Refactored anchor blurring

src/assets/javascripts/component/anchor/index.ts

@@ -0,0 +1,181 @@
+/*
+ * 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 { reduce, reverse } from "ramda"
+import { Observable } from "rxjs"
+import {
+  distinctUntilChanged,
+  map,
+  scan,
+  shareReplay
+} from "rxjs/operators"
+
+import { ViewportOffset, getElement } from "../../ui"
+
+/* ----------------------------------------------------------------------------
+ * Types
+ * ------------------------------------------------------------------------- */
+
+/**
+ * Anchors
+ */
+export interface Anchors {
+  past: HTMLAnchorElement[][]          /* Past anchors */
+  next: HTMLAnchorElement[][]          /* Next anchors */
+}
+
+/* ----------------------------------------------------------------------------
+ * Function types
+ * ------------------------------------------------------------------------- */
+
+/**
+ * Options
+ */
+interface Options {
+  offset$: Observable<ViewportOffset>  /* Viewport offset observable */
+}
+
+/* ----------------------------------------------------------------------------
+ * Functions
+ * ------------------------------------------------------------------------- */
+
+/**
+ * Set anchor blur
+ *
+ * @param anchor - Anchor HTML element
+ * @param blur - Anchor blur
+ */
+export function setAnchorBlur(
+  anchor: HTMLAnchorElement, blur: boolean
+): void {
+  anchor.setAttribute("data-md-state", blur ? "blur" : "")
+}
+
+/**
+ * Set sidebar state lock
+ *
+ * @param anchor - Anchor HTML element
+ * @param active - Whether the anchor is active
+ */
+export function setAnchorActive(
+  anchor: HTMLAnchorElement, active: boolean
+): void {
+  anchor.classList.toggle("md-nav__link--active", active)
+}
+
+/**
+ * Reset anchor
+ *
+ * @param anchor - Anchor HTML element
+ */
+export function resetAnchor(anchor: HTMLAnchorElement) {
+  anchor.removeAttribute("data-md-state")
+  anchor.classList.remove("md-nav__link--active")
+}
+
+/* ------------------------------------------------------------------------- */
+
+/**
+ * Create an observable to monitor all anchors in respect to viewport offset
+ *
+ * @param anchors - Anchor elements
+ * @param header - Header element
+ * @param options - Options
+ *
+ * @return Sidebar observable
+ */
+export function watchAnchors(
+  anchors: HTMLAnchorElement[], header: HTMLElement, { offset$ }: Options
+): Observable<Anchors> {
+
+  /* Adjust for header offset if fixed */
+  const adjust = getComputedStyle(header)
+    .getPropertyValue("position") === "fixed"
+      ? 18 + header.offsetHeight
+      : 18
+
+  /* Build index to map anchors to their targets */
+  const index = new Map<HTMLAnchorElement, HTMLElement>()
+  for (const anchor of anchors) {
+    const target = getElement(decodeURIComponent(anchor.hash))
+    if (typeof target !== "undefined")
+      index.set(anchor, target)
+  }
+
+  /* Build table to map anchor paths to vertical offsets */
+  const table = new Map<HTMLAnchorElement[], number>()
+  reduce((path, [anchor, target]) => {
+    while (path.length) {
+      const last = index.get(path[path.length - 1])!
+      if (last.tagName >= target.tagName)
+        path.pop()
+      else
+        break
+    }
+    table.set(reverse(path = [...path, anchor]), target.offsetTop)
+    return path
+  }, [] as HTMLAnchorElement[], [...index])
+
+  /* Compute partition of past and next anchors */
+  const partition$ = offset$
+    .pipe(
+      scan(([past, next], { y }) => {
+        y = y + adjust
+
+        /* Look forward */
+        while (next.length) {
+          const [, offset] = next[0]
+          if (offset < y) {
+            past = [...past, next.shift()!]
+          } else {
+            break
+          }
+        }
+
+        /* Look backward */
+        while (past.length) {
+          const [, offset] = past[past.length - 1]
+          if (offset >= y) {
+            next = [past.pop()!, ...next]
+          } else {
+            break
+          }
+        }
+
+        /* Return new partition */
+        return [past, next]
+      }, [[], [...table]]),
+      distinctUntilChanged(([a0, a1], [b0, b1]) => {
+        return a0 === b0 && a1 === b1
+      })
+    )
+
+  /* Extract anchors and return hot observable */
+  return partition$
+    .pipe(
+      map(([past, next]) => ({
+        past: past.map(([els]) => els),
+        next: next.map(([els]) => els)
+      })),
+      shareReplay(1)
+    )
+}

src/assets/javascripts/component/container/index.ts

@@ -30,11 +30,11 @@ import { ViewportOffset, ViewportSize } from "../../ui"
  * ------------------------------------------------------------------------- */
 
