Classwizard Example#
Demonstrates the use of QDialog in a wizard application
This example demonstrates the use a custom QDialog in a wizard, which generates Python class template code.
<!DOCTYPE RCC><RCC version="1.0">
<qresource>
<file>images/background.png</file>
<file>images/banner.png</file>
<file>images/watermark1.png</file>
</qresource>
</RCC>
# Copyright (C) 2013 Riverbank Computing Limited.
# Copyright (C) 2022 The Qt Company Ltd.
# SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
import os
from pathlib import Path
import sys
from PySide6.QtCore import QDir, QFileInfo, QUrl, Slot
from PySide6.QtGui import QDesktopServices, QPixmap
from PySide6.QtWidgets import (QApplication, QComboBox, QCheckBox, QFormLayout,
QFileDialog, QHBoxLayout, QLabel, QLineEdit,
QMessageBox, QToolButton, QVBoxLayout, QWizard,
QWizardPage)
from listchooser import PropertyChooser, SignalChooser
import classwizard_rc # noqa: F401
BASE_CLASSES = ['<None>', 'PySide6.QtCore.QObject',
'PySide6.QtWidgets.QDialog', 'PySide6.QtWidgets.QMainWindow',
'PySide6.QtWidgets.QWidget']
PYTHON_TYPES = ['int', 'list', 'str']
INTRODUCTION = ("This wizard will generate a skeleton Python class definition, "
"including a few functions. You simply need to specify the class name and set "
"a few options to produce a Python file.")
def property_accessors(property_type, name):
"""Generate the property accessor functions."""
return (f' @Property({property_type})\n'
f' def {name}(self):\n'
f' return self._{name}\n\n'
f' @{name}.setter\n'
f' def {name}(self, value):\n'
f' self._{name} = value\n')
def property_initialization(property_type, name):
"""Generate the property initialization for __init__()."""
return f' self._{name} = {property_type}()\n'
def signal_initialization(signature):
"""Generate the Signal initialization from the function signature."""
paren_pos = signature.find('(')
name = signature[:paren_pos]
parameters = signature[paren_pos:]
return f' {name} = Signal{parameters}\n'
class ClassWizard(QWizard):
def __init__(self, parent=None):
super().__init__(parent)
self.addPage(IntroPage())
self._class_info_index = self.addPage(ClassInfoPage())
self._qobject_index = self.addPage(QObjectPage())
self._output_index = self.addPage(OutputFilesPage())
self.addPage(ConclusionPage())
self.setPixmap(QWizard.BannerPixmap,
QPixmap(':/images/banner.png'))
self.setPixmap(QWizard.BackgroundPixmap,
QPixmap(':/images/background.png'))
self.setWindowTitle("Class Wizard")
def nextId(self):
"""Overrides QWizard.nextId() to insert the property/signal
page in case the class is a QObject."""
idx = self.currentId()
if idx == self._class_info_index:
qobject = self.field('qobject')
return self._qobject_index if qobject else self._output_index
return super(ClassWizard, self).nextId()
def generate_code(self):
imports = [] # Classes to be imported
module_imports = {} # Module->class list
def add_import(class_str):
"""Add a class to the import list or module hash depending on
whether it is 'class' or 'module.class'. Returns the
class name."""
dot = class_str.rfind('.')
