From 73d6f348615e34770df431298febc002ef21dae9 Mon Sep 17 00:00:00 2001
From: etienne-k <2804556+etienne-k@users.noreply.github.com>
Date: Sun, 8 May 2022 15:31:53 +0200
Subject: [PATCH] refactor(statusline): split the statusline implementation
 into different functions

---
 helix-term/src/ui/statusline.rs | 250 +++++++++++++++++++++++++-------
 1 file changed, 197 insertions(+), 53 deletions(-)

diff --git a/helix-term/src/ui/statusline.rs b/helix-term/src/ui/statusline.rs
index a123cb1fd..2735b51ec 100644
--- a/helix-term/src/ui/statusline.rs
+++ b/helix-term/src/ui/statusline.rs
@@ -1,13 +1,28 @@
-use helix_core::{coords_at_pos, encoding};
+use helix_core::{
+    coords_at_pos,
+    encoding::{self, Encoding},
+    Position,
+};
 use helix_view::{
     document::{Mode, SCRATCH_BUFFER_NAME},
     graphics::Rect,
-    Document, Editor, View,
+    theme::Style,
+    Document, Editor, Theme, View,
 };
 
 use crate::ui::ProgressSpinners;
 
 use tui::buffer::Buffer as Surface;
+use tui::text::{Span, Spans};
+
+struct StatusLineElement {
+    /// The element
+    pub text: String,
+
+    /// The style to be used to render the element (this style will be merged with the base style).
+    /// If not set, a default base style will be used.
+    pub style: Option<Style>,
+}
 
 pub struct StatusLine;
 
@@ -21,33 +36,38 @@ impl StatusLine {
         is_focused: bool,
         spinners: &ProgressSpinners,
     ) {
-        use tui::text::{Span, Spans};
-
         //-------------------------------
         // Left side of the status line.
         //-------------------------------
 
-        let mode = match doc.mode() {
-            Mode::Insert => "INS",
-            Mode::Select => "SEL",
-            Mode::Normal => "NOR",
-        };
-        let progress = doc
-            .language_server()
-            .and_then(|srv| spinners.get(srv.id()).and_then(|spinner| spinner.frame()))
-            .unwrap_or("");
-
         let base_style = if is_focused {
             editor.theme.get("ui.statusline")
         } else {
             editor.theme.get("ui.statusline.inactive")
         };
-        // statusline
+
         surface.set_style(viewport.with_height(1), base_style);
+
         if is_focused {
-            surface.set_string(viewport.x + 1, viewport.y, mode, base_style);
+            let mode = Self::render_mode(doc);
+            surface.set_string(
+                viewport.x + 1,
+                viewport.y,
+                mode.text,
+                mode.style
+                    .map_or(base_style, |s| base_style.clone().patch(s)),
+            );
         }
-        surface.set_string(viewport.x + 5, viewport.y, progress, base_style);
+
+        let spinner = Self::render_lsp_spinner(doc, spinners);
+        surface.set_string(
+            viewport.x + 5,
+            viewport.y,
+            spinner.text,
+            spinner
+                .style
+                .map_or(base_style, |s| base_style.clone().patch(s)),
+        );
 
         //-------------------------------
         // Right side of the status line.
@@ -68,33 +88,47 @@ impl StatusLine {
             counts
         });
         let (warnings, errors) = diags;
-        let warning_style = editor.theme.get("warning");
-        let error_style = editor.theme.get("error");
+
         for i in 0..2 {
-            let (count, style) = match i {
-                0 => (warnings, warning_style),
-                1 => (errors, error_style),
+            let (count, state_element, count_element) = match i {
+                0 => (
+                    warnings,
+                    Self::render_diagnostics_warning_state(&editor.theme),
+                    Self::render_diagnostics_warning_count(warnings),
+                ),
+                1 => (
+                    errors,
+                    Self::render_diagnostics_error_state(&editor.theme),
+                    Self::render_diagnostics_error_count(errors),
+                ),
                 _ => unreachable!(),
             };
-            if count == 0 {
-                continue;
+
+            if count > 0 {
+                right_side_text.0.push(Span::styled(
+                    state_element.text,
+                    state_element
+                        .style
+                        .map_or(base_style, |s| base_style.clone().patch(s)),
+                ));
+
+                right_side_text.0.push(Span::styled(
+                    count_element.text,
+                    count_element
+                        .style
+                        .map_or(base_style, |s| base_style.clone().patch(s)),
+                ));
             }
-            let style = base_style.patch(style);
-            right_side_text.0.push(Span::styled("●", style));
-            right_side_text
-                .0
-                .push(Span::styled(format!(" {} ", count), base_style));
         }
 
         // Selections
         let sels_count = doc.selection(view.id).len();
+        let selections_element = Self::render_selections(sels_count);
         right_side_text.0.push(Span::styled(
-            format!(
-                " {} sel{} ",
-                sels_count,
-                if sels_count == 1 { "" } else { "s" }
-            ),
-            base_style,
+            selections_element.text,
+            selections_element
+                .style
+                .map_or(base_style, |s| base_style.clone().patch(s)),
         ));
 
