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# Source code for pyqtgraph.graphicsItems.PlotItem.PlotItem

    import collections.abc
    import os
    import warnings
    import weakref

    from typing import Iterable

    import numpy as np

    from ... import functions as fn
    from ... import icons
    from ...Qt import QtCore, QtWidgets
    from ...WidgetGroup import WidgetGroup
    from ...widgets.FileDialog import FileDialog
    from ..AxisItem import AxisItem
    from ..ButtonItem import ButtonItem
    from ..GraphicsWidget import GraphicsWidget
    from ..InfiniteLine import InfiniteLine
    from ..LabelItem import LabelItem
    from ..LegendItem import LegendItem
    from ..PlotCurveItem import PlotCurveItem
    from ..PlotDataItem import PlotDataItem
    from ..ViewBox import ViewBox

    translate = QtCore.QCoreApplication.translate

    from . import plotConfigTemplate_generic as ui_template

    __all__ = ['PlotItem']

    class PlotItem(GraphicsWidget):
        """
        GraphicsWidget implementing a standard 2D plotting area with axes.

        **Bases:** :class:`GraphicsWidget <pyqtgraph.GraphicsWidget>`

        This class provides the ViewBox-plus-axes that appear when using
        :func:`pg.plot() <pyqtgraph.plot>`, :class:`PlotWidget <pyqtgraph.PlotWidget>`,
        and :meth :`GraphicsLayout.addPlot() <pyqtgraph.GraphicsLayout.addPlot>`.

        It's main functionality is:

          - Manage placement of ViewBox, AxisItems, and LabelItems
          - Create and manage a list of PlotDataItems displayed inside the ViewBox
          - Implement a context menu with commonly used display and analysis options

        Use :func:`plot() <pyqtgraph.PlotItem.plot>` to create a new PlotDataItem and
        add it to the view. Use :func:`addItem() <pyqtgraph.PlotItem.addItem>` to
        add any QGraphicsItem to the view.

        This class wraps several methods from its internal ViewBox:
          - :func:`setXRange <pyqtgraph.ViewBox.setXRange>`
          - :func:`setYRange <pyqtgraph.ViewBox.setYRange>`
          - :func:`setRange <pyqtgraph.ViewBox.setRange>`
          - :func:`autoRange <pyqtgraph.ViewBox.autoRange>`
          - :func:`setDefaultPadding <pyqtgraph.ViewBox.setDefaultPadding>`
          - :func:`setXLink <pyqtgraph.ViewBox.setXLink>`
          - :func:`setYLink <pyqtgraph.ViewBox.setYLink>`
          - :func:`setAutoPan <pyqtgraph.ViewBox.setAutoPan>`
          - :func:`setAutoVisible <pyqtgraph.ViewBox.setAutoVisible>`
          - :func:`setLimits <pyqtgraph.ViewBox.setLimits>`
          - :func:`viewRect <pyqtgraph.ViewBox.viewRect>`
          - :func:`viewRange <pyqtgraph.ViewBox.viewRange>`
          - :func:`setMouseEnabled <pyqtgraph.ViewBox.setMouseEnabled>`
          - :func:`enableAutoRange <pyqtgraph.ViewBox.enableAutoRange>`
          - :func:`disableAutoRange <pyqtgraph.ViewBox.disableAutoRange>`
          - :func:`setAspectLocked <pyqtgraph.ViewBox.setAspectLocked>`
          - :func:`invertY <pyqtgraph.ViewBox.invertY>`
          - :func:`invertX <pyqtgraph.ViewBox.invertX>`
          - :func:`register <pyqtgraph.ViewBox.register>`
          - :func:`unregister <pyqtgraph.ViewBox.unregister>`

        The ViewBox itself can be accessed by calling :func:`getViewBox() <pyqtgraph.PlotItem.getViewBox>`

        Parameters
        ----------
        parent : QObject or None, default None
            Parent :class:`QObject` assign to the :class:`~pyqtgraph.PlotItem`.
        name : str or None, default None
            Register the value for this view so that others may link to it.
        labels :  dict of str or None, default None
            A dictionary specifying the axis labels to display

            .. code-block:: python

                {'left': (args), 'bottom': (args), ...}

            The name of each axis and the corresponding arguments are passed to
            :meth:`PlotItem.setLabel() <pyqtgraph.PlotItem.setLabel>`
            Optionally, PlotItem my also be initialized with the keyword arguments left,
            right, top, or bottom to achieve the same effect.
        title : str
            Text to set the title of the PlotItem to.
        viewBox : :class:`~pyqtgraph.ViewBox` or None, default None
            Have the PlotItem use the provided :class:`~pyqtgraph.ViewBox`. If not
            specified, the PlotItem will be constructed with this as its ViewBox.
        axisItems : dict of {'left', 'bottom', 'right', 'top } and AxisItem or None
            Pass pre-constructed :class:`~pyqtgraph.AxisItem` objects to be used for the
            `left`, `bottom`, `right` or `top` axis.  Default is None.
        enableMenu : bool
            Toggle the enabling or disabling of the right-click context menu.
        **kwargs : dict, optional
            Any extra keyword arguments are passed to
            :func:`PlotItem.plot() <pyqtgraph.PlotItem.plot>`.

        Signals
        -------
        sigYRangeChanged : Signal
            Signal is emitted when the range on the y-axis changes. Signal contains a
            reference to the :class:`~pyqtgraph.ViewBox`, and tuple of (xmin, xmax).
        sigXRangeChanged : Signal
            Signal is emitted when the range on the x-axis changes. Signal contains a
            reference to the :class:`~pyqtgraph.ViewBox`, and tuple of (ymin, ymax).
        sigRangeChanged : Signal
            Signal is emitted when the range on either x or y-axis changes. Signal contains
            a reference to the :class:`~pyqtgraph.ViewBox`, a list of lists of the form,
            ``[[x_min, x_max], [y_min, y_max]]`` and a list of two booleans, indicating if
            the range on which axis has changed of the form
            ``[x_range_changed, y_range_changed]``.
        """

        sigRangeChanged = QtCore.Signal(object, object)    ## Emitted when the ViewBox range has changed
        sigYRangeChanged = QtCore.Signal(object, object)   ## Emitted when the ViewBox Y range has changed
        sigXRangeChanged = QtCore.Signal(object, object)   ## Emitted when the ViewBox X range has changed
        sigRangeChangedManually = QtCore.Signal(object)    ## Emitted when the ViewBox range is changed via user interaction

        lastFileDir = None

        def __init__(
            self,
            parent : QtCore.QObject | None = None,
            name: str | None = None,
            labels: dict[str, str] | None = None,
            title: str | None = None,
            viewBox: ViewBox | None = None,
            axisItems: dict[str, AxisItem] | None = None,
            enableMenu: bool = True,
            **kwargs
        ):
            super().__init__(parent)

            self.setSizePolicy(
                QtWidgets.QSizePolicy.Policy.Expanding,
                QtWidgets.QSizePolicy.Policy.Expanding
            )

