From a1699ff612f27dd2916e0616096a4eaead6a8dc3 Mon Sep 17 00:00:00 2001
From: Paul Davis <paul@linuxaudiosystems.com>
Date: Sun, 3 Oct 2021 19:47:18 -0600
Subject: [PATCH] canvas: size_allocate() from GTK gives origin in parent
 coordinates.

Convert to canvas-relative origin when passing to root group for allocation
---
 libs/canvas/canvas.cc | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/libs/canvas/canvas.cc b/libs/canvas/canvas.cc
index 05b1f10aa3..2be916eebd 100644
--- a/libs/canvas/canvas.cc
+++ b/libs/canvas/canvas.cc
@@ -916,7 +916,11 @@ GtkCanvas::on_size_allocate (Gtk::Allocation& a)
 	}
 #endif
 
-	Rect r (a.get_x(), a.get_y(), a.get_width(), a.get_height());
+	/* x, y in a are relative to the parent. When passing this down to the
+	   root group, this origin is effectively 0,0
+	*/
+
+	Rect r (0., 0., a.get_width(), a.get_height());
 	_root.size_allocate (r);
 }