Use RStudio source marker API to display lints

When running under a version of RStudio that supports the source marker API display lints using the Markers pane (this behavior can be disabled via a global option).

DESCRIPTION

@@ -16,7 +16,8 @@ Imports:
     stringdist,
     testthat,
     digest,
-    igraph
+    igraph,
+    rstudioapi (>= 0.2)
 License: MIT + file LICENSE
 LazyData: true
 Suggests:

R/lint.R

@@ -118,6 +118,8 @@ lint_package <- function(path = NULL, relative_path = TRUE, ...) {
 
   lints <- reorder_lints(lints)
   class(lints) <- "lints"
+  attr(lints, "package_path") <- path
+  attr(lints, "relative_path") <- relative_path
   lints
 }
 
@@ -198,10 +200,45 @@ print.lint <- function(x, ...) {
 
 #' @export
 print.lints <- function(x, ...) {
-  lapply(x, print, ...)
+  if (getOption("lintr.rstudio_source_markers", TRUE) && 
+      rstudioapi::hasFun("sourceMarkers"))
+    rstudio_source_markers(x)
+  else
+    lapply(x, print, ...)
   invisible(x)
 }
 
+rstudio_source_markers <- function(lints) {
+
+  # if relative paths were requested then save the package_path
+  # to be passed along as the basePath to the sourceMarker function
+  relative_path <- isTRUE(attr(lints, "relative_path"))
+  if (relative_path)
+    package_path <- attr(lints, "package_path")
+  else
+    package_path <- NULL
+
+  # generate the markers
+  markers <- lapply(lints, function(x) {
+    marker <- list()
+    marker$type <- x$type
+    if (relative_path)
+      x$filename <- file.path(package_path, x$filename)
+    marker$file <- x$filename
+    marker$line <- x$line_number
+    marker$column <- x$column_number
+    marker$message <- x$message
+    marker
+  })
+
+  # request source markers
+  rstudioapi::callFun("sourceMarkers", 
+                      name = "lintr", 
+                      markers = markers, 
+                      basePath = package_path,
+                      autoSelect = "first")
+}
+
 highlight_string <- function(message, column_number = NULL, ranges = NULL) {
 
   maximum <- max(column_number, unlist(ranges))