Source code for qwt.qtdesigner
# -*- coding: utf-8 -*-
#
# Licensed under the terms of the Qwt License
# Copyright (c) 2015 Pierre Raybaut, for the Qt Designer plugin helpers
# (see LICENSE file for more details)
"""
Qt Designer
-----------
The :mod:`qwt.qtdesigner` module provides helpers to integrate :mod:`qwt`
widgets into Qt Designer:
* :py:class:`QwtPlotWidget`
* :py:func:`loadui`
* :py:func:`compileui`
* :py:func:`create_qtdesigner_plugin`
:class:`QwtPlotWidget` is a thin :class:`qwt.QwtPlot` subclass exposing the
standard Qt widget constructor (``__init__(self, parent=None)``). It is the
widget promoted by the Qt Designer plugin, so that the code generated by
``uic`` (e.g. ``QwtPlotWidget(parent=...)`` with PyQt6) instantiates it
correctly. :class:`qwt.QwtPlot` itself keeps its historical constructor.
.. note::
Qt Designer custom widget plugins rely on
:class:`QtDesigner.QPyDesignerCustomWidgetPlugin`, which is only available
with PyQt5/PyQt6. PySide6 does not expose this class.
.. autoclass:: QwtPlotWidget
.. autofunction:: loadui
.. autofunction:: compileui
.. autofunction:: create_qtdesigner_plugin
"""
from __future__ import annotations
import io
from qtpy import QtGui as QG
from qtpy import uic
from qwt.plot import QwtPlot
[docs]
def loadui(fname: str, replace_class: str | None = None):
"""Return Widget or Window class from a Qt Designer ``.ui`` file.
When a promoted widget inherits from a class that is not known to the
``uic`` parser (i.e. not a standard Qt widget), ``loadUiType`` fails to
resolve the widget hierarchy. Passing the offending base class name as
``replace_class`` neutralizes it by substituting ``QFrame`` (the base
class of :class:`qwt.QwtPlot`) before the file is parsed.
For a plain :class:`qwt.QwtPlot` widget (which already inherits from
``QFrame``), no replacement is required and ``replace_class`` can be left
to ``None``.
Args:
fname: Path to the ``.ui`` file
replace_class: Base class name to replace by ``QFrame``, or ``None``
to load the file unchanged
Returns:
The generated form class
"""
with open(fname) as f:
uifile_text = f.read()
if replace_class is not None:
uifile_text = uifile_text.replace(replace_class, "QFrame")
ui, base_class = uic.loadUiType(io.StringIO(uifile_text))
class Form(base_class, ui):
"""Form class generated from the ``.ui`` file"""
def __init__(self, parent=None):
super().__init__(parent)
self.setupUi(self)
return Form
[docs]
def compileui(fname: str, replace_class: str | None = None) -> None:
"""Compile a Qt Designer ``.ui`` file into a Python module.
Args:
fname: Path to the ``.ui`` file
replace_class: Base class name to replace by ``QFrame``, or ``None``
to compile the file unchanged
"""
with open(fname) as f:
uifile_text = f.read()
if replace_class is not None:
uifile_text = uifile_text.replace(replace_class, "QFrame")
with open(fname.replace(".ui", "_ui.py"), "w") as pyfile:
uic.compileUi(io.StringIO(uifile_text), pyfile, pyqt3_wrapper=True)
[docs]
def create_qtdesigner_plugin(
group: str,
module_name: str,
class_name: str,
icon: str | QG.QIcon | None = None,
tooltip: str = "",
whatsthis: str = "",
):
"""Return a custom Qt Designer plugin class.
Args:
group: Name of the group the widget belongs to in Qt Designer
module_name: Name of the module where the widget class is defined
class_name: Name of the widget class
icon: Icon shown in Qt Designer (path to an image file or
:class:`QtGui.QIcon` instance)
tooltip: Tool tip shown in Qt Designer
whatsthis: "What's this" help text shown in Qt Designer
Returns:
A :class:`QtDesigner.QPyDesignerCustomWidgetPlugin` subclass
Example::
Plugin = create_qtdesigner_plugin(
group="PythonQwt",
module_name="qwt.qtdesigner",
class_name="QwtPlotWidget",
)
"""
from qtpy.QtDesigner import QPyDesignerCustomWidgetPlugin
Widget = getattr(__import__(module_name, fromlist=[class_name]), class_name)
class CustomWidgetPlugin(QPyDesignerCustomWidgetPlugin):
"""Qt Designer plugin for the ``%s`` widget""" % class_name
def __init__(self, parent=None):
QPyDesignerCustomWidgetPlugin.__init__(self)
self.initialized = False
def initialize(self, core):
"""Initialize the plugin"""
if self.initialized:
return
self.initialized = True
def isInitialized(self):
"""Return whether the plugin has been initialized"""
return self.initialized
def createWidget(self, parent):
"""Return a new instance of the custom widget"""
return Widget(parent)
def name(self):
"""Return the name of the custom widget class"""
return class_name
def group(self):
"""Return the name of the group the widget belongs to"""
return group
def icon(self):
"""Return the icon shown in Qt Designer"""
if isinstance(icon, QG.QIcon):
return icon
elif isinstance(icon, str):
return QG.QIcon(icon)
return QG.QIcon()
def toolTip(self):
"""Return the tool tip shown in Qt Designer"""
return tooltip
def whatsThis(self):
"""Return the "What's this" help text shown in Qt Designer"""
return whatsthis
def isContainer(self):
"""Return whether the widget is a container"""
return False
def domXml(self):
"""Return the XML used to define the widget in Qt Designer"""
return f'<widget class="{class_name}" name="{class_name.lower()}" />\n'
def includeFile(self):
"""Return the module name where the widget class is defined"""
return module_name
return CustomWidgetPlugin
