python: render <svg> via _repr_html_

Work around a recent decision in Jupyter Lab and Notebook to render
<svg> is inline <img>, breaking tooltips or text selection.

(Rerendering all notebooks was painful.)

* NEWS: Mention the change.
* python/spot/__init__.py: Add a _repr_html_ method to all
classes that had a _repr_svg_.  It seems Jupyter will use
_repr_html_ by default.
* python/spot/jupyter.py: SVG replace the _repr_svg_ method
by a _repr_html.
* tests/python/_altscc.ipynb, tests/python/_autparserr.ipynb,
tests/python/_aux.ipynb, tests/python/_mealy.ipynb,
tests/python/_partitioned_relabel.ipynb,
tests/python/_product_susp.ipynb, tests/python/_product_weak.ipynb,
tests/python/_synthesis.ipynb, tests/python/aliases.ipynb,
tests/python/alternation.ipynb, tests/python/atva16-fig2a.ipynb,
tests/python/atva16-fig2b.ipynb, tests/python/automata-io.ipynb,
tests/python/automata.ipynb, tests/python/cav22-figs.ipynb,
tests/python/contains.ipynb, tests/python/decompose.ipynb,
tests/python/formulas.ipynb, tests/python/games.ipynb,
tests/python/gen.ipynb, tests/python/highlighting.ipynb,
tests/python/ltsmin-dve.ipynb, tests/python/ltsmin-pml.ipynb,
tests/python/parity.ipynb, tests/python/product.ipynb,
tests/python/randaut.ipynb, tests/python/satmin.ipynb,
tests/python/stutter-inv.ipynb, tests/python/synthesis.ipynb,
tests/python/testingaut.ipynb, tests/python/twagraph-internals.ipynb,
tests/python/word.ipynb, tests/python/zlktree.ipynb: Update all
notebooks.

python/spot/__init__.py

@@ -145,6 +145,10 @@ class aig:
         print_dot(ostr, self, opt)
         return _ostream_to_svg(ostr)
 
+    # see spot.jupyter.SVG for why we need _repr_html_ instead of _repr_svg_
+    def _repr_html_(self):
+        return self._repr_svg_()
+
     def show(self, opt=None):
         from spot.jupyter import SVG
         return SVG(self._repr_svg_(opt))
@@ -210,6 +214,10 @@ class twa:
         print_dot(ostr, self, opt)
         return _ostream_to_svg(ostr)
 
+    # see spot.jupyter.SVG for why we need _repr_html_ instead of _repr_svg_
+    def _repr_html_(self):
+        return self._repr_svg_()
+
     def show(self, opt=None):
         """Display the automaton as SVG, in the IPython/Jupyter notebook"""
         if opt is None:
@@ -479,6 +487,10 @@ class zielonka_tree:
         self.dot(ostr)
         return _ostream_to_svg(ostr)
 
+    # see spot.jupyter.SVG for why we need _repr_html_ instead of _repr_svg_
+    def _repr_html_(self):
+        return self._repr_svg_()
+
 _acdnum = 0
 
 @_extend(acd)

python/spot/jupyter.py

@@ -23,19 +23,24 @@ Auxiliary functions for Spot's Python bindings.
 from IPython.display import display, HTML, DisplayObject
 
 class SVG(DisplayObject):
-    """
-    Replacement for IPython.display.SVG that does not use
+    """Replacement for IPython.display.SVG that does not use
     minidom to extract the <svg> element.
 
-    We need that because prior to Python 3.8, minidom used
-    sort all attributes, and in Python 3.8 this was changed
-    to keep the same order, causing test failures in our
-    diff-based test suite.
+    We need that because prior to Python 3.8, minidom used sort all
+    attributes, and in Python 3.8 this was changed to keep the same
+    order, causing test failures in our diff-based test suite.
 
     We do not need the <svg> extraction when processing
     GraphViz output.
+
+    Also nowadays Jupyter Notebook 7 started to render <svg> as inline
+    <img> instead of inlining the <svg> directly, breaking many useful
+    usages of SVG in the name of easier copy/paste.
+
+    https://github.com/jupyter/notebook/issues/7114
+    https://github.com/jupyterlab/jupyterlab/issues/10464
     """
-    def _repr_svg_(self):
+    def _repr_html_(self):
         return self.data
 
 def display_inline(*args, per_row=None, show=None):
@@ -52,11 +57,11 @@ def display_inline(*args, per_row=None, show=None):
     for arg in args:
         dpy = 'inline-block'
         if show is not None and hasattr(arg, 'show'):
-            rep = arg.show(show)._repr_svg_()
+            arg = arg.show(show)
+        if hasattr(arg, '_repr_html_'):
+            rep = arg._repr_html_()
         elif hasattr(arg, '_repr_svg_'):
             rep = arg._repr_svg_()
-        elif hasattr(arg, '_repr_html_'):
-            rep = arg._repr_html_()
         elif hasattr(arg, '_repr_latex_'):
             rep = arg._repr_latex_()
             if not per_row: