Merge branch '1.3_maintenance'

Changes.md

@@ -214,7 +214,10 @@ Build
 1.3.x.x (relative to 1.3.12.0)
 =======
 
+Improvements
+------------
 
+- Viewer : Added <kbd>Ctrl</kbd>+<kbd>PgUp</kbd> shortcut for displaying the RGBA image layer (or the first available layer if RGBA doesn't exist).
 
 1.3.12.0 (relative to 1.3.11.0)
 ========

doc/source/Interface/ControlsAndShortcuts/index.md

@@ -298,6 +298,7 @@ Isolate alpha channel                | {kbd}`A`
 View luminance of RGB                | {kbd}`L`
 Previous layer                       | {kbd}`PgUp`
 Next layer                           | {kbd}`PgDn`
+First layer (RGBA)                   | {kbd}`Ctrl` + {kbd}`PgUp`
 Previous view                        | {kbd}`[`
 Next view                            | {kbd}`]`
 Center image at 1:1 scale            | {kbd}`Home`

python/GafferImageUI/ImageViewUI.py

@@ -910,12 +910,27 @@ def _menuDefinition( self ) :
 			}
 		)
 
+		firstValue = next( iter( self._rgbaChannels().values() ), None )
+		result.append(
+			"/First",
+			{
+				"command" : functools.partial( Gaffer.WeakMethod( self.__setValue ), value = firstValue ),
+				"shortCut" : "Ctrl+PgUp",
+				"active" : firstValue is not None and firstValue != currentValue,
+			}
+		)
+
 		return result
 
 	def __keyPress( self, gadget, event ) :
 
 		if event.key in ( "PageUp", "PageDown" ) :
-			value = self.__incrementedValue( -1 if event.key == "PageUp" else 1 )
+			if event.key == "PageDown" :
+				value = self.__incrementedValue( 1 )
+			elif event.modifiers == event.Modifiers.Control :
+				value = next( iter( self._rgbaChannels().values() ), None )
+			else :
+				value = self.__incrementedValue( -1 )
 			if value is not None :
 				self.__setValue( value )
 			return True