Blocks: lazy load LEDRow to avoid blocks being cleared at the wrong time

modules/juce_blocks_basics/blocks/juce_Block.h

@@ -151,7 +151,7 @@ public:
         neither delete it or use it after the lifetime of this Block object has finished.
         If there are no LEDs, then this method will return nullptr.
     */
-    virtual LEDRow* getLEDRow() const = 0;
+    virtual LEDRow* getLEDRow() = 0;
 
     /** If this block has any status LEDs, this will return an array of objects to control them.
         Note that the objects in the array belong to this Block object, and the caller must

modules/juce_blocks_basics/topology/juce_PhysicalTopologySource.cpp

@@ -1470,9 +1470,6 @@ struct PhysicalTopologySource::Internal
             for (auto&& s : modelData.statusLEDs)
                 statusLights.add (new StatusLightImplementation (*this, s));
 
-            if (modelData.numLEDRowLEDs > 0)
-                ledRow.reset (new LEDRowImplementation (*this));
-
             updateMidiConnectionListener();
         }
 
@@ -1546,7 +1543,14 @@ struct PhysicalTopologySource::Internal
 
         TouchSurface* getTouchSurface() const override                  { return touchSurface.get(); }
         LEDGrid* getLEDGrid() const override                            { return ledGrid.get(); }
-        LEDRow* getLEDRow() const override                              { return ledRow.get(); }
+
+        LEDRow* getLEDRow() override
+        {
+            if (ledRow == nullptr && modelData.numLEDRowLEDs > 0)
+                ledRow.reset (new LEDRowImplementation (*this));
+
+            return ledRow.get();
+        }
 
         juce::Array<ControlButton*> getButtons() const override
         {