Merge pull request #137 from BKWLD/rtl-support-via-changing-slide-order

RTL support via changing slide order

README.md

@@ -66,6 +66,7 @@ For more examples, see the demo: https://vue-ssr-carousel.netlify.app.
 | `no-drag`           | `false`     | Disables the ability to drag the carousel.
 | `show-arrows`       | `false`     | Whether to show back/forward arrows. See https://vue-ssr-carousel.netlify.app/ui.
 | `show-dots`         | `false`     | Whether to show dot style pagination dots. See https://vue-ssr-carousel.netlify.app/ui.
+| `rtl`               | `false`     | Adjust layout for right to left sites. See https://vue-ssr-carousel.netlify.app/accessibility.
 | `value`             | `undefined` | Used as part of `v-model` to set the initial slide to show.  See https://vue-ssr-carousel.netlify.app/events.
 | `responsive`        | `[]`        | Adjust settings at breakpoints. See https://vue-ssr-carousel.netlify.app/responsive. Note, `loop` and `paginate-by-slide` cannot be set responsively.
 

demo/components/demos/accessibility/rtl.vue

@@ -0,0 +1,11 @@
+<template>
+
+<div :style='{ direction: "rtl" }'>
+	<ssr-carousel rtl show-dots show-arrows>
+		<slide :index='1'></slide>
+		<slide :index='2'></slide>
+		<slide :index='3'></slide>
+	</ssr-carousel>
+</div>
+
+</template>