         // Position
@@ -104,24 +138,35 @@ impl StatusLine {
                 .primary()
                 .cursor(doc.text().slice(..)),
         );
+        let position_element = Self::render_position(&pos);
         right_side_text.0.push(Span::styled(
-            format!(" {}:{} ", pos.row + 1, pos.col + 1), // Convert to 1-indexing.
-            base_style,
+            position_element.text,
+            position_element
+                .style
+                .map_or(base_style, |s| base_style.clone().patch(s)),
         ));
 
         // Encoding
         let enc = doc.encoding();
         if enc != encoding::UTF_8 {
-            right_side_text
-                .0
-                .push(Span::styled(format!(" {} ", enc.name()), base_style));
+            let encoding_element = Self::render_encoding(enc);
+            right_side_text.0.push(Span::styled(
+                encoding_element.text,
+                encoding_element
+                    .style
+                    .map_or(base_style, |s| base_style.clone().patch(s)),
+            ));
         }
 
         // File type
         let file_type = doc.language_id().unwrap_or("text");
-        right_side_text
-            .0
-            .push(Span::styled(format!(" {} ", file_type), base_style));
+        let file_type_element = Self::render_file_type(file_type);
+        right_side_text.0.push(Span::styled(
+            file_type_element.text,
+            file_type_element
+                .style
+                .map_or(base_style, |s| base_style.clone().patch(s)),
+        ));
 
         // Render to the statusline.
         surface.set_spans(
@@ -137,26 +182,125 @@ impl StatusLine {
         //-------------------------------
         // Middle / File path / Title
         //-------------------------------
-        let title = {
-            let rel_path = doc.relative_path();
-            let path = rel_path
-                .as_ref()
-                .map(|p| p.to_string_lossy())
-                .unwrap_or_else(|| SCRATCH_BUFFER_NAME.into());
-            format!("{}{}", path, if doc.is_modified() { "[+]" } else { "" })
-        };
+        let title_element = Self::render_file_name(doc);
 
         surface.set_string_truncated(
             viewport.x + 8, // 8: 1 space + 3 char mode string + 1 space + 1 spinner + 1 space
             viewport.y,
-            &title,
+            title_element.text.as_str(),
             viewport
                 .width
                 .saturating_sub(6)
                 .saturating_sub(right_side_text.width() as u16 + 1) as usize, // "+ 1": a space between the title and the selection info
-            |_| base_style,
+            |_| {
+                title_element
+                    .style
+                    .map_or(base_style, |s| base_style.clone().patch(s))
+            },
             true,
             true,
         );
     }
+
+    fn render_mode(doc: &Document) -> StatusLineElement {
+        return StatusLineElement {
+            text: format!(
+                "{}",
+                match doc.mode() {
+                    Mode::Insert => "INS",
+                    Mode::Select => "SEL",
+                    Mode::Normal => "NOR",
+                }
+            ),
+            style: None,
+        };
+    }
+
+    fn render_lsp_spinner(doc: &Document, spinners: &ProgressSpinners) -> StatusLineElement {
+        return StatusLineElement {
+            text: format!(
+                "{}",
+                doc.language_server()
+                    .and_then(|srv| spinners.get(srv.id()).and_then(|spinner| spinner.frame()))
+                    .unwrap_or("")
+            ),
+            style: None,
+        };
+    }
+
+    fn render_diagnostics_warning_state(theme: &Theme) -> StatusLineElement {
+        return StatusLineElement {
+            text: format!("●"),
+            style: Some(theme.get("warning")),
+        };
+    }
+
+    fn render_diagnostics_warning_count(warnings: usize) -> StatusLineElement {
+        return StatusLineElement {
+            text: format!(" {} ", warnings),
+            style: None,
+        };
+    }
+
+    fn render_diagnostics_error_state(theme: &Theme) -> StatusLineElement {
+        return StatusLineElement {
+            text: format!("●"),
+            style: Some(theme.get("error")),
+        };
+    }
+
+    fn render_diagnostics_error_count(errors: usize) -> StatusLineElement {
+        return StatusLineElement {
+            text: format!(" {} ", errors),
+            style: None,
+        };
+    }
+
+    fn render_selections(selections: usize) -> StatusLineElement {
+        return StatusLineElement {
+            text: format!(
+                " {} sel{} ",
+                &selections,
+                if selections == 1 { "" } else { "s" }
+            ),
+            style: None,
+        };
+    }
+
+    fn render_position(position: &Position) -> StatusLineElement {
+        return StatusLineElement {
+            text: format!(" {}:{} ", position.row + 1, position.col + 1),
+            style: None,
+        };
+    }
+
+    fn render_encoding(encoding: &'static Encoding) -> StatusLineElement {
+        return StatusLineElement {
+            text: format!(" {} ", encoding.name()),
+            style: None,
+        };
+    }
+
+    fn render_file_type(file_type: &str) -> StatusLineElement {
+        return StatusLineElement {
+            text: format!(" {} ", file_type),
+            style: None,
+        };
+    }
+
+    fn render_file_name(doc: &Document) -> StatusLineElement {
+        let title = {
+            let rel_path = doc.relative_path();
+            let path = rel_path
+                .as_ref()
+                .map(|p| p.to_string_lossy())
+                .unwrap_or_else(|| SCRATCH_BUFFER_NAME.into());
+            format!("{}{}", path, if doc.is_modified() { "[+]" } else { "" })
+        };
+
+        return StatusLineElement {
+            text: title,
+            style: None,
+        };
+    }
 }