API: Add support for retrieving user names for all layers

api/proto/board/board_commands.proto

@@ -115,6 +115,20 @@ message SetBoardOrigin
   kiapi.common.types.Vector2 origin = 3;
 }
 
+message GetBoardLayerName
+{
+  kiapi.common.types.DocumentSpecifier board = 1;
+
+  kiapi.board.types.BoardLayer layer = 2;
+}
+
+message BoardLayerNameResponse
+{
+  // The name of the layer shown in the KiCad GUI, which may be a default value like "F.Cu" or may
+  // have been customized by the user.
+  string name = 1;
+}
+
 /*
  * Net management
  */

pcbnew/api/api_handler_pcb.cpp

@@ -90,6 +90,7 @@ API_HANDLER_PCB::API_HANDLER_PCB( PCB_EDIT_FRAME* aFrame ) :
             &API_HANDLER_PCB::handleExpandTextVariables );
     registerHandler<GetBoardOrigin, types::Vector2>( &API_HANDLER_PCB::handleGetBoardOrigin );
     registerHandler<SetBoardOrigin, Empty>( &API_HANDLER_PCB::handleSetBoardOrigin );
+    registerHandler<GetBoardLayerName, BoardLayerNameResponse>( &API_HANDLER_PCB::handleGetBoardLayerName );
 
     registerHandler<InteractiveMoveItems, Empty>( &API_HANDLER_PCB::handleInteractiveMoveItems );
     registerHandler<GetNets, NetsResponse>( &API_HANDLER_PCB::handleGetNets );
@@ -1099,6 +1100,25 @@ HANDLER_RESULT<Empty> API_HANDLER_PCB::handleSetBoardOrigin(
 }
 
 
+HANDLER_RESULT<BoardLayerNameResponse> API_HANDLER_PCB::handleGetBoardLayerName(
+            const HANDLER_CONTEXT<GetBoardLayerName>& aCtx )
+{
+    if( HANDLER_RESULT<bool> documentValidation = validateDocument( aCtx.Request.board() );
+        !documentValidation )
+    {
+        return tl::unexpected( documentValidation.error() );
+    }
+
+    BoardLayerNameResponse response;
+
+    PCB_LAYER_ID id = FromProtoEnum<PCB_LAYER_ID>( aCtx.Request.layer() );
+
+    response.set_name( frame()->GetBoard()->GetLayerName( id ) );
+
+    return response;
+}
+
+
 HANDLER_RESULT<GetBoundingBoxResponse> API_HANDLER_PCB::handleGetBoundingBox(
         const HANDLER_CONTEXT<GetBoundingBox>& aCtx )
 {

pcbnew/api/api_handler_pcb.h

@@ -103,6 +103,9 @@ private:
 
     HANDLER_RESULT<Empty> handleSetBoardOrigin( const HANDLER_CONTEXT<SetBoardOrigin>& aCtx );
 
+    HANDLER_RESULT<BoardLayerNameResponse> handleGetBoardLayerName(
+            const HANDLER_CONTEXT<GetBoardLayerName>& aCtx );
+
     HANDLER_RESULT<commands::GetBoundingBoxResponse> handleGetBoundingBox(
             const HANDLER_CONTEXT<commands::GetBoundingBox>& aCtx );