From 39b05730d4d4436c6cd9e8f747dabbbdbffb1dac Mon Sep 17 00:00:00 2001
From: Vadim <korobeinikovv@mail.ru>
Date: Wed, 8 Sep 2021 00:09:11 +0300
Subject: [PATCH] #69 : Apply partial offset

---
 src/components/Carousel/Carousel.svelte | 12 ++----------
 src/store.js                            |  2 ++
 src/utils/page.js                       | 20 ++++----------------
 3 files changed, 8 insertions(+), 26 deletions(-)

diff --git a/src/components/Carousel/Carousel.svelte b/src/components/Carousel/Carousel.svelte
index bc55785..9ca96ac 100644
--- a/src/components/Carousel/Carousel.svelte
+++ b/src/components/Carousel/Carousel.svelte
@@ -21,7 +21,6 @@
     getCurrentPageIndexWithoutClones,
     getPagesCountWithoutClones,
     getClonesCount,
-    getIsPartialOffset,
   } from '../../utils/page'
   import { get } from '../../utils/object'
   import { ProgressManager } from '../../utils/ProgressManager'
@@ -292,14 +291,6 @@
       // _duration is an offset animation time
       _duration = animated ? duration : 0
 
-      const isPartialOffset = getIsPartialOffset({
-        pagesCountWithoutClones,
-        headClonesCount: clonesCount.head,
-        pagesToScroll,
-        currentPageIndexWithoutClones,
-      })
-      console.log('isPartialOffset', isPartialOffset)
-
       offset = -currentPageIndex * pageWidth
 
       setTimeout(() => {
@@ -315,7 +306,7 @@
       if (currentPageIndex === 0) {
         await showPage(pagesCount - clonesCount.total, { animated: false })
         jumped = true
-      } else if (currentPageIndex === pagesCount - clonesCount.head ) {
+      } else if (currentPageIndex === pagesCount - clonesCount.tail) {
         await showPage(clonesCount.head, { animated: false })
         jumped = true
       }
@@ -363,6 +354,7 @@
         infinite,
         pagesCount,
         pagesToScroll,
+        clonesCountTail: clonesCount.tail,
       }),
       options,
     )
diff --git a/src/store.js b/src/store.js
index 6f117e2..58be6b2 100644
--- a/src/store.js
+++ b/src/store.js
@@ -40,12 +40,14 @@ function createStore() {
     infinite,
     pagesCount,
     pagesToScroll,
+    clonesCountTail,
   }) {
     update(store => {
       const newCurrentPageIndex = getNextPageIndexFn(infinite)({
         currentPageIndex: store.currentPageIndex,
         pagesCount,
         pagesToScroll,
+        clonesCountTail,
       })
       return {
         ...store,
diff --git a/src/utils/page.js b/src/utils/page.js
index cb3489c..875fd32 100644
--- a/src/utils/page.js
+++ b/src/utils/page.js
@@ -2,6 +2,7 @@ export function getNextPageIndexLimited({
   currentPageIndex,
   pagesCount,
   pagesToScroll,
+  clonesCountTail,
 }) {
   if (pagesCount < 1) throw new Error('pagesCount must be at least 1')
   return Math.min(Math.max(currentPageIndex + pagesToScroll, 0), pagesCount - 1)
@@ -11,9 +12,10 @@ export function getNextPageIndexInfinte({
   currentPageIndex,
   pagesCount,
   pagesToScroll,
+  clonesCountTail,
 }) {
   if (pagesCount < 1) throw new Error('pagesCount must be at least 1')
-  const newCurrentPageIndex = Math.max(currentPageIndex, 0) + pagesToScroll
+  const newCurrentPageIndex = Math.max(currentPageIndex, 0) + Math.min(pagesCount - clonesCountTail - currentPageIndex, pagesToScroll)
   return newCurrentPageIndex > pagesCount - 1 ? 0 : Math.max(newCurrentPageIndex, 0)
 }
 
@@ -36,7 +38,7 @@ export function getPrevPageIndexInfinte({
   pagesToScroll,
 }) {
   if (pagesCount < 1) throw new Error('pagesCount must be at least 1')
-  const newCurrentPageIndex = Math.min(currentPageIndex, pagesCount - 1) - pagesToScroll
+  const newCurrentPageIndex = Math.min(currentPageIndex, pagesCount - 1) - Math.min(currentPageIndex, pagesToScroll)
   return newCurrentPageIndex >= 0 ? Math.min(newCurrentPageIndex, pagesCount - 1) : pagesCount - 1
 }
 
@@ -168,7 +170,6 @@ export function getPagesCountWithoutClones({
 
 export function getClonesCount({
   infinite,
-  // pagesToScroll,
   pagesToShow,
   partialPageSize,
 }) {
@@ -190,16 +191,3 @@ export function getClonesCount({
     total: clonesCount.head + clonesCount.tail,
   }
 }
-
-export function getIsPartialOffset({
-  pagesCountWithoutClones,
-  headClonesCount,
-  pagesToScroll,
-  currentPageIndexWithoutClones,
-}) {
-  return (
-    pagesCountWithoutClones + headClonesCount ===
-    currentPageIndexWithoutClones + pagesToScroll
-  )
-}
-