Moved keyboard handlers to separate module

src/assets/javascripts/integrations/keyboard/index.ts

@@ -0,0 +1,129 @@
+/*
+ * Copyright (c) 2016-2020 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 } from "rxjs"
+import { switchMap, withLatestFrom } from "rxjs/operators"
+
+import { useComponent } from "components"
+import {
+  Key,
+  getActiveElement,
+  getElements,
+  isSusceptibleToKeyboard,
+  setElementFocus,
+  setToggle,
+  useToggle,
+  watchKeyboard,
+  watchToggle
+} from "observables"
+import { not, takeIf } from "utilities"
+
+/* ----------------------------------------------------------------------------
+ * Functions
+ * ------------------------------------------------------------------------- */
+
+/**
+ * Setup keyboard
+ *
+ * @return Keyboard observable
+ */
+export function setupKeyboard(): Observable<Key> {
+  const keyboard$ = watchKeyboard()
+
+  /* Setup keyboard handlers in search mode */
+  const toggle$ = useToggle("search")
+  keyboard$
+    .pipe(
+      takeIf(toggle$.pipe(switchMap(watchToggle))),
+      withLatestFrom(
+        toggle$,
+        useComponent("search-query"),
+        useComponent("search-result")
+      )
+    )
+      .subscribe(([key, toggle, query, result]) => {
+        const active = getActiveElement()
+        switch (key.type) {
+
+          /* Enter: prevent form submission */
+          case "Enter":
+            if (active === query)
+              key.claim()
+            break
+
+          /* Escape or Tab: close search */
+          case "Escape":
+          case "Tab":
+            setToggle(toggle, false)
+            setElementFocus(query, false)
+            break
+
+          /* Vertical arrows: select previous or next search result */
+          case "ArrowUp":
+          case "ArrowDown":
+            if (typeof active === "undefined") {
+              setElementFocus(query)
+            } else {
+              const els = [query, ...getElements("[href]", result)]
+              const i = Math.max(0, (
+                Math.max(0, els.indexOf(active)) + els.length + (
+                  key.type === "ArrowUp" ? -1 : +1
+                )
+              ) % els.length)
+              setElementFocus(els[i])
+            }
+
+            /* Prevent scrolling of page */
+            key.claim()
+            break
+
+          /* All other keys: hand to search query */
+          default:
+            if (query !== getActiveElement())
+              setElementFocus(query)
+        }
+      })
+
+  /* Setup general keyboard handlers */
+  keyboard$
+    .pipe(
+      takeIf(not(toggle$.pipe(switchMap(watchToggle)))),
+      withLatestFrom(useComponent("search-query"))
+    )
+      .subscribe(([key, query]) => {
+        const active = getActiveElement()
+        switch (key.type) {
+
+          /* [s]earch / [f]ind: open search  */
+          case "s":
+          case "f":
+            if (!(active && isSusceptibleToKeyboard(active))) {
+              setElementFocus(query)
+              key.claim()
+            }
+            break
+        }
+      })
+
+  /* Return keyboard observable */
+  return keyboard$
+}