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', 'loadUiType']
  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         try:
  85             from pysideuic import compileUi
  86         except ImportError:
  87             pass
  88     elif PYSIDE2:
  89         from PySide2.QtCore import QMetaObject
  90         from PySide2.QtUiTools import QUiLoader
  91         try:
  92             from pyside2uic import compileUi
  93         except ImportError:
  94             pass
  95
  96     class UiLoader(QUiLoader):
  97         """
  98         Subclass of :class:`~PySide.QtUiTools.QUiLoader` to create the user
  99         interface in a base instance.
 100
 101         Unlike :class:`~PySide.QtUiTools.QUiLoader` itself this class does not
 102         create a new instance of the top-level widget, but creates the user
 103         interface in an existing instance of the top-level class if needed.
 104
 105         This mimics the behaviour of :func:`PyQt4.uic.loadUi`.
 106         """
 107
 108         def __init__(self, baseinstance, customWidgets=None):
 109             """
 110             Create a loader for the given ``baseinstance``.
 111
 112             The user interface is created in ``baseinstance``, which must be an
 113             instance of the top-level class in the user interface to load, or a
 114             subclass thereof.
 115
 116             ``customWidgets`` is a dictionary mapping from class name to class
 117             object for custom widgets. Usually, this should be done by calling
 118             registerCustomWidget on the QUiLoader, but with PySide 1.1.2 on
 119             Ubuntu 12.04 x86_64 this causes a segfault.
 120
 121             ``parent`` is the parent object of this loader.
 122             """
 123
 124             QUiLoader.__init__(self, baseinstance)
 125
 126             self.baseinstance = baseinstance
 127
 128             if customWidgets is None:
 129                 self.customWidgets = {}
 130             else:
 131                 self.customWidgets = customWidgets
 132
 133         def createWidget(self, class_name, parent=None, name=''):
 134             """
 135             Function that is called for each widget defined in ui file,
 136             overridden here to populate baseinstance instead.
 137             """
 138
 139             if parent is None and self.baseinstance:
 140                 # supposed to create the top-level widget, return the base
 141                 # instance instead
 142                 return self.baseinstance
 143
 144             else:
 145
 146                 # For some reason, Line is not in the list of available
 147                 # widgets, but works fine, so we have to special case it here.
 148                 if class_name in self.availableWidgets() or class_name == 'Line':
 149                     # create a new widget for child widgets
 150                     widget = QUiLoader.createWidget(self, class_name, parent, name)
 151
 152                 else:
 153                     # If not in the list of availableWidgets, must be a custom
 154                     # widget. This will raise KeyError if the user has not
 155                     # supplied the relevant class_name in the dictionary or if
 156                     # customWidgets is empty.
 157                     try:
 158                         widget = self.customWidgets[class_name](parent)
 159                     except KeyError:
 160                         raise Exception('No custom widget ' + class_name + ' '
 161                                         'found in customWidgets')
 162
 163                 if self.baseinstance:
 164                     # set an attribute for the new child widget on the base
 165                     # instance, just like PyQt4.uic.loadUi does.
 166                     setattr(self.baseinstance, name, widget)
 167
 168                 return widget
 169
 170     def _get_custom_widgets(ui_file):
 171         """
 172         This function is used to parse a ui file and look for the <customwidgets>
 173         section, then automatically load all the custom widget classes.
 174         """
 175
 176         import sys
 177         import importlib
 178         from xml.etree.ElementTree import ElementTree
 179
 180         # Parse the UI file
 181         etree = ElementTree()
 182         ui = etree.parse(ui_file)
 183
 184         # Get the customwidgets section
 185         custom_widgets = ui.find('customwidgets')
 186
 187         if custom_widgets is None:
 188             return {}
 189
 190         custom_widget_classes = {}
 191
 192         for custom_widget in list(custom_widgets):
 193
 194             cw_class = custom_widget.find('class').text
 195             cw_header = custom_widget.find('header').text
 196
 197             module = importlib.import_module(cw_header)
 198
 199             custom_widget_classes[cw_class] = getattr(module, cw_class)
 200
 201         return custom_widget_classes
 202
 203     def loadUi(uifile, baseinstance=None, workingDirectory=None):
 204         """
 205         Dynamically load a user interface from the given ``uifile``.
 206
 207         ``uifile`` is a string containing a file name of the UI file to load.
 208
 209         If ``baseinstance`` is ``None``, the a new instance of the top-level
 210         widget will be created. Otherwise, the user interface is created within
 211         the given ``baseinstance``. In this case ``baseinstance`` must be an
 212         instance of the top-level widget class in the UI file to load, or a
 213         subclass thereof. In other words, if you've created a ``QMainWindow``
 214         interface in the designer, ``baseinstance`` must be a ``QMainWindow``
 215         or a subclass thereof, too. You cannot load a ``QMainWindow`` UI file
 216         with a plain :class:`~PySide.QtGui.QWidget` as ``baseinstance``.
 217
 218         :method:`~PySide.QtCore.QMetaObject.connectSlotsByName()` is called on
 219         the created user interface, so you can implemented your slots according
 220         to its conventions in your widget class.
 221
 222         Return ``baseinstance``, if ``baseinstance`` is not ``None``. Otherwise
 223         return the newly created instance of the user interface.
 224         """
 225
 226         # We parse the UI file and import any required custom widgets
 227         customWidgets = _get_custom_widgets(uifile)
 228
 229         loader = UiLoader(baseinstance, customWidgets)
 230
 231         if workingDirectory is not None:
 232             loader.setWorkingDirectory(workingDirectory)
 233
 234         widget = loader.load(uifile)
 235         QMetaObject.connectSlotsByName(widget)
 236         return widget
 237
 238     def loadUiType(uifile, from_imports=False):
 239         """Load a .ui file and return the generated form class and
 240         the Qt base class.
 241
 242         The "loadUiType" command convert the ui file to py code
 243         in-memory first and then execute it in a special frame to
 244         retrieve the form_class.
 245
 246         Credit: https://stackoverflow.com/a/14195313/15954282
 247         """
 248
 249         import sys
 250         if sys.version_info >= (3, 0):
 251             from io import StringIO
 252         else:
 253             from io import BytesIO as StringIO
 254         from xml.etree.ElementTree import ElementTree
 255         from . import QtWidgets
 256
 257         # Parse the UI file
 258         etree = ElementTree()
 259         ui = etree.parse(uifile)
 260
 261         widget_class = ui.find('widget').get('class')
 262         form_class = ui.find('class').text
 263
 264         with open(uifile, 'r') as fd:
 265             code_stream = StringIO()
 266             frame = {}
 267
 268             compileUi(fd, code_stream, indent=0, from_imports=from_imports)
 269             pyc = compile(code_stream.getvalue(), '<string>', 'exec')
 270             exec(pyc, frame)
 271
 272             # Fetch the base_class and form class based on their type in the
 273             # xml from designer
 274             form_class = frame['Ui_%s' % form_class]
 275             base_class = getattr(QtWidgets, widget_class)
 276
 277         return form_class, base_class