From 1564d96b0168c2acc4146b4163f76cdf43280ae2 Mon Sep 17 00:00:00 2001
From: Juergen <juergen@localhost>
Date: Mon, 13 Apr 2026 22:18:45 +0200
Subject: [PATCH] fix: polish initial flipbook reveal and update third-party
 metadata

---
 THIRD_PARTY_LICENSES.md                       |  2 +-
 .../blatterbares_pdf.html.twig                | 12 +++---
 public/assets/flipbook-module.css             | 31 ++++++++++++++
 public/assets/flipbook-module.js              | 41 +++++++++++++++++++
 4 files changed, 79 insertions(+), 7 deletions(-)

diff --git a/THIRD_PARTY_LICENSES.md b/THIRD_PARTY_LICENSES.md
index 949c6a0..766861e 100644
--- a/THIRD_PARTY_LICENSES.md
+++ b/THIRD_PARTY_LICENSES.md
@@ -6,7 +6,7 @@ This bundle contains the following third-party open source libraries in `public/
 
 - Project: https://github.com/mozilla/pdf.js
 - Package: `pdfjs-dist`
-- Version: `4.9.155`
+- Version: `5.6.205`
 - License: Apache-2.0
 
 ## flipbook-js
diff --git a/contao/templates/content_element/blatterbares_pdf.html.twig b/contao/templates/content_element/blatterbares_pdf.html.twig
index 5e37380..11101f4 100644
--- a/contao/templates/content_element/blatterbares_pdf.html.twig
+++ b/contao/templates/content_element/blatterbares_pdf.html.twig
@@ -1,7 +1,7 @@
 {% set hasPdf = pdfUrl|default('') is not empty %}
 
 <div
-    class="ce-blatterbares-pdf mod-pdf-flipbook"
+    class="ce-blatterbares-pdf mod-pdf-flipbook is-loading"
     data-pdf-flipbook-element="1"
     data-pdf-url="{{ pdfUrl|default('')|e('html_attr') }}"
     data-initial-pages="{{ initialRenderPages|default(4)|e('html_attr') }}"
@@ -12,12 +12,12 @@
 >
     <div class="mod-pdf-flipbook__status" data-flipbook-loader="1" aria-live="polite">PDF wird geladen ...</div>
 
-    <div class="mod-pdf-flipbook__stage" data-flipbook-stage="1">
+    <div class="mod-pdf-flipbook__stage" data-flipbook-stage="1" style="visibility:hidden;opacity:0">
         <div id="flipbook-{{ data.id|default(random()) }}" class="c-flipbook" data-flipbook-book="1"></div>
     </div>
 
     {% if showNavigation %}
-        <div class="mod-pdf-flipbook__controls" aria-label="Flipbook Navigation">
+        <div class="mod-pdf-flipbook__controls" data-flipbook-controls="1" aria-label="Flipbook Navigation" style="visibility:hidden;opacity:0">
             <button type="button" data-flipbook-prev="1">Zurück</button>
             <button type="button" data-flipbook-next="1">Weiter</button>
         </div>
@@ -28,6 +28,6 @@
     {% endif %}
 </div>
 
-<link rel="stylesheet" href="/bundles/flipbook/assets/vendor/flipbook.min.css?v=20260414f">
-<link rel="stylesheet" href="/bundles/flipbook/assets/flipbook-module.css?v=20260414f">
-<script type="module" src="/bundles/flipbook/assets/flipbook-module.js?v=20260414f"></script>
+<link rel="stylesheet" href="/bundles/flipbook/assets/vendor/flipbook.min.css?v=20260414j">
+<link rel="stylesheet" href="/bundles/flipbook/assets/flipbook-module.css?v=20260414j">
+<script type="module" src="/bundles/flipbook/assets/flipbook-module.js?v=20260414j"></script>
diff --git a/public/assets/flipbook-module.css b/public/assets/flipbook-module.css
index 003a323..8cabf40 100644
--- a/public/assets/flipbook-module.css
+++ b/public/assets/flipbook-module.css
@@ -13,11 +13,24 @@
 }
 
 .mod-pdf-flipbook__status {
+    display: inline-flex;
+    align-items: center;
+    gap: 0.55rem;
     margin-bottom: 0.8rem;
     font-size: 0.92rem;
     color: var(--flipbook-text);
 }
 
+.mod-pdf-flipbook__status::before {
+    content: '';
+    width: 0.9rem;
+    height: 0.9rem;
+    border: 2px solid rgba(48, 45, 41, 0.25);
+    border-top-color: rgba(48, 45, 41, 0.85);
+    border-radius: 50%;
+    animation: mod-pdf-flipbook-spin 0.75s linear infinite;
+}
+
 .mod-pdf-flipbook__status.is-hidden {
     display: none;
 }
@@ -26,18 +39,29 @@
     color: #9f1f1f;
 }
 
