input: Improve TextWrapper data structure. (#1237)

crates/ui/src/input/cursor.rs

@@ -70,6 +70,15 @@ impl From<rope::Point> for LineColumn {
     }
 }
 
+impl From<LineColumn> for rope::Point {
+    fn from(value: LineColumn) -> Self {
+        Self {
+            row: value.line.saturating_sub(1) as u32,
+            column: value.column.saturating_sub(1) as u32,
+        }
+    }
+}
+
 impl From<LineColumn> for tree_sitter::Point {
     fn from(value: LineColumn) -> Self {
         Self {

crates/ui/src/input/element.rs

@@ -392,7 +392,7 @@ impl TextElement {
         let mut visible_range = 0..total_lines;
         let mut line_bottom = px(0.);
         for (ix, line) in state.text_wrapper.lines.iter().enumerate() {
-            let wrapped_height = (line.wrap_lines + 1) * line_height;
+            let wrapped_height = line.height(line_height);
             line_bottom += wrapped_height;
 
             if line_bottom < -scroll_top {
@@ -717,12 +717,14 @@ impl Element for TextElement {
             .expect("failed to shape text");
         // measure.end();
 
+        let mut longest_line_width = px(0.);
+        if state.mode.is_multi_line() && lines.len() > 1 {
             let longtest_line: SharedString = state
                 .text
                 .line(state.text.summary().longest_row as usize)
                 .to_string()
                 .into();
-        let max_line_width = window
+            longest_line_width = window
                 .text_system()
                 .shape_line(
                     longtest_line.clone(),
@@ -738,14 +740,15 @@ impl Element for TextElement {
                     wrap_width,
                 )
                 .width;
+        }
 
         let total_wrapped_lines = state.text_wrapper.len();
 
         let scroll_size = size(
-            if max_line_width + line_number_width + RIGHT_MARGIN > bounds.size.width {
+            if longest_line_width + line_number_width + RIGHT_MARGIN > bounds.size.width {
-                max_line_width + line_number_width + RIGHT_MARGIN
+                longest_line_width + line_number_width + RIGHT_MARGIN
             } else {
-                max_line_width
+                longest_line_width
             },
             (total_wrapped_lines as f32 * line_height).max(bounds.size.height),
         );

crates/ui/src/input/marker.rs

@@ -3,7 +3,6 @@ use crate::{
     input::{InputState, LineColumn},
 };
 use gpui::{px, App, HighlightStyle, Hsla, SharedString, UnderlineStyle};
-use itertools::Itertools;
 use std::ops::Range;
 
 /// Marker represents a diagnostic message, such as an error or warning, in the code editor.
@@ -36,41 +35,19 @@ impl Marker {
 
     /// Prepare the marker to convert line, column to byte offsets.
     pub(super) fn prepare(&mut self, state: &InputState) {
-        let Some(start_line) = state
+        let mut start_point: rope::Point = self.start.into();
-            .text_wrapper
+        let mut end_point: rope::Point = self.end.into();
-            .lines
-            .get(self.start.line.saturating_sub(1))
-        else {
-            return;
-        };
 
-        let start_line_str = state.text.slice(start_line.range.clone());
+        // limit column avoid overflow
+        let start_line_len = state.text.line_len(start_point.row);
+        start_point.column = start_point.column.min(start_line_len);
+        let end_line_len = state.text.line_len(end_point.row);
+        end_point.column = end_point.column.min(end_line_len);
 
-        let Some(end_line) = state
+        let start = state.text.point_to_offset(start_point);
-            .text_wrapper
+        let end = state.text.point_to_offset(end_point);
-            .lines
-            .get(self.end.line.saturating_sub(1))
-        else {
-            return;
-        };
-        let end_line_str = state.text.slice(end_line.range.clone());
 
-        let start_byte = start_line.range.start
+        self.range = Some(start..end);
-            + start_line_str
-                .chars()
-                .take(self.start.column.saturating_sub(1))
-                .counts_by(|c| c.len_utf8())
-                .values()
-                .sum::<usize>();
-        let end_byte = end_line.range.start
-            + end_line_str
-                .chars()
-                .take(self.end.column.saturating_sub(1))
-                .counts_by(|c| c.len_utf8())
-                .values()
-                .sum::<usize>();
-
-        self.range = Some(start_byte..end_byte);
     }
 }
 

crates/ui/src/input/mode.rs

@@ -105,7 +105,7 @@ impl InputMode {
     }
 
     pub(super) fn update_auto_grow(&mut self, text_wrapper: &TextWrapper) {
-        let wrapped_lines = text_wrapper.wrapped_lines.len();
+        let wrapped_lines = text_wrapper.len();
         self.set_rows(wrapped_lines);
     }
 

crates/ui/src/input/rope_ext.rs

@@ -88,9 +88,8 @@ impl std::iter::FusedIterator for RopeLines {}
 
 impl RopeExt for Rope {
     fn line(&self, row: usize) -> Rope {
-        let row = row as u32;
+        let start = self.line_start_offset(row);
-        let start = self.point_to_offset(Point::new(row, 0));
+        let end = start + self.line_len(row as u32) as usize;
-        let end = start + self.line_len(row) as usize;
         self.slice(start..end)
     }
 
