qtpy/uic.py

   1 import os
   2
   3 from . import PYSIDE, PYSIDE2, PYQT4, PYQT5
   4 from .QtWidgets import QComboBox
   5
   6
   7 if PYQT5:
   8
   9     from PyQt5.uic import *
  10
  11 elif PYQT4:
  12
  13     from PyQt4.uic import *
  14
  15 else:
  16
  17     __all__ = ['loadUi']
  18
  19     # In PySide, loadUi does not exist, so we define it using QUiLoader, and
  20     # then make sure we expose that function. This is adapted from qt-helpers
  21     # which was released under a 3-clause BSD license:
  22     # qt-helpers - a common front-end to various Qt modules
  23     #
  24     # Copyright (c) 2015, Chris Beaumont and Thomas Robitaille
  25     #
  26     # All rights reserved.
  27     #
  28     # Redistribution and use in source and binary forms, with or without
  29     # modification, are permitted provided that the following conditions are
  30     # met:
  31     #
  32     #  * Redistributions of source code must retain the above copyright
  33     #    notice, this list of conditions and the following disclaimer.
  34     #  * Redistributions in binary form must reproduce the above copyright
  35     #    notice, this list of conditions and the following disclaimer in the
  36     #    documentation and/or other materials provided with the
  37     #    distribution.
  38     #  * Neither the name of the Glue project nor the names of its contributors
  39     #    may be used to endorse or promote products derived from this software
  40     #    without specific prior written permission.
  41     #
  42     # THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
  43     # IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
  44     # THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  45     # PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
  46     # CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  47     # EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  48     # PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  49     # PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
  50     # LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
  51     # NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  52     # SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  53     #
  54     # Which itself was based on the solution at
  55     #
  56     # https://gist.github.com/cpbotha/1b42a20c8f3eb9bb7cb8
  57     #
  58     # which was released under the MIT license:
  59     #
  60     # Copyright (c) 2011 Sebastian Wiesner <lunaryorn@gmail.com>
  61     # Modifications by Charl Botha <cpbotha@vxlabs.com>
  62     #
  63     # Permission is hereby granted, free of charge, to any person obtaining a
  64     # copy of this software and associated documentation files (the "Software"),
  65     # to deal in the Software without restriction, including without limitation
  66     # the rights to use, copy, modify, merge, publish, distribute, sublicense,
  67     # and/or sell copies of the Software, and to permit persons to whom the
  68     # Software is furnished to do so, subject to the following conditions:
  69     #
  70     # The above copyright notice and this permission notice shall be included in
  71     # all copies or substantial portions of the Software.
  72     #
  73     # THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  74     # IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  75     # FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  76     # THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  77     # LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  78     # FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  79     # DEALINGS IN THE SOFTWARE.
  80
  81     if PYSIDE:
  82         from PySide.QtCore import QMetaObject
  83         from PySide.QtUiTools import QUiLoader
  84     elif PYSIDE2:
  85         from PySide2.QtCore import QMetaObject
  86         from PySide2.QtUiTools import QUiLoader
  87
  88     class UiLoader(QUiLoader):
  89         """
  90         Subclass of :class:`~PySide.QtUiTools.QUiLoader` to create the user
  91         interface in a base instance.
  92
  93         Unlike :class:`~PySide.QtUiTools.QUiLoader` itself this class does not
  94         create a new instance of the top-level widget, but creates the user
  95         interface in an existing instance of the top-level class if needed.
  96
  97         This mimics the behaviour of :func:`PyQt4.uic.loadUi`.
  98         """
  99
 100         def __init__(self, baseinstance, customWidgets=None):
 101             """
 102             Create a loader for the given ``baseinstance``.
 103
 104             The user interface is created in ``baseinstance``, which must be an
 105             instance of the top-level class in the user interface to load, or a
 106             subclass thereof.
 107
 108             ``customWidgets`` is a dictionary mapping from class name to class
 109             object for custom widgets. Usually, this should be done by calling
 110             registerCustomWidget on the QUiLoader, but with PySide 1.1.2 on
 111             Ubuntu 12.04 x86_64 this causes a segfault.
 112
 113             ``parent`` is the parent object of this loader.
