Dynamically adjusting layout to maximize screen space used for document previews. Row width changes with aspect ratio of items on that row. Server side tracking of size as part of the main listing.

cista/preview.py

@@ -20,7 +20,8 @@ from sanic import Blueprint, empty, raw, redirect
 from sanic.exceptions import NotFound
 from sanic.log import logger
 
-from cista import auth, config, onlyoffice, sharefs
+from cista import auth, config, onlyoffice, sharefs, watching
+from cista.fileio import fuid
 from cista.preview_worker import (
     DOC_PREVIEW_SUFFIXES,
     OFFICE_PREVIEW_SUFFIXES,
@@ -656,6 +657,12 @@ async def preview(req, path):
         # Preview generation failed, redirect to the file itself
         return redirect(f"/files/{path}", status=303)
 
+    # Store aspect ratio if the worker returned dimensions
+    if preview_resp and preview_resp.width and preview_resp.height:
+        ar = round(preview_resp.height / preview_resp.width, 2)
+        fuid_str = fuid(stat)
+        watching.notify_ar(fuid_str, ar)
+
     # Build headers and cache the full response
     preview_mime = (
         preview_resp.mime

cista/preview_worker.py

@@ -95,6 +95,8 @@ class PreviewResponse(msgspec.Struct, omit_defaults=True):
     timings: list[float] | None = None
     error: str | None = None
     stderr: str | None = None
+    width: int | None = None
+    height: int | None = None
 
 
 _enc = msgspec.json.Encoder()
@@ -173,6 +175,7 @@ def _get_image_dimensions(path: Path) -> tuple[int, int] | None:
     """
     try:
         img = pyvips.Image.new_from_file(str(path))
+        img = img.autorot()
     except pyvips.error.Error:
         return None
     else:
@@ -228,6 +231,8 @@ def process_image_pyvips(path, *, maxsize, quality):
     # HEIC/HEIF: ffmpeg handles tile assembly and HDR correctly;
     # skip pyvips entirely.
     if suffix in (".heic", ".heif"):
+        heic_dims = _get_image_dimensions(path)
+        width, height = heic_dims or (None, None)
         ret = _image_via_ffmpeg(path, maxsize, quality)
         t_end = perf_counter()
         return ret, PreviewResponse(
@@ -235,13 +240,17 @@ def process_image_pyvips(path, *, maxsize, quality):
             mime="image/avif",
             backend="ffmpeg",
             timings=[round((t_end - t_start) * 1000, 1)],
+            width=width,
+            height=height,
         )
 
     # Other image formats: pyvips first, ffmpeg fallback.
     load_opts = {"access": "sequential"}
+    orig_w = orig_h = None
     try:
         img = pyvips.Image.new_from_file(str(path), **load_opts)
         img = img.autorot()
+        orig_w, orig_h = img.width, img.height
         scale = min(maxsize / img.width, maxsize / img.height, 1.0)
         if scale < 1.0:
             img = img.resize(scale)
@@ -253,6 +262,7 @@ def process_image_pyvips(path, *, maxsize, quality):
         )
         backend = "pyvips"
     except pyvips.error.Error:
+        orig_w, orig_h = None, None
         ret = _image_via_ffmpeg(path, maxsize, quality)
         backend = "ffmpeg"
     t_end = perf_counter()
@@ -262,6 +272,8 @@ def process_image_pyvips(path, *, maxsize, quality):
         mime="image/avif",
         backend=backend,
         timings=[round((t_end - t_start) * 1000, 1)],
+        width=orig_w,
+        height=orig_h,
     )
 
 
@@ -270,6 +282,7 @@ def process_image_buffer(data: bytes, *, quality, maxsize, maxzoom):
     t_start = perf_counter()
     img = pyvips.Image.new_from_buffer(data, "")
     img = img.autorot()
+    orig_w, orig_h = img.width, img.height
     scale = min(maxsize / img.width, maxsize / img.height, 1.0)
     if scale < 1.0:
         img = img.resize(scale)
@@ -286,6 +299,8 @@ def process_image_buffer(data: bytes, *, quality, maxsize, maxzoom):
         mime="image/avif",
         backend="pyvips",
         timings=[round((t_end - t_start) * 1000, 1)],
+        width=orig_w,
+        height=orig_h,
     )
 
 
@@ -315,6 +330,8 @@ def process_pdf(path, *, maxsize, maxzoom, quality, page_number=0):
             round((t_load_end - t_load_start) * 1000, 1),
             round((t_save_end - t_save_start) * 1000, 1),
         ],
+        width=round(w),
+        height=round(h),
     )
 
