extras/qtpy/qtpy/uic.py

   1 import os
   2
   3 from qtpy import PYSIDE, PYQT4, PYQT5
   4 from qtpy.QtWidgets import QComboBox
   5
   6 __all__ = ['loadUi']
   7
   8 if PYQT5:
   9
  10     from PyQt5.uic import loadUi
  11
  12 elif PYQT4:
  13
  14     from PyQt4.uic import loadUi
  15
  16 elif PYSIDE:
  17
  18     # In PySide, loadUi does not exist, so we define it using QUiLoader, and
  19     # then make sure we expose that function. This is adapted from qt-helpers
  20     # which was released under a 3-clause BSD license:
  21     # qt-helpers - a common front-end to various Qt modules
  22     #
  23     # Copyright (c) 2015, Chris Beaumont and Thomas Robitaille
  24     #
  25     # All rights reserved.
  26     #
  27     # Redistribution and use in source and binary forms, with or without
  28     # modification, are permitted provided that the following conditions are
  29     # met:
  30     #
  31     #  * Redistributions of source code must retain the above copyright
  32     #    notice, this list of conditions and the following disclaimer.
  33     #  * Redistributions in binary form must reproduce the above copyright
  34     #    notice, this list of conditions and the following disclaimer in the
  35     #    documentation and/or other materials provided with the
  36     #    distribution.
  37     #  * Neither the name of the Glue project nor the names of its contributors
  38     #    may be used to endorse or promote products derived from this software
  39     #    without specific prior written permission.
  40     #
  41     # THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
  42     # IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
  43     # THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  44     # PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
  45     # CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  46     # EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  47     # PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  48     # PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
  49     # LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
  50     # NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  51     # SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  52     #
  53     # Which itself was based on the solution at
  54     #
  55     # https://gist.github.com/cpbotha/1b42a20c8f3eb9bb7cb8
  56     #
  57     # which was released under the MIT license:
  58     #
  59     # Copyright (c) 2011 Sebastian Wiesner <lunaryorn@gmail.com>
  60     # Modifications by Charl Botha <cpbotha@vxlabs.com>
  61     #
  62     # Permission is hereby granted, free of charge, to any person obtaining a
  63     # copy of this software and associated documentation files (the "Software"),
  64     # to deal in the Software without restriction, including without limitation
  65     # the rights to use, copy, modify, merge, publish, distribute, sublicense,
  66     # and/or sell copies of the Software, and to permit persons to whom the
  67     # Software is furnished to do so, subject to the following conditions:
  68     #
  69     # The above copyright notice and this permission notice shall be included in
  70     # all copies or substantial portions of the Software.
  71     #
  72     # THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  73     # IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  74     # FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  75     # THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  76     # LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  77     # FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  78     # DEALINGS IN THE SOFTWARE.
  79
  80     from PySide.QtCore import QMetaObject
  81     from PySide.QtUiTools import QUiLoader
  82
  83     class UiLoader(QUiLoader):
  84         """
  85         Subclass of :class:`~PySide.QtUiTools.QUiLoader` to create the user
  86         interface in a base instance.
  87
  88         Unlike :class:`~PySide.QtUiTools.QUiLoader` itself this class does not
  89         create a new instance of the top-level widget, but creates the user
  90         interface in an existing instance of the top-level class if needed.
  91
  92         This mimics the behaviour of :func:`PyQt4.uic.loadUi`.
  93         """
  94
  95         def __init__(self, baseinstance, customWidgets=None):
  96             """
  97             Create a loader for the given ``baseinstance``.
  98
  99             The user interface is created in ``baseinstance``, which must be an
 100             instance of the top-level class in the user interface to load, or a
 101             subclass thereof.
 102
 103             ``customWidgets`` is a dictionary mapping from class name to class
 104             object for custom widgets. Usually, this should be done by calling
 105             registerCustomWidget on the QUiLoader, but with PySide 1.1.2 on
 106             Ubuntu 12.04 x86_64 this causes a segfault.
 107
 108             ``parent`` is the parent object of this loader.
