popout: let open animation play on first fit

resize() and resize_and_move() gain an animate flag — when True, skip
the no_anim setprop so Hyprland's windowsIn/popin animation plays
through. Popout passes animate=_first_fit_pending so the first fit
after open animates; subsequent navigation fits still suppress anim
to avoid resize flicker.

behavior change: popout now animates in on open instead of snapping.

HYPRLAND.md

@@ -89,7 +89,9 @@ windowrule {
   popout geometry
 - `dispatch togglefloating` on the main window at launch
 - `dispatch setprop address:<addr> no_anim 1` applied during popout
-  transitions
+  transitions (skipped on the first fit after open so Hyprland's
+  `windowsIn` / `popin` animation can play — subsequent navigation
+  fits still suppress anim to avoid resize flicker)
 - The startup "prime" sequence that warms Hyprland's per-window
   floating cache
 

booru_viewer/gui/popout/hyprland.py

@@ -54,7 +54,7 @@ def get_window(window_title: str) -> dict | None:
     return None
 
 
-def resize(window_title: str, w: int, h: int) -> None:
+def resize(window_title: str, w: int, h: int, animate: bool = False) -> None:
     """Ask Hyprland to resize the popout and lock its aspect ratio.
 
     No-op on non-Hyprland systems. Tiled windows skip the resize
@@ -86,12 +86,12 @@ def resize(window_title: str, w: int, h: int) -> None:
     if not win.get("floating"):
         # Tiled — don't resize (fights the layout). Optionally set
         # aspect lock and no_anim depending on the env vars.
-        if rules_on:
+        if rules_on and not animate:
             cmds.append(f"dispatch setprop address:{addr} no_anim 1")
         if aspect_on:
             cmds.append(f"dispatch setprop address:{addr} keep_aspect_ratio 1")
     else:
-        if rules_on:
+        if rules_on and not animate:
             cmds.append(f"dispatch setprop address:{addr} no_anim 1")
         if aspect_on:
             cmds.append(f"dispatch setprop address:{addr} keep_aspect_ratio 0")
@@ -111,6 +111,7 @@ def resize_and_move(
     x: int,
     y: int,
     win: dict | None = None,
+    animate: bool = False,
 ) -> None:
     """Atomically resize and move the popout via a single hyprctl batch.
 
@@ -140,7 +141,7 @@ def resize_and_move(
     if not addr:
         return
     cmds: list[str] = []
-    if rules_on:
+    if rules_on and not animate:
         cmds.append(f"dispatch setprop address:{addr} no_anim 1")
     if aspect_on:
         cmds.append(f"dispatch setprop address:{addr} keep_aspect_ratio 0")

booru_viewer/gui/popout/window.py

@@ -1325,7 +1325,7 @@ class FullscreenPreview(QMainWindow):
         else:
             floating = None
         if floating is False:
-            hyprland.resize(self.windowTitle(), 0, 0)  # tiled: just set keep_aspect_ratio
+            hyprland.resize(self.windowTitle(), 0, 0, animate=self._first_fit_pending)  # tiled: just set keep_aspect_ratio
             self._tiled_pending_content = (content_w, content_h)
             return
         self._tiled_pending_content = None
@@ -1373,7 +1373,10 @@ class FullscreenPreview(QMainWindow):
                 # Hyprland: hyprctl is the sole authority. Calling self.resize()
                 # here would race with the batch below and produce visible flashing
                 # when the window also has to move.
-                hyprland.resize_and_move(self.windowTitle(), w, h, x, y, win=win)
+                hyprland.resize_and_move(
+                    self.windowTitle(), w, h, x, y, win=win,
+                    animate=self._first_fit_pending,
+                )
             else:
                 # Non-Hyprland fallback: Qt drives geometry directly. Use
                 # setGeometry with the computed top-left rather than resize()