import warnings

from ..Qt import QtCore, QtGui, QtWidgets
from ..widgets.VerticalLabel import VerticalLabel
from .DockDrop import DockDrop


class Dock(QtWidgets.QWidget):

    sigStretchChanged = QtCore.Signal()
    sigClosed = QtCore.Signal(object)

    def __init__(self, name, area=None, size=(10, 10), widget=None, hideTitle=False, autoOrientation=True, label=None, **kargs):
        QtWidgets.QWidget.__init__(self)
        self.dockdrop = DockDrop(self)
        self._container = None
        self._name = name
        self.area = area
        self.label = label
        if self.label is None:
            self.label = DockLabel(name, **kargs)
        self.label.dock = self
        if self.label.isClosable():
            self.label.sigCloseClicked.connect(self.close)
        self.labelHidden = False
        self.moveLabel = True  ## If false, the dock is no longer allowed to move the label.
        self.autoOrient = autoOrientation
        self.orientation = 'horizontal'
        #self.label.setAlignment(QtCore.Qt.AlignmentFlag.AlignHCenter)
        self.topLayout = QtWidgets.QGridLayout()
        self.topLayout.setContentsMargins(0, 0, 0, 0)
        self.topLayout.setSpacing(0)
        self.setLayout(self.topLayout)
        self.topLayout.addWidget(self.label, 0, 1)
        self.widgetArea = QtWidgets.QWidget()
        self.topLayout.addWidget(self.widgetArea, 1, 1)
        self.layout = QtWidgets.QGridLayout()
        self.layout.setContentsMargins(0, 0, 0, 0)
        self.layout.setSpacing(0)
        self.widgetArea.setLayout(self.layout)
        self.widgetArea.setSizePolicy(QtWidgets.QSizePolicy.Policy.Expanding, QtWidgets.QSizePolicy.Policy.Expanding)
        self.widgets = []
        self.currentRow = 0
        #self.titlePos = 'top'
        self.dockdrop.raiseOverlay()
        self.hStyle = """
        Dock > QWidget {
            border: 1px solid #000;
            border-radius: 5px;
            border-top-left-radius: 0px;
            border-top-right-radius: 0px;
            border-top-width: 0px;
        }"""
        self.vStyle = """
        Dock > QWidget {
            border: 1px solid #000;
            border-radius: 5px;
            border-top-left-radius: 0px;
            border-bottom-left-radius: 0px;
            border-left-width: 0px;
        }"""
        self.nStyle = """
        Dock > QWidget {
            border: 1px solid #000;
            border-radius: 5px;
        }"""
        self.dragStyle = """
        Dock > QWidget {
            border: 4px solid #00F;
            border-radius: 5px;
        }"""
        self.setAutoFillBackground(False)
        self.widgetArea.setStyleSheet(self.hStyle)

        self.setStretch(*size)

        if widget is not None:
            self.addWidget(widget)

        if hideTitle:
            self.hideTitleBar()

    def implements(self, name=None):
        if name is None:
            return ['dock']
        else:
            return name == 'dock'

    def setStretch(self, x=None, y=None):
        """
        Set the 'target' size for this Dock.
        The actual size will be determined by comparing this Dock's
        stretch value to the rest of the docks it shares space with.
        """
        if x is None:
            x = 0
        if y is None:
            y = 0
        self._stretch = (x, y)
        self.sigStretchChanged.emit()
        
    def stretch(self):
        return self._stretch

    def hideTitleBar(self):
        """
        Hide the title bar for this Dock.
        This will prevent the Dock being moved by the user.
        """
        self.label.hide()
        self.labelHidden = True
        self.dockdrop.removeAllowedArea('center')
        self.updateStyle()

    def showTitleBar(self):
        """
        Show the title bar for this Dock.
        """
        self.label.show()
        self.labelHidden = False
        self.dockdrop.addAllowedArea('center')
        self.updateStyle()

    def title(self):
        """
        Gets the text displayed in the title bar for this dock.
        """
        return self.label.text()

