Support lightbox gallery navigation via arrow buttons and keyboard

src/components/media_modal/media_modal.js

@@ -11,27 +11,62 @@ const MediaModal = {
     showing () {
       return this.$store.state.mediaViewer.activated
     },
+    media () {
+      return this.$store.state.mediaViewer.media
+    },
     currentIndex () {
       return this.$store.state.mediaViewer.currentIndex
     },
     currentMedia () {
-      return this.$store.state.mediaViewer.media[this.currentIndex]
+      return this.media[this.currentIndex]
+    },
+    canNavigate () {
+      return this.media.length > 1
     },
     type () {
       return this.currentMedia ? fileTypeService.fileType(this.currentMedia.mimetype) : null
     }
   },
-  created () {
-    document.addEventListener('keyup', e => {
-      if (e.keyCode === 27 && this.showing) { // escape
-        this.hide()
-      }
-    })
-  },
   methods: {
     hide () {
       this.$store.dispatch('closeMediaViewer')
+    },
+    goPrev () {
+      if (this.canNavigate) {
+        const prevIndex = this.currentIndex === 0 ? this.media.length - 1 : (this.currentIndex - 1)
+        this.$store.dispatch('setCurrent', this.media[prevIndex])
+      }
+    },
+    goNext () {
+      if (this.canNavigate) {
+        const nextIndex = this.currentIndex === this.media.length - 1 ? 0 : (this.currentIndex + 1)
+        this.$store.dispatch('setCurrent', this.media[nextIndex])
+      }
+    },
+    handleKeyupEvent (e) {
+      if (this.showing && e.keyCode === 27) { // escape
+        this.hide()
+      }
+    },
+    handleKeydownEvent (e) {
+      if (!this.showing) {
+        return
+      }
+
+      if (e.keyCode === 39) { // arrow right
+        this.goNext()
+      } else if (e.keyCode === 37) { // arrow left
+        this.goPrev()
+      }
     }
+  },
+  mounted () {
+    document.addEventListener('keyup', this.handleKeyupEvent)
+    document.addEventListener('keydown', this.handleKeydownEvent)
+  },
+  destroyed () {
+    document.removeEventListener('keyup', this.handleKeyupEvent)
+    document.removeEventListener('keydown', this.handleKeydownEvent)
   }
 }