Python PyQt4.QtCore() Examples

def qt_import(shi=False, cui=False):
    """
    import pyside/pyQt

    Returns:
        multi: QtGui, QtCore, QtWidgets, wrapInstance

    """
    lookup = ["PySide2", "PySide", "PyQt4"]

    preferredBinding = os.environ.get("MGEAR_PYTHON_QT_BINDING", None)
    if preferredBinding is not None and preferredBinding in lookup:
        lookup.remove(preferredBinding)
        lookup.insert(0, preferredBinding)

    for binding in lookup:
        try:
            return _qt_import(binding, shi, cui)
        except Exception:
            pass

    raise _qt_import("ThisBindingSurelyDoesNotExist", False, False) 

def _qt_import(binding, shi=False, cui=False):
    QtGui = None
    QtCore = None
    QtWidgets = None
    wrapInstance = None

    if binding == "PySide2":
        from PySide2 import QtGui, QtCore, QtWidgets
        import shiboken2 as shiboken
        from shiboken2 import wrapInstance
        from pyside2uic import compileUi

    elif binding == "PySide":
        from PySide import QtGui, QtCore
        import PySide.QtGui as QtWidgets
        import shiboken
        from shiboken import wrapInstance
        from pysideuic import compileUi

    elif binding == "PyQt4":
        from PyQt4 import QtGui
        from PyQt4 import QtCore
        import PyQt4.QtGui as QtWidgets
        from sip import wrapinstance as wrapInstance
        from PyQt4.uic import compileUi
        print("Warning: 'shiboken' is not supported in 'PyQt4' Qt binding")
        shiboken = None

    else:
        raise Exception("Unsupported python Qt binding '%s'" % binding)

    rv = [QtGui, QtCore, QtWidgets, wrapInstance]
    if shi:
        rv.append(shiboken)
    if cui:
        rv.append(compileUi)
    return rv 

def _pyside2_as_qt_object(widget):
    from PySide2.QtCore import QObject
    from PySide2.QtWidgets import QWidget
    from PySide2 import QtWidgets
    from shiboken2 import wrapInstance
    if hasattr(widget, '__qt_object__'):
        return widget.__qt_object__
    ptr = _find_widget_ptr(widget)
    qobject = wrapInstance(long(ptr), QObject)
    meta = qobject.metaObject()
    _class = meta.className()
    _super = meta.superClass().className()
    qclass = getattr(QtWidgets, _class, getattr(QtWidgets, _super, QWidget))
    return wrapInstance(long(ptr), qclass) 

def _pyside_as_qt_object(widget):
    from PySide.QtCore import QObject
    from PySide.QtGui import QWidget
    from PySide import QtGui
    from shiboken import wrapInstance
    if hasattr(widget, '__qt_object__'):
        return widget.__qt_object__
    ptr = _find_widget_ptr(widget)
    qobject = wrapInstance(long(ptr), QObject)
    meta = qobject.metaObject()
    _class = meta.className()
    _super = meta.superClass().className()
    qclass = getattr(QtGui, _class, getattr(QtGui, _super, QWidget))
    return wrapInstance(long(ptr), qclass) 

def setupUi(self, MainWindow):
        MainWindow.setObjectName(_fromUtf8("MainWindow"))
        MainWindow.resize(993, 692)
        self.centralwidget = QtGui.QWidget(MainWindow)
        self.centralwidget.setObjectName(_fromUtf8("centralwidget"))
        self.horizontalLayout = QtGui.QHBoxLayout(self.centralwidget)
        self.horizontalLayout.setObjectName(_fromUtf8("horizontalLayout"))
        self.pbLevel = QtGui.QProgressBar(self.centralwidget)
        self.pbLevel.setMaximum(1000)
        self.pbLevel.setProperty("value", 123)
        self.pbLevel.setTextVisible(False)
        self.pbLevel.setOrientation(QtCore.Qt.Vertical)
        self.pbLevel.setObjectName(_fromUtf8("pbLevel"))
        self.horizontalLayout.addWidget(self.pbLevel)
        self.frame = QtGui.QFrame(self.centralwidget)
        self.frame.setFrameShape(QtGui.QFrame.NoFrame)
        self.frame.setFrameShadow(QtGui.QFrame.Plain)
        self.frame.setObjectName(_fromUtf8("frame"))
        self.verticalLayout = QtGui.QVBoxLayout(self.frame)
        self.verticalLayout.setMargin(0)
        self.verticalLayout.setObjectName(_fromUtf8("verticalLayout"))
        self.label = QtGui.QLabel(self.frame)
        self.label.setObjectName(_fromUtf8("label"))
        self.verticalLayout.addWidget(self.label)
        self.grFFT = PlotWidget(self.frame)
        self.grFFT.setObjectName(_fromUtf8("grFFT"))
        self.verticalLayout.addWidget(self.grFFT)
        self.label_2 = QtGui.QLabel(self.frame)
        self.label_2.setObjectName(_fromUtf8("label_2"))
        self.verticalLayout.addWidget(self.label_2)
        self.grPCM = PlotWidget(self.frame)
        self.grPCM.setObjectName(_fromUtf8("grPCM"))
        self.verticalLayout.addWidget(self.grPCM)
        self.horizontalLayout.addWidget(self.frame)
        MainWindow.setCentralWidget(self.centralwidget)