if dot < 0:
imports.append(class_str)
return class_str
module = class_str[0:dot]
class_name = class_str[dot + 1:]
class_list = module_imports.get(module)
if class_list:
if class_name not in class_list:
class_list.append(class_name)
else:
module_imports[module] = [class_name]
return class_name
class_name = self.field('className')
qobject = self.field('qobject')
base_class = self.field('baseClass')
if base_class.startswith('<'): # <None>
base_class = ''
if qobject and not base_class:
base_class = 'PySide6.QtCore.QObject'
if base_class:
base_class = add_import(base_class)
signals = self.field('signals')
if signals:
add_import('PySide6.QtCore.Signal')
property_types = []
property_names = []
for p in self.field('properties'):
property_type, property_name = str(p).split(' ')
if property_type not in PYTHON_TYPES:
property_type = add_import(property_type)
property_types.append(property_type)
property_names.append(property_name)
if property_names:
add_import('PySide6.QtCore.Property')
signals = self.field('signals')
if signals:
add_import('PySide6.QtCore.Signal')
property_types = []
property_names = []
for p in self.field('properties'):
property_type, property_name = str(p).split(' ')
if property_type not in PYTHON_TYPES:
property_type = add_import(property_type)
property_types.append(property_type)
property_names.append(property_name)
if property_names:
add_import('PySide6.QtCore.Property')
# Generate imports
block = '# This Python file uses the following encoding: utf-8\n\n'
for module, class_list in module_imports.items():
class_list.sort()
class_list_str = ', '.join(class_list)
block += f'from {module} import {class_list_str}\n'
for klass in imports:
block += f'import {klass}\n'
# Generate class definition
block += f'\n\nclass {class_name}'
if base_class:
block += f'({base_class})'
block += ':\n'
description = self.field('description')
if description:
block += f' """{description}"""\n'
if signals:
block += '\n'
for s in signals:
block += signal_initialization(str(s))
# Generate __init__ function
block += '\n def __init__(self'
if qobject:
block += ', parent=None'
block += '):\n'
if base_class:
block += ' super().__init__('
if qobject:
block += 'parent'
block += ')\n'
for i, name in enumerate(property_names):
block += property_initialization(property_types[i], name)
if not base_class and not property_names:
block += ' pass\n'
# Generate property accessors
for i, name in enumerate(property_names):
block += '\n' + property_accessors(property_types[i], name)
return block
def accept(self):
file_name = self.field('file')
output_dir = self.field('outputDir')
python_file = Path(output_dir) / file_name
name = os.fspath(python_file)
try:
python_file.write_text(self.generate_code())
except (OSError, PermissionError) as e:
reason = str(e)
QMessageBox.warning(None, "Class Wizard",
f"Cannot write file {name}:\n{reason}")
return
if self.field('launch'):
url = QUrl.fromLocalFile(QDir.fromNativeSeparators(name))
QDesktopServices.openUrl(url)
super(ClassWizard, self).accept()
class IntroPage(QWizardPage):
def __init__(self, parent=None):
super().__init__(parent)
self.setTitle("Introduction")
self.setPixmap(QWizard.WatermarkPixmap,
QPixmap(':/images/watermark1.png'))
label = QLabel(INTRODUCTION)
label.setWordWrap(True)
layout = QVBoxLayout(self)
layout.addWidget(label)
class ClassInfoPage(QWizardPage):
def __init__(self, parent=None):
super().__init__(parent)
self.setTitle("Class Information")
self.setSubTitle("Specify basic information about the class for "
"which you want to generate a skeleton source code file.")
self.setPixmap(QWizard.LogoPixmap,
QPixmap(':/qt-project.org/logos/pysidelogo.png'))
class_name_line_edit = QLineEdit()
class_name_line_edit.setClearButtonEnabled(True)
self._base_class_combo = QComboBox()
self._base_class_combo.addItems(BASE_CLASSES)
self._base_class_combo.setEditable(True)
base_class_line_edit = self._base_class_combo.lineEdit()
base_class_line_edit.setPlaceholderText('Module.Class')
self._base_class_combo.currentTextChanged.connect(self._base_class_changed)
description_line_edit = QLineEdit()
description_line_edit.setClearButtonEnabled(True)
self._qobject_check_box = QCheckBox("Inherits QObject")
self.registerField('className*', class_name_line_edit)
self.registerField('baseClass', base_class_line_edit)
self.registerField('description', description_line_edit)
self.registerField('qobject', self._qobject_check_box)
layout = QFormLayout(self)
layout.addRow("&Class name:", class_name_line_edit)
layout.addRow("B&ase class:", self._base_class_combo)
layout.addRow("&Description:", description_line_edit)
layout.addRow(self._qobject_check_box)
@Slot(str)
def _base_class_changed(self, text):
is_qobject = text.startswith('PySide')
self._qobject_check_box.setChecked(is_qobject)
class QObjectPage(QWizardPage):
"""Allows for adding properties and signals to a QObject."""
def __init__(self, parent=None):
super().__init__(parent)
self.setTitle("QObject parameters")
self.setSubTitle("Specify the signals, slots and properties.")
