allow whitespace to be rendered

Co-authored-by: Michael Davis <mcarsondavis@gmail.com>

2 files changed, 50 insertions, 6 deletions

diff --git a/helix-term/src/ui/editor.rs b/helix-term/src/ui/editor.rs
index 318180d7..798b8ac8 100644
--- a/helix-term/src/ui/editor.rs
+++ b/helix-term/src/ui/editor.rs
@@ -124,7 +124,15 @@ impl EditorView {
             Box::new(highlights)
         };
 
-        Self::render_text_highlights(doc, view.offset, inner, surface, theme, highlights);
+        Self::render_text_highlights(
+            doc,
+            view.offset,
+            inner,
+            surface,
+            theme,
+            highlights,
+            &editor.config().whitespace,
+        );
         Self::render_gutter(editor, doc, view, view.area, surface, theme, is_focused);
         Self::render_rulers(editor, doc, view, inner, surface, theme);
 
@@ -344,7 +352,10 @@ impl EditorView {
         surface: &mut Surface,
         theme: &Theme,
         highlights: H,
+        whitespace: &helix_view::editor::WhitespaceConfig,
     ) {
+        use helix_view::editor::WhitespaceRenderValue;
+
         // It's slightly more efficient to produce a full RopeSlice from the Rope, then slice that a bunch
         // of times than it is to always call Rope::slice/get_slice (it will internally always hit RSEnum::Light).
         let text = doc.text().slice(..);
@@ -353,9 +364,20 @@ impl EditorView {
         let mut visual_x = 0u16;
         let mut line = 0u16;
         let tab_width = doc.tab_width();
-        let tab = " ".repeat(tab_width);
+        let tab = if whitespace.render.tab() == WhitespaceRenderValue::All {
+            (1..tab_width).fold(whitespace.characters.tab.to_string(), |s, _| s + " ")
+        } else {
+            " ".repeat(tab_width)
+        };
+        let space = whitespace.characters.space.to_string();
+        let newline = if whitespace.render.newline() == WhitespaceRenderValue::All {
+            whitespace.characters.newline.to_string()
+        } else {
+            " ".to_string()
+        };
 
         let text_style = theme.get("ui.text");
+        let whitespace_style = theme.get("ui.virtual.whitespace");
 
         'outer: for event in highlights {
             match event {
@@ -374,6 +396,14 @@ impl EditorView {
                         .iter()
                         .fold(text_style, |acc, span| acc.patch(theme.highlight(span.0)));
 
+                    let space = if whitespace.render.space() == WhitespaceRenderValue::All
+                        && text.len_chars() < end
+                    {
+                        &space
+                    } else {
+                        " "
+                    };
+
                     use helix_core::graphemes::{grapheme_width, RopeGraphemes};
 
                     for grapheme in RopeGraphemes::new(text) {
@@ -386,8 +416,8 @@ impl EditorView {
                                 surface.set_string(
                                     viewport.x + visual_x - offset.col as u16,
                                     viewport.y + line,
-                                    " ",
-                                    style,
+                                    &newline,
+                                    style.patch(whitespace_style),
                                 );
                             }
 
@@ -400,12 +430,21 @@ impl EditorView {
                             }
                         } else {
                             let grapheme = Cow::from(grapheme);
+                            let is_whitespace;
 
                             let (grapheme, width) = if grapheme == "\t" {
+                                is_whitespace = true;
                                 // make sure we display tab as appropriate amount of spaces
                                 let visual_tab_width = tab_width - (visual_x as usize % tab_width);
-                                (&tab[..visual_tab_width], visual_tab_width)
+                                let grapheme_tab_width =
+                                    ropey::str_utils::char_to_byte_idx(&tab, visual_tab_width);
+
+                                (&tab[..grapheme_tab_width], visual_tab_width)
+                            } else if grapheme == " " {
+                                is_whitespace = true;
+                                (space, 1)
                             } else {
+                                is_whitespace = false;
                                 // Cow will prevent allocations if span contained in a single slice
                                 // which should really be the majority case
                                 let width = grapheme_width(&grapheme);
@@ -418,7 +457,11 @@ impl EditorView {
                                     viewport.x + visual_x - offset.col as u16,
                                     viewport.y + line,
                                     grapheme,
-                                    style,
+                                    if is_whitespace {
+                                        style.patch(whitespace_style)
+                                    } else {
+                                        style
+                                    },
                                 );
                             }
 
diff --git a/helix-term/src/ui/picker.rs b/helix-term/src/ui/picker.rs
index dec59c89..3ca6965c 100644
--- a/helix-term/src/ui/picker.rs
+++ b/helix-term/src/ui/picker.rs
@@ -240,6 +240,7 @@ impl<T: 'static> Component for FilePicker<T> {
                 surface,
                 &cx.editor.theme,
                 highlights,
+                &cx.editor.config().whitespace,
             );
 
             // highlight the line