        self.retranslateUi(MainWindow)
        QtCore.QMetaObject.connectSlotsByName(MainWindow) 

def new_load_qt(api):
    """
    Directly import the Qt libraries rather than autodiscovering them
    """
    from PyQt4 import QtCore, QtGui, QtSvg
    return QtCore, QtGui, QtSvg, 'pyqt' 

def load_stylesheet_pyqt5():
    """
    Load the stylesheet for use in a pyqt5 application.

    :param pyside: True to load the pyside rc file, False to load the PyQt rc file

    :return the stylesheet string
    """
    warnings.warn(
        "load_stylesheet_pyqt5() will be deprecated in version 3,"
        "set QtPy environment variable to specify the Qt binding and "
        "use load_stylesheet()",
        PendingDeprecationWarning
    )
    # Smart import of the rc file
    import qdarkstyle.pyqt5_style_rc

    # Load the stylesheet content from resources
    from PyQt5.QtCore import QFile, QTextStream

    f = QFile(":qdarkstyle/style.qss")
    if not f.exists():
        _logger().error("Unable to load stylesheet, file not found in "
                        "resources")
        return ""
    else:
        f.open(QFile.ReadOnly | QFile.Text)
        ts = QTextStream(f)
        stylesheet = ts.readAll()
        if platform.system().lower() == 'darwin':  # see issue #12 on github
            mac_fix = '''
            QDockWidget::title
            {
                background-color: #31363b;
                text-align: center;
                height: 12px;
            }
            '''
            stylesheet += mac_fix
        return stylesheet 

def PyQt4_version():
    # FIXME, pyqt5 is also ok
    from PyQt4 import QtCore
    return module_stdinfo_dict(QtCore, 'PYQT_VERSION_STR') 

def eventFilter(self, obj, event):
        if event.type() == QtCore.QEvent.FileOpen:
            if len(self.windows) >= 1:
                self.windows[0].set_url(event.url().toEncoded())
                return True
        return False 

def keyPressEvent(self, e):
        if e.key() == QtCore.Qt.Key_Return:
            apply(self.func,()) 

def connect_slots(self, sender):
        self.connect(sender, QtCore.SIGNAL('timersignal'), self.timer_actions)
        self.previous_payto_e='' 

def change_currency_dialog(self):
        import operator
        d = QDialog(self)
        d.setWindowTitle(_('Change Currency'))
        main_layout = QVBoxLayout()
        change_info = QLabel( _("Note that you will need to enter your password the first time you use a new currency.\n") )
        change_info.setWordWrap(True)
        main_layout.addWidget(change_info)

        key_info = QLabel( _("PoW: Whether this wallet verifies proof-of-work.\nServers: Number of default servers to get data from.") )
        key_info.setWordWrap(True)
        main_layout.addWidget(key_info)

