From 8077d8dae05746e2e50034ccdda9c08656018360 Mon Sep 17 00:00:00 2001
From: zeljan1 <zeljko@holobit.hr>
Date: Mon, 3 Feb 2025 16:56:46 +0100
Subject: [PATCH] Gtk3: fixed GetWindowRect() so it return proper values on x11
 and wayland.

---
 lcl/interfaces/gtk3/gtk3winapi.inc | 21 +++++++++++++++++++--
 1 file changed, 19 insertions(+), 2 deletions(-)

diff --git a/lcl/interfaces/gtk3/gtk3winapi.inc b/lcl/interfaces/gtk3/gtk3winapi.inc
index 3a62fbfcc1..76cadc9d30 100644
--- a/lcl/interfaces/gtk3/gtk3winapi.inc
+++ b/lcl/interfaces/gtk3/gtk3winapi.inc
@@ -2952,6 +2952,7 @@ var
   AWindow: PGtkWindow;
   x, y, aWidth, aHeight: gint;
   Allocation: TGtkAllocation;
+  AGdkWindow: PGdkWindow;
 begin
   Result := 0;
   if IsValidHandle(Handle) then
@@ -2961,18 +2962,34 @@ begin
       AWindow := PGtkWindow(TGtk3Widget(Handle).Widget);
       if not TGtk3Window(Handle).WidgetMapped then
         AWindow := nil;
+
+      if AWindow <> nil then
+        AGdkWindow := AWindow^.get_window
+      else
+        AGdkWindow := nil;
+
     end else
       AWindow := nil;
     if AWindow <> nil then
     begin
-      AWindow^.get_position(@x, @y);
-      AWindow^.get_size(@aWidth, @aHeight);
+      if Assigned(AGdkWindow) then
+      begin
+        AGdkWindow^.get_origin(@x, @y);
+        AGdkWindow^.get_frame_extents(@Allocation);
+        AWidth := Allocation.Width;
+        AHeight := Allocation.Height;
+      end else
+      begin
+        AWindow^.get_position(@x, @y);
+        AWindow^.get_size(@aWidth, @aHeight);
+      end;
       ARect := Bounds(x, Y, AWidth, AHeight);
       Result := 1;
     end else
     begin
       TGtk3Widget(Handle).Widget^.get_allocation(@Allocation);
       ARect := Bounds(Allocation.x, Allocation.y, Allocation.width, Allocation.height);
+      Result := -1;
     end;
   end;
 end;