Pinch/drag library photo inside polaroid & wall frame windows with export parity

The framed windows (polaroid card / wall frame opening) now take the same pinch + double-tap gestures as plain library, clamped so the photo keeps covering the mat opening, and the visible sub-rectangle is handed to the export engine so the file matches the preview.

Wall frame export also stopped crashing: on Android release an image asset resolves to a drawable *name* ('wallframe') and is flagged downloaded, so Asset.downloadAsync short-circuited and readAsStringAsync threw 'Unsupported scheme for location wallframe'. Clearing that state lets the native module copy the drawable into the cache.

src/components/Viewfinder.tsx

@@ -101,6 +101,15 @@ export interface ViewfinderHandle {
    * hardware bias change re-locks AE on some devices and flashes the preview).
    */
   flushExposureBias(): Promise<void>;
+  /**
+   * Current interactive photo reposition inside a framed library window
+   * (RETRO POLAROID / WALL FRAME): scale s (>=1) and the visible window-center
+   * as 0..1 fractions of the photo's cover plane (the area that fills the
+   * window at 1x). Null when no framed window is showing or the photo is
+   * unzoomed. App passes it to the export engine so the saved file shows
+   * exactly the crop the user framed after pinch/drag.
+   */
+  getFrameWindowZoom(): { s: number; u: number; v: number } | null;
 }
 
