# Source code for taurus.qt.qtgui.display.qfallback

    #!/usr/bin/env python

    # ###########################################################################
    #
    # This file is part of Taurus
    #
    # http://taurus-scada.org
    #
    # Copyright 2011 CELLS / ALBA Synchrotron, Bellaterra, Spain
    #
    # Taurus is free software: you can redistribute it and/or modify
    # it under the terms of the GNU Lesser General Public License as published by
    # the Free Software Foundation, either version 3 of the License, or
    # (at your option) any later version.
    #
    # Taurus is distributed in the hope that it will be useful,
    # but WITHOUT ANY WARRANTY; without even the implied warranty of
    # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    # GNU Lesser General Public License for more details.
    #
    # You should have received a copy of the GNU Lesser General Public License
    # along with Taurus.  If not, see <http://www.gnu.org/licenses/>.
    #
    # ###########################################################################

    """A pure Qt widget designed to be displayed when a real widget cannot be
    loaded for any reason (example: a dependency library is not installed)
    """

    __docformat__ = "restructuredtext"

    import sys
    import functools
    from taurus.external.qt import Qt
    from taurus.qt.qtgui.base import TaurusBaseWidget

    def create_fallback(widget_klass_name):
        return functools.partial(
            QFallBackWidget, replaces=widget_klass_name, exc_info=sys.exc_info()
        )

    def create_taurus_fallback(widget_klass_name):
        return functools.partial(
            TaurusFallBackWidget,
            replaces=widget_klass_name,
            exc_info=sys.exc_info(),
        )

    class QFallBackWidget(Qt.QWidget):
        """A FallBack widget to be used when a real widget cannot be loaded for any
        reason (example: a dependency library is not installed)
        """

        def __init__(self, replaces=None, parent=None, *args, **kwargs):
            Qt.QWidget.__init__(self, parent)
            if replaces is None:
                replaces = self.__class__.__name__
            self.replaces = replaces
            self.exc_info = exc_info = kwargs.get("exc_info")
            layout = Qt.QVBoxLayout(self)
            layout.setContentsMargins(2, 2, 2, 2)
            layout.setSpacing(2)
            self.setLayout(layout)
            self.label = Qt.QLabel(self)
            self.label.setText("'{0}' could not be displayed".format(replaces))
            layout.addWidget(self.label, 0, Qt.Qt.AlignVCenter)
            if exc_info is not None and exc_info[0] is not None:
                self.details_button = Qt.QPushButton("Details...", self)
                layout.addWidget(self.details_button, 0, Qt.Qt.AlignTop)
                self.details_button.clicked.connect(self.onShowDetails)
            layout.addStretch(1)

        def onShowDetails(self):
            import taurus.qt.qtgui.dialog

            msgbox = taurus.qt.qtgui.dialog.TaurusMessageBox(
                *self.exc_info, parent=self
            )
            msgbox.setWindowTitle("{0} Error".format(self.replaces))
            msgbox.setText(self.label.text())
            msgbox.exec_()

    class TaurusFallBackWidget(QFallBackWidget, TaurusBaseWidget):
        def __init__(self, replaces=None, parent=None, *args, **kwargs):
            self.call__init__(
                QFallBackWidget, replaces=replaces, parent=parent, *args, **kwargs
            )
            designMode = kwargs.get("designMode", False)
            self.call__init__(TaurusBaseWidget, replaces, designMode=designMode)