Merge pull request 'Making still-image better' (#341) from Mergan/pleroma-fe:still-image-ultimate into develop

Reviewed-on: https://akkoma.dev/AkkomaGang/akkoma-fe/pulls/341

src/components/still-image/still-image.js

@@ -13,6 +13,7 @@ const StillImage = {
     return {
       stopGifs: this.$store.getters.mergedConfig.stopGifs || window.matchMedia('(prefers-reduced-motion: reduce)').matches,
       isAnimated: false,
+      imageTypeLabel: ''
     }
   },
   computed: {
@@ -39,27 +40,22 @@ const StillImage = {
       this.imageLoadError && this.imageLoadError()
     },
     detectAnimation (image) {
-      // If there are no file extensions, the mimetype isn't set, and no mediaproxy is available, we can't figure out
-      // the mimetype of the image.
-      const hasFileExtension = this.src.split('/').pop().includes('.') // TODO: Better check?
       const mediaProxyAvailable = this.$store.state.instance.mediaProxyAvailable
-      if (!hasFileExtension && this.mimetype === undefined && !mediaProxyAvailable) {
+
+      // harmless CORS errors without-- clean console with
+      if (!mediaProxyAvailable) {
         // It's a bit aggressive to assume all images we can't find the mimetype of is animated, but necessary for
         // people in need of reduced motion accessibility. As such, we'll consider those images animated if the user
         // agent is set to prefer reduced motion. Otherwise, it'll just be used as an early exit.
-        if (window.matchMedia('(prefers-reduced-motion: reduce)').matches)
+        if (window.matchMedia('(prefers-reduced-motion: reduce)').matches) {
+          // Only for no media-proxy for now, since we're capturing gif, webp, and apng (are there others?)
+          // Since the canvas and images are not pixel-perfect matching (due to scaling),
+          // It makes the images jiggle on hover, which is not ideal for accessibility, methinks
           this.isAnimated = true
+        }
         return
       }
       
-      if (this.mimetype === 'image/gif' || this.src.endsWith('.gif')) {
-        this.isAnimated = true
-        return
-      }
-      // harmless CORS errors without-- clean console with
-      if (!mediaProxyAvailable) return
-      // Animated JPEGs?
-      if (!(this.src.endsWith('.webp') || this.src.endsWith('.png'))) return
       // Browser Cache should ensure image doesn't get loaded twice if cache exists
       fetch(image.src, {
         referrerPolicy: 'same-origin'
@@ -68,12 +64,20 @@ const StillImage = {
           // We don't need to read the whole file so only call it once
           data.body.getReader().read()
             .then(reader => {
-              if (this.src.endsWith('.webp') && this.isAnimatedWEBP(reader.value)) {
+              // Ordered from least to most intensive
+              if (this.isGIF(reader.value)) {
                 this.isAnimated = true
+                this.setLabel('GIF')
                 return
               }
-              if (this.src.endsWith('.png') && this.isAnimatedPNG(reader.value)) {
+              if (this.isAnimatedWEBP(reader.value)) {
                 this.isAnimated = true
+                this.setLabel('WEBP')
+                return
+              }
+              if (this.isAnimatedPNG(reader.value)) {
+                this.isAnimated = true
+                this.setLabel('APNG')
               }
             })
         })
@@ -81,6 +85,23 @@ const StillImage = {
           // this.imageLoadError && this.imageLoadError()
         })
     },
+    setLabel (name) {
+      this.imageTypeLabel = name;
+    },
+    isGIF (data) {
+      // I am a perfectly sane individual
+      //
+      // GIF HEADER CHUNK
+      // === START HEADER ===
+      // 47 49 46 38 ("GIF8")
+      const gifHeader = [0x47, 0x49, 0x46];
+      for (let i = 0; i < 3; i++) {
+        if (data[i] !== gifHeader[i]) {
+          return false;
+        }
+      }
+      return true
+    },
     isAnimatedWEBP (data) {
       /**
        * WEBP HEADER CHUNK
@@ -115,14 +136,53 @@ const StillImage = {
       return (str.substring(0, idatPos > 0 ? idatPos : 0).indexOf('acTL') > 0)
     },
     drawThumbnail() {
-      const canvas = this.$refs.canvas
-      if (!this.$refs.canvas) return
-      const image = this.$refs.src
-      const width = image.naturalWidth
-      const height = image.naturalHeight
-      canvas.width = width
-      canvas.height = height
-      canvas.getContext('2d').drawImage(image, 0, 0, width, height)
+      const canvas = this.$refs.canvas;
+      if (!canvas) return;
+    
+      const context = canvas.getContext('2d');
+      const image = this.$refs.src;
+      const parentElement = canvas.parentElement;
+    
+      // Draw the quick, unscaled version first
+      context.drawImage(image, 0, 0, parentElement.clientWidth, parentElement.clientHeight);
+    
+      // Use requestAnimationFrame to schedule the scaling to the next frame
+      requestAnimationFrame(() => {
+        // Compute scaling ratio between the natural dimensions of the image and its display dimensions
+        const scalingRatioWidth = parentElement.clientWidth / image.naturalWidth;
+        const scalingRatioHeight = parentElement.clientHeight / image.naturalHeight;
+
+        // Adjust for high-DPI displays
+        const ratio = window.devicePixelRatio || 1;
+        canvas.width = image.naturalWidth * scalingRatioWidth * ratio;
+        canvas.height = image.naturalHeight * scalingRatioHeight * ratio;
+        canvas.style.width = `${parentElement.clientWidth}px`;
+        canvas.style.height = `${parentElement.clientHeight}px`;
+        context.scale(ratio, ratio);
+    
+        // Maintain the aspect ratio of the image
+        const imgAspectRatio = image.naturalWidth / image.naturalHeight;
+        const canvasAspectRatio = parentElement.clientWidth / parentElement.clientHeight;
+    
+        let drawWidth, drawHeight;
+    
+        if (imgAspectRatio > canvasAspectRatio) {
+          drawWidth = parentElement.clientWidth;
+          drawHeight = parentElement.clientWidth / imgAspectRatio;
+        } else {
+          drawHeight = parentElement.clientHeight;
+          drawWidth = parentElement.clientHeight * imgAspectRatio;
+        }
+    
+        context.clearRect(0, 0, canvas.width, canvas.height);  // Clear the previous unscaled image
+        context.imageSmoothingEnabled = true;
+        context.imageSmoothingQuality = 'high';
+
+        // Draw the good one for realsies
+        const dx = (parentElement.clientWidth - drawWidth) / 2;
+        const dy = (parentElement.clientHeight - drawHeight) / 2;
+        context.drawImage(image, dx, dy, drawWidth, drawHeight);
+      });
     }    
   },
   updated () {

src/components/still-image/still-image.vue

@@ -1,9 +1,15 @@
 <template>
   <div
+    ref="still-image"
     class="still-image"
     :class="{ animated: animated }"
     :style="style"
   >
+    <div
+      v-if="animated && imageTypeLabel"
+      class="image-type-label">
+        {{ imageTypeLabel }}
+    </div>
     <canvas
       v-if="animated"
       ref="canvas"
@@ -57,30 +63,26 @@
     }
   }
 
-  &.animated {
-    &::before {
-      zoom: var(--_still_image-label-scale, 1);
-      content: 'gif';
+  .image-type-label {
     position: absolute;
+    top: 0.25em;
+    left: 0.25em;
     line-height: 1;
-      font-size: 0.7em;
-      top: 0.5em;
-      left: 0.5em;
+    font-size: 0.6em;
     background: rgba(127, 127, 127, 0.5);
     color: #fff;
-      display: block;
     padding: 2px 4px;
-      border-radius: $fallback--tooltipRadius;
     border-radius: var(--tooltipRadius, $fallback--tooltipRadius);
     z-index: 2;
     visibility: var(--_still-image-label-visibility, visible);
   }
 
+  &.animated {
     &:hover canvas {
       display: none;
     }
 
-    &:hover::before {
+    &:hover .image-type-label {
       visibility: var(--_still-image-label-visibility, hidden);
     }
 

src/components/user_avatar/user_avatar.vue

@@ -33,7 +33,7 @@
   --_avatarShadowBox: var(--avatarStatusShadow);
   --_avatarShadowFilter: var(--avatarStatusShadowFilter);
   --_avatarShadowInset: var(--avatarStatusShadowInset);
-  --_still-image-label-visibility: hidden;
+  // --_still-image-label-visibility: hidden;
 
   display: inline-block;
   position: relative;