 114             """
 115
 116             QUiLoader.__init__(self, baseinstance)
 117
 118             self.baseinstance = baseinstance
 119
 120             if customWidgets is None:
 121                 self.customWidgets = {}
 122             else:
 123                 self.customWidgets = customWidgets
 124
 125         def createWidget(self, class_name, parent=None, name=''):
 126             """
 127             Function that is called for each widget defined in ui file,
 128             overridden here to populate baseinstance instead.
 129             """
 130
 131             if parent is None and self.baseinstance:
 132                 # supposed to create the top-level widget, return the base
 133                 # instance instead
 134                 return self.baseinstance
 135
 136             else:
 137
 138                 # For some reason, Line is not in the list of available
 139                 # widgets, but works fine, so we have to special case it here.
 140                 if class_name in self.availableWidgets() or class_name == 'Line':
 141                     # create a new widget for child widgets
 142                     widget = QUiLoader.createWidget(self, class_name, parent, name)
 143
 144                 else:
 145                     # If not in the list of availableWidgets, must be a custom
 146                     # widget. This will raise KeyError if the user has not
 147                     # supplied the relevant class_name in the dictionary or if
 148                     # customWidgets is empty.
 149                     try:
 150                         widget = self.customWidgets[class_name](parent)
 151                     except KeyError:
 152                         raise Exception('No custom widget ' + class_name + ' '
 153                                         'found in customWidgets')
 154
 155                 if self.baseinstance:
 156                     # set an attribute for the new child widget on the base
 157                     # instance, just like PyQt4.uic.loadUi does.
 158                     setattr(self.baseinstance, name, widget)
 159
 160                 return widget
 161
 162     def _get_custom_widgets(ui_file):
 163         """
 164         This function is used to parse a ui file and look for the <customwidgets>
 165         section, then automatically load all the custom widget classes.
 166         """
 167
 168         import sys
 169         import importlib
 170         from xml.etree.ElementTree import ElementTree
 171
 172         # Parse the UI file
 173         etree = ElementTree()
 174         ui = etree.parse(ui_file)
 175
 176         # Get the customwidgets section
 177         custom_widgets = ui.find('customwidgets')
 178
 179         if custom_widgets is None:
 180             return {}
 181
 182         custom_widget_classes = {}
 183
 184         for custom_widget in custom_widgets.getchildren():
 185
 186             cw_class = custom_widget.find('class').text
 187             cw_header = custom_widget.find('header').text
 188
 189             module = importlib.import_module(cw_header)
 190
 191             custom_widget_classes[cw_class] = getattr(module, cw_class)
 192
 193         return custom_widget_classes
 194
 195     def loadUi(uifile, baseinstance=None, workingDirectory=None):
 196         """
 197         Dynamically load a user interface from the given ``uifile``.
 198
 199         ``uifile`` is a string containing a file name of the UI file to load.
 200
 201         If ``baseinstance`` is ``None``, the a new instance of the top-level
 202         widget will be created. Otherwise, the user interface is created within
 203         the given ``baseinstance``. In this case ``baseinstance`` must be an
 204         instance of the top-level widget class in the UI file to load, or a
 205         subclass thereof. In other words, if you've created a ``QMainWindow``
 206         interface in the designer, ``baseinstance`` must be a ``QMainWindow``
 207         or a subclass thereof, too. You cannot load a ``QMainWindow`` UI file
 208         with a plain :class:`~PySide.QtGui.QWidget` as ``baseinstance``.
 209
 210         :method:`~PySide.QtCore.QMetaObject.connectSlotsByName()` is called on
 211         the created user interface, so you can implemented your slots according
 212         to its conventions in your widget class.
 213
 214         Return ``baseinstance``, if ``baseinstance`` is not ``None``. Otherwise
 215         return the newly created instance of the user interface.
 216         """
 217
 218         # We parse the UI file and import any required custom widgets
 219         customWidgets = _get_custom_widgets(uifile)
 220
 221         loader = UiLoader(baseinstance, customWidgets)
 222
 223         if workingDirectory is not None:
 224             loader.setWorkingDirectory(workingDirectory)
 225
 226         widget = loader.load(uifile)
 227         QMetaObject.connectSlotsByName(widget)
 228         return widget