improve image preview

app.py

@@ -542,7 +542,12 @@ def list_directory_contents(directory, subpath):
     music_exts = ('.mp3',)
     image_exts = ('.jpg', '.jpeg', '.png', '.gif', '.bmp')
     
-    blocked_filenames = ['Thumbs.db', '*.mrk']
+    blocked_filenames = [
+        'Thumbs.db',
+        '*.mrk',
+        '*.arw', '*.cr2', '*.lrf'
+    ]
+
 
     try:
         with os.scandir(directory) as it:

static/app.js

@@ -3,6 +3,44 @@ let currentMusicFiles = []; // Array of objects with at least { path, index }
 let currentMusicIndex = -1; // Index of the current music file
 let currentTrackPath  = "";
 
+// Check thumb availability in parallel; sequentially generate missing ones to avoid concurrent creation.
+function ensureFirstFivePreviews() {
+  const images = Array.from(document.querySelectorAll('.images-grid img')).slice(0, 5);
+  if (!images.length) return;
+
+  const checks = images.map(img => {
+    const thumbUrl = img.dataset.thumbUrl || img.src;
+    const fullUrl = img.dataset.fullUrl;
+    return fetch(thumbUrl, { method: 'GET', cache: 'no-store' })
+      .then(res => ({
+        img,
+        thumbUrl,
+        fullUrl,
+        hasThumb: res.ok && res.status !== 204
+      }))
+      .catch(() => ({ img, thumbUrl, fullUrl, hasThumb: false }));
+  });
+
+  Promise.all(checks).then(results => {
+    const missing = results.filter(r => !r.hasThumb && r.fullUrl);
+    if (!missing.length) return;
+    generateThumbsSequentially(missing);
+  });
+}
+
+async function generateThumbsSequentially(entries) {
+  for (const { img, thumbUrl, fullUrl } of entries) {
+    try {
+      await fetch(fullUrl, { method: 'GET', cache: 'no-store' });
+      const cacheBust = `_=${Date.now()}`;
+      const separator = thumbUrl.includes('?') ? '&' : '?';
+      img.src = `${thumbUrl}${separator}${cacheBust}`;
+    } catch (e) {
+      // ignore; best effort
+    }
+  }
+}
+
 // Cache common DOM elements
 const mainContainer = document.querySelector('main');
 const searchContainer = document.querySelector('search');
@@ -61,17 +99,20 @@ function renderContent(data) {
   });
   document.getElementById('breadcrumbs').innerHTML = breadcrumbHTML;
 
+  const imageFiles = data.files.filter(file => file.file_type === 'image');
+  const nonImageFiles = data.files.filter(file => file.file_type !== 'image');
+
   // Check for image-only directory (no subdirectories, at least one file, all images)
   const isImageOnly = data.directories.length === 0
-    && data.files.length > 0
+    && imageFiles.length > 0
-    && data.files.every(file => file.file_type === 'image');
+    && nonImageFiles.length === 0;
 
   let contentHTML = '';
 
   if (isImageOnly) {
     // Display thumbnails grid
     contentHTML += '<div class="images-grid">';
-    data.files.forEach(file => {
+    imageFiles.forEach(file => {
       const thumbUrl = `${file.path}?thumbnail=true`;
       contentHTML += `
         <div class="image-item">
@@ -81,6 +122,8 @@ function renderContent(data) {
              data-file-type="${file.file_type}">
             <img
               src="/media/${thumbUrl}"
+              data-thumb-url="/media/${thumbUrl}"
+              data-full-url="/media/${file.path}"
               class="thumbnail"
               onload="this.closest('.image-item').classList.add('loaded')"
             />
@@ -138,9 +181,9 @@ function renderContent(data) {
 
     // Render files (including music and non-image files)
     currentMusicFiles = [];
-    if (data.files.length > 0) {
+    if (nonImageFiles.length > 0) {
       contentHTML += '<ul>';
-      data.files.forEach((file, idx) => {
+      nonImageFiles.forEach((file, idx) => {
         let symbol = '📄';
         if (file.file_type === 'music') {
           symbol = '🔊';
@@ -158,6 +201,32 @@ function renderContent(data) {
       });
       contentHTML += '</ul>';
     }
+
+    // Show images in preview grid after the file list
+    if (imageFiles.length > 0) {
+      contentHTML += '<div class="images-grid">';
+      imageFiles.forEach(file => {
+        const thumbUrl = `${file.path}?thumbnail=true`;
+        contentHTML += `
+          <div class="image-item">
+            
+            <a href="#" class="play-file image-link"
+               data-url="${file.path}"
+               data-file-type="${file.file_type}">
+              <img
+                src="/media/${thumbUrl}"
+                data-thumb-url="/media/${thumbUrl}"
+                data-full-url="/media/${file.path}"
+                class="thumbnail"
+                onload="this.closest('.image-item').classList.add('loaded')"
+              />
+            </a>
+            <span class="file-name">${file.name}</span>
+          </div>
+        `;
+      });
+      contentHTML += '</div>';
+    }
   }
 
   // Insert generated content
@@ -174,7 +243,7 @@ function renderContent(data) {
   });
 
   // Attach event listeners for file items (including images)
-  if (isImageOnly) {
+  if (isImageOnly || imageFiles.length > 0) {
     document.querySelectorAll('.image-item').forEach(item => {
       item.addEventListener('click', function(e) {
         if (!e.target.closest('a')) {
@@ -195,9 +264,8 @@ function renderContent(data) {
   }
 
   // Update gallery images for lightbox or similar
-  currentGalleryImages = data.files
+  currentGalleryImages = imageFiles.map(f => f.path);
-    .filter(f => f.file_type === 'image')
+  ensureFirstFivePreviews();
-    .map(f => f.path);
 
   attachEventListeners();
 }