@@ -145,7 +144,9 @@ mod tests {
         assert_eq!(rope.line(1).to_string(), "World\r");
         assert_eq!(rope.line(2).to_string(), "This is a test 中文");
         assert_eq!(rope.line(3).to_string(), "Rope");
-        assert_eq!(rope.line(4).to_string(), "");
+
+        // over bounds
+        assert_eq!(rope.line(6).to_string(), "");
     }
 
     #[test]

crates/ui/src/input/state.rs

@@ -31,7 +31,7 @@ use super::{
 };
 use crate::input::hover_popover::DiagnosticPopover;
 use crate::input::marker::Marker;
-use crate::input::text_wrapper::LineWrap;
+use crate::input::text_wrapper::LineItem;
 use crate::input::{LineColumn, RopeExt as _, Selection};
 use crate::{history::History, scroll::ScrollbarState, Root};
 
@@ -687,6 +687,11 @@ impl InputState {
                 .unwrap_or(self.input_bounds.size.width);
 
             self.text_wrapper.set_wrap_width(Some(wrap_width), cx);
+
+            // Reset scroll to left 0
+            let mut offset = self.scroll_handle.offset();
+            offset.x = px(0.);
+            self.scroll_handle.set_offset(offset);
         } else {
             self.text_wrapper.set_wrap_width(None, cx);
         }
@@ -725,7 +730,7 @@ impl InputState {
     pub fn default_value(mut self, value: impl Into<SharedString>) -> Self {
         let text: SharedString = value.into();
         self.text = Rope::from(text.as_str());
-        self.text_wrapper.text = self.text.clone();
+        self.text_wrapper.set_default_text(&self.text);
         self
     }
 
@@ -1722,7 +1727,7 @@ impl InputState {
     fn line_origin_with_y_offset(
         &self,
         y_offset: &mut Pixels,
-        line: &LineWrap,
+        line: &LineItem,
         line_height: Pixels,
     ) -> Point<Pixels> {
         // NOTE: About line.wrap_boundaries.len()
@@ -1731,8 +1736,7 @@ impl InputState {
         // If have 2 line, the value is 1
         if self.mode.is_multi_line() {
             let p = point(px(0.), *y_offset);
-            let height = line_height + line.wrap_lines as f32 * line_height;
+            *y_offset += line.height(line_height);
-            *y_offset = *y_offset + height;
             p
         } else {
             point(px(0.), px(0.))

crates/ui/src/input/text_wrapper.rs

@@ -5,48 +5,51 @@ use rope::Rope;
 
 use crate::input::RopeExt as _;
 
-#[allow(unused)]
+/// A line with soft wrapped lines info.
-pub(super) struct LineWrap {
+#[derive(Clone)]
-    /// The number of soft wrapped lines of this line (Not include first line.)
+pub(super) struct LineItem {
+    /// The original line text.
+    line: Rope,
+    /// The soft wrapped lines relative byte range (0..line.len) of this line (Include first line).
     ///
     /// FIXME: Here in somecase, the `line_wrapper.wrap_line` has returned different
     /// like the `window.text_system().shape_text`. So, this value may not equal
     /// the actual rendered lines.
-    pub(super) wrap_lines: usize,
+    wrapped_lines: Vec<Range<usize>>,
-    /// The range of the line text in the entire text (not includes ending `\n`).
-    pub(super) range: Range<usize>,
 }
 
-impl LineWrap {
+impl LineItem {
-    /// Return the bytes length of this line.
+    /// Get the bytes length of this line.
+    #[inline]
     pub(super) fn len(&self) -> usize {
-        self.range.end - self.range.start
+        self.line.len()
     }
 
-    /// Get the total number of lines including wrapped lines.
+    /// Get number of soft wrapped lines of this line (include the first line).
+    #[inline]
     pub(super) fn lines_len(&self) -> usize {
-        self.wrap_lines + 1
+        self.wrapped_lines.len()
     }
 