+.mod-pdf-flipbook__status.is-error::before {
+    display: none;
+}
+
 .mod-pdf-flipbook__stage {
     position: relative;
     width: 100%;
     margin: 0 auto;
     background: #e0e0e0;
     z-index: 1;
+    transition: opacity 1.3s ease 0.5s;
 }
 
 .mod-pdf-flipbook .c-flipbook {
     max-width: 100%;
 }
 
+.mod-pdf-flipbook .c-flipbook.is-booting,
+.mod-pdf-flipbook .c-flipbook.is-booting .c-flipbook__page,
+.mod-pdf-flipbook .c-flipbook.is-booting .c-flipbook__page::before {
+    transition: none !important;
+}
+
 .mod-pdf-flipbook .c-flipbook__page {
     background: #fefdf9;
     overflow: hidden;
@@ -73,6 +97,7 @@
     display: flex;
     gap: 0.6rem;
     margin-top: 0.9rem;
+    transition: opacity 1.3s ease 0.5s;
 }
 
 .mod-pdf-flipbook__error {
@@ -85,3 +110,9 @@
         justify-content: space-between;
     }
 }
+
+@keyframes mod-pdf-flipbook-spin {
+    to {
+        transform: rotate(360deg);
+    }
+}
diff --git a/public/assets/flipbook-module.js b/public/assets/flipbook-module.js
index c8c2d36..2bb44a7 100644
--- a/public/assets/flipbook-module.js
+++ b/public/assets/flipbook-module.js
@@ -36,6 +36,8 @@ class PdfFlipbookModule {
         this.root = root;
         this.dependencies = dependencies;
         this.pdfUrl = (root.dataset.pdfUrl || '').trim();
+        this.root.classList.add('is-loading');
+        this.root.classList.remove('is-ready');
         this.initialPages = Number.isFinite(parsedInitialPages)
             ? Math.min(4, Math.max(2, parsedInitialPages))
             : 4;
@@ -47,6 +49,7 @@ class PdfFlipbookModule {
         this.loader = root.querySelector('[data-flipbook-loader="1"]');
         this.stage = root.querySelector('[data-flipbook-stage="1"]');
         this.bookElement = root.querySelector('[data-flipbook-book="1"]');
+        this.controlsElement = root.querySelector('[data-flipbook-controls="1"]');
         this.nextButton = this.showNavigation ? root.querySelector('[data-flipbook-next="1"]') : null;
         this.prevButton = this.showNavigation ? root.querySelector('[data-flipbook-prev="1"]') : null;
 
@@ -76,6 +79,7 @@ class PdfFlipbookModule {
 
         if (!this.pdfUrl) {
             this.setStatus('Keine PDF-Datei gefunden.', true);
+            this.root.classList.remove('is-loading');
 
             return;
         }
@@ -94,12 +98,47 @@ class PdfFlipbookModule {
             this.bindTouchSwipe();
             this.bindResize();
             this.queuePages(this.getLazyCandidates());
+            await this.showReadyState();
             this.setStatus('');
         } catch {
             this.setStatus('PDF konnte nicht geladen werden.', true);
+            this.root.classList.remove('is-loading');
         }
     }
 
+    async showReadyState() {
+        await new Promise((resolve) => {
+            window.requestAnimationFrame(() => {
+                window.requestAnimationFrame(resolve);
+            });
+        });
+
+        if (this.bookElement) {
+            this.bookElement.classList.remove('is-booting');
+        }
+
+        this.root.classList.remove('is-loading');
+        this.root.classList.add('is-ready');
+
+        if (this.stage) {
+            this.stage.style.visibility = 'visible';
+        }
+
+        if (this.controlsElement) {
+            this.controlsElement.style.visibility = 'visible';
+        }
+
+        window.requestAnimationFrame(() => {
+            if (this.stage) {
+                this.stage.style.opacity = '1';
+            }
+
+            if (this.controlsElement) {
+                this.controlsElement.style.opacity = '1';
+            }
+        });
+    }
+
     async loadPdf() {
         const loadingTask = this.dependencies.pdfjsLib.getDocument({
             url: this.pdfUrl,
@@ -178,6 +217,8 @@ class PdfFlipbookModule {
     initializeFlipbook() {
         const startsWithDoubleSpread = this.startMode === 'spread';
 
+        this.bookElement.classList.add('is-booting');
+
         this.flipbook = new this.dependencies.FlipBook(this.bookElement, {
             nextButton: this.nextButton,
             previousButton: this.prevButton,