gpui: Simplify uniform list API by removing entity param (#32480)

This PR also introduces `Context::processor`, a sibling of
`Context::listener` that takes a strong pointer to entity and allows for
a return result.

Release Notes:

- N/A

Co-authored-by: Mikayla <mikayla@zed.dev>

crates/debugger_ui/src/session/running/breakpoint_list.rs

@@ -1,4 +1,5 @@
 use std::{
+    ops::Range,
     path::{Path, PathBuf},
     sync::Arc,
     time::Duration,
@@ -277,10 +278,9 @@ impl BreakpointList {
         let selected_ix = self.selected_ix;
         let focus_handle = self.focus_handle.clone();
         uniform_list(
-            cx.entity(),
             "breakpoint-list",
             self.breakpoints.len(),
-            move |this, range, window, cx| {
+            cx.processor(move |this, range: Range<usize>, window, cx| {
                 range
                     .clone()
                     .zip(&mut this.breakpoints[range])
@@ -291,7 +291,7 @@ impl BreakpointList {
                             .into_any_element()
                     })
                     .collect()
-            },
+            }),
         )
         .track_scroll(self.scroll_handle.clone())
         .flex_grow()

crates/debugger_ui/src/session/running/module_list.rs

@@ -8,7 +8,7 @@ use project::{
     ProjectItem as _, ProjectPath,
     debugger::session::{Session, SessionEvent},
 };
-use std::{path::Path, sync::Arc};
+use std::{ops::Range, path::Path, sync::Arc};
 use ui::{Scrollbar, ScrollbarState, prelude::*};
 use workspace::Workspace;
 
@@ -281,10 +281,11 @@ impl ModuleList {
 
     fn render_list(&mut self, _window: &mut Window, cx: &mut Context<Self>) -> impl IntoElement {
         uniform_list(
-            cx.entity(),
             "module-list",
             self.entries.len(),
-            |this, range, _window, cx| range.map(|ix| this.render_entry(ix, cx)).collect(),
+            cx.processor(|this, range: Range<usize>, _window, cx| {
+                range.map(|ix| this.render_entry(ix, cx)).collect()
+            }),
         )
         .track_scroll(self.scroll_handle.clone())
         .size_full()

crates/debugger_ui/src/session/running/variable_list.rs

@@ -980,10 +980,11 @@ impl Render for VariableList {
             .on_action(cx.listener(Self::edit_variable))
             .child(
                 uniform_list(
-                    cx.entity().clone(),
                     "variable-list",
                     self.entries.len(),
-                    move |this, range, window, cx| this.render_entries(range, window, cx),
+                    cx.processor(move |this, range: Range<usize>, window, cx| {
+                        this.render_entries(range, window, cx)
+                    }),
                 )
                 .track_scroll(self.list_handle.clone())
                 .gap_1_5()