// 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.Controls;
using System.Windows.Media;
using System.Windows.Media.Animation;
using System.Windows.Threading;
using ICSharpCode.AvalonEdit.Rendering;
using ICSharpCode.AvalonEdit.Utils;
namespace ICSharpCode.AvalonEdit.Editing
{
sealed class CaretLayer : Layer
{
bool isVisible;
Rect caretRectangle;
DispatcherTimer caretBlinkTimer = new DispatcherTimer();
bool blink;
public CaretLayer(TextView textView) : base(textView, KnownLayer.Caret)
{
this.IsHitTestVisible = false;
caretBlinkTimer.Tick += new EventHandler(caretBlinkTimer_Tick);
}
void caretBlinkTimer_Tick(object sender, EventArgs e)
{
blink = !blink;
InvalidateVisual();
}
public void Show(Rect caretRectangle)
{
this.caretRectangle = caretRectangle;
this.isVisible = true;
StartBlinkAnimation();
InvalidateVisual();
}
public void Hide()
{
if (isVisible) {
isVisible = false;
StopBlinkAnimation();
InvalidateVisual();
}
}
void StartBlinkAnimation()
{
TimeSpan blinkTime = Win32.CaretBlinkTime;
blink = true; // the caret should visible initially
// This is important if blinking is disabled (system reports a negative blinkTime)
if (blinkTime.TotalMilliseconds > 0) {
caretBlinkTimer.Interval = blinkTime;
caretBlinkTimer.Start();
}
}
void StopBlinkAnimation()
{
caretBlinkTimer.Stop();
}
internal Brush CaretBrush;
protected override void OnRender(DrawingContext drawingContext)
{
base.OnRender(drawingContext);
if (isVisible && blink) {
Brush caretBrush = this.CaretBrush;
if (caretBrush == null)
caretBrush = (Brush)textView.GetValue(TextBlock.ForegroundProperty);
Rect r = new Rect(caretRectangle.X - textView.HorizontalOffset,
caretRectangle.Y - textView.VerticalOffset,
caretRectangle.Width,
caretRectangle.Height);
drawingContext.DrawRectangle(caretBrush, null, PixelSnapHelpers.Round(r, PixelSnapHelpers.GetPixelSize(this)));
}
}
}
}