demo/content/accessibility.md

@@ -43,3 +43,19 @@ By default, pages are referred to as "Page" in aria labels unless using `paginat
   <slide>Story 3</slide>
 </ssr-carousel>
 ```
+
+## Support RTL
+
+The `rtl` boolean props adjusts the layout and drag behavior for right-to-left sites (like when the `direction: rtl` CSS property has been set).
+
+<demos-accessibility-rtl></demos-accessibility-rtl>
+
+```vue
+<div :style='{ direction: "rtl" }'>
+	<ssr-carousel rtl>
+		<slide :index='1'></slide>
+		<slide :index='2'></slide>
+		<slide :index='3'></slide>
+	</ssr-carousel>
+</div>
+```

src/concerns/dimensions.coffee

@@ -64,6 +64,10 @@ export default
 		# Check if the drag is currently out bounds
 		isOutOfBounds: -> @currentX > 0 or @currentX < @endX
 
+		# Helper for things that are triggered once dimensions are known so
+		# they can be more specific about their dependencies
+		dimensionsKnown: -> @carouselWidth and @viewportWidth
+
 	methods:
 
 		# Measure the component width for various calculations. Using

src/concerns/rtl.coffee

@@ -0,0 +1,30 @@
+###
+Code related to supporting RTL layout
+###
+export default
+
+	# Add RTL prop
+	props: rtl: Boolean
+
+	# As an easy way to support rtl, update the index to the final value
+	# when RTL is enabled. This is change is combined with reversing the order
+	# of the slides in `ssr-carousel-track`. We're testing for the
+	# dimensionsKnown value as way to ensure that the final pages count is known
+	# since it depends on knowing the width of the carousel.
+	mounted: ->
+		return unless @rtl
+		if @dimensionsKnown
+		then @setInitialRtlIndex()
+		else unwatch = @$watch 'dimensionsKnown', =>
+			@setInitialRtlIndex()
+			unwatch()
+
+	methods:
+
+		# This should only be called once.  Wait a tick so we're sure that the
+		# pages value has been calculated
+		setInitialRtlIndex: ->
+			setTimeout =>
+				@index = @pages - @value - 1
+				@jumpToIndex @index
+			, 0

src/ssr-carousel-arrows.vue

@@ -4,21 +4,27 @@
 
 .ssr-carousel-arrows
 
-	//- Back arrow
-	button.ssr-carousel-back-button(
-		:aria-label='`Previous ${pageLabel}`'
-		:aria-disabled='backDisabled'
+	//- Left arrow
+	button.ssr-carousel-left-button(
+		:aria-label='rtl ? nextLabel : backLabel'
+		:aria-disabled='leftDisabled'
+		:class='rtl ? "ssr-carousel-next-button" : "ssr-carousel-back-button"'
 		@click='$emit("back")')
-			slot(name='back' :disabled='backDisabled')
-				span.ssr-carousel-back-icon
-
-	//- Next arrow
-	button.ssr-carousel-next-button(
-		:aria-label='`Next ${pageLabel}`'
-		:aria-disabled='nextDisabled'
+			slot(
+				:name='rtl ? "next" : "back"'
+				:disabled='leftDisabled')
+				span.ssr-carousel-left-icon
+
+	//- Right arrow
+	button.ssr-carousel-right-button(
+		:aria-label='rtl ? backLabel : nextLabel'
+		:aria-disabled='rightDisabled'
+		:class='rtl ? "ssr-carousel-back-button" : "ssr-carousel-next-button"'
 		@click='$emit("next")')
-			slot(name='next' :disabled='nextDisabled')
-				span.ssr-carousel-next-icon
+			slot(
+				:name='rtl ? "back" : "next"'
+				:disabled='rightDisabled')
+				span.ssr-carousel-right-icon
 
 </template>
 
@@ -32,12 +38,18 @@ export default
 		pages: Number
 		shouldLoop: Boolean
 		pageLabel: String
+		rtl: Boolean
 
 	computed:
 
+		# Make the labels
+		backLabel: -> "Previous #{@pageLabel}"
+		nextLabel: -> "Next #{@pageLabel}"
+
 		# Determine if button should be disabled because we're at the limits
-		backDisabled: -> @index == 0 unless @shouldLoop
-		nextDisabled: -> @index == @pages - 1 unless @shouldLoop
+		leftDisabled: -> @index == 0 unless @shouldLoop
+		rightDisabled: -> @index == @pages - 1 unless @shouldLoop
+
 
 </script>
 
@@ -48,20 +60,20 @@ export default
 @import './utils'
 
 // Vertically center buttons
-.ssr-carousel-back-button
-.ssr-carousel-next-button
+.ssr-carousel-left-button
+.ssr-carousel-right-button
 	v-center()
 	resetButton()
 
 // Align buttons near the edges
-.ssr-carousel-back-button
+.ssr-carousel-left-button
 	left 2%
-.ssr-carousel-next-button
+.ssr-carousel-right-button
 	right 2%
 
 // Make a default icon
-.ssr-carousel-back-icon
-.ssr-carousel-next-icon
+.ssr-carousel-left-icon
+.ssr-carousel-right-icon
 
 	// Make a circle shape
 	display inline-block
@@ -88,12 +100,12 @@ export default
 		position relative
 
 // Make triangle icons in the buttons
-.ssr-carousel-back-icon
+.ssr-carousel-left-icon
 	&:before
 		triangle 12px, 18px, white, 'left'
 		left -2px // Massage center
 
-.ssr-carousel-next-icon
+.ssr-carousel-right-icon
 	&:before
 		triangle 12px, 18px, white, 'right'
 		left 2px // Massage center

src/ssr-carousel-dots.vue

@@ -5,7 +5,7 @@
 .ssr-carousel-dots
 	button.ssr-carousel-dot-button(
 		v-for='i in pages' :key='i'
-		:aria-label='`Go to ${pageLabel} ${i}`'
+		:aria-label='makeLabel(i)'
 		:aria-disabled='isDisabled(i)'
 		@click='$emit("goto", i - 1)')
 
@@ -29,9 +29,15 @@ export default
 		boundedIndex: Number
 		pages: Number
 		pageLabel: String
+		rtl: Boolean
 
 	methods:
 
+		# Make the label for the dot
+		makeLabel: (index) ->
+			pageNumber = if @rtl then @pages - index + 1 else index
+			"Go to #{@pageLabel} #{pageNumber}"
+
 		# Check if dot index shuold be disabled
 		isDisabled: (index) -> @boundedIndex == index - 1
 

src/ssr-carousel-track.vue

@@ -11,6 +11,8 @@ export default
 		activeSlides: Array
 		leftPeekingSlideIndex: Number
 		rightPeekingSlideIndex: Number
+		rtl: Boolean
+		dimensionsKnown: Number
 
 	data: ->
 
@@ -109,9 +111,17 @@ export default
 		# Get the list of non-text slides, including peeking clones. This doesn't
 		# work as a computed function
 		getSlideComponents: ->
-			[...(@$slots.default || []), ...(@$slots.clones || [])]
+			slides = [...(@$slots.default || []), ...(@$slots.clones || [])]
 			.filter (vnode) -> !vnode.text
 
+			# Reverses the slide if rtl and if the dimensions are known. This
+			# second condition exists to prevent the reversal from happening on SSR.
+			# Which is important because this logic is paired with setting the
+			# intial index to the last page which can't be known until the slide
+			# width is known.
+			if @rtl and @dimensionsKnown then slides = slides.reverse()
+			return slides
+
 		# Makes a clone of the vnode properties we'll be updating so the changes
 		# get rendered. Based on:
 		# /~https://github.com/vuejs/vue/issues/6052#issuecomment-313705168
@@ -161,7 +171,6 @@ export default
 
 	# Render the track and slotted slides
 	render: (create) ->
-
 		create @trackHTMLElement,
 			attrs: {role: "tablist" if @renderAsTablist}
 			class: [ 'ssr-carousel-track', { @dragging } ]

src/ssr-carousel.vue

@@ -41,6 +41,8 @@
 					activeSlides,
 					leftPeekingSlideIndex,
 					rightPeekingSlideIndex,
+					rtl,
+					dimensionsKnown,
 				}`)
 
 				//- Render the slotted slides
@@ -52,7 +54,7 @@
 		//- Back / Next navigation
 		ssr-carousel-arrows(
 			v-if='showArrows'
-			v-bind='{ index, pages, shouldLoop, pageLabel }'
+			v-bind='{ index, pages, shouldLoop, pageLabel, rtl }'
 			@back='back'
 			@next='next')
 			template(#back='props'): slot(name='back-arrow' v-bind='props')
@@ -61,7 +63,7 @@
 	//- Dots navigation
 	ssr-carousel-dots(
 		v-if='showDots'
-		v-bind='{ boundedIndex, pages, pageLabel }'
+		v-bind='{ boundedIndex, pages, pageLabel, rtl }'
 		@goto='gotoDot')
 		template(#dot='props'): slot(name='dot' v-bind='props')
 
@@ -92,6 +94,7 @@ import looping from './concerns/looping'
 import pagination from './concerns/pagination'
 import peeking from './concerns/peeking'
 import responsive from './concerns/responsive'
+import rtl from './concerns/rtl'
 import tweening from './concerns/tweening'
 import variableWidth from './concerns/variable-width'
 
@@ -112,6 +115,7 @@ export default
 		pagination
 		responsive
 		peeking # After `responsive` so prop can access `gutter` prop
+		rtl
 		tweening
 		variableWidth
 	]
@@ -166,6 +170,9 @@ export default
 .ssr-carousel
 	touch-action pan-y
 
+	// Internal logic expects ltr layout
+	direction ltr
+
 // Posiition arrows relative to this
 .ssr-carousel-slides
 	position relative