Refactored search keyboard handlers

src/assets/javascripts/components2/search/index.ts

@@ -25,6 +25,7 @@ import { map, shareReplay, switchMap } from "rxjs/operators"
 
 import { SearchResult } from "modules"
 import {
+  Key,
   SearchQuery,
   Viewport,
   WorkerHandler,
@@ -57,6 +58,7 @@ export interface Search {
  */
 interface MountOptions {
   viewport$: Observable<Viewport>      /* Viewport observable */
+  keyboard$: Observable<Key>           /* Keyboard observable */
 }
 
 /* ----------------------------------------------------------------------------
@@ -72,7 +74,7 @@ interface MountOptions {
  * @return Search observable
  */
 export function mountSearch(
-  handler: WorkerHandler<SearchMessage>, { viewport$ }: MountOptions
+  handler: WorkerHandler<SearchMessage>, { viewport$, keyboard$ }: MountOptions
 ): OperatorFunction<HTMLElement, Search> {
   return pipe(
     switchMap(() => {
@@ -93,7 +95,7 @@ export function mountSearch(
       /* Mount search result */
       const result$ = useComponent("search-result")
         .pipe(
-          mountSearchResult(handler, { viewport$, query$ })
+          mountSearchResult(handler, { query$, viewport$, keyboard$ })
         )
 
       /* Combine into a single hot observable */

src/assets/javascripts/components2/search/reset/index.ts

@@ -29,7 +29,7 @@ import {
   tap
 } from "rxjs/operators"
 
-import { watchSearchReset } from "observables"
+import { setElementFocus, watchSearchReset } from "observables"
 
 import { useComponent } from "../../_"
 
@@ -47,7 +47,7 @@ export function mountSearchReset(): OperatorFunction<HTMLElement, void> {
   return pipe(
     switchMap(watchSearchReset),
     switchMapTo(query$),
-    tap(el => el.focus()),
+    tap(setElementFocus),
     mapTo(undefined),
     startWith(undefined)
   )

src/assets/javascripts/components2/search/result/index.ts

@@ -28,22 +28,33 @@ import {
   map,
   pluck,
   shareReplay,
-  switchMap
+  switchMap,
+  withLatestFrom
 } from "rxjs/operators"
 
+import { setToggle } from "actions"
 import { SearchResult } from "modules"
 import {
+  Key,
   SearchQuery,
   Viewport,
   WorkerHandler,
+  getActiveElement,
+  getElements,
   paintSearchResult,
-  watchElementOffset
+  setElementFocus,
+  useToggle,
+  watchElementOffset,
+  watchToggle
 } from "observables"
+import { takeIf } from "utilities"
 import {
   SearchMessage,
   isSearchResultMessage
 } from "workers"
 
+import { useComponent } from "../../_"
+
 /* ----------------------------------------------------------------------------
  * Helper types
  * ------------------------------------------------------------------------- */
@@ -54,6 +65,7 @@ import {
 interface MountOptions {
   query$: Observable<SearchQuery>      /* Search query observable */
   viewport$: Observable<Viewport>      /* Viewport observable */
+  keyboard$: Observable<Key>           /* Keyboard observable */
 }
 
 /* ----------------------------------------------------------------------------
@@ -70,8 +82,9 @@ interface MountOptions {
  */
 export function mountSearchResult(
   { rx$ }: WorkerHandler<SearchMessage>,
-  { query$, viewport$ }: MountOptions
+  { query$, viewport$, keyboard$ }: MountOptions
 ): OperatorFunction<HTMLElement, SearchResult[]> {
+  const toggle$ = useToggle("search")
   return pipe(
     switchMap(el => {
       const container = el.parentElement!
@@ -86,6 +99,55 @@ export function mountSearchResult(
           filter(identity)
         )
 
+      /* Setup keyboard navigation in search mode */
+      keyboard$
+        .pipe(
+          takeIf(toggle$.pipe(switchMap(watchToggle))),
+          withLatestFrom(toggle$, useComponent("search-query"))
+        )
+          .subscribe(([key, toggle, query]) => {
+            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]", el)]
+                  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)
+            }
+          })
+
       /* Paint search results */
       return rx$
         .pipe(