added QR code generation

frontend/app.js

@@ -277,6 +277,7 @@ function noteApp() {
         showShareModal: false,
         shareInfo: null,
         shareLoading: false,
+        showShareQR: false,
         shareLinkCopied: false,
         _sharedNotePaths: new Set(),  // O(1) lookup for shared note indicators
         
@@ -5378,13 +5379,40 @@ function noteApp() {
             this.closeQuickSwitcher();
         },
         
+        // Close share modal and reset state after animation
+        closeShareModal() {
+            this.showShareModal = false;
+            // Delay state reset until modal is fully hidden
+            setTimeout(() => {
+                this.showShareQR = false;
+                this.shareInfo = null;
+                this.shareLoading = false;
+            }, 200);
+        },
+        
+        // Generate QR code for share URL
+        generateQRCode(url) {
+            if (!url || typeof qrcode === 'undefined') return '';
+            try {
+                const qr = qrcode(0, 'M'); // 0 = auto version, M = medium error correction
+                qr.addData(url);
+                qr.make();
+                return qr.createDataURL(4); // 4 = module size in pixels
+            } catch (e) {
+                console.error('QR code generation failed:', e);
+                return '';
+            }
+        },
+        
         // Open share modal and fetch current share status
         async openShareModal() {
             if (!this.currentNote) return;
             
-            this.showShareModal = true;
+            // Reset state BEFORE showing modal to prevent flicker
-            this.shareLoading = true;
+            this.showShareQR = false;
             this.shareInfo = null;
+            this.shareLoading = true;
+            this.showShareModal = true;
             
             try {
                 const notePath = this.currentNote.replace('.md', '');

frontend/index.html

@@ -109,6 +109,8 @@
     
     <!-- vis-network for graph visualization (v9.1.9) -->
     <script src="https://unpkg.com/vis-network@9.1.9/standalone/umd/vis-network.min.js"></script>
+    <!-- QR Code generator for share links -->
+    <script src="https://cdn.jsdelivr.net/npm/qrcode-generator@1.4.4/qrcode.min.js"></script>
     
     <!-- Theme styles will be loaded dynamically -->
     <link rel="stylesheet" id="theme-stylesheet" href="">
@@ -3007,8 +3009,8 @@
 
     <!-- Share Modal -->
     <div x-show="showShareModal" 
-         @click.self="showShareModal = false"
+         @click.self="closeShareModal()"
-         @keydown.escape.window="showShareModal && (showShareModal = false)"
+         @keydown.escape.window="showShareModal && closeShareModal()"
          class="fixed inset-0 flex items-center justify-center"
          style="background-color: rgba(0, 0, 0, 0.5); z-index: 1100;"
          x-cloak>
@@ -3073,6 +3075,36 @@
                     </button>
                 </div>
                 
+                <!-- QR Code -->
+                <div class="mb-4 flex flex-col items-center">
+                    <button 
+                        @click="showShareQR = !showShareQR"
+                        class="text-sm flex items-center gap-1 mb-2 transition-colors"
+                        style="color: var(--text-secondary);"
+                        onmouseover="this.style.color='var(--text-primary)'"
+                        onmouseout="this.style.color='var(--text-secondary)'"
+                    >
+                        <svg class="w-4 h-4" fill="none" stroke="currentColor" viewBox="0 0 24 24">
+                            <path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M12 4v1m6 11h2m-6 0h-2v4m0-11v3m0 0h.01M12 12h4.01M16 20h4M4 12h4m12 0h.01M5 8h2a1 1 0 001-1V5a1 1 0 00-1-1H5a1 1 0 00-1 1v2a1 1 0 001 1zm12 0h2a1 1 0 001-1V5a1 1 0 00-1-1h-2a1 1 0 00-1 1v2a1 1 0 001 1zM5 20h2a1 1 0 001-1v-2a1 1 0 00-1-1H5a1 1 0 00-1 1v2a1 1 0 001 1z"></path>
+                        </svg>
+                        <span x-text="showShareQR ? t('share.hide_qr') : t('share.show_qr')"></span>
+                        <svg class="w-3 h-3 transition-transform" :class="showShareQR ? 'rotate-180' : ''" fill="none" stroke="currentColor" viewBox="0 0 24 24">
+                            <path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M19 9l-7 7-7-7"></path>
+                        </svg>
+                    </button>
+                    <div x-show="showShareQR" 
+                         x-transition:enter="transition ease-out duration-200"
+                         x-transition:enter-start="opacity-0 transform scale-95"
+                         x-transition:enter-end="opacity-100 transform scale-100"
+                         x-transition:leave="transition ease-in duration-150"
+                         x-transition:leave-start="opacity-100 transform scale-100"
+                         x-transition:leave-end="opacity-0 transform scale-95"
+                         class="p-3 rounded-lg" 
+                         style="background-color: white;">
+                        <img :src="generateQRCode(shareInfo?.url)" alt="QR Code" class="w-32 h-32" />
+                    </div>
+                </div>
+                
                 <!-- Revoke sharing -->
                 <button 
                     @click="revokeShareLink()"
@@ -3088,7 +3120,7 @@
             <!-- Close button -->
             <div class="mt-4 pt-4 border-t" style="border-color: var(--border-primary);">
                 <button 
-                    @click="showShareModal = false"
+                    @click="closeShareModal()"
                     class="w-full px-4 py-2 rounded font-medium transition-colors"
                     style="background-color: var(--bg-tertiary); color: var(--text-primary);"
                     onmouseover="this.style.backgroundColor='var(--bg-hover)'"

locales/de-DE.json

@@ -127,7 +127,9 @@
     "stop_sharing": "Freigabe beenden",
     "confirm_revoke": "Sind Sie sicher, dass Sie die Freigabe dieser Notiz beenden möchten? Der Freigabelink funktioniert dann nicht mehr.",
     "error_creating": "Fehler beim Erstellen des Freigabelinks: {{error}}",
-    "error_revoking": "Fehler beim Widerrufen des Freigabelinks: {{error}}"
+    "error_revoking": "Fehler beim Widerrufen des Freigabelinks: {{error}}",
+    "show_qr": "QR-Code anzeigen",
+    "hide_qr": "QR-Code ausblenden"
   },
 