    def setTitle(self, text):
        """
        Sets the text displayed in title bar for this Dock.
        """
        self.label.setText(text)

    def setOrientation(self, o='auto', force=False):
        """
        Sets the orientation of the title bar for this Dock.
        Must be one of 'auto', 'horizontal', or 'vertical'.
        By default ('auto'), the orientation is determined
        based on the aspect ratio of the Dock.
        """
        # setOrientation may be called before the container is set in some cases
        # (via resizeEvent), so there's no need to do anything here until called
        # again by containerChanged
        if self.container() is None:
            return

        if o == 'auto' and self.autoOrient:
            if self.container().type() == 'tab':
                o = 'horizontal'
            elif self.width() > self.height()*1.5:
                o = 'vertical'
            else:
                o = 'horizontal'
        if force or self.orientation != o:
            self.orientation = o
            self.label.setOrientation(o)
            self.updateStyle()

    def updateStyle(self):
        ## updates orientation and appearance of title bar
        if self.labelHidden:
            self.widgetArea.setStyleSheet(self.nStyle)
        elif self.orientation == 'vertical':
            self.label.setOrientation('vertical')
            if self.moveLabel:
                self.topLayout.addWidget(self.label, 1, 0)
            self.widgetArea.setStyleSheet(self.vStyle)
        else:
            self.label.setOrientation('horizontal')
            if self.moveLabel:
                self.topLayout.addWidget(self.label, 0, 1)
            self.widgetArea.setStyleSheet(self.hStyle)

    def resizeEvent(self, ev):
        self.setOrientation()
        self.dockdrop.resizeOverlay(self.size())

    def name(self):
        return self._name

    def addWidget(self, widget, row=None, col=0, rowspan=1, colspan=1):
        """
        Add a new widget to the interior of this Dock.
        Each Dock uses a QGridLayout to arrange widgets within.
        """
        if row is None:
            row = self.currentRow
        self.currentRow = max(row+1, self.currentRow)
        self.widgets.append(widget)
        self.layout.addWidget(widget, row, col, rowspan, colspan)
        self.dockdrop.raiseOverlay()
        
    def startDrag(self):
        self.drag = QtGui.QDrag(self)
        mime = QtCore.QMimeData()
        self.drag.setMimeData(mime)
        self.widgetArea.setStyleSheet(self.dragStyle)
        self.update()
        action = self.drag.exec() if hasattr(self.drag, 'exec') else self.drag.exec_()
        self.updateStyle()

    def float(self):
        self.area.floatDock(self)
            
    def container(self):
        return self._container

    def containerChanged(self, c):
        if self._container is not None:
            # ask old container to close itself if it is no longer needed
            self._container.apoptose()
        self._container = c
        if c is None:
            self.area = None
        else:
            self.area = c.area
            if c.type() != 'tab':
                self.moveLabel = True
                self.label.setDim(False)
            else:
                self.moveLabel = False
                
            self.setOrientation(force=True)

    def raiseDock(self):
        """If this Dock is stacked underneath others, raise it to the top."""
        self.container().raiseDock(self)

    def close(self):
        """Remove this dock from the DockArea it lives inside."""
        if self._container is None:
            warnings.warn(f"Cannot close dock {self} because it is not open.", RuntimeWarning, stacklevel=2)
            return

        self.setParent(None)
        QtWidgets.QLabel.close(self.label)
        self.label.setParent(None)
        self._container.apoptose()
        self._container = None
        self.sigClosed.emit(self)

    def __repr__(self):
        return "<Dock %s %s>" % (self.name(), self.stretch())

    def dragEnterEvent(self, *args):
        self.dockdrop.dragEnterEvent(*args)

    def dragMoveEvent(self, *args):
        self.dockdrop.dragMoveEvent(*args)

    def dragLeaveEvent(self, *args):
        self.dockdrop.dragLeaveEvent(*args)

    def dropEvent(self, *args):
        self.dockdrop.dropEvent(*args)


class DockLabel(VerticalLabel):

    sigClicked = QtCore.Signal(object, object)
    sigCloseClicked = QtCore.Signal()

    def __init__(self, text, closable=False, fontSize="12px"):
        self.dim = False
        self.fixedWidth = False
        self.fontSize = fontSize
        VerticalLabel.__init__(self, text, orientation='horizontal', forceWidth=False)
        self.setAlignment(QtCore.Qt.AlignmentFlag.AlignTop|QtCore.Qt.AlignmentFlag.AlignHCenter)
        self.dock = None
        self.updateStyle()
        self.setAutoFillBackground(False)
        self.mouseMoved = False

        self.closeButton = None
        if closable:
            self.closeButton = QtWidgets.QToolButton(self)
            self.closeButton.clicked.connect(self.sigCloseClicked)
            self.closeButton.setIcon(QtWidgets.QApplication.style().standardIcon(QtWidgets.QStyle.StandardPixmap.SP_TitleBarCloseButton))

    def updateStyle(self):
        r = '3px'
        if self.dim:
            fg = '#aaa'
            bg = '#44a'
            border = '#339'
        else:
            fg = '#fff'
            bg = '#66c'
            border = '#55B'

        if self.orientation == 'vertical':
            self.vStyle = """DockLabel {
                background-color : %s;
                color : %s;
                border-top-right-radius: 0px;
                border-top-left-radius: %s;
                border-bottom-right-radius: 0px;
                border-bottom-left-radius: %s;
                border-width: 0px;
                border-right: 2px solid %s;
                padding-top: 3px;
                padding-bottom: 3px;
                font-size: %s;
            }""" % (bg, fg, r, r, border, self.fontSize)
            self.setStyleSheet(self.vStyle)
        else:
            self.hStyle = """DockLabel {
                background-color : %s;
                color : %s;
                border-top-right-radius: %s;
                border-top-left-radius: %s;
                border-bottom-right-radius: 0px;
                border-bottom-left-radius: 0px;
                border-width: 0px;
                border-bottom: 2px solid %s;
                padding-left: 3px;
                padding-right: 3px;
                font-size: %s;
            }""" % (bg, fg, r, r, border, self.fontSize)
            self.setStyleSheet(self.hStyle)

    def setDim(self, d):
        if self.dim != d:
            self.dim = d
            self.updateStyle()

    def setOrientation(self, o):
        VerticalLabel.setOrientation(self, o)
        self.updateStyle()

    def isClosable(self):
        return self.closeButton is not None

    def mousePressEvent(self, ev):
        lpos = ev.position() if hasattr(ev, 'position') else ev.localPos()
        self.pressPos = lpos
        self.mouseMoved = False
        ev.accept()

    def mouseMoveEvent(self, ev):
        if not self.mouseMoved:
            lpos = ev.position() if hasattr(ev, 'position') else ev.localPos()
            self.mouseMoved = (lpos - self.pressPos).manhattanLength() > QtWidgets.QApplication.startDragDistance()

        if self.mouseMoved and ev.buttons() == QtCore.Qt.MouseButton.LeftButton:
            self.dock.startDrag()
        ev.accept()

    def mouseReleaseEvent(self, ev):
        ev.accept()
        if not self.mouseMoved:
            self.sigClicked.emit(self, ev)

    def mouseDoubleClickEvent(self, ev):
        if ev.button() == QtCore.Qt.MouseButton.LeftButton:
            self.dock.float()

    def resizeEvent (self, ev):
        if self.closeButton:
            if self.orientation == 'vertical':
                size = ev.size().width()
                pos = QtCore.QPoint(0, 0)
            else:
                size = ev.size().height()
                pos = QtCore.QPoint(ev.size().width() - size, 0)
            self.closeButton.setFixedSize(QtCore.QSize(size, size))
            self.closeButton.move(pos)
        super(DockLabel,self).resizeEvent(ev)

