intermediate changes

ref:cde9a383711a11544ce7e107a78147fb96cc4029

1 files changed, 129 insertions, 0 deletions

diff --git a/contrib/python/ipython/py3/IPython/external/qt_for_kernel.py b/contrib/python/ipython/py3/IPython/external/qt_for_kernel.py
new file mode 100644
index 0000000000..d2e7bd99f0
--- /dev/null
+++ b/contrib/python/ipython/py3/IPython/external/qt_for_kernel.py
@@ -0,0 +1,129 @@
+""" Import Qt in a manner suitable for an IPython kernel.
+
+This is the import used for the `gui=qt` or `matplotlib=qt` initialization.
+
+Import Priority:
+
+if Qt has been imported anywhere else:
+   use that
+
+if matplotlib has been imported and doesn't support v2 (<= 1.0.1):
+    use PyQt4 @v1
+
+Next, ask QT_API env variable
+
+if QT_API not set:
+    ask matplotlib what it's using. If Qt4Agg or Qt5Agg, then use the
+        version matplotlib is configured with
+
+    else: (matplotlib said nothing)
+        # this is the default path - nobody told us anything
+        try in this order:
+            PyQt default version, PySide, PyQt5
+else:
+    use what QT_API says
+
+"""
+# NOTE: This is no longer an external, third-party module, and should be
+# considered part of IPython. For compatibility however, it is being kept in
+# IPython/external.
+
+import os
+import sys
+
+from IPython.utils.version import check_version
+from IPython.external.qt_loaders import (
+    load_qt,
+    loaded_api,
+    enum_factory,
+    # QT6
+    QT_API_PYQT6,
+    QT_API_PYSIDE6,
+    # QT5
+    QT_API_PYQT5,
+    QT_API_PYSIDE2,
+    # QT4
+    QT_API_PYQTv1,
+    QT_API_PYQT,
+    QT_API_PYSIDE,
+    # default
+    QT_API_PYQT_DEFAULT,
+)
+
+_qt_apis = (
+    # QT6
+    QT_API_PYQT6,
+    QT_API_PYSIDE6,
+    # QT5
+    QT_API_PYQT5,
+    QT_API_PYSIDE2,
+    # QT4
+    QT_API_PYQTv1,
+    QT_API_PYQT,
+    QT_API_PYSIDE,
+    # default
+    QT_API_PYQT_DEFAULT,
+)
+
+
+def matplotlib_options(mpl):
+    """Constraints placed on an imported matplotlib."""
+    if mpl is None:
+        return
+    backend = mpl.rcParams.get('backend', None)
+    if backend == 'Qt4Agg':
+        mpqt = mpl.rcParams.get('backend.qt4', None)
+        if mpqt is None:
+            return None
+        if mpqt.lower() == 'pyside':
+            return [QT_API_PYSIDE]
+        elif mpqt.lower() == 'pyqt4':
+            return [QT_API_PYQT_DEFAULT]
+        elif mpqt.lower() == 'pyqt4v2':
+            return [QT_API_PYQT]
+        raise ImportError("unhandled value for backend.qt4 from matplotlib: %r" %
+                          mpqt)
+    elif backend == 'Qt5Agg':
+        mpqt = mpl.rcParams.get('backend.qt5', None)
+        if mpqt is None:
+            return None
+        if mpqt.lower() == 'pyqt5':
+            return [QT_API_PYQT5]
+        raise ImportError("unhandled value for backend.qt5 from matplotlib: %r" %
+                          mpqt)
+
+def get_options():
+    """Return a list of acceptable QT APIs, in decreasing order of preference."""
+    #already imported Qt somewhere. Use that
+    loaded = loaded_api()
+    if loaded is not None:
+        return [loaded]
+
+    mpl = sys.modules.get('matplotlib', None)
+
+    if mpl is not None and not check_version(mpl.__version__, '1.0.2'):
+        #1.0.1 only supports PyQt4 v1
+        return [QT_API_PYQT_DEFAULT]
+
+    qt_api = os.environ.get('QT_API', None)
+    if qt_api is None:
+        #no ETS variable. Ask mpl, then use default fallback path
+        return matplotlib_options(mpl) or [
+            QT_API_PYQT_DEFAULT,
+            QT_API_PYQT6,
+            QT_API_PYSIDE6,
+            QT_API_PYQT5,
+            QT_API_PYSIDE2,
+            QT_API_PYQT,
+            QT_API_PYSIDE,
+        ]
+    elif qt_api not in _qt_apis:
+        raise RuntimeError("Invalid Qt API %r, valid values are: %r" %
+                           (qt_api, ', '.join(_qt_apis)))
+    else:
+        return [qt_api]
+
+
+api_opts = get_options()
+QtCore, QtGui, QtSvg, QT_API = load_qt(api_opts)
+enum_helper = enum_factory(QT_API, QtCore)