From bdfd4e0b098e85ba1a0bfd75dfa10b74825ff90b Mon Sep 17 00:00:00 2001
From: Sam Reid <reids@colorado.edu>
Date: Tue, 10 Jan 2023 10:27:22 -0700
Subject: [PATCH] Disable the play/pause/step buttons when the sun doesn't
 shine, see https://github.com/phetsims/greenhouse-effect/issues/241

---
 js/common/view/LayersModelTimeControlNode.ts | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/js/common/view/LayersModelTimeControlNode.ts b/js/common/view/LayersModelTimeControlNode.ts
index 75eb6385..c3a5fdf2 100644
--- a/js/common/view/LayersModelTimeControlNode.ts
+++ b/js/common/view/LayersModelTimeControlNode.ts
@@ -65,6 +65,11 @@ class LayersModelTimeControlNode extends TimeControlNode {
         }
       }
     } );
+
+    // This does not need to be disposed/unlinked since it persists for the life of the sim.
+    model.sunEnergySource.isShiningProperty.link( isSunShining => {
+      this.playPauseStepButtons.enabled = isSunShining;
+    } );
   }
 }