 const noiseEffect = Skia.RuntimeEffect.Make(`
@@ -460,6 +469,11 @@ const Viewfinder = forwardRef<ViewfinderHandle, ViewfinderProps>(function Viewfi
           }
         }
       },
+      // Library frame window (polaroid/wall) zoom, for export parity. Read
+      // live through the ref — the handle is captured once with deps [ref].
+      getFrameWindowZoom() {
+        return frameZoomRef.current;
+      },
     }),
     [ref]
   );
@@ -864,6 +878,29 @@ const Viewfinder = forwardRef<ViewfinderHandle, ViewfinderProps>(function Viewfi
     if (selectedFrame !== 'wallframe') return null;
     return wallframeLayout(vw, vh, 'contain');
   }, [selectedFrame, vw, vh]);
+  // Framed photo window (library only) whose content the user may pinch/drag:
+  // polaroid card window or wall-frame opening. Null for plain frames (their
+  // whole composition region is the photo) and for the live camera.
+  const zoomWindowRect = (): { x: number; y: number; w: number; h: number } | null => {
+    if (mode !== 'library') return null;
+    if (polaroidGeo) return polaroidGeo.window;
+    if (selectedFrame === 'wallframe' && wallGeo && wallImage) return wallGeo.window;
+    return null;
+  };
+  // Clamp pan/zoom so the photo always keeps COVERING the framed window (never
+  // drags far enough to reveal the card/mat through the transparent opening).
+  // Transform is P' = s*P + t in canvas coords; with the photo drawn over the
+  // window rect, covering means t in [(x+w)(1-s), x(1-s)] (y likewise).
+  const clampZoomToWindow = (s: number, tx: number, ty: number) => {
+    const win = zoomWindowRect();
+    if (!win) return { s, tx, ty }; // plain library/camera: unchanged
+    if (s <= 1.0001) return { s, tx: 0, ty: 0 };
+    return {
+      s,
+      tx: Math.min(win.x * (1 - s), Math.max((win.x + win.w) * (1 - s), tx)),
+      ty: Math.min(win.y * (1 - s), Math.max((win.y + win.h) * (1 - s), ty)),
+    };
+  };
   // Live feed band rect for the CAMERA preview: the photo-area that must show
   // the export-equivalent sensor crop — the ratio band region (plain frames),
   // the polaroid photo window or the wall-frame window. When present the frame
@@ -980,27 +1017,11 @@ const Viewfinder = forwardRef<ViewfinderHandle, ViewfinderProps>(function Viewfi
     if (wmDragPos) onWmPositionChange(wmDragPos.x, wmDragPos.y);
     setWmDragPos(null);
   };
-  // Library polaroid/wall returns have no pinch responder of their own — this
-  // fullscreen drag layer carries the watermark gesture there (drag = move,
-  // tap = place, lift = commit). Plain-library and camera modes reuse their
-  // existing gesture layers via the wm branches above.
-  const wmDragOverlay = (
-    <View
-      className="absolute inset-0"
-      onStartShouldSetResponder={() => true}
-      onResponderGrant={(e: any) => {
-        const t = e?.nativeEvent?.touches?.[0] ?? e?.nativeEvent;
-        placeWm(t?.pageX ?? t?.locationX ?? 0, t?.pageY ?? t?.locationY ?? 0);
-      }}
-      onResponderMove={(e: any) => {
-        const t = e?.nativeEvent?.touches?.[0] ?? e?.nativeEvent;
-        placeWm(t?.pageX ?? t?.locationX ?? 0, t?.pageY ?? t?.locationY ?? 0);
-      }}
-      onResponderRelease={() => commitWm()}
-      onResponderTerminate={() => commitWm()}
-    />
-  );
-
+  // Library framed (polaroid/wall) returns reuse the SAME responder handlers as
+  // plain library (see the framed JSX below): single-finger drags place/move
+  // the text watermark while armed, pinch + double-tap repositions the photo
+  // inside the frame window (watermark stays armed when zoomed so detail can
+  // be inspected without accidentally moving text — matching plain library).
   const onLibTouchStart = (e: any) => {
     const ts = e.nativeEvent.touches;
     if (ts.length >= 2) {
@@ -1047,11 +1068,12 @@ const Viewfinder = forwardRef<ViewfinderHandle, ViewfinderProps>(function Viewfi
       const d = Math.hypot(a.locationX - b.locationX, a.locationY - b.locationY);
       const s = clampZoom((p.s * d) / Math.max(p.d, 1));
       const k = s / p.s;
-      setLibZoom({
+      const next = clampZoomToWindow(
         s,
-        tx: p.fx - k * (p.fx - p.tx),
-        ty: p.fy - k * (p.fy - p.ty),
-      });
+        p.fx - k * (p.fx - p.tx),
+        p.fy - k * (p.fy - p.ty)
+      );
+      setLibZoom(next);
     }
   };
   const onLibTouchEnd = (e: any) => {
@@ -1075,20 +1097,26 @@ const Viewfinder = forwardRef<ViewfinderHandle, ViewfinderProps>(function Viewfi
       lastTapRef.current = null;
       setLibZoom((z) => {
         if (z.s > 1.01) return { s: 1, tx: 0, ty: 0 }; // double-tap again -> 100%
-        // Clamp the focal point into the photo's display rect (composition
-        // region under a ratio band, contain rect otherwise) so a double-tap
-        // that lands in the black letterbox cannot fling the photo away.
+        // Clamp the focal point into the photo's display rect — the framed
+        // window when one is showing (polaroid/wall), the composition region
+        // under a ratio band, or the contain rect — so a double-tap that lands
+        // in the black letterbox cannot fling the photo away.
         let fx = x;
         let fy = y;
-        const fit = regionBand
-          ? { dx: region.x, dy: region.y, dw: region.w, dh: region.h }
-          : imageFitRect;
+        const win = zoomWindowRect();
+        const fit = win
+          ? { dx: win.x, dy: win.y, dw: win.w, dh: win.h }
+          : regionBand
+            ? { dx: region.x, dy: region.y, dw: region.w, dh: region.h }
+            : imageFitRect;
         if (fit) {
           fx = Math.min(Math.max(fx, fit.dx), fit.dx + fit.dw);
           fy = Math.min(Math.max(fy, fit.dy), fit.dy + fit.dh);
         }
         const s = 2.5;
-        return { s, tx: fx - s * fx, ty: fy - s * fy }; // zoom into the tapped point
+        // zoom into the tapped point, then clamp so the photo keeps covering
+        // the framed window (plain library keeps the raw focal transform).
+        return clampZoomToWindow(s, fx - s * fx, fy - s * fy);
       });
     }
   };
@@ -1105,6 +1133,25 @@ const Viewfinder = forwardRef<ViewfinderHandle, ViewfinderProps>(function Viewfi
     [libZoom]
   );
 