 
@@ -347,6 +364,11 @@ def process_video(path, *, maxsize, quality):
             raise RuntimeError("No frames found in video")
 
         # Resize frame to thumbnail size
+        # Capture display dimensions before resize (accounting for rotation)
+        disp_w = frame.width
+        disp_h = frame.height
+        if frame.rotation in (90, 270):
+            disp_w, disp_h = disp_h, disp_w
         if frame.width > maxsize or frame.height > maxsize:
             scale_factor = min(maxsize / frame.width, maxsize / frame.height)
             new_width = int(frame.width * scale_factor)
@@ -442,6 +464,8 @@ def process_video(path, *, maxsize, quality):
             round((t_load_end - t_load_start) * 1000, 1),
             round((t_save_end - t_save_start) * 1000, 1),
         ],
+        width=disp_w,
+        height=disp_h,
     )
     del imgdata, istream, ostream, icc, occ, frame
     gc.collect()

cista/protocol.py

@@ -12,7 +12,7 @@ class ErrorMsg(msgspec.Struct):
 ## Directory listings
 
 
-class FileEntry(msgspec.Struct, array_like=True, frozen=True):
+class FileEntry(msgspec.Struct, array_like=True, frozen=True, omit_defaults=True):
     level: int
     name: str
     key: str
@@ -20,6 +20,7 @@ class FileEntry(msgspec.Struct, array_like=True, frozen=True):
     size: int
     allocated: int
     isfile: int
+    ar: float | None = None
 
     def __str__(self):
         return self.key or "FileEntry()"

cista/watching.py

@@ -154,6 +154,17 @@ stop_event = threading.Event()
 # Thread-safe queue for signaling path updates from websockets
 _update_queue: queue.Queue[PurePosixPath] = queue.Queue()
 
+# Thread-safe queue for AR updates from the preview worker
+_ar_queue: queue.Queue[tuple[str, float]] = queue.Queue()
+
+# AR map: fuid -> aspect ratio (height/width). Written only by the watcher thread.
+_ar_map: dict[str, float] = {}
+
+
+def notify_ar(fuid_key: str, ar: float) -> None:
+    """Called from preview handler to update the AR for a file."""
+    _ar_queue.put_nowait((fuid_key, ar))
+
 
 def notify_change(*paths: PurePosixPath | str):
     """Signal that paths have changed. Called from control/upload websockets."""
@@ -186,14 +197,16 @@ def walk(rel: PurePosixPath, stat: stat_result | None = None) -> list[FileEntry]
         except Exception:
             logger.exception(f"get_allocated_size failed for {path}")
             allocated = st.st_size if isfile else 0
+        key = fuid(st)
         entry = FileEntry(
             level=len(rel.parts),
             name=rel.name,
-            key=fuid(st),
+            key=key,
             mtime=int(st.st_mtime),
             size=st.st_size if isfile else 0,
             allocated=allocated,
             isfile=isfile,
+            ar=_ar_map.get(key) if isfile else None,
         )
         if isfile:
             return [entry]
@@ -775,6 +788,43 @@ def watcher(loop):
                                 broadcast(format_root(fresh), loop)
                                 state.root = fresh
 
+            # Drain AR updates from preview worker (immediate, no debounce)
+            ar_new_root: list[FileEntry] | None = None
+            try:
+                while True:
+                    fuid_key, ar = _ar_queue.get_nowait()
+                    _ar_map[fuid_key] = ar
+                    # Patch the matching entry in the current root
+                    root_to_patch = (
+                        ar_new_root if ar_new_root is not None else path_index.root
+                    )
+                    for i, entry in enumerate(root_to_patch):
+                        if entry.key == fuid_key and entry.isfile and entry.ar != ar:
+                            if ar_new_root is None:
+                                ar_new_root = root_to_patch[:]
+                            ar_new_root[i] = FileEntry(
+                                level=entry.level,
+                                name=entry.name,
+                                key=entry.key,
+                                mtime=entry.mtime,
+                                size=entry.size,
+                                allocated=entry.allocated,
+                                isfile=entry.isfile,
+                                ar=ar,
+                            )
+                            break
+            except queue.Empty:
+                pass
+            if ar_new_root is not None:
+                try:
+                    update_msg = format_update(state.root, ar_new_root)
+                    with state.lock:
+                        broadcast(update_msg, loop)
+                        state.root = ar_new_root
+                    path_index = PathIndex(ar_new_root)
+                except Exception:
+                    logger.exception("AR update broadcast failed")
+
             # Collect events from websocket signals (non-blocking)
             try:
                 while True: