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# Source code for pyqtgraph.parametertree.parameterTypes.pen

    import re
    from contextlib import ExitStack

    from ... import functions as fn
    from ...Qt import QtCore, QtWidgets
    from ...SignalProxy import SignalProxy
    from ...widgets.PenPreviewLabel import PenPreviewLabel
    from . import GroupParameterItem, WidgetParameterItem
    from .basetypes import GroupParameter, Parameter, ParameterItem
    from .qtenum import QtEnumParameter

    class PenParameterItem(GroupParameterItem):
        def __init__(self, param, depth):
            self.defaultBtn = self.makeDefaultButton()
            super().__init__(param, depth)
            self.itemWidget = QtWidgets.QWidget()
            layout = QtWidgets.QHBoxLayout()
            layout.setContentsMargins(0, 0, 0, 0)
            layout.setSpacing(2)

            self.penLabel = PenPreviewLabel(param)
            for child in self.penLabel, self.defaultBtn:
                layout.addWidget(child)
            self.itemWidget.setLayout(layout)

        def optsChanged(self, param, opts):
            if "enabled" in opts or "readonly" in opts:
                self.updateDefaultBtn()

        def treeWidgetChanged(self):
            ParameterItem.treeWidgetChanged(self)
            tw = self.treeWidget()
            if tw is None:
                return
            tw.setItemWidget(self, 1, self.itemWidget)

        defaultClicked = WidgetParameterItem.defaultClicked
        makeDefaultButton = WidgetParameterItem.makeDefaultButton

        def valueChanged(self, param, val):
            self.updateDefaultBtn()

        def updateDefaultBtn(self):
            self.defaultBtn.setEnabled(
                not self.param.valueIsDefault()
                and self.param.opts["enabled"]
                and self.param.writable()
            )

    def cap_first(s: str):
        if not s:
            return s
        return s[0].upper() + s[1:]

    class PenParameter(GroupParameter):
        """
        Controls the appearance of a QPen value.

        When `saveState` is called, the value is encoded as (color, width, style, capStyle, joinStyle, cosmetic)

        ============== ========================================================
        **Options:**
        color          pen color, can be any argument accepted by :func:`~pyqtgraph.mkColor` (defaults to black)
        width          integer width >= 0 (defaults to 1)
        style          String version of QPenStyle enum, i.e. 'SolidLine' (default), 'DashLine', etc.
        capStyle       String version of QPenCapStyle enum, i.e. 'SquareCap' (default), 'RoundCap', etc.
        joinStyle      String version of QPenJoinStyle enum, i.e. 'BevelJoin' (default), 'RoundJoin', etc.
        cosmetic       Boolean, whether or not the pen is cosmetic (defaults to True)
        ============== ========================================================
        """
        itemClass = PenParameterItem

        def __init__(self, **opts):
            self.pen = fn.mkPen(**opts)
            children = self._makeChildren(self.pen)
            if 'children' in opts:
                raise KeyError('Cannot set "children" argument in Pen Parameter opts')
            super().__init__(**opts, children=list(children))
            self.valChangingProxy = SignalProxy(
                self.sigValueChanging,
                delay=1.0,
                slot=self._childrenFinishedChanging,
                threadSafe=False,
            )

        def _childrenFinishedChanging(self, paramAndValue):
            self.setValue(self.pen)

        def setDefault(self, val, **kwargs):
            pen = self._interpretValue(val)
            with self.treeChangeBlocker():
                # Block changes until all are finalized
                for opt in self.names:
                    # Booleans have different naming convention
                    if isinstance(self[opt], bool):
                        attrName = f'is{opt.title()}'
                    else:
                        attrName = opt
                    self.child(opt).setDefault(getattr(pen, attrName)(), **kwargs)
                out = super().setDefault(val, **kwargs)
            return out

        def saveState(self, filter=None):
            state = super().saveState(filter)
            opts = state.pop('children')
            state['value'] = tuple(o['value'] for o in opts.values())
            if 'default' not in state:
                state['default'] = state['value']  # TODO remove this after January 2025
            return state

        def restoreState(self, state, recursive=True, addChildren=True, removeChildren=True, blockSignals=True):
            return super().restoreState(state, recursive=False, addChildren=False, removeChildren=False, blockSignals=blockSignals)

        def _interpretValue(self, v):
            return self.mkPen(v)

        def setValue(self, value, blockSignal=None):
            if not fn.eq(value, self.pen):
                value = self.mkPen(value)
                self.updateFromPen(self, value)
            return super().setValue(self.pen, blockSignal)

