Adding support to the docs for an image carousel

docs/syntax/images.md

@@ -114,3 +114,46 @@ image::images/metrics-alert-filters-and-group.png[Metric threshold filter and gr
 ```asciidoc
 image::images/synthetics-get-started-projects.png[]
 ```
+
+## Image carousel
+
+The image carousel directive builds upon the image directive.
+
+```markdown
+::::{carousel}
+
+:id: nested-carousel-example
+:controls: true
+:indicators: true
+:fixed-height: 350px
+
+:::{image} images/apm.png
+:alt: First image description
+:title: First image title
+:::
+
+:::{image} images/applies.png
+:alt: Second image description
+:title: Second image title
+:::
+
+::::
+```
+::::{carousel}
+
+:id: nested-carousel-example
+:controls: true
+:indicators: true
+:fixed-height: 350px
+
+:::{image} images/apm.png
+:alt: First image description
+:title: First image title
+:::
+
+:::{image} images/applies.png
+:alt: Second image description
+:title: Second image title
+:::
+
+::::

src/Elastic.Documentation.Site/Assets/image-carousel.ts

@@ -0,0 +1,350 @@
+class ImageCarousel {
+    private container: HTMLElement
+    private slides: HTMLElement[]
+    private indicators: HTMLElement[]
+    private prevButton: HTMLElement | null
+    private nextButton: HTMLElement | null
+    private currentIndex: number = 0
+    private touchStartX: number = 0
+    private touchEndX: number = 0
+
+    constructor(containerId: string) {
+        this.container = document.getElementById(containerId)!
+        if (!this.container) {
+            console.warn(
+                `Carousel container with ID "${containerId}" not found`
+            )
+            return
+        }
+
+        this.slides = Array.from(
+            this.container.querySelectorAll('.carousel-slide')
+        )
+        this.indicators = Array.from(
+            this.container.querySelectorAll('.carousel-indicator')
+        )
+        this.prevButton = this.container.querySelector('.carousel-prev')
+        this.nextButton = this.container.querySelector('.carousel-next')
+
+        this.initializeSlides()
+        this.setupEventListeners()
+    }
+
+    private initializeSlides(): void {
+        // Initialize all slides as inactive
+        this.slides.forEach((slide, index) => {
+            this.setSlideState(slide, index === 0)
+        })
+
+        // Initialize indicators
+        this.indicators.forEach((indicator, index) => {
+            this.setIndicatorState(indicator, index === 0)
+        })
+    }
+
+    private setSlideState(slide: HTMLElement, isActive: boolean): void {
+        slide.setAttribute('data-active', isActive.toString())
+        slide.style.display = isActive ? 'block' : 'none'
+        slide.style.opacity = isActive ? '1' : '0'
+    }
+
+    private setIndicatorState(indicator: HTMLElement, isActive: boolean): void {
+        indicator.setAttribute('data-active', isActive.toString())
+    }
+
+    private setupEventListeners(): void {
+        // Navigation controls
+        this.prevButton?.addEventListener('click', () => this.prevSlide())
+        this.nextButton?.addEventListener('click', () => this.nextSlide())
+
+        // Indicators
+        this.indicators.forEach((indicator, index) => {
+            indicator.addEventListener('click', () => this.goToSlide(index))
+        })
+
+        // Keyboard navigation
+        document.addEventListener('keydown', (e) => {
+            if (!this.isInViewport()) return
+
+            if (e.key === 'ArrowLeft') this.prevSlide()
+            else if (e.key === 'ArrowRight') this.nextSlide()
+        })
+
+        // Touch events
+        this.container.addEventListener('touchstart', (e) => {
+            this.touchStartX = e.changedTouches[0].screenX
+        })
+
+        this.container.addEventListener('touchend', (e) => {
+            this.touchEndX = e.changedTouches[0].screenX
+            this.handleSwipe()
+        })
+    }
+
+    private prevSlide(): void {
+        const newIndex =
+            (this.currentIndex - 1 + this.slides.length) % this.slides.length
+        this.goToSlide(newIndex)
+    }
+
+    private nextSlide(): void {
+        const newIndex = (this.currentIndex + 1) % this.slides.length
+        this.goToSlide(newIndex)
+    }
+
+    private goToSlide(index: number): void {
+        // Update slides
+        this.setSlideState(this.slides[this.currentIndex], false)
+        this.setSlideState(this.slides[index], true)
+
+        // Update indicators
+        if (this.indicators.length > 0) {
