Updated trail length viewing options (#1822)

* updated trail length optptions

* Updated trail length options in the view menu

* Updated `prefs` to include length info from `preferences.yaml`

* Added trail length as method of `MainWindow`

* Updated trail length documentation

* black formatting

---------

Co-authored-by: Keya Loding <[email protected]>

docs/guides/gui.md

@@ -60,7 +60,7 @@ Note that many of the menu command have keyboard shortcuts which can be configur
 
 "**Edge Style**" controls whether edges are drawn as thin lines or as wedges which indicate the {ref}`orientation` of the instance (as well as the direction of the part affinity field which would be used to predict the connection between nodes when using a "bottom-up" approach).
 
-"**Trail Length**" allows you to show a trail of where each instance was located in prior frames (the length of the trail is the number of prior frames). This can be useful when proofreading predictions since it can help you detect swaps in the identities of animals across frames.
+"**Trail Length**" allows you to show a trail of where each instance was located in prior frames (the length of the trail is the number of prior frames). This can be useful when proofreading predictions since it can help you detect swaps in the identities of animals across frames. By default, you can only select trail lengths of up to 250 frames. You can use a custom trail length by modifying the default length in the `preferences.yaml` file. However, using trail lengths longer than about 500 frames can result in significant lag.
 
 "**Fit Instances to View**" allows you to toggle whether the view is auto-zoomed to the instances in each frame. This can be useful when proofreading predictions.
 

sleap/gui/app.py

@@ -151,6 +151,7 @@ def __init__(
         self.state["edge style"] = prefs["edge style"]
         self.state["fit"] = False
         self.state["color predicted"] = prefs["color predicted"]
+        self.state["trail_length"] = prefs["trail length"]
         self.state["trail_shade"] = prefs["trail shade"]
         self.state["marker size"] = prefs["marker size"]
         self.state["propagate track labels"] = prefs["propagate track labels"]
@@ -221,6 +222,7 @@ def closeEvent(self, event):
         prefs["edge style"] = self.state["edge style"]
         prefs["propagate track labels"] = self.state["propagate track labels"]
         prefs["color predicted"] = self.state["color predicted"]
+        prefs["trail length"] = self.state["trail_length"]
         prefs["trail shade"] = self.state["trail_shade"]
         prefs["share usage data"] = self.state["share usage data"]
 
@@ -1025,6 +1027,7 @@ def _load_overlays(self):
             labels=self.labels,
             player=self.player,
             trail_shade=self.state["trail_shade"],
+            trail_length=self.state["trail_length"],
         )
         self.overlays["instance"] = InstanceOverlay(
             labels=self.labels, player=self.player, state=self.state

sleap/gui/overlays/tracks.py

@@ -48,7 +48,9 @@ def __attrs_post_init__(self):
 
     @classmethod
     def get_length_options(cls):
-        return (0, 10, 50, 100, 250)
+        if prefs["trail length"] != 0:
+            return (0, 10, 50, 100, 250, 500, prefs["trail length"])
+        return (0, 10, 50, 100, 250, 500)
 
     @classmethod
     def get_shade_options(cls):

sleap/prefs.py

@@ -45,6 +45,10 @@ def load_(self):
             self._prefs = util.get_config_yaml(self._filename)
             if not hasattr(self._prefs, "get"):
                 self._prefs = self._defaults
+            else:
+                self._prefs["trail length"] = self._prefs.get(
+                    "trail length", self._defaults["trail length"]
+                )
         except FileNotFoundError:
             self._prefs = self._defaults