rework positioning/rendering and enable softwrap/virtual text (#5420)

* rework positioning/rendering, enables softwrap/virtual text

This commit is a large rework of the core text positioning and
rendering code in helix to remove the assumption that on-screen
columns/lines correspond to text columns/lines.

A generic `DocFormatter` is introduced that positions graphemes on
and is used both for rendering and for movements/scrolling.
Both virtual text support (inline, grapheme overlay and multi-line)
and a capable softwrap implementation is included.

fix picker highlight

cleanup doc formatter, use word bondaries for wrapping

make visual vertical movement a seperate commnad

estimate line gutter width to improve performance

cache cursor position

cleanup and optimize doc formatter

cleanup documentation

fix typos

Co-authored-by: Daniel Hines <d4hines@gmail.com>

update documentation

fix panic in last_visual_line funciton

improve soft-wrap documentation

add extend_visual_line_up/down commands

fix non-visual vertical movement

streamline virtual text highlighting, add softwrap indicator

fix cursor position if softwrap is disabled

improve documentation of text_annotations module

avoid crashes if view anchor is out of bounds

fix: consider horizontal offset when traslation char_idx -> vpos

improve default configuration

fix: mixed up horizontal and vertical offset

reset view position after config reload

apply suggestions from review

disabled softwrap for very small screens to avoid endless spin

fix wrap_indicator setting

fix bar cursor disappearring on the EOF character

add keybinding for linewise vertical movement

fix: inconsistent gutter highlights

improve virtual text API

make scope idx lookup more ergonomic

allow overlapping overlays

correctly track char_pos for virtual text

adjust configuration

deprecate old position fucntions

fix infinite loop in highlight lookup

fix gutter style

fix formatting

document max-line-width interaction with softwrap

change wrap-indicator example to use empty string

fix: rare panic when view is in invalid state (bis)

* Apply suggestions from code review

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

* improve documentation for positoning functions

* simplify tests

* fix documentation of Grapheme::width

* Apply suggestions from code review

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

* add explicit drop invocation

* Add explicit MoveFn type alias

* add docuntation to Editor::cursor_cache

* fix a few typos

* explain use of allow(deprecated)

* make gj and gk extend in select mode

* remove unneded debug and TODO

* mark tab_width_at #[inline]

* add fast-path to move_vertically_visual in case softwrap is disabled

* rename first_line to first_visual_line

* simplify duplicate if/else

---------

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

1 files changed, 52 insertions, 29 deletions

diff --git a/helix-term/src/ui/picker.rs b/helix-term/src/ui/picker.rs
index 6bd64251..5fa75136 100644
--- a/helix-term/src/ui/picker.rs
+++ b/helix-term/src/ui/picker.rs
@@ -2,7 +2,12 @@ use crate::{
     alt,
     compositor::{Component, Compositor, Context, Event, EventResult},
     ctrl, key, shift,
-    ui::{self, fuzzy_match::FuzzyQuery, EditorView},
+    ui::{
+        self,
+        document::{render_document, LineDecoration, LinePos, TextRenderer},
+        fuzzy_match::FuzzyQuery,
+        EditorView,
+    },
 };
 use futures_util::future::BoxFuture;
 use tui::{
@@ -19,11 +24,15 @@ use std::cmp::{self, Ordering};
 use std::{collections::HashMap, io::Read, path::PathBuf};
 
 use crate::ui::{Prompt, PromptEvent};
-use helix_core::{movement::Direction, unicode::segmentation::UnicodeSegmentation, Position};
+use helix_core::{
+    movement::Direction, text_annotations::TextAnnotations,
+    unicode::segmentation::UnicodeSegmentation, Position,
+};
 use helix_view::{
     editor::Action,
     graphics::{CursorKind, Margin, Modifier, Rect},
     theme::Style,
+    view::ViewPosition,
     Document, DocumentId, Editor,
 };
 
@@ -179,7 +188,7 @@ impl<T: Item> FilePicker<T> {
                             }
                             _ => {
                                 // TODO: enable syntax highlighting; blocked by async rendering
-                                Document::open(path, None, None)
+                                Document::open(path, None, None, editor.config.clone())
                                     .map(|doc| CachedPreview::Document(Box::new(doc)))
                                     .unwrap_or(CachedPreview::NotFound)
                             }
@@ -283,43 +292,57 @@ impl<T: Item + 'static> Component for FilePicker<T> {
                 })
                 .unwrap_or(0);
 
-            let offset = Position::new(first_line, 0);
+            let offset = ViewPosition {
+                anchor: doc.text().line_to_char(first_line),
+                horizontal_offset: 0,
+                vertical_offset: 0,
+            };
 
-            let mut highlights =
-                EditorView::doc_syntax_highlights(doc, offset, area.height, &cx.editor.theme);
+            let mut highlights = EditorView::doc_syntax_highlights(
+                doc,
+                offset.anchor,
+                area.height,
+                &cx.editor.theme,
+            );
             for spans in EditorView::doc_diagnostics_highlights(doc, &cx.editor.theme) {
                 if spans.is_empty() {
                     continue;
                 }
                 highlights = Box::new(helix_core::syntax::merge(highlights, spans));
             }
-            EditorView::render_text_highlights(
+            let mut decorations: Vec<Box<dyn LineDecoration>> = Vec::new();
+
+            if let Some((start, end)) = range {
+                let style = cx
+                    .editor
+                    .theme
+                    .try_get("ui.highlight")
+                    .unwrap_or_else(|| cx.editor.theme.get("ui.selection"));
+                let draw_highlight = move |renderer: &mut TextRenderer, pos: LinePos| {
+                    if (start..=end).contains(&pos.doc_line) {
+                        let area = Rect::new(
+                            renderer.viewport.x,
+                            renderer.viewport.y + pos.visual_line,
+                            renderer.viewport.width,
+                            1,
+                        );
+                        renderer.surface.set_style(area, style)
+                    }
+                };
+                decorations.push(Box::new(draw_highlight))
+            }
+
+            render_document(
+                surface,
+                inner,
                 doc,
                 offset,
-                inner,
-                surface,
-                &cx.editor.theme,
+                &TextAnnotations::default(),
                 highlights,
-                &cx.editor.config(),
+                &cx.editor.theme,
+                &mut decorations,
+                &mut [],
             );
-
-            // highlight the line
-            if let Some((start, end)) = range {
-                let offset = start.saturating_sub(first_line) as u16;
-                surface.set_style(
-                    Rect::new(
-                        inner.x,
-                        inner.y + offset,
-                        inner.width,
-                        (end.saturating_sub(start) as u16 + 1)
-                            .min(inner.height.saturating_sub(offset)),
-                    ),
-                    cx.editor
-                        .theme
-                        .try_get("ui.highlight")
-                        .unwrap_or_else(|| cx.editor.theme.get("ui.selection")),
-                );
-            }
         }
     }