From b5d855d1174711aabdc206a90f1c95fac489f997 Mon Sep 17 00:00:00 2001
From: Benjamin Admin <benjaminadmin@MacBookPro.fritz.box>
Date: Fri, 27 Mar 2026 21:57:23 +0100
Subject: [PATCH] =?UTF-8?q?feat:=20Presenter=20Vor/Zur=C3=BCck-Spulen=20mi?=
 =?UTF-8?q?t=20Folien-Sync?=
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- prevSlide() in usePresenterMode: springt zur vorherigen Folie,
  stoppt aktuelle Audio, startet Präsentation der vorherigen Folie
- SkipBack Button in PresenterOverlay neben SkipForward
- Beide Buttons springen zur korrekten Folie UND starten die Audio

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
---
 pitch-deck/components/PitchDeck.tsx              |  1 +
 .../components/presenter/PresenterOverlay.tsx    | 13 ++++++++++++-
 pitch-deck/lib/hooks/usePresenterMode.ts         | 16 ++++++++++++++++
 3 files changed, 29 insertions(+), 1 deletion(-)

diff --git a/pitch-deck/components/PitchDeck.tsx b/pitch-deck/components/PitchDeck.tsx
index 446ae5b..5966569 100644
--- a/pitch-deck/components/PitchDeck.tsx
+++ b/pitch-deck/components/PitchDeck.tsx
@@ -251,6 +251,7 @@ export default function PitchDeck({ lang, onToggleLanguage }: PitchDeckProps) {
         onResume={presenter.resume}
         onStop={presenter.stop}
         onSkip={presenter.skipSlide}
+        onPrev={presenter.prevSlide}
         isSpeaking={presenter.isSpeaking}
         ttsAvailable={presenter.ttsAvailable}
         ttsEnabled={presenter.ttsEnabled}
diff --git a/pitch-deck/components/presenter/PresenterOverlay.tsx b/pitch-deck/components/presenter/PresenterOverlay.tsx
index e9d7384..d5867b6 100644
--- a/pitch-deck/components/presenter/PresenterOverlay.tsx
+++ b/pitch-deck/components/presenter/PresenterOverlay.tsx
@@ -1,7 +1,7 @@
 'use client'
 
 import { motion, AnimatePresence } from 'framer-motion'
-import { Play, Pause, Square, SkipForward, Volume2, VolumeX } from 'lucide-react'
+import { Play, Pause, Square, SkipForward, SkipBack, Volume2, VolumeX } from 'lucide-react'
 import { Language } from '@/lib/types'
 import { PresenterState } from '@/lib/presenter/types'
 import { SLIDE_ORDER } from '@/lib/hooks/useSlideNavigation'
@@ -18,6 +18,7 @@ interface PresenterOverlayProps {
   onResume: () => void
   onStop: () => void
   onSkip: () => void
+  onPrev?: () => void
   isSpeaking?: boolean
   ttsAvailable?: boolean
   ttsEnabled?: boolean
@@ -35,6 +36,7 @@ export default function PresenterOverlay({
   onResume,
   onStop,
   onSkip,
+  onPrev,
   isSpeaking,
   ttsAvailable,
   ttsEnabled = true,
@@ -108,6 +110,15 @@ export default function PresenterOverlay({
                       </button>
                     )}
 
+                    <button
+                      onClick={onPrev}
+                      className="w-7 h-7 rounded-full bg-white/10 flex items-center justify-center
+                        hover:bg-white/20 transition-colors"
+                      title={lang === 'de' ? 'Vorherige Folie' : 'Previous slide'}
+                    >
+                      <SkipBack className="w-3.5 h-3.5 text-white/60" />
+                    </button>
+
                     <button
                       onClick={onSkip}
                       className="w-7 h-7 rounded-full bg-white/10 flex items-center justify-center
diff --git a/pitch-deck/lib/hooks/usePresenterMode.ts b/pitch-deck/lib/hooks/usePresenterMode.ts
index f76cc43..cc30124 100644
--- a/pitch-deck/lib/hooks/usePresenterMode.ts
+++ b/pitch-deck/lib/hooks/usePresenterMode.ts
@@ -22,6 +22,7 @@ interface UsePresenterModeReturn {
   pause: () => void
   resume: () => void
   skipSlide: () => void
+  prevSlide: () => void
   toggle: () => void
   displayText: string
   progress: number
@@ -386,6 +387,20 @@ export function usePresenterMode({
     }
   }, [cancelAll, totalSlides, goToSlide])
 
+  const prevSlide = useCallback(() => {
+    cancelAll()
+    const prevIdx = slideIndexRef.current - 1
+    if (prevIdx >= 0) {
+      goToSlide(prevIdx)
+      slideIndexRef.current = prevIdx
+      if (stateRef.current === 'presenting' || stateRef.current === 'paused') {
+        setState('presenting')
+        stateRef.current = 'presenting'
+        playSlideRef.current(prevIdx)
+      }
+    }
+  }, [cancelAll, goToSlide])
+
   const toggle = useCallback(() => {
     unlockAudio()
     if (stateRef.current === 'idle') {
@@ -422,6 +437,7 @@ export function usePresenterMode({
     pause,
     resume,
     skipSlide,
+    prevSlide,
     toggle,
     displayText,
     progress,