From b260d12ea11848d2ca05384587d8d73dd2acab64 Mon Sep 17 00:00:00 2001
From: miguel <miguel.de.icaza@gmail.com>
Date: Thu, 10 May 2018 23:22:35 -0400
Subject: [PATCH] HexView: PageUp, PageDown, Home

---
 Terminal.Gui/Views/HexView.cs  | 60 +++++++++++++++++++++++-----------
 Terminal.Gui/Views/TextView.cs |  1 +
 2 files changed, 42 insertions(+), 19 deletions(-)

diff --git a/Terminal.Gui/Views/HexView.cs b/Terminal.Gui/Views/HexView.cs
index ec3558073..905bd6f29 100644
--- a/Terminal.Gui/Views/HexView.cs
+++ b/Terminal.Gui/Views/HexView.cs
@@ -3,7 +3,7 @@
 //
 // TODO:
 // - Support searching and highlighting of the search result
-// - Support PageUp/PageDown/Home/End
+// - Bug showing the last line
 // 
 using System;
 using System.Collections.Generic;
@@ -254,6 +254,32 @@ namespace Terminal.Gui {
 				RedisplayLine (position);
 		}
 
+		void MoveUp (int bytes)
+		{
+			RedisplayLine (position);
+			position -= bytes;
+			if (position < 0)
+				position = 0;
+			if (position < DisplayStart) {
+				SetDisplayStart (DisplayStart - bytes);
+				SetNeedsDisplay ();
+			} else
+				RedisplayLine (position);
+
+		}
+
+		void MoveDown (int bytes)
+		{
+			RedisplayLine (position);
+			if (position + bytes < source.Length)
+				position += bytes;
+			if (position >= (DisplayStart + bytesPerLine * Frame.Height)) {
+				SetDisplayStart (DisplayStart + bytes);
+				SetNeedsDisplay ();
+			} else
+				RedisplayLine (position);			
+		}
+
 		public override bool ProcessKey (KeyEvent keyEvent)
 		{
 			switch (keyEvent.Key) {
@@ -279,32 +305,28 @@ namespace Terminal.Gui {
 				CursorRight ();
 				break;
 			case Key.CursorDown:
-				RedisplayLine (position);
-				if (position + bytesPerLine < source.Length)
-					position += bytesPerLine;
-				if (position >= (DisplayStart + bytesPerLine * Frame.Height)) {
-					SetDisplayStart (DisplayStart + bytesPerLine);
-					SetNeedsDisplay ();
-				} else 
-					RedisplayLine (position);
+				MoveDown (bytesPerLine);
 				break;
 			case Key.CursorUp:
-				RedisplayLine (position);
-				position -= bytesPerLine;
-				if (position < 0)
-					position = 0;
-				if (position < DisplayStart) {
-					SetDisplayStart (DisplayStart - bytesPerLine);
-					SetNeedsDisplay ();
-				}  else 
-					RedisplayLine (position);
+				MoveUp (bytesPerLine);
 				break;
 			case Key.Tab:
 				leftSide = !leftSide;
 				RedisplayLine (position);
 				firstNibble = true;
 				break;
-
+			case ((int)'v' + Key.AltMask):
+			case Key.PageUp:
+				MoveUp (bytesPerLine * Frame.Height);
+				break;
+			case Key.ControlV:
+			case Key.PageDown:
+				MoveDown (bytesPerLine * Frame.Height);
+				break;
+			case Key.Home:
+				DisplayStart = 0;
+				SetNeedsDisplay ();
+				break;
 			default:
 				if (leftSide) {
 					int value = -1;
diff --git a/Terminal.Gui/Views/TextView.cs b/Terminal.Gui/Views/TextView.cs
index ec836ced4..bc3d2476d 100644
--- a/Terminal.Gui/Views/TextView.cs
+++ b/Terminal.Gui/Views/TextView.cs
@@ -6,6 +6,7 @@
 //
 // 
 // TODO:
+// PageUp/PageDown
 // Attributed text on spans
 // Replace insertion with Insert method
 // String accumulation (Control-k, control-k is not preserving the last new line, see StringToRunes