proof of principle example using napari with full 3D interaction in jupyter notebook

napari/_qt/qt_main_window.py

@@ -129,9 +129,10 @@ def __init__(self, viewer: 'Viewer', parent=None) -> None:
         # we need to manually connect them again.
         handle = self.windowHandle()
         if handle is not None:
-            handle.screenChanged.connect(
-                self._qt_viewer.canvas._backend.screen_changed
-            )
+            with contextlib.suppress(AttributeError):
+                handle.screenChanged.connect(
+                    self._qt_viewer.canvas._backend.screen_changed
+                )
 
         self.status_throttler = QSignalThrottler(parent=self)
         self.status_throttler.setTimeout(50)

napari/_qt/widgets/qt_welcome.py

@@ -184,7 +184,8 @@ def __init__(self, parent, widget):
         self._overlay = QtWelcomeWidget(self)
 
         # Widget setup
-        self.addWidget(widget)
+        if isinstance(widget, QWidget):
+            self.addWidget(widget)
         self.addWidget(self._overlay)
         self.setCurrentIndex(0)
 

napari/_vispy/__init__.py

@@ -4,8 +4,11 @@
 from vispy import app
 
 # set vispy application to the appropriate qt backend
-app.use_app(qtpy.API_NAME)
-del app
+try:
+    app.use_app(qtpy.API_NAME)
+    del app
+except RuntimeError:
+    pass
 
 # set vispy logger to show warning and errors only
 vispy_logger = logging.getLogger('vispy')

napari/_vispy/canvas.py

@@ -1,8 +1,11 @@
 """VispyCanvas class.
 """
+
+import contextlib
 from weakref import WeakSet
 
 from qtpy.QtCore import QSize
+from qtpy.QtWidgets import QWidget
 from vispy.scene import SceneCanvas, Widget
 
 from ..utils.colormaps.standardize_color import transform_color
@@ -41,12 +44,16 @@ def __init__(self, *args, **kwargs):
         self.max_texture_sizes = get_max_texture_sizes()
 
         self.events.ignore_callback_errors = False
-        self.native.setMinimumSize(QSize(200, 200))
+        with contextlib.suppress(AttributeError):
+            self.native.setMinimumSize(QSize(200, 200))
         self.context.set_depth_func('lequal')
 
     @property
     def destroyed(self):
-        return self._backend.destroyed
+        if hasattr(self._backend, 'destroyed'):
+            return self._backend.destroyed
+
+        return type("Mock", (), {'connect': lambda *_, **__: None})
 
     @property
     def background_color_override(self):
@@ -57,6 +64,10 @@ def background_color_override(self, value):
         self._background_color_override = value
         self.bgcolor = value or self._last_theme_color
 
+    @property
+    def is_qt(self) -> bool:
+        return isinstance(self._backend, QWidget)
+
     def _on_theme_change(self, event):
         self._set_theme_change(event.value)
 

napari/_vispy/overlays/axes.py

@@ -1,3 +1,5 @@
+from contextlib import suppress
+
 import numpy as np
 from vispy.scene.visuals import Compound, Line, Mesh, Text
 from vispy.visuals.transforms import STTransform
@@ -204,7 +206,8 @@ def __init__(self, viewer, parent=None, order=0):
         self.text_node.anchors = ('center', 'center')
         self.text_node.text = f'{1}'
 
-        self.node.canvas._backend.destroyed.connect(self._set_canvas_none)
+        with suppress(AttributeError):
+            self.node.canvas._backend.destroyed.connect(self._set_canvas_none)
         # End Note
 
         self._viewer.events.theme.connect(self._on_data_change)

napari/_vispy/overlays/scale_bar.py

@@ -1,5 +1,6 @@
 """Scale Bar overlay."""
 import bisect
+from contextlib import suppress
 
 import numpy as np
 from vispy.scene.visuals import Line, Rectangle, Text
@@ -59,9 +60,16 @@ def __init__(self, viewer, parent=None, order=0):
         self.rect_node.transform = STTransform()
 
         # the two canvas are not the same object, better be safe.
-        self.rect_node.canvas._backend.destroyed.connect(self._set_canvas_none)
-        self.line_node.canvas._backend.destroyed.connect(self._set_canvas_none)
-        self.text_node.canvas._backend.destroyed.connect(self._set_canvas_none)
+        with suppress(AttributeError):
+            self.rect_node.canvas._backend.destroyed.connect(
+                self._set_canvas_none
+            )
+            self.line_node.canvas._backend.destroyed.connect(
+                self._set_canvas_none
+            )
+            self.text_node.canvas._backend.destroyed.connect(
+                self._set_canvas_none
+            )
         assert self.rect_node.canvas is self.line_node.canvas
         assert self.line_node.canvas is self.text_node.canvas
         # End Note

napari/viewer.py

@@ -179,6 +179,15 @@ def close_all(cls) -> int:
             viewer.close()
         return ret
 
+    def _repr_mimebundle_(self, *a, **k):
+        rep = getattr(
+            self.window._qt_viewer.canvas.native, '_repr_mimebundle_', None
+        )
+        if rep is not None:
+            self.camera.zoom = 1
+            return rep()
+        raise NotImplementedError()
+
 
 def current_viewer() -> Optional[Viewer]:
     """Return the currently active napari viewer."""