pyqtgraph/dockarea/Dock.py
import warnings

from ..Qt import QtCore, QtGui, QtWidgets
from ..widgets.VerticalLabel import VerticalLabel
from .DockDrop import DockDrop


class Dock(QtWidgets.QWidget):

    sigStretchChanged = QtCore.Signal()
    sigClosed = QtCore.Signal(object)

    def __init__(self, name, area=None, size=(10, 10), widget=None, hideTitle=False, autoOrientation=True, label=None, **kargs):
        QtWidgets.QWidget.__init__(self)
        self.dockdrop = DockDrop(self)
        self._container = None
        self._name = name
        self.area = area
        self.label = label
        if self.label is None:
            self.label = DockLabel(name, **kargs)
        self.label.dock = self
        if self.label.isClosable():
            self.label.sigCloseClicked.connect(self.close)
        self.labelHidden = False
        self.moveLabel = True  ## If false, the dock is no longer allowed to move the label.
        self.autoOrient = autoOrientation
        self.orientation = 'horizontal'
        #self.label.setAlignment(QtCore.Qt.AlignmentFlag.AlignHCenter)
        self.topLayout = QtWidgets.QGridLayout()
        self.topLayout.setContentsMargins(0, 0, 0, 0)
        self.topLayout.setSpacing(0)
        self.setLayout(self.topLayout)
        self.topLayout.addWidget(self.label, 0, 1)
        self.widgetArea = QtWidgets.QWidget()
        self.topLayout.addWidget(self.widgetArea, 1, 1)
        self.layout = QtWidgets.QGridLayout()
        self.layout.setContentsMargins(0, 0, 0, 0)
        self.layout.setSpacing(0)
        self.widgetArea.setLayout(self.layout)
        self.widgetArea.setSizePolicy(QtWidgets.QSizePolicy.Policy.Expanding, QtWidgets.QSizePolicy.Policy.Expanding)
        self.widgets = []
        self.currentRow = 0
        #self.titlePos = 'top'
        self.dockdrop.raiseOverlay()
        self.hStyle = """
        Dock > QWidget {
            border: 1px solid #000;
            border-radius: 5px;
            border-top-left-radius: 0px;
            border-top-right-radius: 0px;
            border-top-width: 0px;
        }"""
        self.vStyle = """
        Dock > QWidget {
            border: 1px solid #000;
            border-radius: 5px;
            border-top-left-radius: 0px;
            border-bottom-left-radius: 0px;
            border-left-width: 0px;
        }"""
        self.nStyle = """
        Dock > QWidget {
            border: 1px solid #000;
            border-radius: 5px;
        }"""
        self.dragStyle = """
        Dock > QWidget {
            border: 4px solid #00F;
            border-radius: 5px;
        }"""
        self.setAutoFillBackground(False)
        self.widgetArea.setStyleSheet(self.hStyle)

        self.setStretch(*size)

        if widget is not None:
            self.addWidget(widget)

        if hideTitle:
            self.hideTitleBar()

    def implements(self, name=None):
        if name is None:
            return ['dock']
        else:
            return name == 'dock'

    def setStretch(self, x=None, y=None):
        """
        Set the 'target' size for this Dock.
        The actual size will be determined by comparing this Dock's
        stretch value to the rest of the docks it shares space with.
        """
        if x is None:
            x = 0
        if y is None:
            y = 0
        self._stretch = (x, y)
        self.sigStretchChanged.emit()
        
    def stretch(self):
        return self._stretch

    def hideTitleBar(self):
        """
        Hide the title bar for this Dock.
        This will prevent the Dock being moved by the user.
        """
        self.label.hide()
        self.labelHidden = True
        self.dockdrop.removeAllowedArea('center')
        self.updateStyle()

    def showTitleBar(self):
        """
        Show the title bar for this Dock.
        """
        self.label.show()
        self.labelHidden = False
        self.dockdrop.addAllowedArea('center')
        self.updateStyle()

    def title(self):
        """
        Gets the text displayed in the title bar for this dock.
        """
        return self.label.text()

