Merge pull request #5994 from johnhaddon/dotContextTracker

DotNodeGadget : Use ContextTracker to evaluate custom label

Changes.md

@@ -16,6 +16,7 @@ Improvements
   - Improved highlighting of active nodes, with more accurate tracking of Loop node iterations.
   - Annotation `{plug}` substitutions are now evaluated in a context determined relative to the focus node.
   - The strike-through for disabled nodes is now evaluated in a context determined relative to the focus node.
+  - Custom dot labels are now evaluated in a context determined relative to the focus node.
 - LightEditor :
   - Improved formatting of column headers containing whitespace.
   - The "Double-click to toggle" tooltip is no longer displayed while hovering over non-editable cells, and a "Double-click to edit" tooltip is now displayed while hovering over other non-toggleable but editable cells.
@@ -29,7 +30,9 @@ Fixes
 - Scene Editors : Fixed update when ScenePlugs are added to or removed from the node being viewed.
 - PrimitiveInspector : Fixed failure to update when the location being viewed ceases to exist, or is recreated.
 - Shuffle, ShuffleAttributes, ShufflePrimitiveVariables : Fixed some special cases where shuffling a source to itself would fail to have the expected effect.
-- GraphEditor : Fixed dimming of labels for BoxIn and BoxOut nodes.
+- GraphEditor :
+  - Fixed dimming of labels for BoxIn and BoxOut nodes.
+  - Fixed update of custom context-sensitive labels on Dot nodes.
 - GafferCortexUI : Removed usage of legacy PlugValueWidget API.
 - Dispatcher : Fixed crashes caused by a dispatcher's `SetupPlugsFn` attempting to access the TaskNode it was being called for. Dispatchers may now introspect the TaskNode and add different plugs based on type (#915).
 

include/Gaffer/Context.h

@@ -193,6 +193,7 @@ class GAFFER_API Context : public IECore::RefCounted
 			public :
 
 				/// Constructing the Scope pushes the current context.
+				/// If context is `nullptr` then this is a no-op.
 				Scope( const Context *context );
 				/// Destruction of the Scope pops the previously pushed context.
 				~Scope();

include/GafferUI/DotNodeGadget.h

@@ -43,6 +43,7 @@
 namespace Gaffer
 {
 
+IE_CORE_FORWARDDECLARE( Context )
 IE_CORE_FORWARDDECLARE( Plug )
 
 } // namespace Gaffer
@@ -65,6 +66,7 @@ class GAFFERUI_API DotNodeGadget : public StandardNodeGadget
 	protected :
 
 		void renderLayer( Layer layer, const Style *style, RenderReason reason ) const override;
+		void updateFromContextTracker( const ContextTracker *contextTracker ) override;
 
 	private :
 
@@ -82,6 +84,7 @@ class GAFFERUI_API DotNodeGadget : public StandardNodeGadget
 
 		Gaffer::Signals::ScopedConnection m_upstreamNameChangedConnection;
 
+		Gaffer::ConstContextPtr m_labelContext;
 		std::string m_label;
 		Imath::V2f m_labelPosition;
 

src/GafferUI/DotNodeGadget.cpp

@@ -82,7 +82,9 @@ DotNodeGadget::DotNodeGadget( Gaffer::NodePtr node )
 	dropSignal().connect( boost::bind( &DotNodeGadget::drop, this, ::_2 ) );
 
 	updateUpstreamNameChangedConnection();
-	updateLabel();
+	// Don't need to call `updateLabel()` explicitly, because GraphGadget will
+	// call `updateFromContextTracker()` immediately after construction, and we'll
+	// update there.
 }
 
 DotNodeGadget::~DotNodeGadget()
@@ -116,6 +118,13 @@ void DotNodeGadget::renderLayer( Layer layer, const Style *style, RenderReason r
 	}
 }
 
+void DotNodeGadget::updateFromContextTracker( const ContextTracker *contextTracker )
+{
+	StandardNodeGadget::updateFromContextTracker( contextTracker );
+	m_labelContext = contextTracker->context( node() );
+	updateLabel();
+}
+
 Gaffer::Dot *DotNodeGadget::dotNode()
 {
 	return static_cast<Dot *>( node() );
@@ -186,13 +195,11 @@ void DotNodeGadget::updateLabel()
 		}
 		else
 		{
-			const auto script = dot->scriptNode();
-			const Context *context = script ? script->context() : nullptr;
-			Context::Scope scope( context );
+			Context::Scope scope( m_labelContext.get() );
 			m_label = dot->labelPlug()->getValue();
-			if( context )
+			if( m_labelContext )
 			{
-				m_label = context->substitute( m_label );
+				m_label = m_labelContext->substitute( m_label );
 			}
 		}
 	}