            ## Set up control buttons
            self.autoBtn = ButtonItem(icons.getGraphPixmap('auto'), 14, self)
            self.autoBtn.mode = 'auto'
            self.autoBtn.clicked.connect(self.autoBtnClicked)
            self.buttonsHidden = False  # has the user has requested buttons to be hidden?
            self.mouseHovering = False

            self.layout = QtWidgets.QGraphicsGridLayout()
            self.layout.setContentsMargins(1,1,1,1)
            self.setLayout(self.layout)
            self.layout.setHorizontalSpacing(0)
            self.layout.setVerticalSpacing(0)

            if viewBox is None:
                viewBox = ViewBox(parent=self, enableMenu=enableMenu)
            self.vb = viewBox
            self.vb.sigStateChanged.connect(self.viewStateChanged)

            # Enable or disable plotItem menu
            self.setMenuEnabled(enableMenu, None)

            if name is not None:
                self.vb.register(name)
            self.vb.sigRangeChanged.connect(self.sigRangeChanged)
            self.vb.sigXRangeChanged.connect(self.sigXRangeChanged)
            self.vb.sigYRangeChanged.connect(self.sigYRangeChanged)
            self.vb.sigRangeChangedManually.connect(self.sigRangeChangedManually)

            self.layout.addItem(self.vb, 2, 1)
            self.alpha = 1.0
            self.autoAlpha = True
            self.spectrumMode = False

            self.legend = None

            # Initialize axis items
            self.axes = {}
            self.setAxisItems(axisItems)

            self.titleLabel = LabelItem('', size='11pt', parent=self)
            self.layout.addItem(self.titleLabel, 0, 1)
            self.setTitle(None)  ## hide

            for i in range(4):
                self.layout.setRowPreferredHeight(i, 0)
                self.layout.setRowMinimumHeight(i, 0)
                self.layout.setRowSpacing(i, 0)
                self.layout.setRowStretchFactor(i, 1)

            for i in range(3):
                self.layout.setColumnPreferredWidth(i, 0)
                self.layout.setColumnMinimumWidth(i, 0)
                self.layout.setColumnSpacing(i, 0)
                self.layout.setColumnStretchFactor(i, 1)
            self.layout.setRowStretchFactor(2, 100)
            self.layout.setColumnStretchFactor(1, 100)

            self.items = []
            self.curves = []
            self.itemMeta = weakref.WeakKeyDictionary()
            self.dataItems = []
            self.paramList = {}
            self.avgCurves = {}
            # Change these properties to adjust the appearance of the averaged curve:
            self.avgPen = fn.mkPen((0, 200, 0))
            self.avgShadowPen = fn.mkPen((0, 0, 0), width=4)

            ### Set up context menu

            w = QtWidgets.QWidget()
            self.ctrl = c = ui_template.Ui_Form()
            c.setupUi(w)

            menuItems = [
                (translate("PlotItem", 'Transforms'), c.transformGroup),
                (translate("PlotItem", 'Downsample'), c.decimateGroup),
                (translate("PlotItem", 'Average'), c.averageGroup),
                (translate("PlotItem", 'Alpha'), c.alphaGroup),
                (translate("PlotItem", 'Grid'), c.gridGroup),
                (translate("PlotItem", 'Points'), c.pointsGroup),
            ]

            self.ctrlMenu = QtWidgets.QMenu(translate("PlotItem", 'Plot Options'))

            for name, grp in menuItems:
                sm = self.ctrlMenu.addMenu(name)
                act = QtWidgets.QWidgetAction(self)
                act.setDefaultWidget(grp)
                sm.addAction(act)

            self.stateGroup = WidgetGroup()
            for name, w in menuItems:
                self.stateGroup.autoAdd(w)

            self.fileDialog = None

            c.alphaGroup.toggled.connect(self.updateAlpha)
            c.alphaSlider.valueChanged.connect(self.updateAlpha)
            c.autoAlphaCheck.toggled.connect(self.updateAlpha)

            c.xGridCheck.toggled.connect(self.updateGrid)
            c.yGridCheck.toggled.connect(self.updateGrid)
            c.gridAlphaSlider.valueChanged.connect(self.updateGrid)

            c.fftCheck.toggled.connect(self.updateSpectrumMode)
            c.subtractMeanCheck.toggled.connect(self.updateSubtractMeanMode)
            c.logXCheck.toggled.connect(self.updateLogMode)
            c.logYCheck.toggled.connect(self.updateLogMode)
            c.derivativeCheck.toggled.connect(self.updateDerivativeMode)
            c.phasemapCheck.toggled.connect(self.updatePhasemapMode)

            c.downsampleSpin.valueChanged.connect(self.updateDownsampling)
            c.downsampleCheck.toggled.connect(self.updateDownsampling)
            c.autoDownsampleCheck.toggled.connect(self.updateDownsampling)
            c.subsampleRadio.toggled.connect(self.updateDownsampling)
            c.meanRadio.toggled.connect(self.updateDownsampling)
            c.clipToViewCheck.toggled.connect(self.updateDownsampling)

            self.ctrl.avgParamList.itemClicked.connect(self.avgParamListClicked)
            self.ctrl.averageGroup.toggled.connect(self.avgToggled)

            self.ctrl.maxTracesCheck.toggled.connect(self._handle_max_traces_toggle)
            self.ctrl.forgetTracesCheck.toggled.connect(self.updateDecimation)
            self.ctrl.maxTracesSpin.valueChanged.connect(self.updateDecimation)

            if labels is None:
                labels = {}
            for label in list(self.axes.keys()):
                if label in kwargs:
                    labels[label] = kwargs[label]
                    del kwargs[label]
            for k in labels:
                if isinstance(labels[k], str):
                    labels[k] = (labels[k],)
                self.setLabel(k, *labels[k])

            if title is not None:
                self.setTitle(title)

            if kwargs:
                self.plot(**kwargs)

        def implements(self, interface=None):
            return interface in ['ViewBoxWrapper']

        def getViewBox(self) -> ViewBox:
            """
            Return the embedded :class:`~pyqtgraph.ViewBox`.

            Returns
            -------
            ViewBox
                The :class:`ViewBox <pyqtgraph.ViewBox>` that this PlotItem uses.
            """
            return self.vb

        # Wrap a few methods from viewBox.
        # Important: don't use settattr(m, getattr(self.vb, m)) as we'd be leaving the
        # viewbox alive because we had a reference to an instance method (creating wrapper
        # methods at runtime instead).

        # Note: If you update this list, please update the class docstring as well
        for m in ['setXRange', 'setYRange', 'setXLink', 'setYLink', 'setAutoPan',
                  'setAutoVisible', 'setDefaultPadding', 'setRange', 'autoRange',
                  'viewRect', 'viewRange', 'setMouseEnabled', 'setLimits',
                  'enableAutoRange', 'disableAutoRange', 'setAspectLocked', 'invertY',
                  'invertX', 'register', 'unregister']:

            def _create_method(name):
                def method(self, *args, **kwargs):
                    return getattr(self.vb, name)(*args, **kwargs)
                method.__name__ = name
                return method

            locals()[m] = _create_method(m)

        del _create_method

        def setAxisItems(self, axisItems: 'dict[str, AxisItem] | None' = None) -> None:
            """
            Place axis items and initializes non-existing axis items.

