// 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.Windows;
using System.Windows.Media;
using ICSharpCode.AvalonEdit.Rendering;
namespace ICSharpCode.AvalonEdit.Editing
{
sealed class SelectionLayer : Layer, IWeakEventListener
{
readonly TextArea textArea;
public SelectionLayer(TextArea textArea) : base(textArea.TextView, KnownLayer.Selection)
{
this.IsHitTestVisible = false;
this.textArea = textArea;
TextViewWeakEventManager.VisualLinesChanged.AddListener(textView, this);
TextViewWeakEventManager.ScrollOffsetChanged.AddListener(textView, this);
}
bool IWeakEventListener.ReceiveWeakEvent(Type managerType, object sender, EventArgs e)
{
if (managerType == typeof(TextViewWeakEventManager.VisualLinesChanged)
|| managerType == typeof(TextViewWeakEventManager.ScrollOffsetChanged))
{
InvalidateVisual();
return true;
}
return false;
}
protected override void OnRender(DrawingContext drawingContext)
{
base.OnRender(drawingContext);
BackgroundGeometryBuilder geoBuilder = new BackgroundGeometryBuilder();
geoBuilder.AlignToMiddleOfPixels = true;
geoBuilder.ExtendToFullWidthAtLineEnd = textArea.Selection.EnableVirtualSpace;
geoBuilder.CornerRadius = textArea.SelectionCornerRadius;
foreach (var segment in textArea.Selection.Segments) {
geoBuilder.AddSegment(textView, segment);
}
Geometry geometry = geoBuilder.CreateGeometry();
if (geometry != null) {
drawingContext.DrawGeometry(textArea.SelectionBrush, textArea.SelectionBorder, geometry);
}
}
}
}