Restructured project

src/assets/javascripts/components/header/_/index.ts

@@ -0,0 +1,64 @@
+/*
+ * Copyright (c) 2016-2019 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, defer, of } from "rxjs"
+
+/* ----------------------------------------------------------------------------
+ * Types
+ * ------------------------------------------------------------------------- */
+
+/**
+ * Header
+ */
+export interface Header {
+  sticky: boolean                      /* Header stickyness */
+  height: number                       /* Header visible height */
+}
+
+/* ----------------------------------------------------------------------------
+ * Functions
+ * ------------------------------------------------------------------------- */
+
+/**
+ * Watch header
+ *
+ * The header is wrapped in an observable to pave the way for auto-hiding or
+ * other dynamic behaviors that may be implemented later on.
+ *
+ * @param el - Header element
+ *
+ * @return Header observable
+ */
+export function watchHeader(
+  el: HTMLElement
+): Observable<Header> {
+  return defer(() => {
+    const sticky = getComputedStyle(el)
+      .getPropertyValue("position") === "fixed"
+
+    /* Return header as hot observable */
+    return of({
+      sticky,
+      height: sticky ? el.offsetHeight : 0
+    })
+  })
+}