Ctrl + Click and Drag to copy instance

docs/guides/gui.md

@@ -148,6 +148,8 @@ Note that many of the menu command have keyboard shortcuts which can be configur
 
 **Click** elsewhere on image: Clear selection
 
+**Control + left-click (hold) + drag** on instance: Duplicate the selected instance and drag the entire copied instance
+
 ## Navigation Keys
 
 **Right arrow**: Move one frame forward

sleap/gui/widgets/video.py

@@ -12,6 +12,7 @@
     >>> vp.addInstance(instance=my_instance, color=(r, g, b))
 
 """
+
 from collections import deque
 
 # FORCE_REQUESTS controls whether we emit a signal to process frame requests
@@ -1568,6 +1569,9 @@ def mousePressEvent(self, event):
             # Shift-click to mark all points as complete
             elif event.modifiers() == Qt.ShiftModifier:
                 self.parentObject().updatePoints(complete=True, user_change=True)
+            # Ctrl-click to duplicate instance
+            elif event.modifiers() == Qt.ControlModifier:
+                self.parentObject().mousePressEvent(event)
             else:
                 self.dragParent = False
                 super(QtNode, self).mousePressEvent(event)
@@ -1886,7 +1890,7 @@ def __init__(
         self.track_label.setHtml(instance_label_text)
 
         # Add nodes
-        for (node, point) in self.instance.nodes_points:
+        for node, point in self.instance.nodes_points:
             if point.visible or self.show_non_visible:
                 node_item = QtNode(
                     parent=self,
@@ -1901,7 +1905,7 @@ def __init__(
                 self.nodes[node.name] = node_item
 
         # Add edges
-        for (src, dst) in self.skeleton.edge_names:
+        for src, dst in self.skeleton.edge_names:
             # Make sure that both nodes are present in this instance before drawing edge
             if src in self.nodes and dst in self.nodes:
                 edge_item = QtEdge(
@@ -2124,6 +2128,75 @@ def hoverLeaveEvent(self, event):
         self.updateBox()
         return super().hoverLeaveEvent(event)
 
+    def mousePressEvent(self, event):
+        """Custom event handler for mouse press."""
+        if event.buttons() == Qt.LeftButton:
+            if event.modifiers() == Qt.ControlModifier:
+                self.duplicate_instance()
+            else:
+                # Default behavior is to select the instance
+                super(QtInstance, self).mousePressEvent(event)
+
+    def duplicate_instance(self):
+        """Duplicate the instance and add it to the scene."""
+        # Add instance to the context
+        if self.player.context is None:
+            return
+
+        # Copy the instance and add it to the context
+        context = self.player.context
+        context.newInstance(copy_instance=self.instance)
+
+        # Find the new instance and its last label
+        lf = context.labels.find(
+            context.state["video"], context.state["frame_idx"], return_new=True
+        )[0]
+        new_instance = lf.instances[-1]
+
+        # Select the duplicated QtInstance object
+        self.player.state["instance"] = new_instance
+
+        # Refresh the plot
+        self.player.plot()
+
+        def on_selection_update():
+            """Callback to set the new QtInstance to be movable."""
+            # Find the QtInstance corresponding to the newly created instance
+            for qt_inst in self.player.view.all_instances:
+                if qt_inst.instance == new_instance:
+                    self.player.view.updatedSelection.disconnect(on_selection_update)
+
+                    # Set this QtInstance to be movable
+                    qt_inst.setFlag(QGraphicsItem.ItemIsMovable)
+
+                    # Optionally grab the mouse and change cursor, so user can immediately drag
+                    qt_inst.setCursor(Qt.ClosedHandCursor)
+                    qt_inst.grabMouse()
+                    break
+
+        # Connect the callback to the updatedSelection signal
+        self.player.view.updatedSelection.connect(on_selection_update)
+        self.player.view.updatedSelection.emit()
+
+    def mouseMoveEvent(self, event):
+        """Custom event handler to emit signal on event."""
+        is_move = self.flags() & QGraphicsItem.ItemIsMovable
+        is_ctrl_pressed = (event.modifiers() & Qt.ControlModifier) == Qt.ControlModifier
+        is_alt_pressed = (event.modifiers() & Qt.AltModifier) == Qt.AltModifier
+
+        # Only allow moving if the instance is selected
+        if is_move and (is_ctrl_pressed or is_alt_pressed):
+            super().mouseMoveEvent(event)
+
+    def mouseReleaseEvent(self, event):
+        """Custom event handler for mouse release."""
+        if self.flags() & QGraphicsItem.ItemIsMovable:
+            self.setFlag(QGraphicsItem.ItemIsMovable, False)
+            self.updatePoints(user_change=True)
+            self.updateBox()
+            self.ungrabMouse()
+            super().mouseReleaseEvent(event)
+
 
 class VisibleBoundingBox(QtWidgets.QGraphicsRectItem):
     """QGraphicsRectItem for user instance bounding boxes.