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