 109             """
 110
 111             QUiLoader.__init__(self, baseinstance)
 112
 113             self.baseinstance = baseinstance
 114
 115             if customWidgets is None:
 116                 self.customWidgets = {}
 117             else:
 118                 self.customWidgets = customWidgets
 119
 120         def createWidget(self, class_name, parent=None, name=''):
 121             """
 122             Function that is called for each widget defined in ui file,
 123             overridden here to populate baseinstance instead.
 124             """
 125
 126             if parent is None and self.baseinstance:
 127                 # supposed to create the top-level widget, return the base
 128                 # instance instead
 129                 return self.baseinstance
 130
 131             else:
 132
 133                 # For some reason, Line is not in the list of available
 134                 # widgets, but works fine, so we have to special case it here.
 135                 if class_name in self.availableWidgets() or class_name == 'Line':
 136                     # create a new widget for child widgets
 137                     widget = QUiLoader.createWidget(self, class_name, parent, name)
 138
 139                 else:
 140                     # If not in the list of availableWidgets, must be a custom
 141                     # widget. This will raise KeyError if the user has not
 142                     # supplied the relevant class_name in the dictionary or if
 143                     # customWidgets is empty.
 144                     try:
 145                         widget = self.customWidgets[class_name](parent)
 146                     except KeyError:
 147                         raise Exception('No custom widget ' + class_name + ' '
 148                                         'found in customWidgets')
 149
 150                 if self.baseinstance:
 151                     # set an attribute for the new child widget on the base
 152                     # instance, just like PyQt4.uic.loadUi does.
 153                     setattr(self.baseinstance, name, widget)
 154
 155                 return widget
 156
 157     def _get_custom_widgets(ui_file):
 158         """
 159         This function is used to parse a ui file and look for the <customwidgets>
 160         section, then automatically load all the custom widget classes.
 161         """
 162
 163         import sys
 164         import importlib
 165         from xml.etree.ElementTree import ElementTree
 166
 167         # Parse the UI file
 168         etree = ElementTree()
 169         ui = etree.parse(ui_file)
 170
 171         # Get the customwidgets section
 172         custom_widgets = ui.find('customwidgets')
 173
 174         if custom_widgets is None:
 175             return {}
 176
 177         custom_widget_classes = {}
 178
 179         for custom_widget in custom_widgets.getchildren():
 180
 181             cw_class = custom_widget.find('class').text
 182             cw_header = custom_widget.find('header').text
 183
 184             module = importlib.import_module(cw_header)
 185
 186             custom_widget_classes[cw_class] = getattr(module, cw_class)
 187
 188         return custom_widget_classes
 189
 190     def loadUi(uifile, baseinstance=None, workingDirectory=None):
 191         """
 192         Dynamically load a user interface from the given ``uifile``.
 193
 194         ``uifile`` is a string containing a file name of the UI file to load.
 195
 196         If ``baseinstance`` is ``None``, the a new instance of the top-level
 197         widget will be created. Otherwise, the user interface is created within
 198         the given ``baseinstance``. In this case ``baseinstance`` must be an
 199         instance of the top-level widget class in the UI file to load, or a
 200         subclass thereof. In other words, if you've created a ``QMainWindow``
 201         interface in the designer, ``baseinstance`` must be a ``QMainWindow``
 202         or a subclass thereof, too. You cannot load a ``QMainWindow`` UI file
 203         with a plain :class:`~PySide.QtGui.QWidget` as ``baseinstance``.
 204
 205         :method:`~PySide.QtCore.QMetaObject.connectSlotsByName()` is called on
 206         the created user interface, so you can implemented your slots according
 207         to its conventions in your widget class.
 208
 209         Return ``baseinstance``, if ``baseinstance`` is not ``None``. Otherwise
 210         return the newly created instance of the user interface.
 211         """
 212
 213         # We parse the UI file and import any required custom widgets
 214         customWidgets = _get_custom_widgets(uifile)
 215
 216         loader = UiLoader(baseinstance, customWidgets)
 217
 218         if workingDirectory is not None:
 219             loader.setWorkingDirectory(workingDirectory)
 220
 221         widget = loader.load(uifile)
 222         QMetaObject.connectSlotsByName(widget)
 223         return widget