implement variable width pagination

demo/components/demos/responsive/variable-width-with-arrows.vue

@@ -0,0 +1,13 @@
+<template>
+  <ssr-carousel data-cy="variable-width" :slides-per-page="null" show-arrows show-dots>
+    <slide :index="1" :style="{ width: '65%', height: '30vw' }"></slide>
+    <slide :index="2" :style="{ width: '50%', height: '30vw' }"></slide>
+    <slide :index="3" :style="{ width: '30%', height: '30vw' }"></slide>
+    <slide :index="4" :style="{ width: '65%', height: '30vw' }"></slide>
+    <slide :index="5" :style="{ width: '30%', height: '30vw' }"></slide>
+    <slide :index="6" :style="{ width: '50%', height: '30vw' }"></slide>
+    <slide :index="7" :style="{ width: '50%', height: '30vw' }"></slide>
+    <slide :index="8" :style="{ width: '65%', height: '30vw' }"></slide>
+    <slide :index="9" :style="{ width: '30%', height: '30vw' }"></slide>
+  </ssr-carousel>
+</template>

demo/content/responsive.md

@@ -70,7 +70,10 @@ While it's not the primary use case of this package, you if you set `slidesPerPa
 
 - If there are not enough slides to fill the viewport, slides will be left aligned rather than center aligned.
 - This hasn't been tested with responsive props or looping. Peeking doesn't make sense for this use case but care hasn't been taken to disabling it.
-- Pagination controls aren't supported yet, this is purely drag only.
+- Pagination controls are in beta
+  - Pagination is done on a per slide basis
+  - Looping still has not been implemented
+  - Slides are left aligned
 
 <demos-responsive-variable-width></demos-responsive-variable-width>
 
@@ -82,6 +85,24 @@ While it's not the primary use case of this package, you if you set `slidesPerPa
 </ssr-carousel>
 ```
 
+Carousel with variable width and arrows:
+
+<demos-responsive-variable-width-with-arrows></demos-responsive-variable-width-with-arrows>
+
+```vue
+<ssr-carousel data-cy="variable-width" :slides-per-page="null">
+  <slide :index="1" :style="{ width: '65%', height: '30vw' }"></slide>
+  <slide :index="2" :style="{ width: '50%', height: '30vw' }"></slide>
+  <slide :index="3" :style="{ width: '30%', height: '30vw' }"></slide>
+  <slide :index="4" :style="{ width: '65%', height: '30vw' }"></slide>
+  <slide :index="5" :style="{ width: '30%', height: '30vw' }"></slide>
+  <slide :index="6" :style="{ width: '50%', height: '30vw' }"></slide>
+  <slide :index="7" :style="{ width: '50%', height: '30vw' }"></slide>
+  <slide :index="8" :style="{ width: '65%', height: '30vw' }"></slide>
+  <slide :index="9" :style="{ width: '30%', height: '30vw' }"></slide>
+</ssr-carousel>
+```
+
 Here's an example where there aren't enough slides to exceed the carouel width:
 
 <demos-responsive-variable-width-disabled></demos-responsive-variable-width-disabled>

src/concerns/dimensions.coffee

@@ -80,7 +80,7 @@ export default
 			@carouselWidth = @$el.getBoundingClientRect().width + @gutterWidth
 			@viewportWidth = window.innerWidth
 			@capturePeekingMeasurements()
-			@captureTrackWidth() if @isVariableWidth
+			@captureCarouselDims() if @isVariableWidth
 
 		# Make the width style that gives a slide it's width given
 		# slidesPerPage. Reduce this width by the gutter if present
@@ -114,3 +114,10 @@ export default
 				(#{@autoUnit(peekLeft)} + #{@autoUnit(peekRight)}) / #{slidesPerPage} -
 				(#{@autoUnit(gutter)} * #{slidesPerPage - 1}) / #{slidesPerPage}
 			)"
+
+
+		# Get the target X scroll position of a given slide
+		targetXOfIdx: (idx) ->
+			if @isVariableWidth
+			then @measuredSlidesWidths[idx].targetXScroll
+			else @pageWidth / @currentSlidesPerPage

src/concerns/dragging.coffee

@@ -73,6 +73,8 @@ export default
 		fractionalIndex: ->
 			return 0 unless @trackWidth
 
+			if @isVariableWidth then return @fractionalIndexFromMeasurements
+
 			# Work in positive numbers
 			x = @currentX * -1
 
@@ -104,6 +106,16 @@ export default
 			# Return the final value by adding all the passed index values
 			return pageProgressPercent + setIndex * @pages + pageIndex
 
+		fractionalIndexFromMeasurements: ->
+			# Work in positive numbers
+			x = @currentX * -1
+
+			slideIdx = @measuredSlidesWidths.findIndex((measuredSlide) => measuredSlide.targetXScroll > x) - 1
+
+			percentage = (x - @measuredSlidesWidths[slideIdx].targetXScroll) / @measuredSlidesWidths[slideIdx].width
+
+			return slideIdx + percentage
+
 		# Determine if the user is dragging vertically
 		isVerticalDrag: ->
 			return unless @dragDirectionRatio
@@ -141,7 +153,7 @@ export default
 					else @gotoEnd()
 
 				# If rendering variable width slides, don't come to a rest at an index
-				else if @isVariableWidth then @tweenToStop()
+				else if @isVariableWidth then @goto @dragIndex
 
 				# If user was vertically dragging, reset the index
 				else if @isVerticalDrag then @goto @index

src/concerns/pagination.coffee

@@ -22,6 +22,8 @@ export default
 
 		# The current number of pages
 		pages: -> switch
+			# When variable width, pages is slide count
+			when @isVariableWidth then @slidesCount
 
 			# When looping and paginating per slide, make a dot per slide
 			when @paginateBySlide and @shouldLoop then @slidesCount
@@ -146,9 +148,10 @@ export default
 		getXForIndex: (index) ->
 
 			# Figure out the new x position
-			x = if @paginateBySlide
-			then index * @slideWidth * -1
-			else index * @pageWidth * -1
+			x = switch
+				when @isVariableWidth then @targetXOfIdx(@applyIndexBoundaries(index)) * -1
+				when @paginateBySlide then index * @slideWidth * -1
+				else index * @pageWidth * -1
 
 			# Apply adjustments to x value and persist
 			x += @makeIncompletePageOffset index

src/concerns/variable-width.coffee

@@ -3,16 +3,36 @@ Functionality related to supporting variable width slides
 ###
 export default
 
-	data: -> measuredTrackWidth: 0
+	data: ->
+		measuredTrackWidth: 0
+		measuredSlidesWidths: []
 
 	computed:
 
 		# Is the carousel in variable width mode
 		isVariableWidth: -> @slidesPerPage == null
 
 	methods:
+		# Capture all dimensions of carousel
+		captureCarouselDims: ->
+			@captureTrackWidth()
+			@captureSlideWidths()
 
 		# Measure the width of the track
 		captureTrackWidth: ->
 			return unless @$refs.track
 			@measuredTrackWidth = @$refs.track.$el.scrollWidth
+
+		# Capture slide dims and place them into an array of data
+		captureSlideWidths: ->
+			return unless @$refs.track
+			@measuredSlidesWidths = @$refs?.track?.$children.reduce((acc, child, idx, arr) =>
+				return [
+					...acc
+					{
+						width: child.$el.clientWidth
+						targetXScroll: (acc[idx - 1]?.targetXScroll || 0) + (acc[idx - 1]?.width || 0) + @gutter * (idx > 0)
+					}
+				]
+			, [] )
+