From c3a7f80706dc69818e9cd6cab19d8a2d20ab5ff8 Mon Sep 17 00:00:00 2001
From: zeljan1 <zeljko@holobit.hr>
Date: Sat, 22 Feb 2025 21:07:52 +0100
Subject: [PATCH] Gtk3: implemented color property for TCustomGroupBox.

---
 lcl/interfaces/gtk3/gtk3widgets.pas | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/lcl/interfaces/gtk3/gtk3widgets.pas b/lcl/interfaces/gtk3/gtk3widgets.pas
index 23298e2f0c..2f33786c44 100644
--- a/lcl/interfaces/gtk3/gtk3widgets.pas
+++ b/lcl/interfaces/gtk3/gtk3widgets.pas
@@ -702,6 +702,7 @@ type
     FGroupBoxType:TGtk3GroupBoxType;
     function GetInnerClientRect(Frame:PGtkWidget):TRect;
   protected
+    procedure DoBeforeLCLPaint; override;
     procedure ConnectSizeAllocateSignal(ToWidget: PGtkWidget); override;
     function CreateWidget(const {%H-}Params: TCreateParams):PGtkWidget; override;
     function getText: String; override;
@@ -3779,6 +3780,23 @@ begin
   Result := RectFromGdkRect(FinalRect);
 end;
 
+procedure TGtk3GroupBox.DoBeforeLCLPaint;
+var
+  DC: TGtk3DeviceContext;
+  NColor: TColor;
+begin
+  inherited DoBeforeLCLPaint;
+  if not Visible then
+    exit;
+  DC := TGtk3DeviceContext(Context);
+  NColor := LCLObject.Color;
+  if (NColor <> clNone) and (NColor <> clDefault) then
+  begin
+    DC.CurrentBrush.Color := ColorToRGB(NColor);
+    DC.fillRect(0, 0, getContainerWidget^.get_allocated_width, getContainerWidget^.get_allocated_height);
+  end;
+end;
+
 procedure TGtk3GroupBox.ConnectSizeAllocateSignal(ToWidget:PGtkWidget);
 begin
   g_signal_connect_data(ToWidget,'size-allocate',TGCallback(@GroupBoxSizeAllocate), Self, nil, G_CONNECT_DEFAULT);