            Parameters
            ----------
            axisItems : dict of str and AxisItem or None
                Optional dictionary instructing the PlotItem to use pre-constructed items
                for its axes. The dict keys must be axis names
                {'left', 'bottom', 'right', 'top'} and the values must be instances of
                :class:`~pyqtgraph.AxisItem`.
            """

            if axisItems is None:
                axisItems = {}

            # Array containing visible axis items
            # Also containing potentially hidden axes, but they are not touched so it does
            # not matter
            visibleAxes = ['left', 'bottom']
            # Note that it does not matter that this adds
            # some values to visibleAxes a second time
            visibleAxes.extend(axisItems.keys())

            for k, pos in (('top', (1,1)), ('bottom', (3,1)), ('left', (2,0)), ('right', (2,2))):
                if k in self.axes:
                    if k not in axisItems:
                        continue # Nothing to do here

                    # Remove old axis
                    oldAxis = self.axes[k]['item']
                    self.layout.removeItem(oldAxis)
                    if oldAxis.scene() is not None:
                        oldAxis.scene().removeItem(oldAxis)
                    oldAxis.unlinkFromView()

                # Create new axis
                if k in axisItems:
                    axis = axisItems[k]
                    if (
                        axis.scene() is not None
                        and (k not in self.axes or axis != self.axes[k]["item"])
                    ):
                        raise RuntimeError(
                            "Can't add an axis to multiple plots. Shared axes "
                            "can be achieved with multiple AxisItem instances "
                            "and set[X/Y]Link."
                        )
                else:
                    axis = AxisItem(orientation=k, parent=self)

                # Set up new axis
                axis.linkToView(self.vb)
                self.axes[k] = {'item': axis, 'pos': pos}
                self.layout.addItem(axis, *pos)
                # place axis above images at z=0, items that want to draw over the axes
                # should be placed at z>=1
                axis.setZValue(0.5)
                axis.setFlag(
                    QtWidgets.QGraphicsItem.GraphicsItemFlag.ItemNegativeZStacksBehindParent
                )
                axisVisible = k in visibleAxes
                self.showAxis(k, axisVisible)

        def setLogMode(self, x=None, y=None):
            """
            Set log scaling for `x` and/or `y` axes.

            This informs PlotDataItems to transform logarithmically and switches the axes to
            use log ticking.

            Parameters
            ----------
            x : bool or None
                If ``True``, set the x-axis to log mode. A value of ``None`` is ignored.
            y : bool or None
                If ``True``, set the y-axis to log mode. A value of ``None`` is ignored.

            Notes
            -----
            No other items, in the scene will be affected by this; there is (currently)
            no generic way to redisplay a :class:`~pyqtgraph.GraphicsItem` with log
            coordinates.
            """
            if x is not None:
                self.ctrl.logXCheck.setChecked(x)
            if y is not None:
                self.ctrl.logYCheck.setChecked(y)

        def showGrid(self, x=None, y=None, alpha=None):
            """
            Show or hide the grid for either axis.

            Parameters
            ----------
            x : bool or None
                Show the X grid, a value of ``None`` is ignored.
            y : bool or None
                Show the Y grid, a value of ``None`` is ignored.
            alpha : float or None
                Opacity of the grid, float values need to be between [0.0, 1.0].
            """
            if x is None and y is None and alpha is None:
                # prevent people getting confused if they just call showGrid()
                raise ValueError("Must specify at least one of x, y, or alpha.")

            if x is not None:
                self.ctrl.xGridCheck.setChecked(x)
            if y is not None:
                self.ctrl.yGridCheck.setChecked(y)
            if alpha is not None:
                v = fn.clip_scalar(alpha, 0, 1) * self.ctrl.gridAlphaSlider.maximum() # slider range 0 to 255
                self.ctrl.gridAlphaSlider.setValue( int(v) )

        def close(self):
            ## Most of this crap is needed to avoid PySide trouble.
            ## The problem seems to be whenever scene.clear() leads to deletion of widgets (either through proxies or qgraphicswidgets)
            ## the solution is to manually remove all widgets before scene.clear() is called
            if self.ctrlMenu is None: ## already shut down
                return
            self.ctrlMenu.setParent(None)
            self.ctrlMenu = None

            self.autoBtn.setParent(None)
            self.autoBtn = None

            for k in self.axes:
                i = self.axes[k]['item']
                i.close()

            self.axes = None
            self.scene().removeItem(self.vb)
            self.vb = None

        def registerPlot(self, name):   ## for backward compatibility
            self.vb.register(name)

        @QtCore.Slot(bool)
        @QtCore.Slot(int)
        def updateGrid(self, *args):
            alpha = self.ctrl.gridAlphaSlider.value()
            x = alpha if self.ctrl.xGridCheck.isChecked() else False
            y = alpha if self.ctrl.yGridCheck.isChecked() else False
            self.getAxis('top').setGrid(x)
            self.getAxis('bottom').setGrid(x)
            self.getAxis('left').setGrid(y)
            self.getAxis('right').setGrid(y)

        def viewGeometry(self) -> QtCore.QRectF:
            """
            Return the screen geometry of the viewbox.

            Returns
            -------
            QRectF
                The QRectF instance that contains the view area.
            """
            v = self.scene().views()[0]
            b = self.vb.mapRectToScene(self.vb.boundingRect())
            wr = v.mapFromScene(b).boundingRect()
            pos = v.mapToGlobal(v.pos())
            wr.adjust(pos.x(), pos.y(), pos.x(), pos.y())
            return wr

        @QtCore.Slot(bool)
        def avgToggled(self, b: bool):
            if b:
                self.recomputeAverages()
            for k in self.avgCurves:
                self.avgCurves[k][1].setVisible(b)

        @QtCore.Slot(QtWidgets.QListWidgetItem)
        def avgParamListClicked(self, item):
            name = str(item.text())
            self.paramList[name] = (item.checkState() == QtCore.Qt.CheckState.Checked)
            self.recomputeAverages()

        def recomputeAverages(self):
            if not self.ctrl.averageGroup.isChecked():
                return
            for k in self.avgCurves:
                self.removeItem(self.avgCurves[k][1])
            self.avgCurves = {}
            for c in self.curves:
                self.addAvgCurve(c)
            self.replot()

        def addAvgCurve(self, curve):
            ## Add a single curve into the pool of curves averaged together

            ## If there are plot parameters, then we need to determine which to average together.
            remKeys = []
            addKeys = []
            if self.ctrl.avgParamList.count() > 0:

