Math.Max(0, end.Offset - start.Offset));
+		}
+		
+		public event EventHandler TextChanged;
+		
+		bool IWeakEventListener.ReceiveWeakEvent(Type managerType, object sender, EventArgs e)
+		{
+			if (managerType == typeof(TextDocumentWeakEventManager.TextChanged)) {
+				string newText = GetText();
+				if (this.Text != newText) {
+					this.Text = newText;
+					if (TextChanged != null)
+						TextChanged(this, e);
+				}
+				return true;
+			}
+			return false;
+		}
+		
+		public bool IsEditable {
+			get { return true; }
+		}
+		
+		public ISegment Segment {
+			get {
+				if (start.IsDeleted || end.IsDeleted)
+					return null;
+				else
+					return new SimpleSegment(start.Offset, Math.Max(0, end.Offset - start.Offset));
+			}
+		}
+		
+		sealed class Renderer : IBackgroundRenderer
+		{
+			static readonly Brush backgroundBrush = CreateBackgroundBrush();
+			static readonly Pen activeBorderPen = CreateBorderPen();
+			
+			static Brush CreateBackgroundBrush()
+			{
+				SolidColorBrush b = new SolidColorBrush(Colors.LimeGreen);
+				b.Opacity = 0.4;
+				b.Freeze();
+				return b;
+			}
+			
+			static Pen CreateBorderPen()
+			{
+				Pen p = new Pen(Brushes.Black, 1);
+				p.DashStyle = DashStyles.Dot;
+				p.Freeze();
+				return p;
+			}
+			
+			internal ReplaceableActiveElement element;
+			
+			public KnownLayer Layer { get; set; }
+			
+			public void Draw(TextView textView, System.Windows.Media.DrawingContext drawingContext)
+			{
+				ISegment s = element.Segment;
+				if (s != null) {
+					BackgroundGeometryBuilder geoBuilder = new BackgroundGeometryBuilder();
+					geoBuilder.AlignToMiddleOfPixels = true;
+					if (Layer == KnownLayer.Background) {
+						geoBuilder.AddSegment(textView, s);
+						drawingContext.DrawGeometry(backgroundBrush, null, geoBuilder.CreateGeometry());
+					} else {
+						// draw foreground only if active
+						if (element.isCaretInside) {
+							geoBuilder.AddSegment(textView, s);
+							foreach (BoundActiveElement boundElement in element.context.ActiveElements.OfType<BoundActiveElement>()) {
+								if (boundElement.targetElement == element) {
+									geoBuilder.AddSegment(textView, boundElement.Segment);
+									geoBuilder.CloseFigure();
+								}
+							}
+							drawingContext.DrawGeometry(null, activeBorderPen, geoBuilder.CreateGeometry());
+						}
+					}
+				}
+			}
+		}
+	}
+}