From 8b23c0636128b9ae7f2987f4a49e35bf8791ad0b Mon Sep 17 00:00:00 2001
From: David Perez Alvarez <david@leddgroup.com>
Date: Thu, 25 Oct 2018 04:55:42 -0400
Subject: [PATCH] refactor: change public api

BREAKING CHANGE: Change exported api
change scrollTo functions to centerElement, scrollTo, and scrollBy
and add screen scroll type
---
 src/scroll.ts | 120 ++++++++++++++++++++++++++++++++------------------
 1 file changed, 76 insertions(+), 44 deletions(-)

diff --git a/src/scroll.ts b/src/scroll.ts
index 0cfebf7..0cfa1d6 100644
--- a/src/scroll.ts
+++ b/src/scroll.ts
@@ -1,19 +1,34 @@
-import { ScrollElement } from "./element"
-import { AnimationManager } from "./animation-manager"
-import { EasingFunction, defaultEasingFunction } from "./easing"
 import { Animation } from "./animation"
-
-const defaultSettings = {
-  easing: defaultEasingFunction,
-}
+import { AnimationManager } from "./animation-manager"
+import { defaultEasingFunction, EasingFunction } from "./easing"
+import { ScrollElement } from "./element"
 
 export type onScroll = (() => void) | null
 
+enum ScrollType {
+  value = "value",
+  percent = "percent",
+  screen = "screen",
+}
+
 interface ISettings {
   easing: EasingFunction
-  onScroll?: onScroll
-  onUtilityScroll?: onScroll
-  onExternalScroll?: onScroll
+  onScroll: onScroll
+  onUtilityScroll: onScroll
+  onExternalScroll: onScroll
+  options: Required<IOptions>
+}
+
+const defaultSettings: ISettings = {
+  easing: defaultEasingFunction,
+  onScroll: null,
+  onUtilityScroll: null,
+  onExternalScroll: null,
+  options: {
+    value: 0,
+    duration: 1000,
+    horizontal: false,
+  },
 }
 
 interface IOptions {
@@ -22,53 +37,70 @@ interface IOptions {
   horizontal?: boolean
 }
 
-interface IScrollToElementOptions extends IOptions {
-  center?: number
-}
-
 class Scroll {
   private element: ScrollElement
+  private settings: ISettings
   private animationManager: AnimationManager
-  constructor(element?: HTMLElement, private settings: ISettings = defaultSettings) {
+  constructor(element?: HTMLElement | Window, settings: Partial<ISettings> = defaultSettings) {
     this.element = new ScrollElement(element)
     this.animationManager = new AnimationManager(
       () => this.settings.onUtilityScroll && this.settings.onUtilityScroll(),
       () => this.settings.onExternalScroll && this.settings.onExternalScroll(),
       this.element.position,
     )
-    this.element.onScroll = () => this.settings.onScroll && this.settings.onScroll()
+    this.settings = defaultSettings
+    this.updateSettings(settings)
+  }
+  public updateSettings(settings: Partial<ISettings>) {
+    this.settings = Object.assign(this.settings, settings)
+    this.element.onScroll = this.settings.onScroll
   }
   public stopAllAnimations() {
     this.animationManager.stopAllAnimations()
   }
-  public readonly scroll = {
-    toElement: (element: HTMLElement, options: IScrollToElementOptions = {}): Animation => {
-      const ratio = (options.value || 0) / 100
-      const horizontal = !!options.horizontal
-      const elementWrapper = new ScrollElement(element)
-      const screenOffset = (this.element.size(horizontal) - elementWrapper.size(horizontal)) * ratio
-      const elementPosition = elementWrapper.offset(horizontal) - this.element.offset(horizontal)
-      return this.scroll.offset(elementPosition - screenOffset, options)
-    },
-    toPercent: (percent: number, options: IOptions = {}): Animation => {
-      const horizontal = !!options.horizontal
-      const position =
-        ((this.element.scrollSize(horizontal) - this.element.size(horizontal)) * percent) / 100
-      return this.scroll.toPosition(position, options)
-    },
-    toPosition: (position: number, options: IOptions = {}): Animation => {
-      const dist = position - this.element.position(!!options.horizontal)
-      return this.scroll.offset(dist, options)
-    },
-    offset: (amount: number, options: IOptions = {}): Animation => {
-      return this.animationManager.createScrollAnimation({
-        distToScroll: amount,
-        duration: options.duration || 0,
-        horizontal: options.horizontal || false,
-        easing: this.settings.easing,
-      })
-    },
+  public centerElement(
+    element: HTMLElement,
+    _options: IOptions = this.settings.options,
+  ): Animation {
+    const options = this.getDefault(_options)
+    const ratio = (options.value || 0) / 100
+    const horizontal = options.horizontal
+    const elementWrapper = new ScrollElement(element)
+    const screenOffset = (this.element.size(horizontal) - elementWrapper.size(horizontal)) * ratio
+    const elementPosition = elementWrapper.offset(horizontal) - this.element.offset(horizontal)
+    return this.offsetScroll({ ...options, value: elementPosition - screenOffset })
+  }
+  public scrollTo(scrollType: ScrollType, _options: IOptions = this.settings.options) {
+    const options = this.getDefault(_options)
+    const dist = this.getDist(scrollType, options.value, options.horizontal)
+    this.offsetScroll({ ...options, value: dist - this.element.position(options.horizontal) })
+  }
+  public scrollBy(scrollType: ScrollType, _options: IOptions = this.settings.options) {
+    const options = this.getDefault(_options)
+    const dist = this.getDist(scrollType, options.value, options.horizontal)
+    this.offsetScroll({ ...options, value: dist })
+  }
+  private offsetScroll(options: Required<IOptions>) {
+    return this.animationManager.createScrollAnimation({
+      distToScroll: options.value,
+      easing: this.settings.easing,
+      duration: options.duration,
+      horizontal: options.horizontal,
+    })
+  }
+  private getDist(scrollType: ScrollType, value: number, horizontal: boolean): number {
+    switch (scrollType) {
+      case ScrollType.percent:
+        return ((this.element.scrollSize(horizontal) - this.element.size(horizontal)) * value) / 100
+      case ScrollType.screen:
+        return this.element.size(horizontal) * value
+      default:
+        return value
+    }
+  }
+  private getDefault(options: IOptions): Required<IOptions> {
+    return Object.assign(this.settings.options, options)
   }
 }
 
-export { Scroll, IOptions, IScrollToElementOptions, Animation }
+export { Scroll, IOptions, Animation }