Render other tab icons in the start slot (#14683)

This PR reworks the rendering for tab icons to allow us to render all of
the tab icons—not just file icons—in the tab's start slot.

The `Item` trait now has a separate `tab_icon` method that can be used
to indicate what icon should be shown for the tab.

Release Notes:

- N/A

crates/workspace/src/item.rs

@@ -31,7 +31,7 @@ use std::{
     time::Duration,
 };
 use theme::Theme;
-use ui::Element as _;
+use ui::{Element as _, Icon};
 use util::ResultExt;
 
 pub const LEADER_UPDATE_THROTTLE: Duration = Duration::from_millis(200);
@@ -147,6 +147,11 @@ pub trait Item: FocusableView + EventEmitter<Self::Event> {
     fn tab_content(&self, _params: TabContentParams, _cx: &WindowContext) -> AnyElement {
         gpui::Empty.into_any()
     }
+
+    fn tab_icon(&self, _cx: &WindowContext) -> Option<Icon> {
+        None
+    }
+
     fn to_item_events(_event: &Self::Event, _f: impl FnMut(ItemEvent)) {}
 
     fn deactivated(&mut self, _: &mut ViewContext<Self>) {}
@@ -330,6 +335,7 @@ pub trait ItemHandle: 'static + Send {
     fn tab_tooltip_text(&self, cx: &AppContext) -> Option<SharedString>;
     fn tab_description(&self, detail: usize, cx: &AppContext) -> Option<SharedString>;
     fn tab_content(&self, params: TabContentParams, cx: &WindowContext) -> AnyElement;
+    fn tab_icon(&self, cx: &WindowContext) -> Option<Icon>;
     fn telemetry_event_text(&self, cx: &WindowContext) -> Option<&'static str>;
     fn dragged_tab_content(&self, params: TabContentParams, cx: &WindowContext) -> AnyElement;
     fn project_path(&self, cx: &AppContext) -> Option<ProjectPath>;
@@ -441,6 +447,10 @@ impl<T: Item> ItemHandle for View<T> {
         self.read(cx).tab_content(params, cx)
     }
 
+    fn tab_icon(&self, cx: &WindowContext) -> Option<Icon> {
+        self.read(cx).tab_icon(cx)
+    }
+
     fn dragged_tab_content(&self, params: TabContentParams, cx: &WindowContext) -> AnyElement {
         self.read(cx).tab_content(
             TabContentParams {

crates/workspace/src/pane.rs

@@ -10,7 +10,6 @@ use crate::{
 };
 use anyhow::Result;
 use collections::{BTreeSet, HashMap, HashSet, VecDeque};
-use file_icons::FileIcons;
 use futures::{stream::FuturesUnordered, StreamExt};
 use gpui::{
     actions, anchored, deferred, impl_actions, prelude::*, Action, AnchorCorner, AnyElement,
@@ -1590,6 +1589,7 @@ impl Pane {
             },
             cx,
         );
+        let icon = item.tab_icon(cx);
         let close_side = &ItemSettings::get_global(cx).close_position;
         let indicator = render_item_indicator(item.boxed_clone(), cx);
         let item_id = item.item_id();
@@ -1597,14 +1597,6 @@ impl Pane {
         let is_last_item = ix == self.items.len() - 1;
         let position_relative_to_active_item = ix.cmp(&self.active_item_index);
 
-        let file_icon = ItemSettings::get_global(cx)
-            .file_icons
-            .then(|| {
-                item.project_path(cx)
-                    .and_then(|path| FileIcons::get_icon(path.path.as_ref(), cx))
-            })
-            .flatten();
-
         let tab = Tab::new(ix)
             .position(if is_first_item {
                 TabPosition::First
@@ -1675,14 +1667,12 @@ impl Pane {
             })
             .map(|tab| match indicator {
                 Some(indicator) => tab.start_slot(indicator),
-                None => tab.start_slot::<Icon>(file_icon.map(|icon| {
-                    Icon::from_path(icon.to_string())
-                        .size(IconSize::XSmall)
-                        .color(if is_active {
-                            Color::Default
-                        } else {
-                            Color::Muted
-                        })
+                None => tab.start_slot::<Icon>(icon.map(|icon| {
+                    icon.size(IconSize::XSmall).color(if is_active {
+                        Color::Default
+                    } else {
+                        Color::Muted
+                    })
                 })),
             })
             .end_slot(

crates/workspace/src/shared_screen.rs

@@ -7,12 +7,12 @@ use call::participant::{Frame, RemoteVideoTrack};
 use client::{proto::PeerId, User};
 use futures::StreamExt;
 use gpui::{
-    div, img, AppContext, Element, EventEmitter, FocusHandle, FocusableView, InteractiveElement,
+    div, img, AppContext, EventEmitter, FocusHandle, FocusableView, InteractiveElement,
     ParentElement, Render, SharedString, Styled, Task, View, ViewContext, VisualContext,
     WindowContext,
 };
 use std::sync::{Arc, Weak};
-use ui::{h_flex, prelude::*, Icon, IconName, Label};
+use ui::{prelude::*, Icon, IconName, Label};
 
 pub enum Event {
     Close,
@@ -93,24 +93,18 @@ impl Item for SharedScreen {
         }
     }
 
+    fn tab_icon(&self, _cx: &WindowContext) -> Option<Icon> {
+        Some(Icon::new(IconName::Screen))
+    }
+
     fn tab_content(&self, params: TabContentParams, _: &WindowContext<'_>) -> gpui::AnyElement {
-        h_flex()
-            .gap_1()
-            .child(Icon::new(IconName::Screen).color(if params.selected {
+        Label::new(format!("{}'s screen", self.user.github_login))
+            .color(if params.selected {
                 Color::Default
             } else {
                 Color::Muted
-            }))
-            .child(
-                Label::new(format!("{}'s screen", self.user.github_login)).color(
-                    if params.selected {
-                        Color::Default
-                    } else {
-                        Color::Muted
-                    },
-                ),
-            )
-            .into_any()
+            })
+            .into_any_element()
     }
 
     fn telemetry_event_text(&self) -> Option<&'static str> {