   "quick_switcher": {

locales/en-GB.json

@@ -126,7 +126,9 @@
     "stop_sharing": "Stop Sharing",
     "confirm_revoke": "Are you sure you want to stop sharing this note? The share link will no longer work.",
     "error_creating": "Failed to create share link: {{error}}",
-    "error_revoking": "Failed to revoke share link: {{error}}"
+    "error_revoking": "Failed to revoke share link: {{error}}",
+    "show_qr": "Show QR Code",
+    "hide_qr": "Hide QR Code"
   },
 
   "quick_switcher": {

locales/en-US.json

@@ -127,7 +127,9 @@
     "stop_sharing": "Stop Sharing",
     "confirm_revoke": "Are you sure you want to stop sharing this note? The share link will no longer work.",
     "error_creating": "Failed to create share link: {{error}}",
-    "error_revoking": "Failed to revoke share link: {{error}}"
+    "error_revoking": "Failed to revoke share link: {{error}}",
+    "show_qr": "Show QR Code",
+    "hide_qr": "Hide QR Code"
   },
 
   "quick_switcher": {

locales/es-ES.json

@@ -127,7 +127,9 @@
     "stop_sharing": "Dejar de compartir",
     "confirm_revoke": "¿Estás seguro de que quieres dejar de compartir esta nota? El enlace dejará de funcionar.",
     "error_creating": "Error al crear el enlace: {{error}}",
-    "error_revoking": "Error al revocar el enlace: {{error}}"
+    "error_revoking": "Error al revocar el enlace: {{error}}",
+    "show_qr": "Mostrar código QR",
+    "hide_qr": "Ocultar código QR"
   },
 
   "quick_switcher": {

locales/fr-FR.json

@@ -127,7 +127,9 @@
     "stop_sharing": "Arrêter le partage",
     "confirm_revoke": "Êtes-vous sûr de vouloir arrêter le partage de cette note ? Le lien ne fonctionnera plus.",
     "error_creating": "Échec de la création du lien : {{error}}",
-    "error_revoking": "Échec de la révocation du lien : {{error}}"
+    "error_revoking": "Échec de la révocation du lien : {{error}}",
+    "show_qr": "Afficher le code QR",
+    "hide_qr": "Masquer le code QR"
   },
 
   "quick_switcher": {

locales/it-IT.json

@@ -126,7 +126,9 @@
     "stop_sharing": "Interrompi condivisione",
     "confirm_revoke": "Sei sicuro di voler interrompere la condivisione di questa nota? Il link non funzionerà più.",
     "error_creating": "Impossibile creare il link: {{error}}",
-    "error_revoking": "Impossibile revocare il link: {{error}}"
+    "error_revoking": "Impossibile revocare il link: {{error}}",
+    "show_qr": "Mostra codice QR",
+    "hide_qr": "Nascondi codice QR"
   },
 
   "quick_switcher": {

locales/ja-JP.json

@@ -126,7 +126,9 @@
     "stop_sharing": "共有を停止",
     "confirm_revoke": "このノートの共有を停止してもよろしいですか？共有リンクは機能しなくなります。",
     "error_creating": "共有リンクの作成に失敗しました: {{error}}",
-    "error_revoking": "共有リンクの取り消しに失敗しました: {{error}}"
+    "error_revoking": "共有リンクの取り消しに失敗しました: {{error}}",
+    "show_qr": "QRコードを表示",
+    "hide_qr": "QRコードを非表示"
   },
 
   "quick_switcher": {

locales/ru-RU.json

@@ -126,7 +126,9 @@
     "stop_sharing": "Прекратить доступ",
     "confirm_revoke": "Вы уверены, что хотите прекратить доступ к этой заметке? Ссылка перестанет работать.",
     "error_creating": "Не удалось создать ссылку: {{error}}",
-    "error_revoking": "Не удалось отозвать ссылку: {{error}}"
+    "error_revoking": "Не удалось отозвать ссылку: {{error}}",
+    "show_qr": "Показать QR-код",
+    "hide_qr": "Скрыть QR-код"
   },
 
   "quick_switcher": {

locales/sl-SI.json

@@ -126,7 +126,9 @@
     "stop_sharing": "Prenehaj deliti",
     "confirm_revoke": "Ali ste prepričani, da želite prenehati deliti ta zapis? Povezava ne bo več delovala.",
     "error_creating": "Napaka pri ustvarjanju povezave: {{error}}",
-    "error_revoking": "Napaka pri preklicu povezave: {{error}}"
+    "error_revoking": "Napaka pri preklicu povezave: {{error}}",
+    "show_qr": "Prikaži QR kodo",
+    "hide_qr": "Skrij QR kodo"
   },
 
   "quick_switcher": {

locales/zh-CN.json

@@ -126,7 +126,9 @@
     "stop_sharing": "停止分享",
     "confirm_revoke": "您确定要停止分享此笔记吗？分享链接将不再有效。",
     "error_creating": "创建分享链接失败：{{error}}",
-    "error_revoking": "撤销分享链接失败：{{error}}"
+    "error_revoking": "撤销分享链接失败：{{error}}",
+    "show_qr": "显示二维码",
+    "hide_qr": "隐藏二维码"
   },
 
   "quick_switcher": {