 /**
- * Container state
+ * Container
  */
 export interface Container {
   offset: number                       /* Container top offset */
-  height: number                       /* Container height */
+  height: number                       /* Container visible height */
   active: boolean                      /* Scrolled past top offset */
 }
 
@@ -55,7 +55,7 @@ interface Options {
  * ------------------------------------------------------------------------- */
 
 /**
- * Create an observable for the container component
+ * Create an observable to monitor the container
  *
  * The container represents the main content area including the sidebars (table
  * of contents and navigation), as well as the actual page content.
@@ -64,9 +64,9 @@ interface Options {
  * @param header - Header element
  * @param options - Options
  *
- * @return Container state observable
+ * @return Container observable
  */
-export function fromContainer(
+export function watchContainer(
   container: HTMLElement, header: HTMLElement, { size$, offset$ }: Options
 ): Observable<Container> {
 
@@ -76,7 +76,7 @@ export function fromContainer(
       ? header.offsetHeight
       : 0
 
-  /* Compute the container's available height */
+  /* Compute the container's visible height */
   const height$ = combineLatest(offset$, size$)
     .pipe(
       map(([{ y }, { height }]) => {

src/assets/javascripts/component/index.ts

@@ -20,5 +20,7 @@
  * IN THE SOFTWARE.
  */
 
+export * from "./anchor"
 export * from "./container"
+export * from "./header"
 export * from "./sidebar"

src/assets/javascripts/component/sidebar/index.ts

@@ -31,7 +31,7 @@ import { Container } from "../container"
  * ------------------------------------------------------------------------- */
 
 /**
- * Sidebar state
+ * Sidebar
  */
 export interface Sidebar {
   height: number                       /* Sidebar height */
@@ -46,7 +46,7 @@ export interface Sidebar {
  * Options
  */
 interface Options {
-  container$: Observable<Container>    /* Container state observable */
+  container$: Observable<Container>    /* Container observable */
   offset$: Observable<ViewportOffset>  /* Viewport offset observable */
 }
 
@@ -60,51 +60,45 @@ interface Options {
  * @param sidebar - Sidebar HTML element
  * @param height - Sidebar height
  */
-export function setSidebarHeight(sidebar: HTMLElement, height: number): void {
+export function setSidebarHeight(
+  sidebar: HTMLElement, height: number
+): void {
   sidebar.style.height = `${height}px`
 }
 
 /**
- * Unset sidebar height
+ * Set sidebar lock
+ *
+ * @param sidebar - Sidebar HTML element
+ * @param lock - Whether the sidebar is locked
+ */
+export function setSidebarLock(
+  sidebar: HTMLElement, lock: boolean
+): void {
+  sidebar.setAttribute("data-md-state", lock ? "lock" : "")
+}
+
+/**
+ * Reset sidebar
  *
  * @param sidebar - Sidebar HTML element
  */
-export function unsetSidebarHeight(sidebar: HTMLElement): void {
+export function resetSidebar(sidebar: HTMLElement): void {
+  sidebar.removeAttribute("data-md-state")
   sidebar.style.height = ""
 }
 
 /* ------------------------------------------------------------------------- */
 
 /**
- * Set sidebar lock
- *
- * @param sidebar - Sidebar HTML element
- * @param lock - Sidebar lock
- */
-export function setSidebarLock(sidebar: HTMLElement, lock: boolean): void {
-  sidebar.setAttribute("data-md-state", lock ? "lock" : "")
-}
-
-/**
- * Unset sidebar lock
- *
- * @param sidebar - Sidebar HTML element
- */
-export function unsetSidebarLock(sidebar: HTMLElement): void {
-  sidebar.removeAttribute("data-md-state")
-}
-
-/* ------------------------------------------------------------------------- */
-
-/**
- * Create an observable for a sidebar component
+ * Create an observable to monitor the sidebar
  *
  * @param sidebar - Sidebar element
  * @param options - Options
  *
- * @return Sidebar state observable
+ * @return Sidebar observable
  */
-export function fromSidebar(
+export function watchSidebar(
   sidebar: HTMLElement, { container$, offset$ }: Options
 ): Observable<Sidebar> {
 

src/assets/javascripts/ui/element/index.ts

@@ -59,7 +59,9 @@ export function getElements<T extends HTMLElement>(
   return toArray(document.querySelectorAll<T>(selector))
 }
 
-/* ------------------------------------------------------------------------- */
+/* ----------------------------------------------------------------------------
+ * Operators
+ * ------------------------------------------------------------------------- */
 
 /**
  * Retrieve an element matching the query selector
@@ -76,3 +78,18 @@ export function withElement<
     filter<T>(Boolean)
   )
 }
+
+/**
+ * Retrieve all elements matching the query selector
+ *
+ * @template T - Element type
+ *
+ * @return HTML elements observable
+ */
+export function withElements<
+  T extends HTMLElement
+>(): OperatorFunction<string, T[]> {
+  return pipe(
+    map(selector => getElements<T>(selector))
+  )
+}

src/assets/javascripts/ui/index.ts

@@ -22,4 +22,5 @@
 
 export * from "./element"
 export * from "./location"
+export * from "./media"
 export * from "./viewport"

src/assets/javascripts/ui/location/index.ts

@@ -37,11 +37,11 @@ const hash$ = fromEvent<HashChangeEvent>(window, "hashchange")
  * ------------------------------------------------------------------------- */
 
 /**
- * Create an observable emitting changes in location hashes
+ * Create an observable to monitor the location hash
  *
  * @return Location hash observable
  */
-export function fromLocationHash(): Observable<string> {
+export function watchLocationHash(): Observable<string> {
   return hash$
     .pipe(
       map(() => document.location.hash),

src/assets/javascripts/ui/media/index.ts

@@ -20,30 +20,21 @@
  * IN THE SOFTWARE.
  */
 
-import {
-  Observable,
-  OperatorFunction,
-  fromEventPattern
-} from "rxjs"
-import {
-  filter,
-  shareReplay,
-  startWith,
-  windowToggle
-} from "rxjs/operators"
+import { Observable, fromEventPattern } from "rxjs"
+import { shareReplay, startWith } from "rxjs/operators"
 
 /* ----------------------------------------------------------------------------
  * Functions
  * ------------------------------------------------------------------------- */
 
 /**
- * Create an observable for a media query
+ * Create an observable from a media query
  *
  * @param query - Media query
  *
- * @return Media query observable
+ * @return Media observable
  */
-export function fromMediaQuery(query: string): Observable<boolean> {
+export function watchMedia(query: string): Observable<boolean> {
   const media = window.matchMedia(query)
   return fromEventPattern<boolean>(next =>
     media.addListener(() => next(media.matches))
@@ -53,20 +44,3 @@ export function fromMediaQuery(query: string): Observable<boolean> {
       shareReplay(1)
     )
 }
-
-/**
- * Only emit values from the source observable when a media query matches
- *
- * @template T - Observable value type
- *
- * @param query - Media query observable
- *
- * @return Observable of source observable values
- */
-export function withMediaQuery<T>(
-  query$: Observable<boolean>
-): OperatorFunction<T, Observable<T>> {
-  const start$ = query$.pipe(filter(match => match === true))
-  const until$ = query$.pipe(filter(match => match === false))
-  return windowToggle<T, boolean>(start$, () => until$)
-}

src/assets/javascripts/ui/viewport/_/index.ts

@@ -1,116 +0,0 @@
-/*
- * 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, fromEvent, merge } from "rxjs"
-import { map, shareReplay, startWith } from "rxjs/operators"
-
-/* ----------------------------------------------------------------------------
- * Data
- * ------------------------------------------------------------------------- */
-
-/**
- * Observable for window scroll events
- */
-const scroll$ = fromEvent<UIEvent>(window, "scroll")
-
-/**
- * Observable for window resize events
- */
-const resize$ = fromEvent<UIEvent>(window, "resize")
-
-/* ----------------------------------------------------------------------------
- * Types
- * ------------------------------------------------------------------------- */
-
-/**
- * Viewport offset
- */
-export interface ViewportOffset {
-  x: number                            /* Horizontal offset */
-  y: number                            /* Vertical offset */
-}
-
-/**
- * Viewport size
- */
-export interface ViewportSize {
-  width: number                        /* Viewport width */
-  height: number                       /* Viewport height */
-}
-
-/* ----------------------------------------------------------------------------
- * Functions
- * ------------------------------------------------------------------------- */
-
-/**
- * Retrieve the viewport offset
- *
- * @return Viewport offset
- */
-export function getViewportOffset(): ViewportOffset {
-  return {
-    x: window.pageXOffset,
-    y: window.pageYOffset
-  }
-}
-
-/**
- * Retrieve the viewport size
- *
- * @return Viewport size
- */
-export function getViewportSize(): ViewportSize {
-  return {
-    width:  window.innerWidth,
-    height: window.innerHeight
-  }
-}
-
-/* ------------------------------------------------------------------------- */
-
-/**
- * Create an observable emitting changes in viewport offset
- *
- * @return Viewport offset observable
- */
-export function fromViewportOffset(): Observable<ViewportOffset> {
-  return merge(scroll$, resize$)
-    .pipe(
-      map(getViewportOffset),
-      startWith(getViewportOffset()),
-      shareReplay(1)
-    )
-}
-
-/**
- * Create an observable emitting changes in viewport size
- *
- * @return Viewport size observable
- */
-export function fromViewportSize(): Observable<ViewportSize> {
-  return resize$
-    .pipe(
-      map(getViewportSize),
-      startWith(getViewportSize()),
-      shareReplay(1)
-    )
-}

