From ca84f4dfead09ec23ca5ee663af2cc3bb49cc3b4 Mon Sep 17 00:00:00 2001
From: rbalsleyMSFT <53497092+rbalsleyMSFT@users.noreply.github.com>
Date: Mon, 14 Jul 2025 17:56:51 -0700
Subject: [PATCH] Implement conditional autoscroll in log monitor

Improves the user experience in the monitor tab by making the log output autoscroll conditional.

Autoscrolling is now disabled when the user selects a log entry other than the last one, allowing them to inspect previous output without interruption. Selecting the last item in the list re-enables autoscrolling.
---
 FFUDevelopment/BuildFFUVM_UI.ps1              | 17 +++++++++++--
 .../FFUUI.Core/FFUUI.Core.Handlers.psm1       | 25 +++++++++++++++++++
 2 files changed, 40 insertions(+), 2 deletions(-)

diff --git a/FFUDevelopment/BuildFFUVM_UI.ps1 b/FFUDevelopment/BuildFFUVM_UI.ps1
index 08f70ae..dfa01b4 100644
--- a/FFUDevelopment/BuildFFUVM_UI.ps1
+++ b/FFUDevelopment/BuildFFUVM_UI.ps1
@@ -120,9 +120,10 @@ $script:uiState.Controls.btnRun.Add_Click({
             # Switch to Monitor Tab
             $script:uiState.Controls.MainTabControl.SelectedItem = $script:uiState.Controls.MonitorTab
             
-            # Clear previous log data
+            # Clear previous log data and reset autoscroll
             if ($null -ne $script:uiState.Data.logData) {
                 $script:uiState.Data.logData.Clear()
+                $script:uiState.Flags.autoScrollLog = $true
             }
 
             $progressBar = $script:uiState.Controls.pbOverallProgress
@@ -201,7 +202,10 @@ $script:uiState.Controls.btnRun.Add_Click({
                         while ($null -ne ($line = $script:uiState.Data.logStreamReader.ReadLine())) {
                             # Add the full line to the log view first to maintain consistency
                             $script:uiState.Data.logData.Add($line)
-                            $script:uiState.Controls.lstLogOutput.ScrollIntoView($line)
+                            if ($script:uiState.Flags.autoScrollLog) {
+                                $script:uiState.Controls.lstLogOutput.ScrollIntoView($line)
+                                $script:uiState.Controls.lstLogOutput.SelectedIndex = $script:uiState.Controls.lstLogOutput.Items.Count - 1
+                            }
 
                             # Now, check if it's a progress line and update the UI accordingly
                             if ($line -match '\[PROGRESS\] (\d{1,3}) \| (.*)') {
@@ -234,9 +238,11 @@ $script:uiState.Controls.btnRun.Add_Click({
                         
                         # Final read of the log stream
                         if ($null -ne $script:uiState.Data.logStreamReader) {
+                            $lastLine = $null
                             while ($null -ne ($line = $script:uiState.Data.logStreamReader.ReadLine())) {
                                 # Add the full line to the log view first
                                 $script:uiState.Data.logData.Add($line)
+                                $lastLine = $line
 
                                 # Now, check if it's a progress line and update the UI accordingly
                                 if ($line -match '\[PROGRESS\] (\d{1,3}) \| (.*)') {
@@ -247,6 +253,13 @@ $script:uiState.Controls.btnRun.Add_Click({
                                     $script:uiState.Controls.txtStatus.Text = $message
                                 }
                             }
+                            
+                            # After the final read, scroll to the last line if autoscroll is enabled
+                            if ($script:uiState.Flags.autoScrollLog -and $null -ne $lastLine) {
+                                $script:uiState.Controls.lstLogOutput.ScrollIntoView($lastLine)
+                                $script:uiState.Controls.lstLogOutput.SelectedIndex = $script:uiState.Controls.lstLogOutput.Items.Count - 1
+                            }
+
                             $script:uiState.Data.logStreamReader.Close()
                             $script:uiState.Data.logStreamReader.Dispose()
                             $script:uiState.Data.logStreamReader = $null
diff --git a/FFUDevelopment/FFUUI.Core/FFUUI.Core.Handlers.psm1 b/FFUDevelopment/FFUUI.Core/FFUUI.Core.Handlers.psm1
index 86d9d6e..718aefd 100644
--- a/FFUDevelopment/FFUUI.Core/FFUUI.Core.Handlers.psm1
+++ b/FFUDevelopment/FFUUI.Core/FFUUI.Core.Handlers.psm1
@@ -778,5 +778,30 @@ function Register-EventHandlers {
                 $keyEventArgs.Handled = $true
             }
         })
+
+    $State.Controls.lstLogOutput.Add_SelectionChanged({
+            param($eventSource, $selectionChangedEventArgs)
+            $listBox = $eventSource
+            $window = [System.Windows.Window]::GetWindow($listBox)
+            if ($null -eq $window) { return }
+            $localState = $window.Tag
+
+            # If nothing is selected or the list is empty, do nothing.
+            if ($listBox.SelectedIndex -eq -1 -or $listBox.Items.Count -eq 0) {
+                return
+            }
+
+            # Check if the last item is selected
+            $isLastItemSelected = ($listBox.SelectedIndex -eq ($listBox.Items.Count - 1))
+
+            # Update the flag
+            $localState.Flags.autoScrollLog = $isLastItemSelected
+            if ($isLastItemSelected) {
+                WriteLog "Monitor tab autoscroll enabled (last item selected)."
+            }
+            else {
+                WriteLog "Monitor tab autoscroll disabled (user selected item #$($listBox.SelectedIndex))."
+            }
+        })
 }
 Export-ModuleMember -Function *
\ No newline at end of file