From 8d3fd927843da18d959c54292c135e760f8bd4c8 Mon Sep 17 00:00:00 2001
From: ed <eddavies95@gmail.com>
Date: Thu, 7 Jan 2021 12:25:21 +0000
Subject: [PATCH] macOS:  Redraw drop-shadow on repaint for transparent
 NSWindows to fix some drawing artifacts

---
 .../native/juce_mac_NSViewComponentPeer.mm            | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/modules/juce_gui_basics/native/juce_mac_NSViewComponentPeer.mm b/modules/juce_gui_basics/native/juce_mac_NSViewComponentPeer.mm
index 98c05fc7ca..d41bf96d69 100644
--- a/modules/juce_gui_basics/native/juce_mac_NSViewComponentPeer.mm
+++ b/modules/juce_gui_basics/native/juce_mac_NSViewComponentPeer.mm
@@ -876,13 +876,18 @@ public:
                     drawRect (cg, rect, displayScale);
                     CGContextRestoreGState (cg);
                 }
-
-                return;
             }
         }
+        else
        #endif
+        {
+            drawRect (cg, r, displayScale);
+        }
 
-        drawRect (cg, r, displayScale);
+        // transparent NSWindows with a drop-shadow need to redraw their shadow when the content
+        // changes to avoid stale shadows being drawn behind the window
+        if (! isSharedWindow && ! [window isOpaque] && [window hasShadow])
+            [window invalidateShadow];
     }
 
     void drawRect (CGContextRef cg, NSRect r, float displayScale)