Goto instance change key binding

sleap/config/shortcuts.yaml

@@ -18,6 +18,8 @@ goto next user: Ctrl+U
 goto next labeled: Alt+Right
 goto prev suggestion: Shift+Space
 goto prev labeled: Alt+Left
+goto next instance change: Ctrl+Shift+Right
+goto prev instance change: Ctrl+Shift+Left
 learning: Ctrl+L
 mark frame: Ctrl+M
 new: Ctrl+N

sleap/gui/app.py

@@ -575,6 +575,20 @@ def add_submenu_choices(menu, title, options, key):
             self.commands.nextTrackFrame,
         )
 
+        add_menu_item(
+            goMenu,
+            "goto next instance change",
+            "Next Instance Count Change",
+            self.commands.nextInstanceChange,
+        )
+
+        add_menu_item(
+            goMenu,
+            "goto prev instance change",
+            "Previous Instance Count Change",
+            self.commands.prevInstanceChange,
+        )
+
         goMenu.addSeparator()
 
         def next_vid():

sleap/gui/commands.py

@@ -632,6 +632,14 @@ def openPrereleaseVersion(self):
         """Open the current prerelease version."""
         self.execute(OpenPrereleaseVersion)
 
+    def nextInstanceChange(self):
+        """Go to next frame where number of instances changes."""
+        self.execute(GoNextInstanceChange)
+
+    def prevInstanceChange(self):
+        """Goes to previous frame with different instance count."""
+        self.execute(GoPrevInstanceChange)
+
 
 # File Commands
 
@@ -1601,6 +1609,54 @@ class GoPrevSuggestedFrame(GoNextSuggestedFrame):
     seek_direction = -1
 
 
+class GoNextInstanceChange(NavCommand):
+    @classmethod
+    def do_action(cls, context: CommandContext, params: dict):
+        video = context.state["video"]
+        cur_idx = context.state["frame_idx"]
+
+        # Get current number of instances
+        current_frame = context.labels.find(video, cur_idx, return_new=True)[0]
+        current_instance_count = len(current_frame.instances_to_show)
+
+        # Get all labeled frames after current frame
+        for frame in range(cur_idx + 1, video.frames):
+            if (
+                len(
+                    context.labels.find(video, frame, return_new=True)[
+                        0
+                    ].instances_to_show
+                )
+                != current_instance_count
+            ):
+                cls.go_to(context, frame)
+                break
+
+
+class GoPrevInstanceChange(NavCommand):
+    @classmethod
+    def do_action(cls, context: CommandContext, params: dict):
+        video = context.state["video"]
+        cur_idx = context.state["frame_idx"]
+
+        # Get current number of instances
+        current_frame = context.labels.find(video, cur_idx, return_new=True)[0]
+        current_instance_count = len(current_frame.instances_to_show)
+
+        # Get all labeled frames after current frame
+        for frame in range(cur_idx - 1, -1, -1):
+            if (
+                len(
+                    context.labels.find(video, frame, return_new=True)[
+                        0
+                    ].instances_to_show
+                )
+                != current_instance_count
+            ):
+                cls.go_to(context, frame)
+                break
+
+
 class GoNextTrackFrame(NavCommand):
     @classmethod
     def do_action(cls, context: CommandContext, params: dict):

sleap/gui/shortcuts.py

@@ -41,6 +41,8 @@ class Shortcuts(object):
         "goto next suggestion",
         "goto prev suggestion",
         "goto next track spawn",
+        "goto next instance change",
+        "goto prev instance change",
         "show instances",
         "show labels",
         "show edges",

tests/gui/test_commands.py

@@ -22,6 +22,8 @@
     SaveProjectAs,
     DeleteFrameLimitPredictions,
     get_new_version_filename,
+    GoNextInstanceChange,
+    GoPrevInstanceChange,
 )
 from sleap.instance import Instance, LabeledFrame
 from sleap.io.convert import default_analysis_filename
@@ -1046,3 +1048,63 @@ def on_triggered():
     )
     diff = np.nan_to_num(new_inst.numpy() - copy_instance.numpy(), nan=offset)
     assert np.all(diff == offset)
+
+
+def test_go_next_instance_change(centered_pair_predictions: Labels):
+    """Test that goto next instance change command works correctly."""
+    # Set up test data
+    labels = centered_pair_predictions
+    video = labels.videos[0]
+
+    # Create frames with different numbers of instances
+    lf1 = labels.find(video, 0, return_new=True)[0]  # First frame (already exists)
+    initial_count = len(lf1.instances_to_show)
+
+    for frame_idx in range(1, video.num_frames):
+        lf = labels.find(video, frame_idx, return_new=True)[0]
+        if len(lf.instances_to_show) != initial_count:
+            skipped_to_frame = lf.frame_idx
+            break
+
+    # Set up command context
+    context = CommandContext.from_labels(labels)
+    context.state["video"] = video
+    context.state["frame_idx"] = lf1.frame_idx
+
+    # Execute the command
+    context.execute(GoNextInstanceChange)
+
+    # Verify that we moved to the frame with different instance count
+    assert context.state["frame_idx"] == skipped_to_frame
+    assert len(labels.find(video, skipped_to_frame)[0].instances) != initial_count
+
+
+def test_go_prev_instance_change(centered_pair_predictions: Labels):
+    """Test that goto next instance change command works correctly."""
+    # Set up test data
+    labels = centered_pair_predictions
+    video = labels.videos[0]
+
+    # Create frames with different numbers of instances
+    lf1 = labels.find(video, video.num_frames - 1, return_new=True)[
+        0
+    ]  # First frame (already exists)
+    initial_count = len(lf1.instances_to_show)
+
+    for frame_idx in range(video.num_frames - 1, 0, -1):
+        lf = labels.find(video, frame_idx, return_new=True)[0]
+        if len(lf.instances_to_show) != initial_count:
+            skipped_to_frame = lf.frame_idx
+            break
+
+    # Set up command context
+    context = CommandContext.from_labels(labels)
+    context.state["video"] = video
+    context.state["frame_idx"] = lf1.frame_idx
+
+    # Execute the command
+    context.execute(GoPrevInstanceChange)
+
+    # Verify that we moved to the frame with different instance count
+    assert context.state["frame_idx"] == skipped_to_frame
+    assert len(labels.find(video, skipped_to_frame)[0].instances) != initial_count