overshoot navigation: add overshooting for history navigation

- makes it a bit less jarring when jumping around all over the place
- decrease defaults from 20 to 10
- allow overshooting when moving backwards too (previously only worked moving forwards)

Diz.Controllers/Diz.Controllers/src/controllers/IProjectView.cs

@@ -42,5 +42,6 @@ public class HistoryArgs
         /// <param name="pcOffset">PC [not SNES] offset</param>
         /// <param name="historyArgs">if non-null, record this event in the project history</param>
         void SelectOffset(int pcOffset, HistoryArgs historyArgs = null);
+        void SelectOffsetWithOvershoot(int pcOffset, int overshootAmount = 0);
     }
 }

DiztinGUIsh/window/MainWindow.Actions.cs

@@ -1,5 +1,4 @@
-using System;
-using System.Diagnostics;
+using System.Diagnostics;
 using System.IO;
 using System.Windows.Forms;
 using Diz.Controllers.controllers;
@@ -9,12 +8,17 @@
 using Diz.Core.util;
 using Diz.Cpu._65816;
 using Diz.Ui.Winforms.dialogs;
-using DiztinGUIsh.Properties;
 
 namespace DiztinGUIsh.window;
 
 public partial class MainWindow
 {
+    // when navigating near the edge of the grid, this controls how close we'll allow getting to the bottom row before
+    // scrolling the screen a bit (because it's helpful to be able to see where you're going and not always be operating on
+    // the edge of the grid)
+    // arbitrary: increase if using bigger grid sizes. ideally, this would be dynamically generated in the future based on a % of the grid
+    private const int standardOvershootAmount = 12;
+
     private void OpenLastProject()
     {
         if (Document.LastProjectFilename == "")
@@ -86,7 +90,7 @@ private void Step(int offset)
 
         ProjectController.MarkChanged();
         var newOffset = snesData.Step(offset, false, false, offset - 1);
-        SelectOffset(newOffset, -1, new ISnesNavigation.HistoryArgs {Description = "Step Over"}, overshootAmount: 20);
+        SelectOffset(newOffset, -1, new ISnesNavigation.HistoryArgs {Description = "Step Over"}, overshootAmount: standardOvershootAmount);
         UpdateUi_TimerAndPercent();
     }
 
@@ -97,7 +101,7 @@ private void StepIn(int offset)
 
         ProjectController.MarkChanged();
         var newOffset = Project.Data.GetSnesApi().Step(offset, true, false, offset - 1);
-        SelectOffset(newOffset, -1, new ISnesNavigation.HistoryArgs {Description = "Step Into"}, overshootAmount: 20);
+        SelectOffset(newOffset, -1, new ISnesNavigation.HistoryArgs {Description = "Step Into"}, overshootAmount: standardOvershootAmount);
         UpdateUi_TimerAndPercent();
     }
 
@@ -109,7 +113,7 @@ private void AutoStepSafe(int offset)
         ProjectController.MarkChanged();
         var destination = Project.Data.GetSnesApi().AutoStepSafe(offset);
         if (moveWithStep) 
-            SelectOffset(destination, -1, new ISnesNavigation.HistoryArgs {Description = "AutoStep (Safe)"}, overshootAmount: 20);
+            SelectOffset(destination, -1, new ISnesNavigation.HistoryArgs {Description = "AutoStep (Safe)"}, overshootAmount: standardOvershootAmount);
 
         UpdateUi_TimerAndPercent();
     }
@@ -126,7 +130,7 @@ private void AutoStepHarsh(int offset)
         var destination = Project.Data.GetSnesApi().AutoStepHarsh(newOffset, count);
 
         if (moveWithStep) 
-            SelectOffset(destination, -1, new ISnesNavigation.HistoryArgs {Description = "AutoStep (Harsh)"}, overshootAmount:20);
+            SelectOffset(destination, -1, new ISnesNavigation.HistoryArgs {Description = "AutoStep (Harsh)"}, overshootAmount: standardOvershootAmount);
 
         UpdateUi_TimerAndPercent();
     }
@@ -139,7 +143,7 @@ private void Mark(int offset)
         ProjectController.MarkChanged();
         var newOffset = Project.Data.GetSnesApi().MarkTypeFlag(offset, markFlag, RomUtil.GetByteLengthForFlag(markFlag));
 
-        SelectOffset(newOffset, -1, new ISnesNavigation.HistoryArgs {Description = "Mark (single)"}, overshootAmount: 20);
+        SelectOffset(newOffset, -1, new ISnesNavigation.HistoryArgs {Description = "Mark (single)"}, overshootAmount: standardOvershootAmount);
 
         UpdateUi_TimerAndPercent();
     }
@@ -193,7 +197,7 @@ private void GoToIntermediateAddress(int offset)
     public void GoTo(int offset)
     {
         if (IsOffsetInRange(offset))
-            SelectOffset(offset, -1, new ISnesNavigation.HistoryArgs {Description = "Goto"}, overshootAmount: 20);
+            SelectOffset(offset, -1, new ISnesNavigation.HistoryArgs {Description = "Goto"}, overshootAmount: standardOvershootAmount);
         else
             ShowOffsetOutOfRangeMsg();
     }
@@ -263,7 +267,7 @@ private void GoToNextUnreachedInPoint(int offset)
         }
 