                # First determine the key of the curve to which this new data should be averaged
                for i in range(self.ctrl.avgParamList.count()):
                    item = self.ctrl.avgParamList.item(i)
                    if item.checkState() == QtCore.Qt.CheckState.Checked:
                        remKeys.append(str(item.text()))
                    else:
                        addKeys.append(str(item.text()))

                if not remKeys:
                    # In this case,there would be 1 avg plot for each data plot; not useful
                    return

            p = self.itemMeta.get(curve,{}).copy()
            for k in p:
                if type(k) is tuple:
                    p['.'.join(k)] = p[k]
                    del p[k]
            for rk in remKeys:
                if rk in p:
                    del p[rk]
            for ak in addKeys:
                if ak not in p:
                    p[ak] = None
            key = tuple(p.items())

            ### Create a new curve if needed
            if key not in self.avgCurves:
                plot = PlotDataItem()
                plot.setPen( self.avgPen )
                plot.setShadowPen(  self.avgShadowPen )
                plot.setAlpha(1.0, False)
                plot.setZValue(100)
                self.addItem(plot, skipAverage=True)
                self.avgCurves[key] = [0, plot]
            self.avgCurves[key][0] += 1
            (n, plot) = self.avgCurves[key]

            ### Average data together
            (x, y) = curve.getData()
            stepMode = curve.opts['stepMode']
            if plot.yData is not None and y.shape == plot.yData.shape:
                # note that if shapes do not match, then the average resets.
                newData = plot.yData * (n-1) / float(n) + y * 1.0 / float(n)
                plot.setData(plot.xData, newData, stepMode=stepMode)
            else:
                plot.setData(x, y, stepMode=stepMode)

        @QtCore.Slot()
        def autoBtnClicked(self):
            if self.autoBtn.mode == 'auto':
                self.enableAutoRange()
                self.autoBtn.hide()
                self.sigRangeChangedManually.emit(self.vb.mouseEnabled()[:])
            else:
                self.disableAutoRange()

        @QtCore.Slot()
        def viewStateChanged(self):
            self.updateButtons()

        def addItem(self, item, *args, **kwargs):
            """
            Add a :class:`~pyqtgraph.GraphicsItem` to the :class:`~pyqtgraph.ViewBox`.

            If the item has plot data (:class:`PlotDataItem <pyqtgraph.PlotDataItem>` ,
            :class:`~pyqtgraph.PlotCurveItem`, :class:`~pyqtgraph.ScatterPlotItem` ), it may
            be included in analysis performed by the PlotItem.

            Parameters
            ----------
            item : GraphicsItem
                Item to add to the ViewBox.
            *args : tuple
                Arguments relayed to :meth:`~pyqtgraph.ViewBox.addItem`.
            **kwargs : dict
                Keyword arguments for adding an item.  Supported arguments include.

                ============ ===============================================================
                Property     Description
                ============ ===============================================================
                ignoreBounds ``bool`` - Keyword argument relayed to
                             :meth:`~pyqtgraph.ViewBox.addItem`.

                skipAverage  ``bool`` - If ``True``, do not use curve to compute average
                             curves.
                ============ ===============================================================

            See Also
            --------
            :meth:`~pyqtgraph.ViewBox.addItem`
                See method for supported arguments to be passed.
            """
            if item in self.items:
                warnings.warn('Item already added to PlotItem, ignoring.')
                return
            self.items.append(item)
            vbargs = {}
            if 'ignoreBounds' in kwargs:
                vbargs['ignoreBounds'] = kwargs['ignoreBounds']
            self.vb.addItem(item, *args, **vbargs)
            name = None
            if hasattr(item, 'implements') and item.implements('plotData'):
                name = item.name()
                self.dataItems.append(item)
                params = kwargs.get('params', {})
                self.itemMeta[item] = params
                self.curves.append(item)

            # Toggle log mode if item implements setLogMode and selected in the context menu
            if hasattr(item, 'setLogMode'):
                item.setLogMode(
                    self.ctrl.logXCheck.isChecked(),
                    self.ctrl.logYCheck.isChecked()
                )

            if isinstance(item, PlotDataItem):
                ## configure curve for this plot
                (alpha, auto) = self.alphaState()
                item.setAlpha(alpha, auto)
                item.setSubtractMeanMode(self.ctrl.subtractMeanCheck.isChecked())
                item.setFftMode(self.ctrl.fftCheck.isChecked())
                item.setDownsampling(*self.downsampleMode())
                item.setClipToView(self.clipToViewMode())

                ## Hide older plots if needed
                self.updateDecimation()

                ## Add to average if needed
                self.updateParamList()
                if self.ctrl.averageGroup.isChecked() and 'skipAverage' not in kwargs:
                    self.addAvgCurve(item)

            # conditionally add item to the legend
            if name is not None and hasattr(self, 'legend') and self.legend is not None:
                self.legend.addItem(item, name=name)

        def listDataItems(self):
            """
            Return a list of all data items current plotted.

            Returns
            -------
            list of PlotCurveItem, ScatterPlotItem or PlotDataItem
                A copy of a list of the data items.
            """
            return self.dataItems[:]

        def addLine(self, x=None, y=None, z=None, **kwargs):
            """
            Create a new :class:`~pyqtgraph.InfiniteLine` and add it to the plot.

            Parameters
            ----------
            x : float or None
                Position in the x-axis to draw the line. If specified, the line will be
                vertical. Default ``None``.
            y : float or None
                Position in the y-axis to draw the line. If specified, the line will be
                horizontal. Default ``None``.
            z : int or None
                Z value to set the line to. This is used to determine which items are on top
                of the other.  See :meth:`~QtWidgets.QGraphicsItem.setZValue`.
            **kwargs : dict
                Keyword arguments to pass to the :class:`~pyqtgraph.InfiniteLine` instance.

            Returns
            -------
            InfiniteLine
                The new :class:`~pyqtgraph.InfiniteLine` added.
            """
            kwargs['pos'] = kwargs.get('pos', x if x is not None else y)
            kwargs['angle'] = kwargs.get('angle', 0 if x is None else 90)
            line = InfiniteLine(**kwargs)
            self.addItem(line)
            if z is not None:
                line.setZValue(z)
            return line

        def removeItem(self, item):
            """
            Remove an item from the plot.

            Parameters
            ----------
            item : GraphicsItem
                The item to remove.
            """
            if item not in self.items:
                return
            self.items.remove(item)
            if item in self.dataItems:
                self.dataItems.remove(item)

            self.vb.removeItem(item)

            if item in self.curves:
                self.curves.remove(item)
                self.updateDecimation()
                self.updateParamList()

            if self.legend is not None:
                self.legend.removeItem(item)

        def clear(self):
            """
            Remove all items from the PlotItem's :class:`~pyqtgraph.ViewBox`.
            """
            for i in self.items[:]:
                self.removeItem(i)
            self.avgCurves = {}

        def clearPlots(self):
            """
            Remove all curves from the PlotItem's :class:`~pyqtgraph.ViewBox`.
            """
            for i in self.curves[:]:
                self.removeItem(i)
            self.avgCurves = {}

        def plot(self, *args, **kwargs):
            """
            Add and return a new :class:`~pyqtgraph.PlotDataItem`.