self.setPixmap(QWizard.LogoPixmap,
QPixmap(':/qt-project.org/logos/pysidelogo.png'))
layout = QVBoxLayout(self)
self._properties_chooser = PropertyChooser()
self.registerField('properties', self._properties_chooser, 'items')
layout.addWidget(self._properties_chooser)
self._signals_chooser = SignalChooser()
self.registerField('signals', self._signals_chooser, 'items')
layout.addWidget(self._signals_chooser)
class OutputFilesPage(QWizardPage):
def __init__(self, parent=None):
super().__init__(parent)
self.setTitle("Output Files")
self.setSubTitle("Specify where you want the wizard to put the "
"generated skeleton code.")
self.setPixmap(QWizard.LogoPixmap,
QPixmap(':/qt-project.org/logos/pysidelogo.png'))
output_dir_label = QLabel("&Output directory:")
output_dir_layout = QHBoxLayout()
self._output_dir_line_edit = QLineEdit()
output_dir_layout.addWidget(self._output_dir_line_edit)
output_dir_label.setBuddy(self._output_dir_line_edit)
output_dir_button = QToolButton()
output_dir_button.setText('...')
output_dir_button.clicked.connect(self._choose_output_dir)
output_dir_layout.addWidget(output_dir_button)
self._file_line_edit = QLineEdit()
self.registerField('outputDir*', self._output_dir_line_edit)
self.registerField('file*', self._file_line_edit)
layout = QFormLayout(self)
layout.addRow(output_dir_label, output_dir_layout)
layout.addRow("&File name:", self._file_line_edit)
def initializePage(self):
class_name = self.field('className')
self._file_line_edit.setText(class_name.lower() + '.py')
self.set_output_dir(QDir.tempPath())
def set_output_dir(self, directory):
self._output_dir_line_edit.setText(QDir.toNativeSeparators(directory))
def output_dir(self):
return QDir.fromNativeSeparators(self._output_dir_line_edit.text())
def file_name(self):
return f"{self.output_dir()}/{self._file_line_edit.text()}"
def _choose_output_dir(self):
directory = QFileDialog.getExistingDirectory(self, "Output Directory",
self.output_dir())
if directory:
self.set_output_dir(directory)
def validatePage(self):
"""Ensure we do not overwrite existing files."""
name = self.file_name()
if QFileInfo.exists(name):
question = f'{name} already exists. Would you like to overwrite it?'
r = QMessageBox.question(self, 'File Exists', question)
if r != QMessageBox.Yes:
return False
return True
class ConclusionPage(QWizardPage):
def __init__(self, parent=None):
super().__init__(parent)
self.setTitle("Conclusion")
self.setPixmap(QWizard.WatermarkPixmap,
QPixmap(':/images/watermark1.png'))
self.label = QLabel()
self.label.setWordWrap(True)
self._launch_check_box = QCheckBox("Launch")
self.registerField('launch', self._launch_check_box)
layout = QVBoxLayout(self)
layout.addWidget(self.label)
layout.addWidget(self._launch_check_box)
def initializePage(self):
finish_text = self.wizard().buttonText(QWizard.FinishButton)
finish_text = finish_text.replace('&', '')
self.label.setText(f"Click {finish_text} to generate the class skeleton.")
self._launch_check_box.setChecked(True)
if __name__ == '__main__':
app = QApplication(sys.argv)
wizard = ClassWizard()
wizard.show()
sys.exit(app.exec())
# Copyright (C) 2022 The Qt Company Ltd.
# SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
from PySide6.QtCore import QRegularExpression, Property, Slot
from PySide6.QtGui import QRegularExpressionValidator
from PySide6.QtWidgets import (QComboBox, QDialog, QDialogButtonBox,
QFormLayout, QGroupBox, QHBoxLayout,
QLineEdit, QListWidget,
QListWidgetItem, QPushButton, QVBoxLayout,
)
DEFAULT_TYPES = ['int', 'str', 'PySide6.QtCore.QPoint', 'PySide6.QtCore.QRect',
'PySide6.QtCore.QSize', 'PySide6.QtGui.QColor']
FUNCTION_PATTERN = r'^\w+\([\w ,]*\)$'
class ValidatingInputDialog(QDialog):
"""A dialog for text input with a regular expression validation."""
