Stick REPL icon in quick action bar (#14064)

REPL Quick Actions

<img width="325" alt="image"
src="https://github.com/zed-industries/zed/assets/836375/faaf4c8f-ef12-4417-a9dd-158d5beae8ba">

When the Jupyter REPL is enabled and a kernel is available, show the
status in the editor bar:

![quick action bar
repl](https://github.com/zed-industries/zed/assets/836375/f3445283-f1fc-4714-895b-7aa842d4ab76)


Release Notes:

- N/A

---------

Co-authored-by: Nate Butler <iamnbutler@gmail.com>

crates/repl/src/kernels.rs

@@ -82,7 +82,7 @@ pub enum Kernel {
 }
 
 impl Kernel {
-    pub fn dot(&mut self) -> Indicator {
+    pub fn dot(&self) -> Indicator {
         match self {
             Kernel::RunningKernel(kernel) => match kernel.execution_state {
                 ExecutionState::Idle => Indicator::dot().color(Color::Success),

crates/repl/src/repl.rs

@@ -11,7 +11,11 @@ mod session;
 mod stdio;
 
 pub use jupyter_settings::JupyterSettings;
-pub use runtime_panel::RuntimePanel;
+pub use kernels::{Kernel, KernelSpecification};
+pub use runtime_panel::Run;
+pub use runtime_panel::{RuntimePanel, SessionSupport};
+pub use runtimelib::ExecutionState;
+pub use session::Session;
 
 fn zed_dispatcher(cx: &mut AppContext) -> impl Dispatcher {
     struct ZedDispatcher {

crates/repl/src/runtime_panel.rs

@@ -241,6 +241,17 @@ impl RuntimePanel {
         Some((selected_text, language_name, anchor_range))
     }
 
+    pub fn language(
+        &self,
+        editor: WeakView<Editor>,
+        cx: &mut ViewContext<Self>,
+    ) -> Option<Arc<str>> {
+        match self.snippet(editor, cx) {
+            Some((_, language, _)) => Some(language),
+            None => None,
+        }
+    }
+
     pub fn refresh_kernelspecs(&mut self, cx: &mut ViewContext<Self>) -> Task<anyhow::Result<()>> {
         let kernel_specifications = kernel_specifications(self.fs.clone());
         cx.spawn(|this, mut cx| async move {
@@ -336,6 +347,50 @@ impl RuntimePanel {
     }
 }
 
+pub enum SessionSupport {
+    ActiveSession(View<Session>),
+    Inactive(KernelSpecification),
+    RequiresSetup(String),
+    Unsupported,
+}
+
+impl RuntimePanel {
+    pub fn session(
+        &mut self,
+        editor: WeakView<Editor>,
+        cx: &mut ViewContext<Self>,
+    ) -> SessionSupport {
+        let entity_id = editor.entity_id();
+        let session = self.sessions.get(&entity_id).cloned();
+
+        match session {
+            Some(session) => SessionSupport::ActiveSession(session),
+            None => {
+                let language = self.language(editor, cx);
+                let language = match language {
+                    Some(language) => language,
+                    None => return SessionSupport::Unsupported,
+                };
+                // Check for kernelspec
+                let kernelspec = self.kernelspec(&language, cx);
+
+                match kernelspec {
+                    Some(kernelspec) => SessionSupport::Inactive(kernelspec),
+                    None => {
+                        let language: String = language.to_lowercase();
+                        // If no kernelspec but language is one of typescript, python, r, or julia
+                        // then we return RequiresSetup
+                        match language.as_str() {
+                            "typescript" | "python" => SessionSupport::RequiresSetup(language),
+                            _ => SessionSupport::Unsupported,
+                        }
+                    }
+                }
+            }
+        }
+    }
+}
+
 impl Panel for RuntimePanel {
     fn persistent_name() -> &'static str {
         "RuntimePanel"

crates/repl/src/session.rs

@@ -22,11 +22,11 @@ use theme::{ActiveTheme, ThemeSettings};
 use ui::{h_flex, prelude::*, v_flex, ButtonLike, ButtonStyle, Label};
 
 pub struct Session {
-    editor: WeakView<Editor>,
-    kernel: Kernel,
+    pub editor: WeakView<Editor>,
+    pub kernel: Kernel,
     blocks: HashMap<String, EditorBlock>,
-    messaging_task: Task<()>,
-    kernel_specification: KernelSpecification,
+    pub messaging_task: Task<()>,
+    pub kernel_specification: KernelSpecification,
 }
 
 struct EditorBlock {
@@ -310,7 +310,7 @@ impl Session {
         }
     }
 
-    fn interrupt(&mut self, cx: &mut ViewContext<Self>) {
+    pub fn interrupt(&mut self, cx: &mut ViewContext<Self>) {
         match &mut self.kernel {
             Kernel::RunningKernel(_kernel) => {
                 self.send(InterruptRequest {}.into(), cx).ok();
@@ -322,7 +322,7 @@ impl Session {
         }
     }
 
-    fn shutdown(&mut self, cx: &mut ViewContext<Self>) {
+    pub fn shutdown(&mut self, cx: &mut ViewContext<Self>) {
         let kernel = std::mem::replace(&mut self.kernel, Kernel::ShuttingDown);
 
         match kernel {