mirror of https://github.com/helix-editor/helix
streamline text decoration API
This commit brings the text decoration API inline with the LineAnnotation API (so they are consistent) resulting in a single streamlined API instead of multiple ADHOK callbacks.pull/6417/head
Pascal Kuthe
10 months ago
parent
9a93240d27
commit
2c0506aa96
@ -0,0 +1,175 @@
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use std::cmp::Ordering;
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use helix_core::doc_formatter::FormattedGrapheme;
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use helix_core::Position;
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use helix_view::editor::CursorCache;
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use crate::ui::document::{LinePos, TextRenderer};
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pub use diagnostics::InlineDiagnostics;
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mod diagnostics;
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/// Decorations are the primary mechanism for extending the text rendering.
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///
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/// Any on-screen element which is anchored to the rendered text in some form
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/// should be implemented using this trait. Translating char positions to
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/// on-screen positions can be expensive and should not be done manually in the
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/// ui loop. Instead such translations are automatically performed on the fly
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/// while the text is being rendered. The results are provided to this trait by
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/// the rendering infrastructure.
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///
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/// To reserve space for virtual text lines (which is then filled by this trait) emit appropriate
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/// [`LineAnnotation`](helix_core::text_annotations::LineAnnotation)s in [`helix_view::View::text_annotations`]
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pub trait Decoration {
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/// Called **before** a **visual** line is rendered. A visual line does not
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/// necessarily correspond to a single line in a document as soft wrapping can
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/// spread a single document line across multiple visual lines.
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///
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/// This function is called before text is rendered as any decorations should
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/// never overlap the document text. That means that setting the forground color
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/// here is (essentially) useless as the text color is overwritten by the
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/// rendered text. This _of course_ doesn't apply when rendering inside virtual lines
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/// below the line reserved by `LineAnnotation`s as no text will be rendered here.
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fn decorate_line(&mut self, _renderer: &mut TextRenderer, _pos: LinePos) {}
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/// Called **after** a **visual** line is rendered. A visual line does not
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/// necessarily correspond to a single line in a document as soft wrapping can
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/// spread a single document line across multiple visual lines.
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///
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/// This function is called after text is rendered so that decorations can collect
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/// horizontal positions on the line (see [`Decoration::decorate_grapheme`]) first and
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/// use those positions` while rendering
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/// virtual text.
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/// That means that setting the forground color
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/// here is (essentially) useless as the text color is overwritten by the
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/// rendered text. This -ofcourse- doesn't apply when rendering inside virtual lines
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/// below the line reserved by `LineAnnotation`s. e as no text will be rendered here.
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/// **Note**: To avoid overlapping decorations in the virtual lines, each decoration
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/// must return the number of virtual text lines it has taken up. Each `Decoration` recieves
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/// an offset `virt_off` based on these return values where it can render virtual text:
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///
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/// That means that a `render_line` implementation that returns `X` can render virtual text
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/// in the following area:
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/// ``` no-compile
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/// let start = inner.y + pos.virtual_line + virt_off;
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/// start .. start + X
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/// ````
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fn render_virt_lines(
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&mut self,
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_renderer: &mut TextRenderer,
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_pos: LinePos,
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_virt_off: Position,
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) -> Position {
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Position::new(0, 0)
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}
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fn reset_pos(&mut self, _pos: usize) -> usize {
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usize::MAX
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}
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fn skip_concealed_anchor(&mut self, conceal_end_char_idx: usize) -> usize {
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self.reset_pos(conceal_end_char_idx)
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}
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/// This function is called **before** the grapheme at `char_idx` is rendered.
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///
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/// # Returns
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///
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/// The char idx of the next grapheme that this function should be called for
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fn decorate_grapheme(
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&mut self,
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_renderer: &mut TextRenderer,
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_grapheme: &FormattedGrapheme,
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) -> usize {
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usize::MAX
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}
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}
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impl<F: FnMut(&mut TextRenderer, LinePos)> Decoration for F {
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fn decorate_line(&mut self, renderer: &mut TextRenderer, pos: LinePos) {
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self(renderer, pos);
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}
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}
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#[derive(Default)]
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pub struct DecorationManager<'a> {
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decorations: Vec<(Box<dyn Decoration + 'a>, usize)>,
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}
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impl<'a> DecorationManager<'a> {
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pub fn add_decoration(&mut self, decoration: impl Decoration + 'a) {
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self.decorations.push((Box::new(decoration), 0));
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}
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pub fn prepare_for_rendering(&mut self, first_visible_char: usize) {
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for (decoration, next_position) in &mut self.decorations {
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*next_position = decoration.reset_pos(first_visible_char)
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}
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}
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pub fn decorate_grapheme(&mut self, renderer: &mut TextRenderer, grapheme: &FormattedGrapheme) {
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for (decoration, hook_char_idx) in &mut self.decorations {
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loop {
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match (*hook_char_idx).cmp(&grapheme.char_idx) {
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// this grapheme has been concealed or we are at the first grapheme
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Ordering::Less => {
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*hook_char_idx = decoration.skip_concealed_anchor(grapheme.char_idx)
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}
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Ordering::Equal => {
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*hook_char_idx = decoration.decorate_grapheme(renderer, grapheme)
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}
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Ordering::Greater => break,
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}
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}
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}
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}
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pub fn decorate_line(&mut self, renderer: &mut TextRenderer, pos: LinePos) {
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for (decoration, _) in &mut self.decorations {
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decoration.decorate_line(renderer, pos);
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}
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}
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pub fn render_virtual_lines(
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&mut self,
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renderer: &mut TextRenderer,
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pos: LinePos,
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line_width: usize,
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) {
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let mut virt_off = Position::new(1, line_width); // start at 1 so the line is never overwritten
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for (decoration, _) in &mut self.decorations {
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virt_off += decoration.render_virt_lines(renderer, pos, virt_off);
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}
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}
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}
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/// Cursor rendering is done externally so all the cursor decoration
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/// does is save the position of primary cursor
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pub struct Cursor<'a> {
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pub cache: &'a CursorCache,
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pub primary_cursor: usize,
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}
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impl Decoration for Cursor<'_> {
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fn reset_pos(&mut self, pos: usize) -> usize {
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if pos <= self.primary_cursor {
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self.primary_cursor
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} else {
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usize::MAX
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}
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}
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fn decorate_grapheme(
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&mut self,
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renderer: &mut TextRenderer,
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grapheme: &FormattedGrapheme,
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) -> usize {
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if renderer.column_in_bounds(grapheme.visual_pos.col)
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&& renderer.offset.row < grapheme.visual_pos.row
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{
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let position = grapheme.visual_pos - renderer.offset;
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self.cache.set(Some(position));
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}
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usize::MAX
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}
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}
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