            Parameters
            ----------
            *args : tuple, optional
                Arguments that are passed to the :class:`~pyqtgraph.PlotDataItem`
                constructor.
            **kwargs : dict, optional
                Keyword arguments that are passed to the :class:`~pyqtgraph.PlotDataItem`
                constructor.  In addition, the following keyword arguments are accepted.

                =========== ================================================================
                Property    Description
                =========== ================================================================
                clear       ``bool`` - Call :meth:`~pyqtgraph.PlotItem.clear` prior to
                            creating the new plot instance.

                params      ``dict`` or ``None`` - Arguments to passed as the `params`
                            argument to :meth:`~pyqtgraph.PlotItem.addItem`.
                =========== ================================================================

            Returns
            -------
            PlotDataItem
                The newly created :class:`~pyqtgraph.PlotDataItem`.
            """
            clear = kwargs.get('clear', False)
            params = kwargs.get('params')

            if clear:
                self.clear()

            item = PlotDataItem(*args, **kwargs)

            if params is None:
                params = {}
            self.addItem(item, params=params)

            return item

        def addLegend(self, offset=(30, 30), **kwargs):
            """
            Add a new :class:`~pyqtgraph.LegendItem`.

            After the LegendItem is created, it is anchored in the internal
            :class:`~pyqtgraph.ViewBox`. Plots added after this will be automatically
            displayed in the legend if they are created with a 'name' argument.

            If a :class:`~pyqtgraph.LegendItem` has already been created using this method,
            that item will be returned rather than creating a new one.

            Parameters
            ----------
            offset : tuple of int, int
                The distance to offset the LegendItem, defaults to ``(30, 30)``.
            **kwargs : dict, optional
                Keyword argument passed to the :class:`~pyqtgraph.LegendItem` constructor.

            Returns
            -------
            LegendItem
                The instance of :class:`~pyqtgraph.LegendItem` that was constructed.
            """
            if self.legend is None:
                self.legend = LegendItem(offset=offset, **kwargs)
                self.legend.setParentItem(self.vb)
            return self.legend

        def addColorBar(self, image, **kwargs):
            """
            Add a ColorBarItem and set to the provided image.

            A call like ``plot.addColorBar(img, colorMap='viridis')`` is a convenient
            method to assign and show a color map.

            Parameters
            ----------
            image : ImageItem or list of ImageItem
                See :meth:`~pyqtgraph.ColorBarItem.setImageItem` for details.
            **kwargs : dict, optional
                Keyword arguments passed to the :class:`~pyqtgraph.ColorBarItem`
                constructor.

            Returns
            -------
            ColorBarItem
                The newly created :class:`~pyqtgraph.ColorBarItem` instance.
            """
            from ..ColorBarItem import ColorBarItem  # avoid circular import
            bar = ColorBarItem(**kwargs)
            bar.setImageItem( image, insert_in=self )
            return bar

        def multiDataPlot(self, *, x=None, y=None, constKwargs=None, **kwargs):
            """
            Allow plotting multiple curves on the same plot in one call.

            Parameters
            ----------
            x, y : array_like
                Can be in the following formats:
                  - {x or y} = [n1, n2, n3, ...]: The named argument iterates through
                    ``n`` curves, while the unspecified argument is range(len(n)) for
                    each curve.
                  - x, [y1, y2, y3, ...]
                  - [x1, x2, x3, ...], [y1, y2, y3, ...]
                  - [x1, x2, x3, ...], y

                where ``x_n`` and ``y_n`` are ``ndarray`` data for each curve. Since
                ``x`` and ``y`` values are matched using ``zip``, unequal lengths mean
                the longer array will be truncated. Note that 2D matrices for either x
                or y are considered lists of curve data.
            constKwargs : dict, optional
                A dict of {str: value} passed to each curve during ``plot()``.
            **kwargs : dict, optional
                A dict of {str: iterable} where the str is the name of a kwarg and the
                iterable is a list of values, one for each plotted curve.

            Returns
            -------
            list of PlotDataItem
                Returns a list of the newly constructed :class:`~pyqtgraph.PlotDataItem`
                instances representing the new curves.
            """
            if (x is not None and not len(x)) or (y is not None and not len(y)):
                # Nothing to plot -- either x or y array will bail out early from
                # zip() below.
                return []
            def scalarOrNone(val):
                return val is None or (len(val) and np.isscalar(val[0]))

            if scalarOrNone(x) and scalarOrNone(y):
                raise ValueError(
                    "If both `x` and `y` represent single curves, use `plot` instead "
                    "of `multiPlot`."
                )
            curves = []
            constKwargs = constKwargs or {}
            xy: dict[str, list | None] = dict(x=x, y=y)
            for key, oppositeVal in zip(('x', 'y'), [y, x]):
                oppositeVal: Iterable | None
                val = xy[key]
                if val is None:
                    # Other curve has all data, make range that supports longest chain
                    val = range(max(len(curveN) for curveN in oppositeVal))
                if np.isscalar(val[0]):
                    # x, [y1, y2, y3, ...] or [x1, x2, x3, ...], y
                    # Repeat the single curve to match length of opposite list
                    val = [val] * len(oppositeVal)
                xy[key] = val
            for ii, (xi, yi) in enumerate(zip(xy['x'], xy['y'])):
                for kk in kwargs:
                    if len(kwargs[kk]) <= ii:
                        raise ValueError(
                            f"Not enough values for kwarg `{kk}`. "
                            f"Expected {ii + 1:d} (number of curves to plot), got"
                            f" {len(kwargs[kk]):d}"
                        )
                kwargs_i = {kk: kwargs[kk][ii] for kk in kwargs}
                constKwargs.update(kwargs_i)
                curves.append(self.plot(xi, yi, **constKwargs))
            return curves

        def scatterPlot(self, *args, **kwargs):
            """
            Create a :class:`~pyqtgraph.PlotDataItem` and add it to the plot.

            The :class:`~pyqtgraph.PlotDataItem` instance will render the underlying data
            in a scatter plot form.

            Parameters
            ----------
            *args : tuple, optional
                Arguments that are passed to the :class:`~pyqtgraph.PlotDataItem`
                constructor.
            **kwargs : dict, optional
                Keyword arguments that are passed to the :class:`~pyqtgraph.PlotDataItem`
                constructor.  In addition, the following keyword arguments are accepted.