-    /// Get the height of this line including wrapped lines.
+    /// Get the height of this line item with given line height.
     pub(super) fn height(&self, line_height: Pixels) -> Pixels {
-        self.lines_len() * line_height
+        self.lines_len() as f32 * line_height
     }
 }
 
-/// Used to prepare the text with soft wrap to be get lines to displayed in the TextArea
+/// Used to prepare the text with soft wrap to be get lines to displayed in the Editor.
 ///
-/// After use lines to calculate the scroll size of the TextArea
+/// After use lines to calculate the scroll size of the Editor.
 pub(super) struct TextWrapper {
-    pub(super) text: Rope,
+    text: Rope,
-    /// The wrapped lines (Inlucde the first line), value is start and end index of the line.
+    /// Total wrapped lines (Inlucde the first line), value is start and end index of the line.
-    pub(super) wrapped_lines: Vec<Range<usize>>,
+    soft_lines: usize,
-    /// The lines by split \n
+    font: Font,
-    pub(super) lines: Vec<LineWrap>,
+    font_size: Pixels,
-    pub(super) font: Font,
-    pub(super) font_size: Pixels,
     /// If is none, it means the text is not wrapped
-    pub(super) wrap_width: Option<Pixels>,
+    wrap_width: Option<Pixels>,
+    /// The lines by split \n
+    pub(super) lines: Vec<LineItem>,
 }
 
 #[allow(unused)]
@@ -57,14 +60,26 @@ impl TextWrapper {
             font,
             font_size,
             wrap_width,
-            wrapped_lines: Vec::new(),
+            soft_lines: 0,
             lines: Vec::new(),
         }
     }
 
+    #[inline]
+    pub(super) fn set_default_text(&mut self, text: &Rope) {
+        self.text = text.clone();
+    }
+
     /// Get the total number of lines including wrapped lines.
+    #[inline]
     pub(super) fn len(&self) -> usize {
-        self.wrapped_lines.len()
+        self.soft_lines
+    }
+
+    /// Get the line item by row index.
+    #[inline]
+    pub(super) fn line(&self, row: usize) -> Option<&LineItem> {
+        self.lines.iter().skip(row).next()
     }
 
     pub(super) fn set_wrap_width(&mut self, wrap_width: Option<Pixels>, cx: &mut App) {
@@ -94,45 +109,39 @@ impl TextWrapper {
             return;
         }
 
-        let mut wrapped_lines = vec![];
-        let mut lines = vec![];
         let wrap_width = self.wrap_width;
         let mut line_wrapper = cx
             .text_system()
             .line_wrapper(self.font.clone(), self.font_size);
-        let mut prev_line_ix = 0;
 
+        self.lines.clear();
         for line in text.lines() {
-            let line = line.to_string();
+            let line_str = line.to_string();
-            let mut line_wraps = vec![];
+            let mut wrapped_lines = vec![];
             let mut prev_boundary_ix = 0;
 
             // If wrap_width is Pixels::MAX, skip wrapping to disable word wrap
             if let Some(wrap_width) = wrap_width {
                 // Here only have wrapped line, if there is no wrap meet, the `line_wraps` result will empty.
-                for boundary in line_wrapper.wrap_line(&[LineFragment::text(&line)], wrap_width) {
+                for boundary in line_wrapper.wrap_line(&[LineFragment::text(&line_str)], wrap_width)
-                    line_wraps.push(prev_boundary_ix..boundary.ix);
+                {
+                    wrapped_lines.push(prev_boundary_ix..boundary.ix);
                     prev_boundary_ix = boundary.ix;
                 }
             }
 
-            lines.push(LineWrap {
-                wrap_lines: line_wraps.len(),
-                range: prev_line_ix..prev_line_ix + line.len(),
-            });
-
-            wrapped_lines.extend(line_wraps);
             // Reset of the line
-            if !line[prev_boundary_ix..].is_empty() || prev_boundary_ix == 0 {
+            if !line_str[prev_boundary_ix..].is_empty() || prev_boundary_ix == 0 {
-                wrapped_lines.push(prev_line_ix + prev_boundary_ix..prev_line_ix + line.len());
+                wrapped_lines.push(prev_boundary_ix..line.len());
             }
 
-            // +1 for \n
+            self.lines.push(LineItem {
-            prev_line_ix += line.len() + 1;
+                line: line.clone(),
+                wrapped_lines,
+            });
         }
 
         self.text = text.clone();
-        self.wrapped_lines = wrapped_lines;
+        self.soft_lines = self.lines.iter().map(|l| l.lines_len()).sum();
-        self.lines = lines;
     }
 }