qtpy/compat.py

   1 # -*- coding: utf-8 -*-
   2 #
   3 # Copyright © 2009- The Spyder Development Team
   4 # Licensed under the terms of the MIT License
   5
   6 """
   7 Compatibility functions
   8 """
   9
  10 from __future__ import print_function
  11 import sys
  12 import collections
  13
  14 from . import PYQT4
  15 from .QtWidgets import QFileDialog
  16 from .py3compat import is_text_string, to_text_string, TEXT_TYPES
  17
  18
  19 # =============================================================================
  20 # QVariant conversion utilities
  21 # =============================================================================
  22 PYQT_API_1 = False
  23 if PYQT4:
  24     import sip
  25     try:
  26         PYQT_API_1 = sip.getapi('QVariant') == 1  # PyQt API #1
  27     except AttributeError:
  28         # PyQt <v4.6
  29         PYQT_API_1 = True
  30
  31     def to_qvariant(pyobj=None):
  32         """Convert Python object to QVariant
  33         This is a transitional function from PyQt API #1 (QVariant exist)
  34         to PyQt API #2 and Pyside (QVariant does not exist)"""
  35         if PYQT_API_1:
  36             # PyQt API #1
  37             from PyQt4.QtCore import QVariant
  38             return QVariant(pyobj)
  39         else:
  40             # PyQt API #2
  41             return pyobj
  42
  43     def from_qvariant(qobj=None, convfunc=None):
  44         """Convert QVariant object to Python object
  45         This is a transitional function from PyQt API #1 (QVariant exist)
  46         to PyQt API #2 and Pyside (QVariant does not exist)"""
  47         if PYQT_API_1:
  48             # PyQt API #1
  49             assert isinstance(convfunc, collections.Callable)
  50             if convfunc in TEXT_TYPES or convfunc is to_text_string:
  51                 return convfunc(qobj.toString())
  52             elif convfunc is bool:
  53                 return qobj.toBool()
  54             elif convfunc is int:
  55                 return qobj.toInt()[0]
  56             elif convfunc is float:
  57                 return qobj.toDouble()[0]
  58             else:
  59                 return convfunc(qobj)
  60         else:
  61             # PyQt API #2
  62             return qobj
  63 else:
  64     def to_qvariant(obj=None):  # analysis:ignore
  65         """Convert Python object to QVariant
  66         This is a transitional function from PyQt API#1 (QVariant exist)
  67         to PyQt API#2 and Pyside (QVariant does not exist)"""
  68         return obj
  69
  70     def from_qvariant(qobj=None, pytype=None):  # analysis:ignore
  71         """Convert QVariant object to Python object
  72         This is a transitional function from PyQt API #1 (QVariant exist)
  73         to PyQt API #2 and Pyside (QVariant does not exist)"""
  74         return qobj
  75
  76
  77 # =============================================================================
  78 # Wrappers around QFileDialog static methods
  79 # =============================================================================
  80 def getexistingdirectory(parent=None, caption='', basedir='',
  81                          options=QFileDialog.ShowDirsOnly):
  82     """Wrapper around QtGui.QFileDialog.getExistingDirectory static method
  83     Compatible with PyQt >=v4.4 (API #1 and #2) and PySide >=v1.0"""
  84     # Calling QFileDialog static method
  85     if sys.platform == "win32":
  86         # On Windows platforms: redirect standard outputs
  87         _temp1, _temp2 = sys.stdout, sys.stderr
  88         sys.stdout, sys.stderr = None, None
  89     try:
  90         result = QFileDialog.getExistingDirectory(parent, caption, basedir,
  91                                                   options)
  92     finally:
  93         if sys.platform == "win32":
  94             # On Windows platforms: restore standard outputs
  95             sys.stdout, sys.stderr = _temp1, _temp2
  96     if not is_text_string(result):
  97         # PyQt API #1
  98         result = to_text_string(result)
  99     return result
 100
 101
 102 def _qfiledialog_wrapper(attr, parent=None, caption='', basedir='',
 103                          filters='', selectedfilter='', options=None):
 104     if options is None:
 105         options = QFileDialog.Options(0)
 106     try:
 107         # PyQt <v4.6 (API #1)
 108         from .QtCore import QString
 109     except ImportError:
 110         # PySide or PyQt >=v4.6
 111         QString = None  # analysis:ignore
 112     tuple_returned = True
 113     try:
 114         # PyQt >=v4.6
 115         func = getattr(QFileDialog, attr+'AndFilter')
 116     except AttributeError:
 117         # PySide or PyQt <v4.6
 118         func = getattr(QFileDialog, attr)
 119         if QString is not None:
 120             selectedfilter = QString()
 121             tuple_returned = False
 122
 123     # Calling QFileDialog static method
 124     if sys.platform == "win32":
 125         # On Windows platforms: redirect standard outputs
 126         _temp1, _temp2 = sys.stdout, sys.stderr
 127         sys.stdout, sys.stderr = None, None
 128     try:
 129         result = func(parent, caption, basedir,
 130                       filters, selectedfilter, options)
 131     except TypeError:
 132         # The selectedfilter option (`initialFilter` in Qt) has only been
 133         # introduced in Jan. 2010 for PyQt v4.7, that's why we handle here
 134         # the TypeError exception which will be raised with PyQt v4.6
 135         # (see Issue 960 for more details)
 136         result = func(parent, caption, basedir, filters, options)
 137     finally:
 138         if sys.platform == "win32":
 139             # On Windows platforms: restore standard outputs
 140             sys.stdout, sys.stderr = _temp1, _temp2
 141
 142     # Processing output
 143     if tuple_returned:
 144         # PySide or PyQt >=v4.6
 145         output, selectedfilter = result
 146     else:
 147         # PyQt <v4.6 (API #1)
 148         output = result
 149     if QString is not None:
 150         # PyQt API #1: conversions needed from QString/QStringList
 151         selectedfilter = to_text_string(selectedfilter)
 152         if isinstance(output, QString):
 153             # Single filename
 154             output = to_text_string(output)
 155         else:
 156             # List of filenames
 157             output = [to_text_string(fname) for fname in output]
 158
 159     # Always returns the tuple (output, selectedfilter)
 160     return output, selectedfilter
 161
 162
 163 def getopenfilename(parent=None, caption='', basedir='', filters='',
 164                     selectedfilter='', options=None):
 165     """Wrapper around QtGui.QFileDialog.getOpenFileName static method
 166     Returns a tuple (filename, selectedfilter) -- when dialog box is canceled,
 167     returns a tuple of empty strings
 168     Compatible with PyQt >=v4.4 (API #1 and #2) and PySide >=v1.0"""
 169     return _qfiledialog_wrapper('getOpenFileName', parent=parent,
 170                                 caption=caption, basedir=basedir,
 171                                 filters=filters, selectedfilter=selectedfilter,
 172                                 options=options)
 173
 174
 175 def getopenfilenames(parent=None, caption='', basedir='', filters='',
 176                      selectedfilter='', options=None):
 177     """Wrapper around QtGui.QFileDialog.getOpenFileNames static method
 178     Returns a tuple (filenames, selectedfilter) -- when dialog box is canceled,
 179     returns a tuple (empty list, empty string)
 180     Compatible with PyQt >=v4.4 (API #1 and #2) and PySide >=v1.0"""
 181     return _qfiledialog_wrapper('getOpenFileNames', parent=parent,
 182                                 caption=caption, basedir=basedir,
 183                                 filters=filters, selectedfilter=selectedfilter,
 184                                 options=options)
 185
 186
 187 def getsavefilename(parent=None, caption='', basedir='', filters='',
 188                     selectedfilter='', options=None):
 189     """Wrapper around QtGui.QFileDialog.getSaveFileName static method
 190     Returns a tuple (filename, selectedfilter) -- when dialog box is canceled,
 191     returns a tuple of empty strings
 192     Compatible with PyQt >=v4.4 (API #1 and #2) and PySide >=v1.0"""
 193     return _qfiledialog_wrapper('getSaveFileName', parent=parent,
 194                                 caption=caption, basedir=basedir,
 195                                 filters=filters, selectedfilter=selectedfilter,
 196                                 options=options)