        chains_view = QTreeWidget()
        chains_view.setColumnCount(4)
        chains_view.setHeaderLabels([ _('Code'), _('Currency'), _('PoW'), _('Servers') ])
        chains_view.setColumnWidth(0, 75)
        chains_view.setColumnWidth(1, 125)
        chains_view.setColumnWidth(2, 60)
        chains_view.setColumnWidth(3, 50)
        chains_view.setMinimumWidth(325)
        chains = chainkey.chainparams._known_chains
        # Yes or No
        y_or_n = lambda x: 'Yes' if x==True else 'No'
        for ch in sorted(chains, key=operator.attrgetter('code')):
            server_trust = chainkey.chainparams.get_server_trust(ch.code)
            uses_pow = server_trust['pow']
            num_servers = server_trust['servers']
            item = QTreeWidgetItem([ch.code, ch.coin_name, y_or_n(uses_pow), str(num_servers)])
            chains_view.addTopLevelItem(item)
        chains_view.setCurrentItem(chains_view.topLevelItem(0))
        main_layout.addWidget(chains_view)

        main_layout.addLayout(ok_cancel_buttons(d))
        d.setLayout(main_layout)

        if not d.exec_(): return
        chaincode = str(chains_view.currentItem().text(0))
        self.emit(QtCore.SIGNAL('change_currency'), chaincode) 

def __init__(self, *args, **kwargs):
        super(QComboBox, self).__init__(*args, **kwargs)
#        self.scrollWidget=scrollWidget
        self.setFocusPolicy(QtCore.Qt.StrongFocus) 

def test_matplotlib_qt_backend():
    print ("testing matplotlib qt backend ...")
    try:
        # Matplot changed its file structure several times in history, so we
        # must test all
        try:
            from matplotlib.backends.qt_compat import QtCore
        except:
            try:
                from matplotlib.backends.qt4_compat import QtCore
            except:
                from matplotlib.backends.qt import QtCore
        from PyQt4 import QtCore as QtCore4

        if QtCore is QtCore4:
            print ("... test passed")
            return True
        else:
            using = QtCore.__name__.split('.')[0]
            expect = QtCore4.__name__.split('.')[0]
            print ("... Qt test FAILURE\n" +
                   "    Matplotlib is using %s\n" % using +
                   "    It must use %s\n" % expect +
                   "    Possible reasons for that are that " +
                   "%s is not installed " % expect +
                   "or the envoriment variable QT_API is overwriting it.")
            return False
    except:
        import traceback
        print(traceback.format_exc())
        print ("... If you experience this test failure, it may be an "
               "expected! We would like to know why, "
               "please report in 'https://github.com/nguy/artview/issues'")
        return None 

def _select_qt_binding(binding_name=None, binding_order=None):
    global QT_BINDING, QT_BINDING_VERSION

    # order of default bindings can be changed here
    DEFAULT_BINDING_ORDER = ['pyqt', 'pyside']
    binding_order = binding_order or DEFAULT_BINDING_ORDER

    # determine binding preference
    if binding_name:
        if binding_name not in binding_order:
            raise ImportError("Qt binding '%s' is unknown" % binding_name)
        binding_order = [binding_name]

    required_modules = [
        'QtCore',
        'QtGui',
        'uic',
    ]
    optional_modules = [
        'QtDeclarative',
        'QtMultimedia',
        'QtNetwork',
        'QtOpenGL',
        'QtOpenVG',
        'QtScript',
        'QtScriptTools'
        'QtSql',
        'QtSvg',
        'QtWebKit',
        'QtXml',
        'QtXmlPatterns',
        'QtUiTools',
    ]

    # try to load preferred bindings
    error_msgs = []
    for binding_name in binding_order:
        try:
            binding_loader = getattr(sys.modules[__name__], '_load_%s' % binding_name, None)
            if binding_loader:
                QT_BINDING_VERSION = binding_loader(required_modules, optional_modules)
                QT_BINDING = binding_name
                break
            else:
                error_msgs.append("  Binding loader '_load_%s' not found." % binding_name)
        except ImportError as e:
            error_msgs.append("  ImportError for '%s': %s" % (binding_name, e))

    if not QT_BINDING:
        raise ImportError("Could not find Qt binding (looked for: %s):\n%s" % (', '.join(["'%s'" % b for b in binding_order]), '\n'.join(error_msgs))) 

def _load_pyqt(required_modules, optional_modules):
    # set environment variable QT_API for matplotlib
    os.environ['QT_API'] = 'pyqt'

