Pause render hotkey

Changes.md

@@ -18,6 +18,10 @@ Improvements
 - PythonEditor, PythonCommand, Expression, UIEditor, OSLCode : Added line numbers to code editors (#6091).
 - CyclesOptions : Added `denoiseDevice` plug for configuring the device used for denoising.
 - AttributeTweaks : Added tooltips and presets for all attribute values.
+- InteractiveRenderer :
+  - Added <kbd>Esc</kbd> hotkey handling to pause an interactive render. This is in addition to the existing behavior of pausing the image viewer.
+  - Added <kbd>Ctrl</kbd> + <kbd>\</kbd> hotkey handling to toggle the interactive renderer between paused and running. If the new state is `Running`, the image viewer will also be unpaused.
+  - Starting or unpausing the render using the viewer control play button will also unpause the image viewer.
 
 Fixes
 -----

doc/source/Interface/ControlsAndShortcuts/index.md

@@ -310,6 +310,16 @@ Duplicate current Catalogue image    | {kbd}`Ctrl` + {kbd}`D`
 Toggle image comparison              | {kbd}`Q`
 Toggle wipes                         | {kbd}`W`
 
+### Interactive Render Viewer ###
+
+> Note :
+> For the following controls and shortcuts, the cursor must hover over the Viewer.
+
+Action                               | Control or shortcut
+-------------------------------------|--------------------
+Pause active render                  | {kdb}`Escape`
+Toggle render running / paused       | {kdb}`Ctrl` + {kbd}`\`
+
 ### Crop window tool ###
 
 Action                               | Control or shortcut

python/GafferSceneUI/InteractiveRenderUI.py

@@ -96,14 +96,17 @@ def __init__( self, view, **kwargs ) :
 			with GafferUI.ListContainer( GafferUI.ListContainer.Orientation.Horizontal, spacing = 4 ) :
 				GafferUI.Spacer( imath.V2i( 1, 1 ), imath.V2i( 1, 1 ) )
 				self.__label = GafferUI.Label( "Render" )
-				self.__stateWidget = _StatePlugValueWidget( None )
+				self.__stateWidget = _StatePlugValueWidget( None, view )
 				self.__messagesWidget = _MessageSummaryPlugValueWidget( None )
 
 		self.__view = view
 
 		if isinstance( self.__view["in"], GafferImage.ImagePlug ) :
 			view.plugDirtiedSignal().connect( Gaffer.WeakMethod( self.__viewPlugDirtied ) )
 
+		if isinstance( self.__view, GafferUI.View ) :
+			self.__view.viewportGadget().keyPressSignal().connect( Gaffer.WeakMethod( self.__keyPress ) )
+
 		self.__update()
 
 	def __update( self ) :
@@ -177,15 +180,34 @@ def __viewPlugDirtied( self, plug ) :
 	def __renderNodePlugDirtied( self, plug ) :
 
 		if plug.getName() == "state" :
-			self.__updateLazily();
+			self.__updateLazily()
+
+	def __keyPress( self, widget, event ) :
+
+		if event.key == "Escape" :
+			renderNode = self._interactiveRenderNode( self.__view )
+			if renderNode is not None :
+				statePlug = renderNode["state"].source()
+				statePlug.setValue( GafferScene.InteractiveRender.State.Paused )
+		elif event.key == "Backslash" and event.modifiers == event.modifiers.Control :
+			renderNode = self._interactiveRenderNode( self.__view )
+			if renderNode is not None :
+				statePlug = renderNode["state"].source()
+				state = statePlug.getValue()
+				if state == GafferScene.InteractiveRender.State.Running :
+					statePlug.setValue( GafferScene.InteractiveRender.State.Paused )
+				else :
+					statePlug.setValue( GafferScene.InteractiveRender.State.Running )
+					if isinstance( self.__view, GafferImageUI.ImageView ) :
+						self.__view.imageGadget().setPaused( False )
 
 ##########################################################################
 # UI for the state plug that allows setting the state through buttons
 ##########################################################################
 
 class _StatePlugValueWidget( GafferUI.PlugValueWidget ) :
 
-	def __init__( self, plug, *args, **kwargs) :
+	def __init__( self, plug, view = None, *args, **kwargs) :
 
 		row = GafferUI.ListContainer( GafferUI.ListContainer.Orientation.Horizontal )
 		GafferUI.PlugValueWidget.__init__( self, row, plug )
@@ -214,6 +236,7 @@ def __init__( self, plug, *args, **kwargs) :
 		}
 
 		self.__state = None
+		self.__view = view
 
 	def _updateFromValues( self, values, exception ) :
 
@@ -235,6 +258,8 @@ def __startPauseClicked( self, button ) :
 		# Not enabling undo here is done so that users won't accidentally restart/stop their renderings.
 		if state != GafferScene.InteractiveRender.State.Running:
 			self.getPlug().setValue( GafferScene.InteractiveRender.State.Running )
+			if isinstance( self.__view, GafferImageUI.ImageView ) :
+				self.__view.imageGadget().setPaused( False )
 		else:
 			self.getPlug().setValue( GafferScene.InteractiveRender.State.Paused )