Canvas · Graphs and boards: a field hands focus back on Enter and Escape

writing::begin records the owner's focus, the mind map's or the tool
layer's, through forms::Editing::returning. The field keeps its words on
Enter's release and drops them on Escape, and both hand focus back, so
the map's arrows and the board's Backspace work at once after a write.

src/canvas/writing.rs

@@ -1,19 +1,20 @@
 use std::rc::Rc;
 
 use gpui::{
-    AnyElement, App, Entity, InteractiveElement, IntoElement, MouseButton, ParentElement, Pixels,
-    SharedString, Styled, Window, div,
+    AnyElement, App, Entity, FocusHandle, InteractiveElement, IntoElement, MouseButton,
+    ParentElement, Pixels, SharedString, Styled, Window, div,
 };
 
 use super::{gesture::OnPair, view::Frame};
 use crate::forms::{Editing, Input};
 
-/// Opens a field on the words of what `key` names. Enter or leaving hands them to the owner; Escape drops them.
+/// Opens a field on the words of what `key` names. Enter or leaving hands them to the owner; Escape drops them. Enter and Escape hand focus back to `back`.
 pub(super) fn begin(
     editing: &Entity<Editing>,
     key: SharedString,
     words: String,
     on_text: Option<OnPair>,
+    back: FocusHandle,
     window: &mut Window,
     cx: &mut App,
 ) {
@@ -29,12 +30,13 @@ pub(super) fn begin(
         ));
     });
     Editing::begin(editing, words, window, cx);
+    editing.update(cx, |editing, _| editing.returning(back));
 }
 
 /// The open field over `frame`, in view pixels.
 pub(super) fn field(editing: &Entity<Editing>, frame: Frame, cx: &App) -> Option<AnyElement> {
     let field = editing.read(cx).field()?;
-    let closing = editing.clone();
+    let (closing, keeping) = (editing.clone(), editing.clone());
     Some(
         div()
             .absolute()
@@ -45,7 +47,19 @@ pub(super) fn field(editing: &Entity<Editing>, frame: Frame, cx: &App) -> Option
             .on_key_down(move |event, window, cx| {
                 if event.keystroke.key == "escape" {
                     cx.stop_propagation();
-                    closing.update(cx, |editing, cx| editing.finish(true, window, cx));
+                    closing.update(cx, |editing, cx| {
+                        editing.finish(true, window, cx);
+                        editing.give_back(window);
+                    });
+                }
+            })
+            .on_key_up(move |event, window, cx| {
+                if event.keystroke.key == "enter" {
+                    cx.stop_propagation();
+                    keeping.update(cx, |editing, cx| {
+                        editing.finish(false, window, cx);
+                        editing.give_back(window);
+                    });
                 }
             })
             .child(Input::new(&field))