feat(version): versions

1 files changed, 81 insertions, 0 deletions

diff --git a/src/templates/assets/javascripts/browser/element/focus/index.ts b/src/templates/assets/javascripts/browser/element/focus/index.ts
new file mode 100644
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+/*
+ * Copyright (c) 2016-2023 Martin Donath <martin.donath@squidfunk.com>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to
+ * deal in the Software without restriction, including without limitation the
+ * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+ * sell copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ */
+
+import {
+  Observable,
+  debounceTime,
+  distinctUntilChanged,
+  fromEvent,
+  map,
+  merge,
+  shareReplay,
+  startWith
+} from "rxjs"
+
+import { getActiveElement } from "../_"
+
+/* ----------------------------------------------------------------------------
+ * Data
+ * ------------------------------------------------------------------------- */
+
+/**
+ * Focus observable
+ *
+ * Previously, this observer used `focus` and `blur` events to determine whether
+ * an element is focused, but this doesn't work if there are focusable elements
+ * within the elements itself. A better solutions are `focusin` and `focusout`
+ * events, which bubble up the tree and allow for more fine-grained control.
+ *
+ * `debounceTime` is necessary, because when a focus change happens inside an
+ * element, the observable would first emit `false` and then `true` again.
+ */
+const observer$ = merge(
+  fromEvent(document.body, "focusin"),
+  fromEvent(document.body, "focusout")
+)
+  .pipe(
+    debounceTime(1),
+    startWith(undefined),
+    map(() => getActiveElement() || document.body),
+    shareReplay(1)
+  )
+
+/* ----------------------------------------------------------------------------
+ * Functions
+ * ------------------------------------------------------------------------- */
+
+/**
+ * Watch element focus
+ *
+ * @param el - Element
+ *
+ * @returns Element focus observable
+ */
+export function watchElementFocus(
+  el: HTMLElement
+): Observable<boolean> {
+  return observer$
+    .pipe(
+      map(active => el.contains(active)),
+      distinctUntilChanged()
+    )
+}