add customizable read-only indicator to statusbar

book/src/configuration.md

@@ -49,6 +49,7 @@ You may also specify a file to use for configuration with the `-c` or
 | `auto-info` | Whether to display infoboxes | `true` |
 | `true-color` | Set to `true` to override automatic detection of terminal truecolor support in the event of a false negative. | `false` |
 | `rulers` | List of column positions at which to display the rulers. Can be overridden by language specific `rulers` in `languages.toml` file. | `[]` |
+| `read-only-indicator` | String to display next to filename in statusbar when configured and if file is read-only. Set to `""` to disable. | `"[RO]"` |
 | `bufferline` | Renders a line at the top of the editor displaying open buffers. Can be `always`, `never` or `multiple` (only shown if more than one buffer is in use) | `never` |
 | `color-modes` | Whether to color the mode indicator with different colors depending on the mode itself | `false` |
 
@@ -64,8 +65,8 @@ Statusline elements can be defined as follows:
 
 ```toml
 [editor.statusline]
-left = ["mode", "spinner"]
-center = ["file-name"]
+left = ["mode", "spinner", "file-name", "read-only-indicator"]
+center = []
 right = ["diagnostics", "selections", "position", "file-encoding", "file-line-ending", "file-type"]
 separator = "│"
 ```
@@ -77,6 +78,7 @@ The following elements can be configured:
 | `mode` | The current editor mode (`NOR`/`INS`/`SEL`) |
 | `spinner` | A progress spinner indicating LSP activity |
 | `file-name` | The path/name of the opened file |
+| `read-only-indicator` | When configured, indicates whether the file is read-only. |
 | `file-encoding` | The encoding of the opened file if it differs from UTF-8 |
 | `file-line-ending` | The file line endings (CRLF or LF) |
 | `file-type` | The type of the opened file |

helix-term/src/ui/statusline.rs

@@ -1,6 +1,6 @@
 use helix_core::{coords_at_pos, encoding, Position};
 use helix_view::{
-    document::{Mode, SCRATCH_BUFFER_NAME},
+    document::{Mode, WritePermission, SCRATCH_BUFFER_NAME},
     graphics::Rect,
     theme::Style,
     Document, Editor, View,
@@ -144,6 +144,7 @@ where
         helix_view::editor::StatusLineElement::Selections => render_selections,
         helix_view::editor::StatusLineElement::Position => render_position,
         helix_view::editor::StatusLineElement::PositionPercentage => render_position_percentage,
+        helix_view::editor::StatusLineElement::ReadOnlyIndicator => render_read_only_indicator,
         helix_view::editor::StatusLineElement::Separator => render_separator,
         helix_view::editor::StatusLineElement::Spacer => render_spacer,
     }
@@ -354,6 +355,19 @@ where
     write(context, title, None);
 }
 
+fn render_read_only_indicator<F>(context: &mut RenderContext, write: F)
+where
+    F: Fn(&mut RenderContext, String, Option<Style>) + Copy,
+{
+    let read_only_indicator = if context.doc.write_permission == WritePermission::ReadOnly {
+        context.editor.config().read_only_indicator.to_string()
+    } else {
+        String::new()
+    };
+
+    write(context, read_only_indicator, None);
+}
+
 fn render_separator<F>(context: &mut RenderContext, write: F)
 where
     F: Fn(&mut RenderContext, String, Option<Style>) + Copy,

helix-view/src/document.rs

@@ -39,6 +39,13 @@ pub enum Mode {
     Insert = 2,
 }
 
+#[derive(Debug, Copy, Clone, PartialEq, Eq, Hash, Serialize)]
+pub enum WritePermission {
+    Writable,
+    ReadOnly,
+    Unknown,
+}
+
 impl Display for Mode {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         match self {
@@ -120,9 +127,11 @@ pub struct Document {
 
     diagnostics: Vec<Diagnostic>,
     language_server: Option<Arc<helix_lsp::Client>>,
+    /// Write permissions of the file - read-only, writable, or unknown.
+    pub write_permission: WritePermission,
 }
 
-use std::{fmt, mem};
+use std::{fmt, fs, mem};
 impl fmt::Debug for Document {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         f.debug_struct("Document")
@@ -141,6 +150,7 @@ impl fmt::Debug for Document {
             .field("version", &self.version)
             .field("modified_since_accessed", &self.modified_since_accessed)
             .field("diagnostics", &self.diagnostics)
+            .field("write_permission", &self.write_permission)
             // .field("language_server", &self.language_server)
             .finish()
     }
@@ -358,6 +368,7 @@ impl Document {
             last_saved_revision: 0,
             modified_since_accessed: false,
             language_server: None,
+            write_permission: WritePermission::Unknown,
         }
     }
 
@@ -388,6 +399,15 @@ impl Document {
         }
 
         doc.detect_indent_and_line_ending();
+        // this seems overly complex but should make it easier
+        // to extend doc.file_stat with more information in the future.
+        doc.write_permission = fs::metadata(path).map_or(WritePermission::Unknown, |f| {
+            if f.permissions().readonly() {
+                WritePermission::ReadOnly
+            } else {
+                WritePermission::Writable
+            }
+        });
 
         Ok(doc)
     }

helix-view/src/editor.rs

@@ -45,6 +45,8 @@ use serde::{ser::SerializeMap, Deserialize, Deserializer, Serialize, Serializer}
 
 use arc_swap::access::{DynAccess, DynGuard};
 
+const DEFAULT_READ_ONLY_INDICATOR: &str = "[RO]";
+
 fn deserialize_duration_millis<'de, D>(deserializer: D) -> Result<Duration, D::Error>
 where
     D: serde::Deserializer<'de>,
@@ -166,6 +168,8 @@ pub struct Config {
     pub bufferline: BufferLine,
     /// Vertical indent width guides.
     pub indent_guides: IndentGuidesConfig,
+    /// String indicating whether a file is read-only. Defaults to `"[RO]"`
+    pub read_only_indicator: String,
     /// Whether to color modes with different colors. Defaults to `false`.
     pub color_modes: bool,
 }
@@ -267,7 +271,7 @@ impl Default for StatusLineConfig {
         use StatusLineElement as E;
 
         Self {
-            left: vec![E::Mode, E::Spinner, E::FileName],
+            left: vec![E::Mode, E::Spinner, E::FileName, E::ReadOnlyIndicator],
             center: vec![],
             right: vec![E::Diagnostics, E::Selections, E::Position, E::FileEncoding],
             separator: String::from("│"),
@@ -305,6 +309,9 @@ pub enum StatusLineElement {
     /// The cursor position
     Position,
 
+    /// The read-only indicator
+    ReadOnlyIndicator,
+
     /// The separator string
     Separator,
 
@@ -576,6 +583,7 @@ impl Default for Config {
             whitespace: WhitespaceConfig::default(),
             bufferline: BufferLine::default(),
             indent_guides: IndentGuidesConfig::default(),
+            read_only_indicator: DEFAULT_READ_ONLY_INDICATOR.to_string(),
             color_modes: false,
         }
     }