Highlight instance box on hover

sleap/gui/widgets/video.py

@@ -1610,6 +1610,10 @@ def mouseDoubleClickEvent(self, event: QMouseEvent):
             view = scene.views()[0]
             view.instanceDoubleClicked.emit(self.parentObject().instance, event)
 
+    def hoverEnterEvent(self, event):
+        print("QtNode: hover enter")
+        return super().hoverEnterEvent(event)
+
 
 class QtEdge(QGraphicsPolygonItem):
     """
@@ -1809,6 +1813,7 @@ def __init__(
         self.labels = {}
         self.labels_shown = True
         self._selected = False
+        self._is_hovering = False
         self._bounding_rect = QRectF()
 
         # Show predicted instances behind non-predicted ones
@@ -1830,6 +1835,7 @@ def __init__(
         box_pen.setStyle(Qt.DashLine)
         box_pen.setCosmetic(True)
         self.box.setPen(box_pen)
+        self.setAcceptHoverEvents(True)
 
         # Add label for highlighted instance
         self.highlight_label = QtTextWithBackground(parent=self)
@@ -1991,7 +1997,12 @@ def updateBox(self, *args, **kwargs):
         select this instance.
         """
         # Only show box if instance is selected
-        op = 0.7 if self._selected else 0
+        op = 0
+        if self._selected:
+            op = 0.8
+        elif self._is_hovering:
+            op = 0.4
+
         self.box.setOpacity(op)
         # Update the position for the box
         rect = self.getPointsBoundingRect()
@@ -2085,6 +2096,16 @@ def paint(self, painter, option, widget=None):
         """Method required by Qt."""
         pass
 
+    def hoverEnterEvent(self, event):
+        self._is_hovering = True
+        self.updateBox()
+        return super().hoverEnterEvent(event)
+
+    def hoverLeaveEvent(self, event):
+        self._is_hovering = False
+        self.updateBox()
+        return super().hoverLeaveEvent(event)
+
 
 class VisibleBoundingBox(QtWidgets.QGraphicsRectItem):
     """QGraphicsRectItem for user instance bounding boxes.