         // now do the real thing
-        SelectOffset(foundOffset, -1, new ISnesNavigation.HistoryArgs { Description = "Find next unreached in-point" }, overshootAmount: 20);
+        SelectOffset(foundOffset, -1, new ISnesNavigation.HistoryArgs { Description = "Find next unreached in-point" }, overshootAmount: standardOvershootAmount);
     }
 
     private static ISnesNavigation.HistoryArgs BuildUnreachedHistoryArgs(bool fromStartOrEnd, bool forwardDirection)

DiztinGUIsh/window/MainWindow.MainTable.cs

@@ -470,6 +470,9 @@ public void MarkHistoryPoint(int pcOffset, ISnesNavigation.HistoryArgs historyAr
             RememberNavigationPoint(SelectedOffset, historyArgs); // save old position
         }
 
+        public void SelectOffsetWithOvershoot(int pcOffset, int overshootAmount = 0)
+            => SelectOffset(pcOffset, -1, null, overshootAmount);
+
         public void SelectOffset(int pcOffset, ISnesNavigation.HistoryArgs historyArgs = null)
             => SelectOffset(pcOffset, -1, historyArgs);
 
@@ -487,10 +490,24 @@ public void SelectOffset(int pcOffset, int column = -1, ISnesNavigation.HistoryA
             // THIS IS 100% OPTIONAL.
             if (overshootAmount > 0)
             {
+                // NEW
+                // which way are we jumping?
+                var direction = SelectedOffset < pcOffset ? 1 : -1; 
+
                 // ideally, we'd calculate this number to be at the center or top. for now, we'll just pick an arbitrary amount
-                var overshotOffset = Math.Min(Project.Data.GetRomSize()-1, pcOffset + overshootAmount);
+                var proposedNewOffset = pcOffset + overshootAmount * direction; // note: may be out of range
+
+                // clamp to actual range
+                var overshotOffset = Util.Clamp(proposedNewOffset, 0, Project.Data.GetRomSize() - 1);
                 InternalSelectOffset(overshotOffset, column);
 
+                // ----
+
+                // ORIGINAL
+                // ideally, we'd calculate this number to be at the center or top. for now, we'll just pick an arbitrary amount
+                // var overshotOffset = Math.Min(Project.Data.GetRomSize()-1, pcOffset + overshootAmount);
+                // InternalSelectOffset(overshotOffset, column);
+
                 // now, the view is scrolled so we've overshot where we really want to go.
                 // when we next call InternalSelectOffset() with the real address, it won't need to scroll, it'll just select something already in view.
             }

DiztinGUIsh/window/MainWindow.SimpleUI.cs

@@ -211,10 +211,14 @@ private void showHistoryToolStripMenuItem_Click(object sender, EventArgs e)
         }
 
         private void goBackToolStripMenuItem_Click(object sender, EventArgs e) => 
-            NavigationForm.Navigate(forwardDirection: false);
+            NavigationForm.Navigate(forwardDirection: false, 
+                overshootAmount: standardOvershootAmount
+            );
 
         private void goForwardToolStripMenuItem_Click(object sender, EventArgs e) => 
-            NavigationForm.Navigate(forwardDirection: true);
+            NavigationForm.Navigate(forwardDirection: true, 
+                overshootAmount: standardOvershootAmount
+            );
 
         private void LabelsOnOnLabelChanged(object? sender, EventArgs e)
         {

DiztinGUIsh/window/NavigationForm.cs

@@ -51,9 +51,9 @@ private void Navigation_Load(object sender, EventArgs e)
 
         }
 
-        public void Navigate(bool forwardDirection)
+        public void Navigate(bool forwardDirection, int overshootAmount = 0)
         {
-            navigationCtrl.Navigate(forwardDirection);
+            navigationCtrl.Navigate(forwardDirection, overshootAmount);
         }
 
         private void navigationCtrl_Load(object sender, EventArgs e)

DiztinGUIsh/window/usercontrols/NavigationUserControl.cs

@@ -61,7 +61,7 @@ public NavigationUserControl()
 
         public int SelectedIndex => navigationEntryBindingSource.Position; // dataGridView1.SelectedRows[0].Index;
 
-        public void Navigate(bool forwardDirection)
+        public void Navigate(bool forwardDirection, int overshootAmount = 0)
         {
             if (navigationEntryBindingSource == null || navigationEntryBindingSource.Count == 0)
                 return;
@@ -70,16 +70,16 @@ public void Navigate(bool forwardDirection)
                 Util.ClampIndex(SelectedIndex + (forwardDirection ? 1 : -1),
                 navigationEntryBindingSource.Count);
 
-            NavigateToEntry(navigationEntryToUse);
+            NavigateToEntry(navigationEntryToUse, overshootAmount);
             SelectDataGridRow(navigationEntryToUse);
         }
 
-        private void NavigateToEntry(int indexToUse)
+        private void NavigateToEntry(int indexToUse, int overshootAmount = 0)
         {
-            NavigateToEntry(GetNavigationEntry(indexToUse));
+            NavigateToEntry(GetNavigationEntry(indexToUse), overshootAmount);
         }
 
-        private void NavigateToEntry(NavigationEntry navigationEntry)
+        private void NavigateToEntry(NavigationEntry navigationEntry, int overshootAmount = 0)
         {
             var newSnesAddress = navigationEntry?.SnesOffset ?? -1;
             if (newSnesAddress == -1)
@@ -89,7 +89,7 @@ private void NavigateToEntry(NavigationEntry navigationEntry)
             if (pcOffset == -1) 
                 return;
 
-            SnesNavigation.SelectOffset(pcOffset);
+            SnesNavigation.SelectOffsetWithOvershoot(pcOffset, overshootAmount);
         }
 
         private NavigationEntry GetNavigationEntry(int index)