+  // Export-facing summary of the current framed-window photo reposition. The
+  // gesture state (libZoom) is canvas-absolute; u/v convert it to the fraction
+  // of the photo's cover plane sitting at the WINDOW CENTER — layout units the
+  // export engine can apply at its own pixel size (the Skia render draws the
+  // source sub-rectangle that stays visible through the frame's opening). The
+  // handle method reads this ref because useImperativeHandle captures once.
+  const frameZoomRef = useRef<{ s: number; u: number; v: number } | null>(null);
+  frameZoomRef.current = (() => {
+    const win = zoomWindowRect();
+    if (!win || libZoom.s <= 1.001) return null;
+    const tlx = libZoom.tx + (libZoom.s - 1) * win.x;
+    const tly = libZoom.ty + (libZoom.s - 1) * win.y;
+    return {
+      s: libZoom.s,
+      u: (win.w / 2 - tlx) / (libZoom.s * win.w),
+      v: (win.h / 2 - tly) / (libZoom.s * win.h),
+    };
+  })();
+
   // Border/bars scale with the composition region so framed exports stay
   // proportional to the cropped photo (region == fullscreen when no ratio).
   const borderWidth = Math.min(region.w, region.h) * 0.05;
@@ -1485,7 +1532,10 @@ const Viewfinder = forwardRef<ViewfinderHandle, ViewfinderProps>(function Viewfi
       <View className="flex-1 relative overflow-hidden bg-black items-center justify-center">
         <Canvas style={StyleSheet.absoluteFill}>
           <Rect x={card.x} y={card.y} width={card.w} height={card.h} color="#faf9f6" />
-          <Group>
+          {/* Photo is clipped to the window and repositioned by pinch/drag;
+              the card, seam, grain and watermarks stay put. */}
+          <Group clip={winRect}>
+          <Group matrix={libZoomMatrix}>
             <ColorMatrix matrix={colorMatrix} />
             {useShaderPass ? (
               <Rect x={win.x} y={win.y} width={win.w} height={win.h}>
@@ -1515,6 +1565,7 @@ const Viewfinder = forwardRef<ViewfinderHandle, ViewfinderProps>(function Viewfi
               <SkiaImage image={skiaImage} fit={polaroidFit} rect={winRect} />
             )}
           </Group>
+          </Group>
           {grainOpacity > 0 && noiseEffect && (
             <Group blendMode="overlay">
               <Rect x={win.x} y={win.y} width={win.w} height={win.h} opacity={grainOpacity}>
@@ -1535,7 +1586,14 @@ const Viewfinder = forwardRef<ViewfinderHandle, ViewfinderProps>(function Viewfi
           {renderGPSWatermark()}
           {renderCustomWatermark()}
         </Canvas>
-        {wmArmed && wmDragOverlay}
+        <View
+          className="absolute inset-0"
+          onStartShouldSetResponder={() => true}
+          onMoveShouldSetResponder={() => true}
+          onResponderGrant={onLibTouchStart}
+          onResponderMove={onLibTouchMove}
+          onResponderRelease={onLibTouchEnd}
+        />
       </View>
     );
   }
@@ -1553,7 +1611,10 @@ const Viewfinder = forwardRef<ViewfinderHandle, ViewfinderProps>(function Viewfi
       <View className="flex-1 relative overflow-hidden bg-black items-center justify-center">
         <Canvas style={StyleSheet.absoluteFill}>
           <Rect x={0} y={0} width={vw} height={vh} color="#000000" />
-          <Group>
+          {/* Photo is clipped to the mat window and repositioned by pinch/
+              drag; the artwork, grain and watermarks stay put. */}
+          <Group clip={winRect}>
+          <Group matrix={libZoomMatrix}>
             <ColorMatrix matrix={colorMatrix} />
             {useShaderPass ? (
               <Rect x={win.x} y={win.y} width={win.w} height={win.h}>
@@ -1583,6 +1644,7 @@ const Viewfinder = forwardRef<ViewfinderHandle, ViewfinderProps>(function Viewfi
               <SkiaImage image={skiaImage} fit="cover" rect={winRect} />
             )}
           </Group>
+          </Group>
           {grainOpacity > 0 && noiseEffect && (
             <Group blendMode="overlay">
               <Rect x={win.x} y={win.y} width={win.w} height={win.h} opacity={grainOpacity}>
@@ -1599,7 +1661,14 @@ const Viewfinder = forwardRef<ViewfinderHandle, ViewfinderProps>(function Viewfi
           {renderGPSWatermark()}
           {renderCustomWatermark()}
         </Canvas>
-        {wmArmed && wmDragOverlay}
+        <View
+          className="absolute inset-0"
+          onStartShouldSetResponder={() => true}
+          onMoveShouldSetResponder={() => true}
+          onResponderGrant={onLibTouchStart}
+          onResponderMove={onLibTouchMove}
+          onResponderRelease={onLibTouchEnd}
+        />
       </View>
     );
   }