+            this.setIndicatorState(this.indicators[this.currentIndex], false)
+            this.setIndicatorState(this.indicators[index], true)
+        }
+
+        this.currentIndex = index
+    }
+
+    private handleSwipe(): void {
+        const threshold = 50
+        const diff = this.touchStartX - this.touchEndX
+
+        if (Math.abs(diff) < threshold) return
+
+        if (diff > 0) this.nextSlide()
+        else this.prevSlide()
+    }
+
+    private isInViewport(): boolean {
+        const rect = this.container.getBoundingClientRect()
+        return (
+            rect.top >= 0 &&
+            rect.left >= 0 &&
+            rect.bottom <=
+                (window.innerHeight || document.documentElement.clientHeight) &&
+            rect.right <=
+                (window.innerWidth || document.documentElement.clientWidth)
+        )
+    }
+}
+
+// Export function to initialize carousels
+export function initImageCarousel(): void {
+    // Find all carousel containers
+    const carousels = document.querySelectorAll('.carousel-container')
+
+    // Process each carousel
+    carousels.forEach((carousel) => {
+        const id = carousel.id
+        if (!id) return
+
+        // Get the existing track
+        let track = carousel.querySelector('.carousel-track')
+        if (!track) {
+            track = document.createElement('div')
+            track.className = 'carousel-track'
+            carousel.appendChild(track)
+        }
+
+        // Clean up any existing slides - this prevents duplicates
+        const existingSlides = Array.from(
+            track.querySelectorAll('.carousel-slide')
+        )
+
+        // Find all image links that might be related to this carousel
+        const section = findSectionForCarousel(carousel)
+        if (!section) return
+
+        // First, collect all images we want in the carousel
+        const allImageLinks = Array.from(
+            section.querySelectorAll('a[href*="epr.elastic.co"]')
+        )
+
+        // Track URLs to prevent duplicates
+        const processedUrls = new Set()
+
+        // Process the existing slides first
+        existingSlides.forEach((slide) => {
+            const imageRef = slide.querySelector('a.carousel-image-reference')
+            if (imageRef && imageRef instanceof HTMLAnchorElement) {
+                processedUrls.add(imageRef.href)
+            }
+        })
+
+        // Find standalone images (not already in carousel slides)
+        const standaloneImages = allImageLinks.filter((img) => {
+            if (processedUrls.has(img.href)) {
+                return false // Skip if already processed
+            }
+
+            // Don't count images already in carousel slides
+            const isInCarousel = img.closest('.carousel-slide') !== null
+            if (isInCarousel) {
+                processedUrls.add(img.href)
+                return false
+            }
+
+            processedUrls.add(img.href)
+            return true
+        })
+
+        // Add the standalone images to the carousel
+        let slideIndex = existingSlides.length
+        standaloneImages.forEach((imgLink) => {
+            // Find container to hide
+            const imgContainer = findClosestContainer(imgLink, carousel)
+
+            // Create a new slide
+            const slide = document.createElement('div')
+            slide.className = 'carousel-slide'
+            slide.setAttribute('data-index', slideIndex.toString())
+            if (slideIndex === 0 && existingSlides.length === 0) {
+                slide.setAttribute('data-active', 'true')
+            }
+
+            // Create a proper carousel image reference wrapper
+            const imageRef = document.createElement('a')
+            imageRef.className = 'carousel-image-reference'
+            imageRef.href = imgLink.href
+            imageRef.target = '_blank'
+
+            // Clone the image
+            const img = imgLink.querySelector('img')
+            if (img) {
+                imageRef.appendChild(img.cloneNode(true))
+            }
+
+            slide.appendChild(imageRef)
+            track.appendChild(slide)
+
+            // Hide the original container properly
+            if (imgContainer) {
+                try {
+                    // Find the parent element that might be a paragraph or div containing the image
+                    let parent = imgContainer
+                    let maxAttempts = 3 // Don't go too far up the tree
+
+                    while (
+                        maxAttempts > 0 &&
