From 62ddff0e30fed0efbc4470e547a79bfb4688053d Mon Sep 17 00:00:00 2001
From: Benjamin Popp <haven1433@gmail.com>
Date: Tue, 15 Jan 2019 21:46:14 -0600
Subject: [PATCH] fix a string truncation undo/redo bug. Make it possible to
 backspace in a string segment in an array. Make it possible to backspace
 multiple times in a string.

---
 src/Gen3Hex.Core/ViewModels/ViewPort.cs | 13 ++++++++++++-
 src/Gen3Hex.Tests/StringModelTests.cs   | 23 ++++++++++++++++++++++-
 2 files changed, 34 insertions(+), 2 deletions(-)

diff --git a/src/Gen3Hex.Core/ViewModels/ViewPort.cs b/src/Gen3Hex.Core/ViewModels/ViewPort.cs
index 88097288..b50a0d60 100644
--- a/src/Gen3Hex.Core/ViewModels/ViewPort.cs
+++ b/src/Gen3Hex.Core/ViewModels/ViewPort.cs
@@ -355,10 +355,21 @@ namespace HavenSoft.Gen3Hex.Core.ViewModels {
 
          run = Model.GetNextRun(index - 1);
          if (run is PCSRun pcs) {
-            for (int i = index - 1; i < run.Start + run.Length; i++) Model[i] = 0xFF;
+            for (int i = index - 1; i < run.Start + run.Length; i++) history.CurrentChange.ChangeData(Model, i, 0xFF);
             var length = PCSString.ReadString(Model, run.Start, true);
             Model.ObserveRunWritten(history.CurrentChange, new PCSRun(run.Start, length, run.PointerSources));
             RefreshBackingData();
+            SilentScroll(index - 1);
+         } else if (run is ArrayRun array) {
+            var offsets = array.ConvertByteOffsetToArrayOffset(index - 1);
+            if (array.ElementContent[offsets.SegmentIndex].Type == ElementContentType.PCS) {
+               for (int i = index - 1; i < offsets.SegmentStart + array.ElementContent[offsets.SegmentIndex].Length; i++) history.CurrentChange.ChangeData(Model, i, 0x00);
+               history.CurrentChange.ChangeData(Model, index - 1, 0xFF);
+               RefreshBackingData();
+               SilentScroll(index - 1);
+            } else {
+               throw new NotImplementedException();
+            }
          } else if (run.Start <= index - 1 && run.Start + run.Length > index - 1) {
             // I want to do a backspace at the end of this run
             SelectionStart = scroll.DataIndexToViewPoint(run.Start);
diff --git a/src/Gen3Hex.Tests/StringModelTests.cs b/src/Gen3Hex.Tests/StringModelTests.cs
index 7f04dfb2..de56e365 100644
--- a/src/Gen3Hex.Tests/StringModelTests.cs
+++ b/src/Gen3Hex.Tests/StringModelTests.cs
@@ -1,4 +1,5 @@
-using HavenSoft.Gen3Hex.Core.Models;
+using HavenSoft.Gen3Hex.Core;
+using HavenSoft.Gen3Hex.Core.Models;
 using HavenSoft.Gen3Hex.Core.ViewModels;
 using HavenSoft.Gen3Hex.Core.ViewModels.DataFormats;
 using System;
@@ -315,5 +316,25 @@ namespace HavenSoft.Gen3Hex.Tests {
          var anchor = (Anchor)viewPort[8, 0].Format;
          Assert.IsType<PCS>(anchor.OriginalFormat);
       }
+
+      [Fact]
+      public void CanUndoStringTruncate() {
+         var buffer = Enumerable.Repeat((byte)0xFF, 0x200).ToArray();
+         var bytes = PCSString.Convert("Hello World!").ToArray();
+         Array.Copy(bytes, 0, buffer, 0x08, bytes.Length);
+         buffer[0] = 0x08;
+         buffer[1] = 0x00;
+         buffer[2] = 0x00;
+         buffer[3] = 0x08;
+         var model = new PointerAndStringModel(buffer);
+         var viewPort = new ViewPort(new LoadedFile("test.txt", buffer), model) { Width = 0x10, Height = 0x10 };
+
+         viewPort.SelectionStart = new Point(0x0C, 0);
+         viewPort.Edit(ConsoleKey.Backspace);
+         viewPort.Undo.Execute();
+
+         Assert.Equal(13, model.GetNextRun(0x08).Length);
+         Assert.Equal("\"Hello World!\"", ((PCS)viewPort[0x0C, 0].Format).FullString);
+      }
    }
 }