    def setTitle(self, text):
        """
        Sets the text displayed in title bar for this Dock.
        """
        self.label.setText(text)

    def setOrientation(self, o='auto', force=False):
        """
        Sets the orientation of the title bar for this Dock.
        Must be one of 'auto', 'horizontal', or 'vertical'.
        By default ('auto'), the orientation is determined
        based on the aspect ratio of the Dock.
        """
        # setOrientation may be called before the container is set in some cases
        # (via resizeEvent), so there's no need to do anything here until called
        # again by containerChanged
        if self.container() is None:
            return

        if o == 'auto' and self.autoOrient:
            if self.container().type() == 'tab':
                o = 'horizontal'
            elif self.width() > self.height()*1.5:
                o = 'vertical'
            else:
                o = 'horizontal'
        if force or self.orientation != o:
            self.orientation = o
            self.label.setOrientation(o)
            self.updateStyle()

    def updateStyle(self):
        ## updates orientation and appearance of title bar
        if self.labelHidden:
            self.widgetArea.setStyleSheet(self.nStyle)
        elif self.orientation == 'vertical':
            self.label.setOrientation('vertical')
            if self.moveLabel:
                self.topLayout.addWidget(self.label, 1, 0)
            self.widgetArea.setStyleSheet(self.vStyle)
        else:
            self.label.setOrientation('horizontal')
            if self.moveLabel:
                self.topLayout.addWidget(self.label, 0, 1)
            self.widgetArea.setStyleSheet(self.hStyle)

    def resizeEvent(self, ev):
        self.setOrientation()
        self.dockdrop.resizeOverlay(self.size())

    def name(self):
        return self._name

    def addWidget(self, widget, row=None, col=0, rowspan=1, colspan=1):
        """
        Add a new widget to the interior of this Dock.
        Each Dock uses a QGridLayout to arrange widgets within.
        """
        if row is None:
            row = self.currentRow
        self.currentRow = max(row+1, self.currentRow)
        self.widgets.append(widget)
        self.layout.addWidget(widget, row, col, rowspan, colspan)
        self.dockdrop.raiseOverlay()
        
    def startDrag(self):
        self.drag = QtGui.QDrag(self)
        mime = QtCore.QMimeData()
        self.drag.setMimeData(mime)
        self.widgetArea.setStyleSheet(self.dragStyle)
        self.update()
        action = self.drag.exec() if hasattr(self.drag, 'exec') else self.drag.exec_()
        self.updateStyle()

    def float(self):
        self.area.floatDock(self)
            
    def container(self):
        return self._container

    def containerChanged(self, c):
        if self._container is not None:
            # ask old container to close itself if it is no longer needed
            self._container.apoptose(propagate=False)
        self._container = c
        if c is None:
            self.area = None
        else:
            self.area = c.area
            if c.type() != 'tab':
                self.moveLabel = True
                self.label.setDim(False)
            else:
                self.moveLabel = False
                
            self.setOrientation(force=True)

    def raiseDock(self):
        """If this Dock is stacked underneath others, raise it to the top."""
        self.container().raiseDock(self)

    def close(self):
        """Remove this dock from the DockArea it lives inside."""
        if self._container is None:
            warnings.warn(f"Cannot close dock {self} because it is not open.", RuntimeWarning, stacklevel=2)
            return

        self.setParent(None)
        QtWidgets.QLabel.close(self.label)
        self.label.setParent(None)
        self._container.apoptose()
        self._container = None
        self.sigClosed.emit(self)

    def __repr__(self):
        return "<Dock %s %s>" % (self.name(), self.stretch())

    def dragEnterEvent(self, *args):
        self.dockdrop.dragEnterEvent(*args)

    def dragMoveEvent(self, *args):
        self.dockdrop.dragMoveEvent(*args)

    def dragLeaveEvent(self, *args):
        self.dockdrop.dragLeaveEvent(*args)

    def dropEvent(self, *args):
        self.dockdrop.dropEvent(*args)