def __init__(self, label, pattern, parent=None):
super().__init__(parent)
layout = QVBoxLayout(self)
self._form_layout = QFormLayout()
self._lineedit = QLineEdit()
self._lineedit.setClearButtonEnabled(True)
re = QRegularExpression(pattern)
assert re.isValid()
self._validator = QRegularExpressionValidator(re, self)
self._lineedit.setValidator(self._validator)
self._form_layout.addRow(label, self._lineedit)
layout.addLayout(self._form_layout)
bb = QDialogButtonBox(QDialogButtonBox.Ok | QDialogButtonBox.Cancel)
layout.addWidget(bb)
bb.rejected.connect(self.reject)
bb.accepted.connect(self.accept)
@Property(str)
def text(self):
return self._lineedit.text()
@text.setter
def text(self, t):
self._lineedit.setText(t)
@Property(str)
def placeholder_text(self):
return self._lineedit.placeholderText()
@placeholder_text.setter
def placeholder_text(self, t):
self._lineedit.setPlaceholderText(t)
@Property(int)
def cursor_position(self):
return self._lineedit.cursorPosition()
@cursor_position.setter
def cursor_position(self, p):
self._lineedit.setCursorPosition(p)
def is_valid(self):
return self.text
def accept(self):
if self.is_valid():
super(ValidatingInputDialog, self).accept()
class FunctionSignatureDialog(ValidatingInputDialog):
"""A dialog for input of function signatures."""
def __init__(self, name, parent=None):
super().__init__(name, FUNCTION_PATTERN, parent)
self.text = '()'
self.cursor_position = 0
class PropertyDialog(ValidatingInputDialog):
"""A dialog for input of a property name and type."""
def __init__(self, parent=None):
super().__init__('&Name:', r'^\w+$', parent)
self.setWindowTitle('Add a Property')
self._type_combo = QComboBox()
self._type_combo.addItems(DEFAULT_TYPES)
self._form_layout.insertRow(0, '&Type:', self._type_combo)
def property_type(self):
return self._type_combo.currentText()
class ListChooser(QGroupBox):
"""A widget for editing a list of strings with a customization point
for creating the strings."""
def __init__(self, title, parent=None):
super().__init__(title, parent)
main_layout = QHBoxLayout(self)
self._list = QListWidget(self)
self._list.currentItemChanged.connect(self._current_item_changed)
main_layout.addWidget(self._list)
vbox_layout = QVBoxLayout()
main_layout.addLayout(vbox_layout)
self._addButton = QPushButton("Add...")
vbox_layout.addWidget(self._addButton)
self._addButton.clicked.connect(self._add)
self._removeButton = QPushButton("Remove")
self._removeButton.setEnabled(False)
self._removeButton.clicked.connect(self._remove_current)
vbox_layout.addWidget(self._removeButton)
vbox_layout.addStretch()
@Property(list)
def items(self):
result = []
for i in range(self._list.count()):
result.append(self._list.item(i).text())
return result
@items.setter
def items(self, item_list):
self._list.clear()
for i in item_list:
self._list.append(i)
@Slot(QListWidgetItem, QListWidgetItem)
def _current_item_changed(self, current, previous):
self._removeButton.setEnabled(current is not None)
@Slot()
def _add(self):
new_item = self._create_new_item()
if new_item:
self._list.addItem(new_item)
def _create_new_item(self):
"""Overwrite to return a new item."""
return 'new_item'
@Slot()
def _remove_current(self):
row = self._list.row(self._list.currentItem())
if row >= 0:
self._list.takeItem(row)
class SignalChooser(ListChooser):
"""A widget for editing a list of signal function signatures."""
def __init__(self, parent=None):
super().__init__('Signals', parent)
def _create_new_item(self):
dialog = FunctionSignatureDialog('&Signal signature:', self)
dialog.setWindowTitle('Enter Signal')
if dialog.exec() != QDialog.Accepted:
return ''
return dialog.text
class PropertyChooser(ListChooser):
"""A widget for editing a list of properties as a string of 'type name'."""
def __init__(self, parent=None):
super().__init__('Properties', parent)
def _create_new_item(self):
dialog = PropertyDialog(self)
if dialog.exec() != QDialog.Accepted:
return ''
name = dialog.text
property_type = dialog.property_type()
return f'{property_type} {name}'