signature_help.rs

  1use crate::actions::ShowSignatureHelp;
  2use crate::hover_popover::open_markdown_url;
  3use crate::{Editor, EditorSettings, ToggleAutoSignatureHelp, hover_markdown_style};
  4use gpui::{
  5    App, Context, Entity, HighlightStyle, MouseButton, ScrollHandle, Size, StyledText, Task,
  6    TextStyle, Window, combine_highlights,
  7};
  8use language::BufferSnapshot;
  9use markdown::{Markdown, MarkdownElement};
 10use multi_buffer::{Anchor, ToOffset};
 11use settings::Settings;
 12use std::ops::Range;
 13use text::Rope;
 14use theme::ThemeSettings;
 15use ui::{
 16    ActiveTheme, AnyElement, ButtonCommon, ButtonStyle, Clickable, FluentBuilder, IconButton,
 17    IconButtonShape, IconName, IconSize, InteractiveElement, IntoElement, Label, LabelCommon,
 18    LabelSize, ParentElement, Pixels, SharedString, StatefulInteractiveElement, Styled, StyledExt,
 19    WithScrollbar, div, relative,
 20};
 21
 22// Language-specific settings may define quotes as "brackets", so filter them out separately.
 23const QUOTE_PAIRS: [(&str, &str); 3] = [("'", "'"), ("\"", "\""), ("`", "`")];
 24
 25#[derive(Debug, Clone, Copy, PartialEq)]
 26pub enum SignatureHelpHiddenBy {
 27    AutoClose,
 28    Escape,
 29    Selection,
 30}
 31
 32impl Editor {
 33    pub fn toggle_auto_signature_help_menu(
 34        &mut self,
 35        _: &ToggleAutoSignatureHelp,
 36        window: &mut Window,
 37        cx: &mut Context<Self>,
 38    ) {
 39        self.auto_signature_help = self
 40            .auto_signature_help
 41            .map(|auto_signature_help| !auto_signature_help)
 42            .or_else(|| Some(!EditorSettings::get_global(cx).auto_signature_help));
 43        match self.auto_signature_help {
 44            Some(true) => {
 45                self.show_signature_help(&ShowSignatureHelp, window, cx);
 46            }
 47            Some(false) => {
 48                self.hide_signature_help(cx, SignatureHelpHiddenBy::AutoClose);
 49            }
 50            None => {}
 51        }
 52    }
 53
 54    pub(super) fn hide_signature_help(
 55        &mut self,
 56        cx: &mut Context<Self>,
 57        signature_help_hidden_by: SignatureHelpHiddenBy,
 58    ) -> bool {
 59        if self.signature_help_state.is_shown() {
 60            self.signature_help_state.task = None;
 61            self.signature_help_state.hide(signature_help_hidden_by);
 62            cx.notify();
 63            true
 64        } else {
 65            false
 66        }
 67    }
 68
 69    pub fn auto_signature_help_enabled(&self, cx: &App) -> bool {
 70        if let Some(auto_signature_help) = self.auto_signature_help {
 71            auto_signature_help
 72        } else {
 73            EditorSettings::get_global(cx).auto_signature_help
 74        }
 75    }
 76
 77    pub(super) fn should_open_signature_help_automatically(
 78        &mut self,
 79        old_cursor_position: &Anchor,
 80        cx: &mut Context<Self>,
 81    ) -> bool {
 82        if !(self.signature_help_state.is_shown() || self.auto_signature_help_enabled(cx)) {
 83            return false;
 84        }
 85        let newest_selection = self.selections.newest::<usize>(&self.display_snapshot(cx));
 86        let head = newest_selection.head();
 87
 88        if !newest_selection.is_empty() && head != newest_selection.tail() {
 89            self.signature_help_state
 90                .hide(SignatureHelpHiddenBy::Selection);
 91            return false;
 92        }
 93
 94        let buffer_snapshot = self.buffer().read(cx).snapshot(cx);
 95        let bracket_range = |position: usize| match (position, position + 1) {
 96            (0, b) if b <= buffer_snapshot.len() => 0..b,
 97            (0, b) => 0..b - 1,
 98            (a, b) if b <= buffer_snapshot.len() => a - 1..b,
 99            (a, b) => a - 1..b - 1,
100        };
101        let not_quote_like_brackets =
102            |buffer: &BufferSnapshot, start: Range<usize>, end: Range<usize>| {
103                let text_start = buffer.text_for_range(start).collect::<String>();
104                let text_end = buffer.text_for_range(end).collect::<String>();
105                QUOTE_PAIRS
