Use new UI event to send a putative path to the system for opening (#877)

* WIP poking around

* Rough in over here in ark

* Regenerate UI comm; actually implement the event

* Normalize on this side

In particular, I'm thinking of expanding `~`, i.e. the home directory

* Align function name with event name

Author: jennybc

crates/amalthea/src/comm/ui_comm.rs

@@ -292,6 +292,13 @@ pub struct ShowHtmlFileParams {
 	pub height: i64,
 }
 
+/// Parameters for the OpenWithSystem method.
+#[derive(Clone, Debug, Serialize, Deserialize, PartialEq)]
+pub struct OpenWithSystemParams {
+	/// The file path to open with the system default application
+	pub path: String,
+}
+
 /**
  * Backend RPC request types for the ui comm
  */
@@ -502,6 +509,10 @@ pub enum UiFrontendEvent {
 	#[serde(rename = "show_html_file")]
 	ShowHtmlFile(ShowHtmlFileParams),
 
+	/// Open a file or folder with the system default application
+	#[serde(rename = "open_with_system")]
+	OpenWithSystem(OpenWithSystemParams),
+
 	/// This event is used to signal that the stored messages the front-end
 	/// replays when constructing multi-output plots should be reset. This
 	/// happens for things like a holoviews extension being changed.

crates/ark/src/browser.rs

@@ -5,15 +5,16 @@
 //
 //
 
-use amalthea::comm::ui_comm::ShowUrlParams;
-use amalthea::comm::ui_comm::UiFrontendEvent;
 use harp::object::RObject;
+use harp::utils::r_normalize_path;
 use libr::Rf_ScalarLogical;
 use libr::SEXP;
 
 use crate::help::message::HelpEvent;
 use crate::help::message::ShowHelpUrlParams;
 use crate::interface::RMain;
+use crate::ui::events::send_open_with_system_event;
+use crate::ui::events::send_show_url_event;
 
 #[harp::register]
 pub unsafe extern "C-unwind" fn ps_browse_url(url: SEXP) -> anyhow::Result<SEXP> {
@@ -35,33 +36,32 @@ fn handle_help_url(url: String) -> anyhow::Result<()> {
 }
 
 unsafe fn ps_browse_url_impl(url: SEXP) -> anyhow::Result<SEXP> {
-    // Extract URL.
-    let url = RObject::view(url).to::<String>()?;
-    let _span = tracing::trace_span!("browseURL", url = %url).entered();
+    // Extract URL string for analysis
+    let url_string = RObject::view(url).to::<String>()?;
+    let _span = tracing::trace_span!("browseURL", url = %url_string).entered();
 
     // Handle help server requests.
-    if is_help_url(&url) {
+    if is_help_url(&url_string) {
         log::trace!("Help is handling URL");
-        handle_help_url(url)?;
+        handle_help_url(url_string)?;
         return Ok(Rf_ScalarLogical(1));
-    } else {
-        log::trace!("Help is not handling URL");
     }
 
-    // TODO: What is the right thing to do outside of Positron when
-    // `options(browser =)` is called? Right now we error.
-
-    // For all other URLs, create a ShowUrl event and send it to the main
-    // thread; Positron will handle it.
-    let params = ShowUrlParams { url };
-    let event = UiFrontendEvent::ShowUrl(params);
-
-    let main = RMain::get();
-    let ui_comm_tx = main
-        .get_ui_comm_tx()
-        .ok_or_else(|| anyhow::anyhow!("UI comm not connected."))?;
-
-    ui_comm_tx.send_event(event);
+    // Handle web URLs
+    if is_web_url(&url_string) {
+        log::trace!("Handling web URL");
+        send_show_url_event(&url_string)?;
+        return Ok(Rf_ScalarLogical(1));
+    }
 
+    // This is probably a file path? Send to the front end and ask for system
+    // default opener.
+    log::trace!("Treating as file path and asking system to open");
+    let path = r_normalize_path(url.into())?;
+    send_open_with_system_event(&path)?;
     Ok(Rf_ScalarLogical(1))
 }
+
+fn is_web_url(url: &str) -> bool {
+    url.starts_with("http://") || url.starts_with("https://")
+}

crates/ark/src/ui/events.rs

@@ -6,6 +6,7 @@
 //
 
 use amalthea::comm::ui_comm::OpenEditorParams;
+use amalthea::comm::ui_comm::OpenWithSystemParams;
 use amalthea::comm::ui_comm::OpenWorkspaceParams;
 use amalthea::comm::ui_comm::Position;
 use amalthea::comm::ui_comm::Range;
@@ -96,23 +97,43 @@ pub unsafe extern "C-unwind" fn ps_ui_set_selection_ranges(ranges: SEXP) -> anyh
     Ok(R_NilValue)
 }
 
-#[harp::register]
-pub unsafe extern "C-unwind" fn ps_ui_show_url(url: SEXP) -> anyhow::Result<SEXP> {
+pub fn send_show_url_event(url: &str) -> anyhow::Result<()> {
     let params = ShowUrlParams {
-        url: RObject::view(url).try_into()?,
+        url: url.to_string(),
     };
-
     let event = UiFrontendEvent::ShowUrl(params);
 
     let main = RMain::get();
     let ui_comm_tx = main
         .get_ui_comm_tx()
-        .ok_or_else(|| ui_comm_not_connected("ui_show_url"))?;
+        .ok_or_else(|| ui_comm_not_connected("show_url"))?;
     ui_comm_tx.send_event(event);
 
+    Ok(())
+}
+
+#[harp::register]
+pub unsafe extern "C-unwind" fn ps_ui_show_url(url: SEXP) -> anyhow::Result<SEXP> {
+    let url_string = RObject::view(url).to::<String>()?;
+    send_show_url_event(&url_string)?;
     Ok(R_NilValue)
 }
 
+pub fn send_open_with_system_event(path: &str) -> anyhow::Result<()> {
+    let params = OpenWithSystemParams {
+        path: path.to_string(),
+    };
+    let event = UiFrontendEvent::OpenWithSystem(params);
+
+    let main = RMain::get();
+    let ui_comm_tx = main
+        .get_ui_comm_tx()
+        .ok_or_else(|| ui_comm_not_connected("open_with_system"))?;
+    ui_comm_tx.send_event(event);
+
+    Ok(())
+}
+
 pub fn ps_ui_robj_as_ranges(ranges: SEXP) -> anyhow::Result<Vec<Range>> {
     let ranges_as_r_objects: Vec<RObject> = RObject::view(ranges).try_into()?;
     let ranges_as_result: Result<Vec<Vec<i32>>, _> = ranges_as_r_objects