1use editor::Editor;
 2use gpui::{
 3    div, Div, IntoElement, ParentElement, Render, Subscription, View, ViewContext, WeakView,
 4};
 5use std::sync::Arc;
 6use ui::{Button, ButtonCommon, Clickable, LabelSize, Tooltip};
 7use workspace::{item::ItemHandle, StatusItemView, Workspace};
 8
 9use crate::LanguageSelector;
10
11pub struct ActiveBufferLanguage {
12    active_language: Option<Option<Arc<str>>>,
13    workspace: WeakView<Workspace>,
14    _observe_active_editor: Option<Subscription>,
15}
16
17impl ActiveBufferLanguage {
18    pub fn new(workspace: &Workspace) -> Self {
19        Self {
20            active_language: None,
21            workspace: workspace.weak_handle(),
22            _observe_active_editor: None,
23        }
24    }
25
26    fn update_language(&mut self, editor: View<Editor>, cx: &mut ViewContext<Self>) {
27        self.active_language = Some(None);
28
29        let editor = editor.read(cx);
30        if let Some((_, buffer, _)) = editor.active_excerpt(cx) {
31            if let Some(language) = buffer.read(cx).language() {
32                self.active_language = Some(Some(language.name()));
33            }
34        }
35
36        cx.notify();
37    }
38}
39
40impl Render for ActiveBufferLanguage {
41    type Element = Div;
42
43    fn render(&mut self, cx: &mut ViewContext<Self>) -> Div {
44        div().when_some(self.active_language.as_ref(), |el, active_language| {
45            let active_language_text = if let Some(active_language_text) = active_language {
46                active_language_text.to_string()
47            } else {
48                "Unknown".to_string()
49            };
50
51            el.child(
52                Button::new("change-language", active_language_text)
53                    .label_size(LabelSize::Small)
54                    .on_click(cx.listener(|this, _, cx| {
55                        if let Some(workspace) = this.workspace.upgrade() {
56                            workspace.update(cx, |workspace, cx| {
57                                LanguageSelector::toggle(workspace, cx)
58                            });
59                        }
60                    }))
61                    .tooltip(|cx| Tooltip::text("Select Language", cx)),
62            )
63        })
64    }
65}
66
67impl StatusItemView for ActiveBufferLanguage {
68    fn set_active_pane_item(
69        &mut self,
70        active_pane_item: Option<&dyn ItemHandle>,
71        cx: &mut ViewContext<Self>,
72    ) {
73        if let Some(editor) = active_pane_item.and_then(|item| item.act_as::<Editor>(cx)) {
74            self._observe_active_editor = Some(cx.observe(&editor, Self::update_language));
75            self.update_language(editor, cx);
76        } else {
77            self.active_language = None;
78            self._observe_active_editor = None;
79        }
80
81        cx.notify();
82    }
83}