                =========== ================================================================
                Property    Description
                =========== ================================================================
                pen         ``QPen`` - Sets the pen used to draw lines or symbols for the
                            plot.  Equivalent to ``symbolPen``.

                brush       ``QBrush`` - Sets the brush used to fill symbols for the plot.
                            Equivalent to ``symbolBrush``.

                size        ``float`` - Sets the symbol size for the plot. Equivalent to
                            ``symbolSize``.
                =========== ================================================================

            Returns
            -------
            PlotDataItem
                The newly created :class:`~pyqtgraph.PlotDataItem`.
            """
            if 'pen' in kwargs:
                kwargs['symbolPen'] = kwargs['pen']
            kwargs['pen'] = None

            if 'brush' in kwargs:
                kwargs['symbolBrush'] = kwargs['brush']
                del kwargs['brush']

            if 'size' in kwargs:
                kwargs['symbolSize'] = kwargs['size']
                del kwargs['size']

            return self.plot(*args, **kwargs)

        def replot(self):
            self.update()

        def updateParamList(self):
            self.ctrl.avgParamList.clear()
            ## Check to see that each parameter for each curve is present in the list
            for c in self.curves:
                for p in list(self.itemMeta.get(c, {}).keys()):
                    if type(p) is tuple:
                        p = '.'.join(p)

                    if matches := self.ctrl.avgParamList.findItems(
                        p, QtCore.Qt.MatchFlag.MatchExactly
                    ):
                        i = matches[0]
                    else:
                        i = QtWidgets.QListWidgetItem(p)
                        if p in self.paramList and self.paramList[p] is True:
                            i.setCheckState(QtCore.Qt.CheckState.Checked)
                        else:
                            i.setCheckState(QtCore.Qt.CheckState.Unchecked)
                        self.ctrl.avgParamList.addItem(i)
                    self.paramList[p] = (i.checkState() == QtCore.Qt.CheckState.Checked)

        def writeSvg(self, fileName=None):
            """
            Write the plot content to an SVG file.

            Parameters
            ----------
            fileName : str, optional
                The name of the file to write to. If not specified, a file dialog will be
                opened.
            """
            if fileName is None:
                self._chooseFilenameDialog(handler=self.writeSvg)
                return

            fileName = str(fileName)
            PlotItem.lastFileDir = os.path.dirname(fileName)

            from ...exporters import SVGExporter
            ex = SVGExporter(self)
            ex.export(fileName)

        def writeImage(self, fileName=None):
            """
            Write the plot content to an image file.

            Parameters
            ----------
            fileName : str, optional
                The name of the file to write to. If not specified, a file dialog will be
                opened.
            """
            if fileName is None:
                self._chooseFilenameDialog(handler=self.writeImage)
                return

            from ...exporters import ImageExporter
            ex = ImageExporter(self)
            ex.export(fileName)

        def writeCsv(self, fileName=None):
            """
            Write the plot data to a CSV file.

            Parameters
            ----------
            fileName : str, optional
                The name of the file to write to. If not specified, a file dialog will be
                opened.
            """
            if fileName is None:
                self._chooseFilenameDialog(handler=self.writeCsv)
                return

            fileName = str(fileName)
            PlotItem.lastFileDir = os.path.dirname(fileName)

            data = [c.getData() for c in self.curves]
            with open(fileName, 'w') as fd:
                i = 0
                while True:
                    done = True
                    for d in data:
                        if i < len(d[0]):
                            fd.write('%g,%g,' % (d[0][i], d[1][i]))
                            done = False
                        else:
                            fd.write(' , ,')
                    fd.write('\n')
                    if done:
                        break
                    i += 1

        def saveState(self):
            state = self.stateGroup.state()
            state['paramList'] = self.paramList.copy()
            state['view'] = self.vb.getState()
            return state

        def restoreState(self, state):
            if 'paramList' in state:
                self.paramList = state['paramList'].copy()

            self.stateGroup.setState(state)
            self.updateSpectrumMode()
            self.updateSubtractMeanMode()
            self.updateDownsampling()
            self.updateAlpha()
            self.updateDecimation()

            if 'powerSpectrumGroup' in state:
                state['fftCheck'] = state['powerSpectrumGroup']
            if 'gridGroup' in state:
                state['xGridCheck'] = state['gridGroup']
                state['yGridCheck'] = state['gridGroup']

            self.stateGroup.setState(state)
            self.updateParamList()

            if 'view' not in state:
                r = [[float(state['xMinText']), float(state['xMaxText'])], [float(state['yMinText']), float(state['yMaxText'])]]
                state['view'] = {
                    'autoRange': [state['xAutoRadio'], state['yAutoRadio']],
                    'linkedViews': [state['xLinkCombo'], state['yLinkCombo']],
                    'targetRange': r,
                    'viewRange': r,
                }
            self.vb.setState(state['view'])

        def widgetGroupInterface(self):
            return (None, PlotItem.saveState, PlotItem.restoreState)

        @QtCore.Slot(bool)
        def updateSpectrumMode(self, b=None):
            if b is None:
                b = self.ctrl.fftCheck.isChecked()
            for c in self.curves:
                c.setFftMode(b)
            self.enableAutoRange()
            self.recomputeAverages()

        @QtCore.Slot()
        def updateSubtractMeanMode(self):
            d = self.ctrl.subtractMeanCheck.isChecked()
            for i in self.items:
                if hasattr(i, 'setSubtractMeanMode'):
                    i.setSubtractMeanMode(d)
            self.enableAutoRange()
            self.recomputeAverages()

        @QtCore.Slot()
        def updateLogMode(self):
            x = self.ctrl.logXCheck.isChecked()
            y = self.ctrl.logYCheck.isChecked()
            for i in self.items:
                if hasattr(i, 'setLogMode'):
                    i.setLogMode(x,y)
            self.getAxis('bottom').setLogMode(x, y)
            self.getAxis('top').setLogMode(x, y)
            self.getAxis('left').setLogMode(x, y)
            self.getAxis('right').setLogMode(x, y)
            self.enableAutoRange()
            self.recomputeAverages()

        @QtCore.Slot()
        def updateDerivativeMode(self):
            d = self.ctrl.derivativeCheck.isChecked()
            for i in self.items:
                if hasattr(i, 'setDerivativeMode'):
                    i.setDerivativeMode(d)
            self.enableAutoRange()
            self.recomputeAverages()

        @QtCore.Slot()
        def updatePhasemapMode(self):
            d = self.ctrl.phasemapCheck.isChecked()
            for i in self.items:
                if hasattr(i, 'setPhasemapMode'):
                    i.setPhasemapMode(d)
            self.enableAutoRange()
            self.recomputeAverages()

        def setDownsampling(self, ds=None, auto=None, mode=None):
            """
            Set the downsampling mode for the PlotItem.

            Downsampling reduces the number of samples drawn to improve performance.
            The downsampling mode can be set to 'subsample', 'mean', 'peak', or None.
            If downsampling is enabled, the view will display downsampled data when zoomed out,
            but will display original data at high zoom levels.

            Parameters
            ----------
            ds : int or bool or None, optional
                The downsampling factor. If ``None``, the downsampling factor is not
                changed. If ``True``, the downsampling factor is set to the value in the
                downsampling spin box. If ``False``, downsampling is disabled. If an
                integer, the downsampling factor is set to this value. Default is ``None``.
            auto : bool or None, optional
                If ``True``, automatic downsampling is enabled. If ``False``, automatic
                downsampling is disabled. If ``None``, the automatic downsampling setting
                is not changed. Default is ``None``.
            mode : {'subsample', 'mean', 'peak'} or None, optional
                The downsampling mode. If ``None``, the downsampling mode is not changed.
                Default is ``None``.

