Allow view-annotate to display in Sage notebook

src/sage/misc/cython.py

@@ -81,7 +81,7 @@ def _standard_libs_libdirs_incdirs_aliases():
 
 def cython(filename, verbose=0, compile_message=False,
            use_cache=False, create_local_c_file=False, annotate=True, view_annotate=False,
-           sage_namespace=True, create_local_so_file=False):
+           view_annotate_callback=webbrowser.open, sage_namespace=True, create_local_so_file=False):
     r"""
     Compile a Cython file. This converts a Cython file to a C (or C++ file),
     and then compiles that. The .c file and the .so file are
@@ -114,6 +114,11 @@ def cython(filename, verbose=0, compile_message=False,
     - ``view_annotate`` -- boolean (default: ``False``); if ``True``, open the
       annotated html file in a web browser using :func:`webbrowser.open`
 
+    - ``view_annotate_callback`` -- function (default: ``webbrowser.open``); a function
+      that takes a string being the path to the html file. This can be overridden to
+      change what to do with the annotated html file. Have no effect unless
+      ``view_annotate`` is ``True``
+
     - ``sage_namespace`` -- boolean (default: ``True``); if ``True``, import
       ``sage.all``
 
@@ -258,6 +263,18 @@ def cython(filename, verbose=0, compile_message=False,
         Traceback (most recent call last):
         ...
         ValueError: Cannot view annotated file without creating it
+
+    ::
+
+        sage: collected_paths = []
+        sage: cython('''
+        ....: def f(int n):
+        ....:     return n*n
+        ....: ''', view_annotate=True, view_annotate_callback=collected_paths.append)
+        sage: collected_paths
+        ['...']
+        sage: len(collected_paths)
+        1
     """
     if not filename.endswith('pyx'):
         print("Warning: file (={}) should have extension .pyx".format(filename), file=sys.stderr)
@@ -416,7 +433,7 @@ def cython(filename, verbose=0, compile_message=False,
     if view_annotate:
         if not annotate:
             raise ValueError("Cannot view annotated file without creating it")
-        webbrowser.open(os.path.join(target_dir, name + ".html"))
+        view_annotate_callback(os.path.join(target_dir, name + ".html"))
 
     # This emulates running "setup.py build" with the correct options
     #

src/sage/repl/ipython_extension.py

@@ -65,13 +65,23 @@
 """
 
 from IPython.core.magic import Magics, magics_class, line_magic, cell_magic
+from IPython.core.display import HTML
+from IPython import get_ipython
 
 from sage.repl.load import load_wrap
 from sage.env import SAGE_IMPORTALL, SAGE_STARTUP_FILE
 from sage.misc.lazy_import import LazyImport
 from sage.misc.misc import run_once
 
 
+def _running_in_notebook():
+    try:
+        from ipykernel.zmqshell import ZMQInteractiveShell
+    except ImportError:
+        return False
+    return isinstance(get_ipython(), ZMQInteractiveShell)
+
+
 @magics_class
 class SageMagics(Magics):
 
@@ -356,6 +366,16 @@ def cython(self, line, cell):
 
           See :func:`~sage.misc.cython.cython` for details.
 
+          For ``--view-annotate``, the following additional choices are allowed:
+
+          - ``--view-annotate=none`` (default)
+          - ``--view-annotate=auto`` (same as ``--view-annotate``); select one of the
+            choices below automatically
+          - ``--view-annotate=webbrowser``; open the annotation in a web browser
+            (preferred if the Sage command line is used)
+          - ``--view-annotate=displayhtml``; display the annotation inline in the notebook
+            (preferred if the Sage notebook is used)
+
         - ``cell`` -- string; the Cython source code to process
 
         OUTPUT: none; the Cython code is compiled and loaded
@@ -396,6 +416,15 @@ def cython(self, line, cell):
             ....: ''')
             UsageError: unrecognized arguments: --help
 
+        Test ``--view-annotate`` invalid arguments::
+
+            sage: # needs sage.misc.cython
+            sage: shell.run_cell('''
+            ....: %%cython --view-annotate=xx
+            ....: print(1)
+            ....: ''')
+            UsageError: argument --view-annotate: invalid choice: 'xx' (choose from 'none', 'auto', 'webbrowser', 'displayhtml')
+
         Test invalid quotes (see :mod:`sage.repl.interpreter` for explanation of the dummy line)::
 
             sage: # needs sage.misc.cython
@@ -428,11 +457,26 @@ def error(self, message):
         parser.add_argument("--use-cache", action=argparse.BooleanOptionalAction)
         parser.add_argument("--create-local-c-file", action=argparse.BooleanOptionalAction)
         parser.add_argument("--annotate", action=argparse.BooleanOptionalAction)
-        parser.add_argument("--view-annotate", action=argparse.BooleanOptionalAction)
+        parser.add_argument("--view-annotate", choices=["none", "auto", "webbrowser", "displayhtml"],
+                            nargs="?", const="auto", default="none")
         parser.add_argument("--sage-namespace", action=argparse.BooleanOptionalAction)
         parser.add_argument("--create-local-so-file", action=argparse.BooleanOptionalAction)
         args = parser.parse_args(shlex.split(line))
-        return cython_compile(cell, **{k: v for k, v in args.__dict__.items() if v is not None})
+        view_annotate = args.view_annotate
+        del args.view_annotate
+        if view_annotate == "auto":
+            if _running_in_notebook():
+                view_annotate = "displayhtml"
+            else:
+                view_annotate = "webbrowser"
+        args_dict = {k: v for k, v in args.__dict__.items() if v is not None}
+        if view_annotate != "none":
+            args_dict["view_annotate"] = True
+            if view_annotate == "displayhtml":
+                path_to_annotate_html_container = []
+                cython_compile(cell, **args_dict, view_annotate_callback=path_to_annotate_html_container.append)
+                return HTML(filename=path_to_annotate_html_container[0])
+        return cython_compile(cell, **args_dict)
 
     @cell_magic
     def fortran(self, line, cell):