From 2508dd9c6ed951100ddc3857175a1dfa65828858 Mon Sep 17 00:00:00 2001
From: Thomas Goyne <plorkyeran@aegisub.org>
Date: Thu, 12 Jun 2014 07:35:49 -0700
Subject: [PATCH] Only scroll the grid to the active line if the row has
 actually changed

Makes it so that undo/redo only scrolls to the active line if it's
different in the two versions of the file.
---
 src/base_grid.cpp | 8 +++++---
 src/base_grid.h   | 2 ++
 2 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/src/base_grid.cpp b/src/base_grid.cpp
index b529642d1..3fa9b776a 100644
--- a/src/base_grid.cpp
+++ b/src/base_grid.cpp
@@ -237,11 +237,13 @@ void BaseGrid::UpdateMaps() {
 
 void BaseGrid::OnActiveLineChanged(AssDialogue *new_active) {
 	if (new_active) {
-		int row = new_active->Row;
-		MakeRowVisible(row);
-		extendRow = row;
+		if (new_active->Row != active_row)
+			MakeRowVisible(new_active->Row);
+		extendRow = active_row = new_active->Row;
 		Refresh(false);
 	}
+	else
+		active_row = -1;
 }
 
 void BaseGrid::MakeRowVisible(int row) {
diff --git a/src/base_grid.h b/src/base_grid.h
index c8511504a..71d1c2f6a 100644
--- a/src/base_grid.h
+++ b/src/base_grid.h
@@ -55,6 +55,8 @@ class BaseGrid final : public wxWindow {
 	/// First row that is visible at the current scroll position
 	int yPos = 0;
 
+	int active_row = -1;
+
 	agi::Context *context; ///< Associated project context
 
 	std::vector<std::unique_ptr<GridColumn>> columns;