        def applyOptsToPen(self, **opts):
            # Transform opts into a value for the current pen
            paramNames = set(opts).intersection(self.names)
            # Value should be overridden by opts
            with self.treeChangeBlocker():
                if 'value' in opts:
                    pen = self.mkPen(opts.pop('value'))
                    if not fn.eq(pen, self.pen):
                        self.updateFromPen(self, pen)
                penOpts = {}
                for kk in paramNames:
                    penOpts[kk] = opts[kk]
                    self[kk] = opts[kk]
            return penOpts

        def setOpts(self, **opts):
            # Transform opts into a value
            if self.applyOptsToPen(**opts):
                self.setValue(self.pen)
            return super().setOpts(**opts)

        def mkPen(self, *args, **kwargs):
            """Thin wrapper around fn.mkPen which accepts the serialized state from saveState"""
            if len(args) == 1 and isinstance(args[0], tuple) and len(args[0]) == len(self.childs):
                opts = dict(zip(self.names, args[0]))
                self.applyOptsToPen(**opts)
                args = (self.pen,)
                kwargs = {}
            return fn.mkPen(*args, **kwargs)

        def _makeChildren(self, boundPen=None):
            cs = QtCore.Qt.PenCapStyle
            js = QtCore.Qt.PenJoinStyle
            ps = QtCore.Qt.PenStyle
            param = Parameter.create(
                name='Params', type='group', children=[
                    dict(name='color', type='color', value='k'),
                    dict(name='width', value=1, type='int', limits=[0, None]),
                    QtEnumParameter(ps, name='style', value='SolidLine'),
                    QtEnumParameter(cs, name='capStyle'),
                    QtEnumParameter(js, name='joinStyle'),
                    dict(name='cosmetic', type='bool', value=True)
                ]
                )

            optsPen = boundPen or fn.mkPen()
            for p in param:
                name = p.name()
                # Qt naming scheme uses isXxx for booleans
                if p.type() == 'bool':
                    attrName = f'is{name.title()}'
                else:
                    attrName = name
                default = getattr(optsPen, attrName)()
                replace = r'\1 \2'
                name = re.sub(r'(\w)([A-Z])', replace, name)
                name = name.title().strip()
                p.setOpts(title=name, default=default)

            if boundPen is not None:
                self.updateFromPen(param, boundPen)
                for p in param:
                    setName = f'set{cap_first(p.name())}'
                    # Instead, set the parameter which will signal the old setter
                    setattr(boundPen, setName, p.setValue)
                    newSetter = self.penPropertySetter
                    # Edge case: color picker uses a dialog with user interaction, so wait until full change there
                    if p.type() != 'color':
                        p.sigValueChanging.connect(newSetter)
                    # Force children to emulate self's value instead of being part of a tree like normal
                    try:
                        p.sigValueChanged.disconnect(p._emitValueChanged)
                    except RuntimeError:
                        # workaround https://bugreports.qt.io/projects/PYSIDE/issues/PYSIDE-2487
                        # that affects PySide 6.5.3
                        # Since the child param was freshly created by us, there can only have been one slot
                        # connected. So we can just disconnect all the slots without specifying which one.
                        assert p.receivers(QtCore.SIGNAL("sigValueChanged(PyObject,PyObject)")) == 1
                        p.sigValueChanged.disconnect()
                    # Some widgets (e.g. checkbox, combobox) don't emit 'changing' signals, so tie to 'changed' as well
                    p.sigValueChanged.connect(newSetter)

            return param

        def penPropertySetter(self, p, value):
            boundPen = self.pen
            setName = f'set{cap_first(p.name())}'
            # boundPen.setName has been monkey-patched
            # so we get the original setter from the class
            getattr(boundPen.__class__, setName)(boundPen, value)
            self.sigValueChanging.emit(self, boundPen)

        @staticmethod
        def updateFromPen(param, pen):
            """
            Applies settings from a pen to either a Parameter or dict. The Parameter or dict must already
            be populated with the relevant keys that can be found in `PenSelectorDialog.mkParam`.
            """
            stack = ExitStack()
            if isinstance(param, Parameter):
                names = param.names
                # Block changes until all are finalized
                stack.enter_context(param.treeChangeBlocker())
            else:
                names = param
            for opt in names:
                # Booleans have different naming convention
                if isinstance(param[opt], bool):
                    attrName = f'is{opt.title()}'
                else:
                    attrName = opt
                param[opt] = getattr(pen, attrName)()
            stack.close()