src/utils/exportEngine.ts

@@ -38,6 +38,13 @@ export interface ExportOptions {
   // (BASELINE anchor + 0.35em drop — same formula as the viewfinder overlay,
   // so the export lands where the preview showed it). Amber mono, no icons.
   watermark?: { text: string; x: number; y: number } | null;
+  // Library framed-window photo reposition (Viewfinder.getFrameWindowZoom):
+  // after pinch/drag inside a polaroid card window or a wall-frame opening,
+  // s = scale and u/v = the fraction of the photo's cover plane sitting at the
+  // WINDOW CENTER. The export draws the source sub-rectangle that stays
+  // visible through the opening, so the file matches the preview. Null /
+  // undefined = centered 1x (the historical full-image draw).
+  frameWindowZoom?: { s: number; u: number; v: number } | null;
 }
 
 // Lightroom-style "Screen" output sharpen: subtle unsharp mask. A 3x3
@@ -332,10 +339,22 @@ export async function processAndExportPhoto(
       const pl = polaroidLayout(outW, outH, width / height, 'contain');
       const win = pl.window;
       // Window aspect == photo aspect → fills exactly, no letterbox inside.
+      // With a framed-window zoom the source rect shrinks to the visible part
+      // (window keeps showing the same geometry as the viewfinder).
       const plainPaint = Skia.Paint();
+      const pz = options?.frameWindowZoom ?? null;
+      const pwz = pz && pz.s > 1.001 ? pz : null;
+      const pVisW = pwz ? width / pwz.s : width;
+      const pVisH = pwz ? height / pwz.s : height;
+      const pSx = pwz
+        ? Math.min(Math.max(width * pwz.u - pVisW / 2, 0), width - pVisW)
+        : 0;
+      const pSy = pwz
+        ? Math.min(Math.max(height * pwz.v - pVisH / 2, 0), height - pVisH)
+        : 0;
       cardCanvas.drawImageRect(
         photoImg,
-        Skia.XYWHRect(0, 0, width, height),
+        Skia.XYWHRect(pSx, pSy, pVisW, pVisH),
         Skia.XYWHRect(win.x, win.y, win.w, win.h),
         plainPaint
       );
@@ -367,6 +386,13 @@ export async function processAndExportPhoto(
       // Decode the frame PNG artwork (bundled asset → base64, same path as the
       // GPS fonts below — embedded assets may not expose a readable file URI).
       const wfAsset = Asset.fromModule(require('../../wallframe.png'));
+      // Android release builds resolve an image asset to a drawable *name*
+      // ('wallframe', no scheme) and mark it downloaded, so downloadAsync()
+      // short-circuits and readAsStringAsync throws 'Unsupported scheme for
+      // location wallframe'. Clear that state so the native module copies the
+      // drawable out of the APK into the cache as a real file path.
+      wfAsset.localUri = null;
+      wfAsset.downloaded = false;
       await wfAsset.downloadAsync();
       const wfDataStr = wfAsset.localUri
         ? await FileSystem.readAsStringAsync(wfAsset.localUri, { encoding: FileSystem.EncodingType.Base64 })
@@ -388,9 +414,23 @@ export async function processAndExportPhoto(
       const scale = Math.max(win.w / pw, win.h / ph);
       const srcW = win.w / scale;
       const srcH = win.h / scale;
+      // Cover plane (center crop) that fills the window; a framed-window zoom
+      // shrinks the visible source sub-rect inside that plane.
+      const planeX = (pw - srcW) / 2;
+      const planeY = (ph - srcH) / 2;
+      const wz = options?.frameWindowZoom ?? null;
+      const wZoom = wz && wz.s > 1.001 ? wz : null;
+      const wVisW = wZoom ? srcW / wZoom.s : srcW;
+      const wVisH = wZoom ? srcH / wZoom.s : srcH;
+      const wSx = wZoom
+        ? Math.min(Math.max(planeX + srcW * wZoom.u - wVisW / 2, planeX), planeX + srcW - wVisW)
+        : planeX;
+      const wSy = wZoom
+        ? Math.min(Math.max(planeY + srcH * wZoom.v - wVisH / 2, planeY), planeY + srcH - wVisH)
+        : planeY;
       cardCanvas.drawImageRect(
         photoImg,
-        Skia.XYWHRect((pw - srcW) / 2, (ph - srcH) / 2, srcW, srcH),
+        Skia.XYWHRect(wSx, wSy, wVisW, wVisH),
         Skia.XYWHRect(win.x, win.y, win.w, win.h),
         plainPaint
       );