    # select PyQt4 API, see http://pyqt.sourceforge.net/Docs/PyQt4/incompatible_apis.html
    import sip
    try:
        sip.setapi('QDate', 2)
        sip.setapi('QDateTime', 2)
        sip.setapi('QString', 2)
        sip.setapi('QTextStream', 2)
        sip.setapi('QTime', 2)
        sip.setapi('QUrl', 2)
        sip.setapi('QVariant', 2)
    except ValueError as e:
        raise RuntimeError('Could not set API version (%s): did you import PyQt4 directly?' % e)

    # register required and optional PyQt4 modules
    for module_name in required_modules:
        _named_import('PyQt4.%s' % module_name)
    for module_name in optional_modules:
        _named_optional_import('PyQt4.%s' % module_name)

    # set some names for compatibility with PySide
    sys.modules['QtCore'].Signal = sys.modules['QtCore'].pyqtSignal
    sys.modules['QtCore'].Slot = sys.modules['QtCore'].pyqtSlot
    sys.modules['QtCore'].Property = sys.modules['QtCore'].pyqtProperty

    # try to register PyQt4.Qwt5 module
    try:
        import PyQt4.Qwt5
        _register_binding_module('Qwt', PyQt4.Qwt5)
    except ImportError:
        pass

    global _loadUi

    def _loadUi(uifile, baseinstance=None, custom_widgets_=None):
        from PyQt4 import uic
        return uic.loadUi(uifile, baseinstance=baseinstance)

    # override specific function to improve compatibility between different bindings
    from QtGui import QFileDialog
    QFileDialog.getOpenFileName = QFileDialog.getOpenFileNameAndFilter
    QFileDialog.getSaveFileName = QFileDialog.getSaveFileNameAndFilter

    import PyQt4.QtCore
    return PyQt4.QtCore.PYQT_VERSION_STR 

def load_stylesheet(pyside=True):
    """
    Load the stylesheet. Takes care of importing the rc module.

    :param pyside: True to load the pyside rc file, False to load the PyQt rc file

    :return the stylesheet string
    """
    warnings.warn(
        "load_stylesheet() will not receive pyside parameter in version 3. "
        "Set QtPy environment variable to specify the Qt binding insteady.",
        FutureWarning
    )
    # Smart import of the rc file
    if pyside:
        import qdarkstyle.pyside_style_rc
    else:
        import qdarkstyle.pyqt_style_rc

    # Load the stylesheet content from resources
    if not pyside:
        from PyQt4.QtCore import QFile, QTextStream
    else:
        from PySide.QtCore import QFile, QTextStream

    f = QFile(":qdarkstyle/style.qss")
    if not f.exists():
        _logger().error("Unable to load stylesheet, file not found in "
                        "resources")
        return ""
    else:
        f.open(QFile.ReadOnly | QFile.Text)
        ts = QTextStream(f)
        stylesheet = ts.readAll()
        if platform.system().lower() == 'darwin':  # see issue #12 on github
            mac_fix = '''
            QDockWidget::title
            {
                background-color: #31363b;
                text-align: center;
                height: 12px;
            }
            '''
            stylesheet += mac_fix
        return stylesheet 

def _select_qt_binding(binding_name=None, binding_order=None):
    global QT_BINDING, QT_BINDING_VERSION

    # order of default bindings can be changed here
    DEFAULT_BINDING_ORDER = ['pyqt', 'pyside']
    binding_order = binding_order or DEFAULT_BINDING_ORDER

    # determine binding preference
    if binding_name:
        if binding_name not in binding_order:
            raise ImportError("Qt binding '%s' is unknown" % binding_name)
        binding_order = [binding_name]

    required_modules = [
        'QtCore',
        'QtGui'
    ]
    optional_modules = [
        'QtDeclarative',
        'QtMultimedia',
        'QtNetwork',
        'QtOpenGL',
        'QtOpenVG',
        'QtScript',
        'QtScriptTools'
        'QtSql',
        'QtSvg',
        'QtWebKit',
        'QtXml',
        'QtXmlPatterns',
    ]

