From edd0d9b68fea39e7141594697651290771daad9a Mon Sep 17 00:00:00 2001
From: Vadim Zeitlin <vadim@wxwidgets.org>
Date: Thu, 28 Nov 2019 23:57:15 +0100
Subject: [PATCH] Ensure DrawCheckBox() fits inside the rectangle passed to it

This results in rather ugly checkboxes when the rectangle is too small,
and even "critical" GTK warnings with wxGTK 3, but is still arguably
better than drawing outside of the provided rectangle.
---
 src/gtk/renderer.cpp | 35 +++++++++++++++++++++++++++++++++--
 1 file changed, 33 insertions(+), 2 deletions(-)

diff --git a/src/gtk/renderer.cpp b/src/gtk/renderer.cpp
index c2d01e4a39..c26901817c 100644
--- a/src/gtk/renderer.cpp
+++ b/src/gtk/renderer.cpp
@@ -633,6 +633,35 @@ struct CheckBoxInfo
     }
 #endif // __WXGTK3__/!__WXGTK3__
 
+    // Make sure we fit into the provided rectangle, eliminating margins and
+    // even reducing the size if necessary.
+    void FitInto(const wxRect& rect)
+    {
+        if ( indicator_width > rect.width )
+        {
+            indicator_width = rect.width;
+            margin_left =
+            margin_right = 0;
+        }
+        else if ( indicator_width + margin_left + margin_right > rect.width )
+        {
+            margin_left =
+            margin_right = (rect.width - indicator_width) / 2;
+        }
+
+        if ( indicator_height > rect.height )
+        {
+            indicator_height = rect.height;
+            margin_top =
+            margin_bottom = 0;
+        }
+        else if ( indicator_height + margin_top + margin_bottom > rect.height )
+        {
+            margin_top =
+            margin_bottom = (rect.height - indicator_height) / 2;
+        }
+    }
+
     gint indicator_width,
          indicator_height;
     gint margin_left,
@@ -695,7 +724,8 @@ wxRendererGTK::DrawCheckBox(wxWindow*,
 
     wxGtkStyleContext sc(dc.GetContentScaleFactor());
 
-    const CheckBoxInfo info(sc, flags);
+    CheckBoxInfo info(sc, flags);
+    info.FitInto(rect);
 
     const int w = info.indicator_width + info.margin_left + info.margin_right;
     const int h = info.indicator_height + info.margin_top + info.margin_bottom;
@@ -728,7 +758,8 @@ wxRendererGTK::DrawCheckBox(wxWindow*,
 #else // !__WXGTK3__
     GtkWidget* button = wxGTKPrivate::GetCheckButtonWidget();
 
-    const CheckBoxInfo info(button, flags);
+    CheckBoxInfo info(button, flags);
+    info.FitInto(rect);
 
     GtkStateType state;