[macdoc] history support, back/fwd images

1 files changed, 101 insertions, 0 deletions

diff --git a/history.cs b/history.cs
new file mode 100644
index 0000000..ca5c6e4
--- /dev/null
+++ b/history.cs
@@ -0,0 +1,101 @@
+using MonoMac.AppKit;
+using System;
+using System.Collections.Generic;
+
+namespace Monodoc {
+
+	public abstract class PageVisit {
+		public abstract void Go ();
+	}
+	
+	delegate void SetSensitive (bool state);
+	
+	public class History {
+		NSSegmentedCell navigation;
+	
+		int pos = -1;
+		List<PageVisit> history = new List<PageVisit> ();
+		
+		public int Count {
+			get { return history.Count; }
+		}
+		
+		public bool Active {
+			get {
+				return active;
+			}
+			set {
+				if (value) {
+					navigation.SetEnabled (pos > 0, 0);
+					navigation.SetEnabled (pos+1 == history.Count, 1);							
+					active = value;
+				}
+			}
+		}
+		bool active, ignoring;
+		
+		public History (NSSegmentedCell navigation)
+		{
+			this.navigation = navigation;
+			active = true;
+			
+			navigation.Activated += delegate(object sender, EventArgs e) {
+				var control = sender as NSSegmentedControl;
+				if (control.SelectedSegment == 0)
+					BackClicked ();
+				else
+					ForwardClicked ();
+			};
+			navigation.SetEnabled (false, 0);
+			navigation.SetEnabled (false, 1);							
+		}
+
+		internal void BackClicked ()
+		{
+			if (!active || pos < 1)
+				return;
+			pos--;
+			PageVisit p = (PageVisit) history [pos];
+			ignoring = true;
+			p.Go ();
+			ignoring = false;
+			navigation.SetEnabled (pos > 0, 0);
+			navigation.SetEnabled (true, 1);
+		}
+	
+		internal void ForwardClicked ()
+		{
+			if (!active || pos+1 == history.Count)
+				return;
+			pos++;
+			var pageVisit = history [pos];
+			ignoring = true;
+			pageVisit.Go ();
+			ignoring = false;
+			navigation.SetEnabled (pos+1 < history.Count, 1);
+			navigation.SetEnabled (true, 0);
+		}
+
+		public void AppendHistory (PageVisit page)
+		{
+			if (ignoring)
+				return;
+			pos++;
+			if (history.Count <= pos)
+				history.Add (page);
+			else
+				history [pos] = page;
+
+			navigation.SetEnabled (pos > 0, 0);
+			navigation.SetEnabled (false, 1);
+		}
+	
+		public void ActivateCurrent ()
+		{
+			if (pos < 0)
+				return;
+			var pageVisit = history [pos];
+			pageVisit.Go ();
+		}
+	}
+}