106                    .into_iter()
107                    .all(|(start, end)| text_start != start && text_end != end)
108            };
109
110        let previous_position = old_cursor_position.to_offset(&buffer_snapshot);
111        let previous_brackets_range = bracket_range(previous_position);
112        let previous_brackets_surround = buffer_snapshot
113            .innermost_enclosing_bracket_ranges(
114                previous_brackets_range,
115                Some(&not_quote_like_brackets),
116            )
117            .filter(|(start_bracket_range, end_bracket_range)| {
118                start_bracket_range.start != previous_position
119                    && end_bracket_range.end != previous_position
120            });
121        let current_brackets_range = bracket_range(head);
122        let current_brackets_surround = buffer_snapshot
123            .innermost_enclosing_bracket_ranges(
124                current_brackets_range,
125                Some(&not_quote_like_brackets),
126            )
127            .filter(|(start_bracket_range, end_bracket_range)| {
128                start_bracket_range.start != head && end_bracket_range.end != head
129            });
130
131        match (previous_brackets_surround, current_brackets_surround) {
132            (None, None) => {
133                self.signature_help_state
134                    .hide(SignatureHelpHiddenBy::AutoClose);
135                false
136            }
137            (Some(_), None) => {
138                self.signature_help_state
139                    .hide(SignatureHelpHiddenBy::AutoClose);
140                false
141            }
142            (None, Some(_)) => true,
143            (Some(previous), Some(current)) => {
144                let condition = self.signature_help_state.hidden_by_selection()
145                    || previous != current
146                    || (previous == current && self.signature_help_state.is_shown());
147                if !condition {
148                    self.signature_help_state
149                        .hide(SignatureHelpHiddenBy::AutoClose);
150                }
151                condition
152            }
153        }
154    }
155
156    pub fn show_signature_help(
157        &mut self,
158        _: &ShowSignatureHelp,
159        window: &mut Window,
160        cx: &mut Context<Self>,
161    ) {
162        if self.pending_rename.is_some() || self.has_visible_completions_menu() {
163            return;
164        }
165
166        let position = self.selections.newest_anchor().head();
167        let Some((buffer, buffer_position)) =
168            self.buffer.read(cx).text_anchor_for_position(position, cx)
169        else {
170            return;
171        };
172        let Some(lsp_store) = self.project().map(|p| p.read(cx).lsp_store()) else {
173            return;
174        };
175        let task = lsp_store.update(cx, |lsp_store, cx| {
176            lsp_store.signature_help(&buffer, buffer_position, cx)
177        });
178        let language = self.language_at(position, cx);
179
180        self.signature_help_state
181            .set_task(cx.spawn_in(window, async move |editor, cx| {
182                let signature_help = task.await;
183                editor
184                    .update(cx, |editor, cx| {
185                        let Some(mut signature_help) =
186                            signature_help.unwrap_or_default().into_iter().next()
187                        else {
188                            editor
189                                .signature_help_state
190                                .hide(SignatureHelpHiddenBy::AutoClose);
191                            return;
192                        };
193
194                        if let Some(language) = language {
195                            for signature in &mut signature_help.signatures {
196                                let text = Rope::from(signature.label.as_ref());
197                                let highlights = language
198                                    .highlight_text(&text, 0..signature.label.len())
199                                    .into_iter()