class DockLabel(VerticalLabel):

    sigClicked = QtCore.Signal(object, object)
    sigCloseClicked = QtCore.Signal()

    def __init__(self, text, closable=False, fontSize="12px"):
        self.dim = False
        self.fixedWidth = False
        self.fontSize = fontSize
        VerticalLabel.__init__(self, text, orientation='horizontal', forceWidth=False)
        self.setAlignment(QtCore.Qt.AlignmentFlag.AlignTop|QtCore.Qt.AlignmentFlag.AlignHCenter)
        self.dock = None
        self.updateStyle()
        self.setAutoFillBackground(False)
        self.mouseMoved = False

        self.closeButton = None
        if closable:
            self.closeButton = QtWidgets.QToolButton(self)
            self.closeButton.clicked.connect(self.sigCloseClicked)
            self.closeButton.setIcon(QtWidgets.QApplication.style().standardIcon(QtWidgets.QStyle.StandardPixmap.SP_TitleBarCloseButton))

    def updateStyle(self):
        r = '3px'
        if self.dim:
            fg = '#aaa'
            bg = '#44a'
            border = '#339'
        else:
            fg = '#fff'
            bg = '#66c'
            border = '#55B'

        if self.orientation == 'vertical':
            self.vStyle = """DockLabel {
                background-color : %s;
                color : %s;
                border-top-right-radius: 0px;
                border-top-left-radius: %s;
                border-bottom-right-radius: 0px;
                border-bottom-left-radius: %s;
                border-width: 0px;
                border-right: 2px solid %s;
                padding-top: 3px;
                padding-bottom: 3px;
                font-size: %s;
            }""" % (bg, fg, r, r, border, self.fontSize)
            self.setStyleSheet(self.vStyle)
        else:
            self.hStyle = """DockLabel {
                background-color : %s;
                color : %s;
                border-top-right-radius: %s;
                border-top-left-radius: %s;
                border-bottom-right-radius: 0px;
                border-bottom-left-radius: 0px;
                border-width: 0px;
                border-bottom: 2px solid %s;
                padding-left: 3px;
                padding-right: 3px;
                font-size: %s;
            }""" % (bg, fg, r, r, border, self.fontSize)
            self.setStyleSheet(self.hStyle)

    def setDim(self, d):
        if self.dim != d:
            self.dim = d
            self.updateStyle()

    def setOrientation(self, o):
        VerticalLabel.setOrientation(self, o)
        self.updateStyle()

    def isClosable(self):
        return self.closeButton is not None

    def mousePressEvent(self, ev):
        lpos = ev.position() if hasattr(ev, 'position') else ev.localPos()
        self.pressPos = lpos
        self.mouseMoved = False
        ev.accept()

    def mouseMoveEvent(self, ev):
        if not self.mouseMoved:
            lpos = ev.position() if hasattr(ev, 'position') else ev.localPos()
            self.mouseMoved = (lpos - self.pressPos).manhattanLength() > QtWidgets.QApplication.startDragDistance()

        if self.mouseMoved and ev.buttons() == QtCore.Qt.MouseButton.LeftButton:
            self.dock.startDrag()
        ev.accept()

    def mouseReleaseEvent(self, ev):
        ev.accept()
        if not self.mouseMoved:
            self.sigClicked.emit(self, ev)

    def mouseDoubleClickEvent(self, ev):
        if ev.button() == QtCore.Qt.MouseButton.LeftButton:
            self.dock.float()

    def resizeEvent (self, ev):
        if self.closeButton:
            if self.orientation == 'vertical':
                size = ev.size().width()
                pos = QtCore.QPoint(0, 0)
            else:
                size = ev.size().height()
                pos = QtCore.QPoint(ev.size().width() - size, 0)
            self.closeButton.setFixedSize(QtCore.QSize(size, size))
            self.closeButton.move(pos)
        super(DockLabel,self).resizeEvent(ev)

pyqtgraph/dockarea/Dock.py
diff --git a/pyqtgraph/dockarea/Dock.py b/pyqtgraph/dockarea/Dock.py
index 99449e1b71..26e43b26ae 100644
--- a/pyqtgraph/dockarea/Dock.py
+++ b/pyqtgraph/dockarea/Dock.py
@@ -210,7 +210,7 @@ def container(self):
     def containerChanged(self, c):
         if self._container is not None:
             # ask old container to close itself if it is no longer needed
-            self._container.apoptose()
+            self._container.apoptose(propagate=False)
         self._container = c
         if c is None:
             self.area = None