+                        parent &&
+                        parent !== document.body
+                    ) {
+                        // If this is one of these elements, hide it
+                        if (
+                            parent.tagName === 'P' ||
+                            (parent.tagName === 'DIV' &&
+                                !parent.classList.contains(
+                                    'carousel-container'
+                                ))
+                        ) {
+                            parent.style.display = 'none'
+                            break
+                        }
+                        parent = parent.parentElement
+                        maxAttempts--
+                    }
+
+                    // If we couldn't find a suitable parent, just hide the container itself
+                    if (maxAttempts === 0) {
+                        imgContainer.style.display = 'none'
+                    }
+                } catch (e) {
+                    console.error('Failed to hide original image:', e)
+                }
+            }
+
+            slideIndex++
+        })
+
+        // Only set up controls if we have multiple slides
+        const totalSlides = track.querySelectorAll('.carousel-slide').length
+        if (totalSlides > 1) {
+            // Add controls if they don't exist
+            if (!carousel.querySelector('.carousel-prev')) {
+                const prevButton = document.createElement('button')
+                prevButton.type = 'button'
+                prevButton.className = 'carousel-control carousel-prev'
+                prevButton.setAttribute('aria-label', 'Previous slide')
+                prevButton.innerHTML = '<span aria-hidden="true">←</span>'
+                carousel.appendChild(prevButton)
+            }
+
+            if (!carousel.querySelector('.carousel-next')) {
+                const nextButton = document.createElement('button')
+                nextButton.type = 'button'
+                nextButton.className = 'carousel-control carousel-next'
+                nextButton.setAttribute('aria-label', 'Next slide')
+                nextButton.innerHTML = '<span aria-hidden="true">→</span>'
+                carousel.appendChild(nextButton)
+            }
+
+            // Add or update indicators
+            let indicators = carousel.querySelector('.carousel-indicators')
+            if (!indicators) {
+                indicators = document.createElement('div')
+                indicators.className = 'carousel-indicators'
+                carousel.appendChild(indicators)
+            } else {
+                indicators.innerHTML = '' // Clear existing indicators
+            }
+
+            for (let i = 0; i < totalSlides; i++) {
+                const indicator = document.createElement('button')
+                indicator.type = 'button'
+                indicator.className = 'carousel-indicator'
+                indicator.setAttribute('data-index', i.toString())
+                if (i === 0) {
+                    indicator.setAttribute('data-active', 'true')
+                }
+                indicator.setAttribute('aria-label', `Go to slide ${i + 1}`)
+                indicators.appendChild(indicator)
+            }
+        }
+
+        // Initialize this carousel
+        new ImageCarousel(id)
+    })
+}
+
+// Helper to find a suitable container for an image
+function findClosestContainer(
+    element: Element,
+    carousel: Element
+): Element | null {
+    let current = element
+    while (
+        current &&
+        !current.contains(carousel) &&
+        current !== document.body
+    ) {
+        // Stop at these elements
+        if (
+            current.tagName === 'P' ||
+            current.tagName === 'DIV' ||
+            current.classList.contains('carousel-container')
+        ) {
+            return current
+        }
+        current = current.parentElement!
+    }
+    return element
+}
+
+// Helper to find the section containing a carousel
+function findSectionForCarousel(carousel: Element): Element | null {
+    // Look for containing section, article, or main element
+    let section = carousel.closest(
+        'section, article, main, div.markdown-content'
+    )
+    if (!section) {
+        // Fallback to parent element
+        section = carousel.parentElement
+    }
+    return section
+}
+
+// Initialize all carousels when DOM is loaded
+document.addEventListener('DOMContentLoaded', () => {
+    initImageCarousel()
+})