200                                    .flat_map(|(range, highlight_id)| {
201                                        Some((range, highlight_id.style(cx.theme().syntax())?))
202                                    });
203                                signature.highlights =
204                                    combine_highlights(signature.highlights.clone(), highlights)
205                                        .collect();
206                            }
207                        }
208                        let settings = ThemeSettings::get_global(cx);
209                        let style = TextStyle {
210                            color: cx.theme().colors().text,
211                            font_family: settings.buffer_font.family.clone(),
212                            font_fallbacks: settings.buffer_font.fallbacks.clone(),
213                            font_size: settings.buffer_font_size(cx).into(),
214                            font_weight: settings.buffer_font.weight,
215                            line_height: relative(settings.buffer_line_height.value()),
216                            ..TextStyle::default()
217                        };
218                        let scroll_handle = ScrollHandle::new();
219                        let signatures = signature_help
220                            .signatures
221                            .into_iter()
222                            .map(|s| SignatureHelp {
223                                label: s.label,
224                                documentation: s.documentation,
225                                highlights: s.highlights,
226                                active_parameter: s.active_parameter,
227                                parameter_documentation: s
228                                    .active_parameter
229                                    .and_then(|idx| s.parameters.get(idx))
230                                    .and_then(|param| param.documentation.clone()),
231                            })
232                            .collect::<Vec<_>>();
233
234                        if signatures.is_empty() {
235                            editor
236                                .signature_help_state
237                                .hide(SignatureHelpHiddenBy::AutoClose);
238                            return;
239                        }
240
241                        let current_signature = signature_help
242                            .active_signature
243                            .min(signatures.len().saturating_sub(1));
244
245                        let signature_help_popover = SignatureHelpPopover {
246                            style,
247                            signatures,
248                            current_signature,
249                            scroll_handle,
250                        };
251                        editor
252                            .signature_help_state
253                            .set_popover(signature_help_popover);
254                        cx.notify();
255                    })
256                    .ok();
257            }));
258    }
259}
260
261#[derive(Default, Debug)]
262pub struct SignatureHelpState {
263    task: Option<Task<()>>,
264    popover: Option<SignatureHelpPopover>,
265    hidden_by: Option<SignatureHelpHiddenBy>,
266}
267
268impl SignatureHelpState {
269    fn set_task(&mut self, task: Task<()>) {
270        self.task = Some(task);
271        self.hidden_by = None;
272    }
273
274    #[cfg(test)]
275    pub fn popover(&self) -> Option<&SignatureHelpPopover> {
276        self.popover.as_ref()
277    }
278
279    pub const fn popover_mut(&mut self) -> Option<&mut SignatureHelpPopover> {
280        self.popover.as_mut()
281    }
282
283    fn set_popover(&mut self, popover: SignatureHelpPopover) {
284        self.popover = Some(popover);
285        self.hidden_by = None;
286    }
287
288    fn hide(&mut self, hidden_by: SignatureHelpHiddenBy) {
289        if self.hidden_by.is_none() {
290            self.popover = None;
291            self.hidden_by = Some(hidden_by);
292        }
293    }
294
295    fn hidden_by_selection(&self) -> bool {
296        self.hidden_by == Some(SignatureHelpHiddenBy::Selection)
297    }
298
299    pub const fn is_shown(&self) -> bool {
300        self.popover.is_some()
301    }
302
303    pub fn has_multiple_signatures(&self) -> bool {
304        self.popover
305            .as_ref()
306            .is_some_and(|popover| popover.signatures.len() > 1)
307    }
308}
309
310#[cfg(test)]
311impl SignatureHelpState {
312    pub fn task(&self) -> Option<&Task<()>> {
313        self.task.as_ref()
314    }
315}
316
317#[derive(Clone, Debug, PartialEq)]
318pub struct SignatureHelp {
319    pub(crate) label: SharedString,
320    documentation: Option<Entity<Markdown>>,
321    highlights: Vec<(Range<usize>, HighlightStyle)>,
322    active_parameter: Option<usize>,
323    parameter_documentation: Option<Entity<Markdown>>,
324}
325
326#[derive(Clone, Debug)]
327pub struct SignatureHelpPopover {
328    pub style: TextStyle,
329    pub signatures: Vec<SignatureHelp>,
330    pub current_signature: usize,
331    scroll_handle: ScrollHandle,
332}
333
334impl SignatureHelpPopover {
335    pub fn render(
336        &mut self,
337        max_size: Size<Pixels>,
338        window: &mut Window,
339        cx: &mut Context<Editor>,
340    ) -> AnyElement {
341        let Some(signature) = self.signatures.get(self.current_signature) else {