            Raises
            ------
            ValueError
                Raised if the specified downsample mode is not recognized.
            """

            if ds is not None:
                if ds is False:
                    self.ctrl.downsampleCheck.setChecked(False)
                elif ds is True:
                    self.ctrl.downsampleCheck.setChecked(True)
                else:
                    self.ctrl.downsampleCheck.setChecked(True)
                    self.ctrl.downsampleSpin.setValue(ds)

            if auto is not None:
                if auto and ds is not False:
                    self.ctrl.downsampleCheck.setChecked(True)
                self.ctrl.autoDownsampleCheck.setChecked(auto)

            if mode is not None:
                if mode == 'subsample':
                    self.ctrl.subsampleRadio.setChecked(True)
                elif mode == 'mean':
                    self.ctrl.meanRadio.setChecked(True)
                elif mode == 'peak':
                    self.ctrl.peakRadio.setChecked(True)
                else:
                    raise ValueError(
                        "mode argument must be 'subsample', 'mean', or 'peak'."
                    )

        @QtCore.Slot()
        def updateDownsampling(self):
            ds, auto, method = self.downsampleMode()
            clip = self.ctrl.clipToViewCheck.isChecked()
            for c in self.curves:
                c.setDownsampling(ds, auto, method)
                c.setClipToView(clip)
            self.recomputeAverages()

        def downsampleMode(self) -> tuple[int, bool, str]:
            if self.ctrl.downsampleCheck.isChecked():
                ds = self.ctrl.downsampleSpin.value()
            else:
                ds = 1

            auto = (
                self.ctrl.downsampleCheck.isChecked() and
                self.ctrl.autoDownsampleCheck.isChecked()
            )

            if self.ctrl.subsampleRadio.isChecked():
                method = 'subsample'
            elif self.ctrl.meanRadio.isChecked():
                method = 'mean'
            elif self.ctrl.peakRadio.isChecked():
                method = 'peak'
            else:
                raise ValueError(
                    "One of the method radios must be selected for: 'subsample', 'mean', "
                    "'peak'."
                )
            return ds, auto, method

        def setClipToView(self, clip):
            """
            Set the default clip-to-view mode for new curves.

            Parameters
            ----------
            clip : bool
                If ``True``, new curves will be clipped to the view box.
            """
            self.ctrl.clipToViewCheck.setChecked(clip)

        def clipToViewMode(self) -> bool:
            """
            Return whether clip-to-view mode is enabled.

            Returns
            -------
            bool
                ``True`` if clip-to-view mode is enabled, ``False`` otherwise.
            """

            return self.ctrl.clipToViewCheck.isChecked()

        @QtCore.Slot(bool)
        def _handle_max_traces_toggle(self, check_state):
            if check_state:
                self.updateDecimation()
            else:
                for curve in self.curves:
                    curve.show()

        @QtCore.Slot()
        def updateDecimation(self):
            """
            Update the number of visible curves.

            Reduce or increase number of visible curves according to value set by the
            `Max Traces` spinner, if `Max Traces` is checked in the context menu. Destroy
            curves that are not visible if `forget traces` is checked. In most cases, this
            function is called automatically when the `Max Traces` GUI elements are
            triggered. It is also called when the state of :class:`~pyqtgraph.PlotItem` is
            updated, its state is restored, or new items added added/removed.

            This can cause an unexpected or conflicting state of curve visibility
            (or destruction) if curve visibilities are controlled externally. In the case of
            external control it is advised to disable the `Max Traces` checkbox (or context
            menu) to prevent unexpected curve state changes.

            :meta private:
            """
            if not self.ctrl.maxTracesCheck.isChecked():
                return
            else:
                numCurves = self.ctrl.maxTracesSpin.value()

            if self.ctrl.forgetTracesCheck.isChecked():
                for curve in self.curves[:-numCurves]:
                    curve.clear()
                    self.removeItem(curve)

            for i, curve in enumerate(reversed(self.curves)):
                if i < numCurves:
                    curve.show()
                else:
                    curve.hide()

        @QtCore.Slot(bool)
        @QtCore.Slot(int)
        def updateAlpha(self, *args):
            (alpha, auto) = self.alphaState()
            for c in self.curves:
                c.setAlpha(alpha**2, auto)

        def alphaState(self):
            enabled = self.ctrl.alphaGroup.isChecked()
            auto = self.ctrl.autoAlphaCheck.isChecked()
            alpha = float(self.ctrl.alphaSlider.value()) / self.ctrl.alphaSlider.maximum()
            if auto:
                alpha = 1.0  ## should be 1/number of overlapping plots
            if not enabled:
                auto = False
                alpha = 1.0
            return (alpha, auto)

        def pointMode(self):
            if self.ctrl.pointsGroup.isChecked():
                return None if self.ctrl.autoPointsCheck.isChecked() else True
            else:
                return False

        def resizeEvent(self, ev):
            if self.autoBtn is None:  ## already closed down
                return
            btnRect = self.mapRectFromItem(self.autoBtn, self.autoBtn.boundingRect())
            y = self.size().height() - btnRect.height()
            self.autoBtn.setPos(0, y)

        def getMenu(self):
            return self.ctrlMenu

        def getContextMenus(self, event):
            ## called when another item is displaying its context menu; we get to add extras to the end of the menu.
            if self.menuEnabled():
                return self.ctrlMenu
            else:
                return None

        def menuEnabled(self):
            """
            Return whether the context menu is enabled.

            Returns
            -------
            bool
                ``True`` if the context menu is enabled, ``False`` otherwise.
            """
            return self._menuEnabled

        def hoverEvent(self, ev):
            if ev.enter:
                self.mouseHovering = True
            if ev.exit:
                self.mouseHovering = False

            self.updateButtons()

        def getLabel(self, key):
            pass

        def _checkScaleKey(self, key):
            if key not in self.axes:
                raise KeyError(
                    f"Scale '{key}' not found. Scales are: {list(self.axes.keys())}"
                )

        def getScale(self, key):
            return self.getAxis(key)

        def getAxis(self, name):
            """
            Return the specified AxisItem.

            Parameters
            ----------
            name : {'left', 'bottom', 'right', 'top'}
                The name of the axis to return.

            Returns
            -------
            AxisItem
                The :class:`~pyqtgraph.AxisItem`.

            Raises
            ------
            KeyError
                If the specified axis is not present.
            """
            self._checkScaleKey(name)
            return self.axes[name]['item']

        def setLabel(self, axis: str, *args, **kwargs):
            """
            Set the label for an axis.

            Basic HTML is allowed. See :func:`AxisItem.setLabel` for formatting options.