    # try to load preferred bindings
    error_msgs = []
    for binding_name in binding_order:
        try:
            binding_loader = globals().get('_load_%s' % binding_name, None)
            if binding_loader:
                QT_BINDING_VERSION = binding_loader(
                        required_modules, optional_modules)
                QT_BINDING = binding_name
                break
            else:
                error_msgs.append(
                        "  Binding loader '_load_%s' not found." % binding_name)
        except ImportError as e:
            error_msgs.append(
                    "  ImportError for '%s': %s" % (binding_name, e))

    if not QT_BINDING:
        raise ImportError(
                "Could not find Qt binding (looked for: %s):\n%s" % (
                    ', '.join(["'%s'" % b for b in binding_order]),
                    '\n'.join(error_msgs))
                ) 

def _load_pyqt(required_modules, optional_modules):
    os.environ['QT_API'] = 'pyqt'

    # select PyQt4 API, see
    # http://pyqt.sourceforge.net/Docs/PyQt4/incompatible_apis.html
    import sip
    try:
        sip.setapi('QDate', 2)
        sip.setapi('QDateTime', 2)
        sip.setapi('QString', 2)
        sip.setapi('QTextStream', 2)
        sip.setapi('QTime', 2)
        sip.setapi('QUrl', 2)
        sip.setapi('QVariant', 2)
    except ValueError as e:
        raise RuntimeError(
                'Could not set API version (%s): did you import PyQt4 '
                'directly?' % e)

    for module_name in required_modules:
        _named_import('PyQt4.%s' % module_name)
    for module_name in optional_modules:
        _named_optional_import('PyQt4.%s' % module_name)

    # set some names for compatibility with PySide
    sys.modules['PyQt4.QtCore'].Signal   = sys.modules['PyQt4.QtCore'].pyqtSignal
    sys.modules['PyQt4.QtCore'].Slot     = sys.modules['PyQt4.QtCore'].pyqtSlot
    sys.modules['PyQt4.QtCore'].Property = sys.modules['PyQt4.QtCore'].pyqtProperty

    try:
        import PyQt4.Qwt5
        _register_binding_module('Qwt', PyQt4.Qwt5)
    except ImportError:
        pass

    global _loadUi

    def _loadUi(uifile, baseinstance=None, custom_widgets_=None):
        from PyQt4 import uic
        return uic.loadUi(uifile, baseinstance=baseinstance)

    # override specific function to improve compatibility between different
    # bindings
    from PyQt4.QtGui import QFileDialog
    QFileDialog.getOpenFileName = QFileDialog.getOpenFileNameAndFilter
    QFileDialog.getSaveFileName = QFileDialog.getSaveFileNameAndFilter

    import PyQt4.QtCore
    return PyQt4.QtCore.PYQT_VERSION_STR 

def main():
    msg = []
    if ImageWriter is None:
        msg.append('Image output disabled (PIL not found), --type option '
                   'disabled.')
    else:
        msg.append('Image output enabled, use --type option to give image '
                   'format (png, jpeg, ...).')
    if QtCore is None:
        msg.append('PyQt not found, gui action disabled.')
    else:
        msg.append('PyQt found. Use gui action to get a simple GUI.')
    parser = ArgumentParser(
        description=barcode.__description__,
        epilog=' '.join(msg))
    parser.add_argument(
        '-v', '--version',
        action='version',
        version='%(prog)s ' + barcode.__release__)
    subparsers = parser.add_subparsers(title='Actions')
    create_parser = subparsers.add_parser(
        'create',
        help='Create a barcode with the given options.')
    create_parser.add_argument(
        'code',
        help='Code to render as barcode.')
    create_parser.add_argument(
        'output',
        help='Filename for output without extension, e.g. mybarcode.')
    create_parser.add_argument(
        '-c', '--compress',
        action='store_true',
        help='Compress output, only recognized if type is svg.')
    create_parser.add_argument(
        '-b', '--barcode',
        help='Barcode to use [default: %(default)s].')
    if ImageWriter is not None:
        create_parser.add_argument(
            '-t', '--type',
            help='Type of output [default: %(default)s].')
    list_parser = subparsers.add_parser(
        'list', help='List available image and code types.')
    list_parser.set_defaults(func=list_types)
    if QtCore is not None:
        gui_parser = subparsers.add_parser(
            'gui', help='Opens a simple PyQt GUI to create barcodes.')
        gui_parser.set_defaults(func=open_gui)
    create_parser.set_defaults(
        barcode='code39',
        compress=False,
        func=create_barcode,
        type='svg')
    args = parser.parse_args()
    args.func(args, parser)