342            return div().into_any_element();
343        };
344
345        let main_content = div()
346            .occlude()
347            .p_2()
348            .child(
349                div()
350                    .id("signature_help_container")
351                    .overflow_y_scroll()
352                    .max_w(max_size.width)
353                    .max_h(max_size.height)
354                    .track_scroll(&self.scroll_handle)
355                    .child(
356                        StyledText::new(signature.label.clone()).with_default_highlights(
357                            &self.style,
358                            signature.highlights.iter().cloned(),
359                        ),
360                    )
361                    .when_some(
362                        signature.parameter_documentation.clone(),
363                        |this, param_doc| {
364                            this.child(div().h_px().bg(cx.theme().colors().border_variant).my_1())
365                                .child(
366                                    MarkdownElement::new(
367                                        param_doc,
368                                        hover_markdown_style(window, cx),
369                                    )
370                                    .code_block_renderer(markdown::CodeBlockRenderer::Default {
371                                        copy_button: false,
372                                        border: false,
373                                        copy_button_on_hover: false,
374                                    })
375                                    .on_url_click(open_markdown_url),
376                                )
377                        },
378                    )
379                    .when_some(signature.documentation.clone(), |this, description| {
380                        this.child(div().h_px().bg(cx.theme().colors().border_variant).my_1())
381                            .child(
382                                MarkdownElement::new(description, hover_markdown_style(window, cx))
383                                    .code_block_renderer(markdown::CodeBlockRenderer::Default {
384                                        copy_button: false,
385                                        border: false,
386                                        copy_button_on_hover: false,
387                                    })
388                                    .on_url_click(open_markdown_url),
389                            )
390                    }),
391            )
392            .vertical_scrollbar_for(self.scroll_handle.clone(), window, cx);
393
394        let controls = if self.signatures.len() > 1 {
395            let prev_button = IconButton::new("signature_help_prev", IconName::ChevronUp)
396                .shape(IconButtonShape::Square)
397                .style(ButtonStyle::Subtle)
398                .icon_size(IconSize::Small)
399                .tooltip(move |window, cx| {
400                    ui::Tooltip::for_action(
401                        "Previous Signature",
402                        &crate::SignatureHelpPrevious,
403                        window,
404                        cx,
405                    )
406                })
407                .on_click(cx.listener(|editor, _, window, cx| {
408                    editor.signature_help_prev(&crate::SignatureHelpPrevious, window, cx);
409                }));
410
411            let next_button = IconButton::new("signature_help_next", IconName::ChevronDown)
412                .shape(IconButtonShape::Square)
413                .style(ButtonStyle::Subtle)
414                .icon_size(IconSize::Small)
415                .tooltip(move |window, cx| {
416                    ui::Tooltip::for_action("Next Signature", &crate::SignatureHelpNext, window, cx)
417                })
418                .on_click(cx.listener(|editor, _, window, cx| {
419                    editor.signature_help_next(&crate::SignatureHelpNext, window, cx);
420                }));
421
422            let page = Label::new(format!(
423                "{}/{}",
424                self.current_signature + 1,
425                self.signatures.len()
426            ))
427            .size(LabelSize::Small);
428
429            Some(
430                div()
431                    .flex()
432                    .flex_col()
433                    .items_center()
434                    .gap_0p5()
435                    .px_0p5()
436                    .py_0p5()
437                    .children([
438                        prev_button.into_any_element(),
439                        div().child(page).into_any_element(),
440                        next_button.into_any_element(),
441                    ])
442                    .into_any_element(),
443            )
444        } else {
445            None
446        };
447        div()
448            .elevation_2(cx)
449            .on_mouse_down(MouseButton::Left, |_, _, cx| cx.stop_propagation())
450            .on_mouse_move(|_, _, cx| cx.stop_propagation())
451            .flex()
452            .flex_row()
453            .when_some(controls, |this, controls| {
454                this.children(vec![
455                    div().flex().items_end().child(controls),
456                    div().w_px().bg(cx.theme().colors().border_variant),
457                ])
458            })
459            .child(main_content)
460            .into_any_element()
461    }
462}