src/assets/javascripts/ui/viewport/index.ts

@@ -20,5 +20,97 @@
  * IN THE SOFTWARE.
  */
 
-export * from "./_"
-export * from "./breakpoint"
+import { Observable, fromEvent, merge } from "rxjs"
+import { map, shareReplay, startWith } from "rxjs/operators"
+
+/* ----------------------------------------------------------------------------
+ * Data
+ * ------------------------------------------------------------------------- */
+
+/**
+ * Observable for window scroll events
+ */
+const scroll$ = fromEvent<UIEvent>(window, "scroll")
+
+/**
+ * Observable for window resize events
+ */
+const resize$ = fromEvent<UIEvent>(window, "resize")
+
+/* ----------------------------------------------------------------------------
+ * Types
+ * ------------------------------------------------------------------------- */
+
+/**
+ * Viewport offset
+ */
+export interface ViewportOffset {
+  x: number                            /* Horizontal offset */
+  y: number                            /* Vertical offset */
+}
+
+/**
+ * Viewport size
+ */
+export interface ViewportSize {
+  width: number                        /* Viewport width */
+  height: number                       /* Viewport height */
+}
+
+/* ----------------------------------------------------------------------------
+ * Functions
+ * ------------------------------------------------------------------------- */
+
+/**
+ * Retrieve the viewport offset
+ *
+ * @return Viewport offset
+ */
+export function getViewportOffset(): ViewportOffset {
+  return {
+    x: window.pageXOffset,
+    y: window.pageYOffset
+  }
+}
+
+/**
+ * Retrieve the viewport size
+ *
+ * @return Viewport size
+ */
+export function getViewportSize(): ViewportSize {
+  return {
+    width:  window.innerWidth,
+    height: window.innerHeight
+  }
+}
+
+/* ------------------------------------------------------------------------- */
+
+/**
+ * Create an observable to monitor the viewport offset
+ *
+ * @return Viewport offset observable
+ */
+export function watchViewportOffset(): Observable<ViewportOffset> {
+  return merge(scroll$, resize$)
+    .pipe(
+      map(getViewportOffset),
+      startWith(getViewportOffset()),
+      shareReplay(1)
+    )
+}
+
+/**
+ * Create an observable to monitor the viewport size
+ *
+ * @return Viewport size observable
+ */
+export function watchViewportSize(): Observable<ViewportSize> {
+  return resize$
+    .pipe(
+      map(getViewportSize),
+      startWith(getViewportSize()),
+      shareReplay(1)
+    )
+}

src/assets/javascripts/utilities/index.ts

@@ -20,6 +20,9 @@
  * IN THE SOFTWARE.
  */
 
+import { Observable, OperatorFunction } from "rxjs"
+import { filter, windowToggle } from "rxjs/operators"
+
 /* ----------------------------------------------------------------------------
  * Functions
  * ------------------------------------------------------------------------- */
@@ -38,3 +41,24 @@ export function toArray<
 >(collection: HTMLCollection | NodeListOf<T>): T[] {
   return Array.from(collection) as T[]
 }
+
+/* ----------------------------------------------------------------------------
+ * Operators
+ * ------------------------------------------------------------------------- */
+
+/**
+ * Toggle emission from a source observable
+ *
+ * @template T - Observable value type
+ *
+ * @param toggle$ - Toggle observable
+ *
+ * @return Observable of source observables
+ */
+export function toggle<T>(
+  toggle$: Observable<boolean>
+): OperatorFunction<T, Observable<T>> {
+  const start$ = toggle$.pipe(filter(match => match === true))
+  const until$ = toggle$.pipe(filter(match => match === false))
+  return windowToggle<T, boolean>(start$, () => until$)
+}

src/assets/stylesheets/extensions/_permalinks.scss

@@ -57,9 +57,9 @@
 
   // Correct anchor offset for link blurring
   @each $level, $delta in (
-    h1: 9px,
+    h1: 8px,
     h2: 8px,
-    h3: 9px,
+    h3: 8px,
     h4: 9px,
     h5: 11px,
     h6: 11px