Dock restoreState fails silently if a dock object is the only item in a V- or HContainer
### Short description
Calling restoreState() on a dockArea where a dock is the only object inside a container leads to the state being not correctly restored.
I don't know how it happened that a dock could appear as the only item in a container but one user managed to do that.
I couldn't find out how to trigger that.
Anyway, in that case way too many container are apoptose'd and the state is nor correctly restored

### Code to reproduce
```python
import json
import sys

import pyqtgraph as pg
from PySide6.QtWidgets import QMainWindow
from pyqtgraph.dockarea import Dock, DockArea


class DockApp(QMainWindow):
    def __init__(self, title):
        super().__init__()
        self.dock_area = DockArea()
        self.setCentralWidget(self.dock_area)
        self.dock_area.addDock(Dock(name="Plot 1", closable=False), 'left')
        self.dock_area.addDock(Dock(name="Plot 2", closable=False), 'left')
        self.dock_area.addDock(Dock(name="Plot 4", closable=False), 'left')
        self.dock_area.addDock(Dock(name="Table 1", closable=False), 'left')
        self.dock_area.addDock(Dock(name="Table 2", closable=False), 'left')
        self.dock_area.addDock(Dock(name="Table 3", closable=False), 'left')

        state = json.loads("""{
          "main": [
            "vertical",
            [
              [
                "horizontal",
                [
                  [
                    "vertical",
                    [
                      [
                        "vertical",
                        [
                          [
                            "dock",
                            "Plot 1",
                            {}
                          ]
                        ],
                        {
                          "sizes": [
                            314
                          ]
                        }
                      ],
                      [
                        "dock",
                        "Plot 2",
                        {}
                      ]
                    ],
                    {
                      "sizes": [
                        314,
                        313
                      ]
                    }
                  ],
                  [
                    "vertical",
                    [
                      [
                        "dock",
                        "Table 3",
                        {}
                      ],
                      [
                        "dock",
                        "Table 2",
                        {}
                      ],
                      [
                        "dock",
                        "Table 1",
                        {}
                      ]
                    ],
                    {
                      "sizes": [
                        208,
                        207,
                        208
                      ]
                    }
                  ]
                ],
                {
                  "sizes": [
                    784,
                    783
                  ]
                }
              ],
              [
                "dock",
                "Plot 4",
                {}
              ]
            ],
            {
              "sizes": [
                631,
                210
              ]
            }
          ],
          "float": []
        }""")
        self.dock_area.restoreState(state)


if __name__ == '__main__':
    app = pg.Qt.mkQApp("LiveTrace")
    window = DockApp(title='Test')
    window.show()
    sys.exit(app.exec())
```

### Expected behavior
All 6 docks should be restored like this:
![image](https://github.com/pyqtgraph/pyqtgraph/assets/627373/850761a7-ce75-418a-858c-0e80449481ee)


### Real behavior
Only 2 docks are visible. All other docks are missing.
![image](https://github.com/pyqtgraph/pyqtgraph/assets/627373/3501edf7-c73d-421c-9f8c-a553f76f19ce)


Note: No exception is thrown

### Tested environment(s)

 * PyQtGraph version: 0.13.3
 * Qt Python binding: PySide6 6.6.0 Qt 6.6.0
 * Python version: 3.10.11 AMD64
 * NumPy version: 1.26.2
 * Operating system: Windows 10 22H2
 * Installation method: pip

### Additional context