            Parameters
            ----------
            axis : {'left', 'bottom', 'right', 'top'}
                Specify which :class:`~pyqtgraph.AxisItem` to set the label for.
            *args : tuple, optional
                All extra arguments are passed to :meth:`~pyqtgraph.AxisItem.setLabel`.
            **kwargs : dict, optional
                Keyword arguments are passed to :meth:`~pyqtgraph.AxisItem.setLabel`.
            """
            self.getAxis(axis).setLabel(*args, **kwargs)
            self.showAxis(axis)

        def setLabels(self, **kwargs):
            """
            Set the axis labels of the plot.

            Parameters
            ----------
            **kwargs : dict, optional
                Keyword arguments are passed to  :meth:`~pyqtgraph.AxisItem.setLabel`.  The
                special keyword ``title`` can be used to set the plot title using
                :meth:`~pyqtgraph.PlotItem.setTitle`.
            """
            for k, v in kwargs.items():
                if k == 'title':
                    self.setTitle(v)
                else:
                    if isinstance(v, str):
                        v = (v,)
                    self.setLabel(k, *v)

        def showLabel(self, axis, show=True):
            """
            Show or hide one of the plot's axis labels.

            Parameters
            ----------
            axis : {'left', 'bottom', 'right', 'top'}
                The axis label to show or hide.
            show : bool, optional
                Whether to show or hide the label, by default True.
            """
            self.getScale(axis).showLabel(show)

        def setTitle(self, title=None, **args):
            """
            Set the title of the plot.

            Parameters
            ----------
            title : str, optional
                The title text. If ``None``, the title will be hidden. The default is
                ``None``.
            **args : dict
                Additional keyword arguments are passed to
                :meth:`~pyqtgraph.LabelItem.setText`.
            """
            if title is None:
                self.titleLabel.setVisible(False)
                self.layout.setRowFixedHeight(0, 0)
                self.titleLabel.setMaximumHeight(0)
            else:
                self.titleLabel.setMaximumHeight(30)
                self.layout.setRowFixedHeight(0, 30)
                self.titleLabel.setVisible(True)
                self.titleLabel.setText(title, **args)

        def showAxis(self, axis: str, show: bool=True):
            """
            Show or hide an axis.

            Parameters
            ----------
            axis : {'left', 'bottom', 'right', 'top'}
                The axis to show or hide.
            show : bool, optional
                Whether to show or hide the axis, by default True.
            """
            s = self.getScale(axis)
            if show:
                s.show()
            else:
                s.hide()

        def hideAxis(self, axis):
            """
            Hide an axis.

            Parameters
            ----------
            axis : {'left', 'bottom', 'right', 'top'}
                The axis to hide.
            """
            self.showAxis(axis, False)

        def showAxes(self, selection, showValues=True, size=False):
            """
            Convenience method for quickly configuring axis settings.

            Parameters
            ----------
            selection : bool or tuple of bool
                Determines which AxisItems will be displayed. If in tuple form, order is
                (left, top, right, bottom). A single boolean value will set all axes, so
                that ``showAxes(True)`` configures the axes to draw a frame.
            showValues : bool or tuple of bool, optional
                Determines if values will be displayed for the ticks of each axis. ``True``
                value shows values for left and bottom axis (default). ``False`` shows no
                values. If in tuple form, order is (left, top, right, bottom). ``None``
                leaves settings unchanged. If not specified, left and bottom axes will be
                drawn with values.
            size : float or tuple of float, optional
                Reserves as fixed amount of space (width for vertical axis, height for
                horizontal axis) for each axis where tick values are enabled. If only a
                single float value is given, it will be applied for both width and height.
                If ``None`` is given instead of a float value, the axis reverts to automatic
                allocation of space. If in tuple form, order is ``(width, height)``.
            """
            if selection is True: # shortcut: enable all axes, creating a frame
                selection = (True, True, True, True)
            elif selection is False: # shortcut: disable all axes
                selection = (False, False, False, False)
            if showValues is True: # shortcut: defaults arrangement with labels at left and bottom
                showValues = (True, False, False, True)
            elif showValues is False: # shortcut: disable all labels
                showValues = (False, False, False, False)
            elif showValues is None: # leave labelling untouched
                showValues = (None, None, None, None)
            if size is not False and not isinstance(size, collections.abc.Sized):
                size = (size, size) # make sure that size is either False or a full set of (width, height)

            all_axes = ('left','top','right','bottom')
            for show_axis, show_value, axis_key in zip(selection, showValues, all_axes):
                if show_axis is not None:
                    if show_axis: self.showAxis(axis_key)
                    else        : self.hideAxis(axis_key)

                if show_value is not None:
                    ax = self.getAxis(axis_key)
                    ax.setStyle(showValues=show_value)
                    if size is not False: # size adjustment is requested
                        if axis_key in ('left','right'):
                            if show_value: ax.setWidth(size[0])
                            else         : ax.setWidth( None )
                        elif axis_key in ('top', 'bottom'):
                            if show_value: ax.setHeight(size[1])
                            else         : ax.setHeight( None )

        def hideButtons(self):
            """
            Hide auto-scale button ('A' in lower-left corner).
            """

            self.buttonsHidden = True
            self.updateButtons()

        def showButtons(self):
            """
            Show auto-scale button ('A' in lower-left corner).
            """
            self.buttonsHidden = False
            self.updateButtons()

        def updateButtons(self):
            try:
                if self._exportOpts is False and self.mouseHovering and not self.buttonsHidden and not all(self.vb.autoRangeEnabled()):
                    self.autoBtn.show()
                else:
                    self.autoBtn.hide()
            except RuntimeError:
                pass  # this can happen if the plot has been deleted.

        def _plotArray(self, arr, x=None, **kargs):
            if arr.ndim != 1:
                raise ValueError(f"Array must be 1D to plot (shape is {arr.shape})")
            if x is None:
                x = np.arange(arr.shape[0])
            if x.ndim != 1:
                raise ValueError(f"X array must be 1D to plot (shape is {x.shape})")
            return PlotCurveItem(arr, x=x, **kargs)

        def setExportMode(self, export: bool, opts=None):
            """
            Set whether the item will allow export via screenshots or image files.

            If export mode is enabled, then the item will allow export and the export
            options dock will be displayed. If export mode is disabled, then no export
            options will be available and the export dock will be hidden.

            Parameters
            ----------
            export : bool
                If ``True``, the item will allow export.
            opts : dict or None, optional
                A dictionary of export options. If ``None``, the default export
                options will be used. By default, ``None``.
            """
            super().setExportMode(export, opts)
            self.updateButtons()

        def _chooseFilenameDialog(self, handler):
            self.fileDialog = FileDialog()
            if PlotItem.lastFileDir is not None:
                self.fileDialog.setDirectory(PlotItem.lastFileDir)
            self.fileDialog.setFileMode(QtWidgets.QFileDialog.FileMode.AnyFile)
            self.fileDialog.setAcceptMode(QtWidgets.QFileDialog.AcceptMode.AcceptSave)
            self.fileDialog.show()
            self.fileDialog.fileSelected.connect(handler)