qt - 有没有办法在父小部件上叠加多个项目(PySide/Qt)

Question

我有一个主要的父小部件，我想要在父小部件之上有几个布局。

使用父小部件初始化布局会将布局放置在父小部件的顶部。我喜欢这个，并希望为同一个父小部件多次(左侧、顶部、底部和右侧)执行此操作。

我使用了具有不同子布局的 QGridLayout，但这会导致布局调整大小并迫使它们变小。最后添加的任何 Overlay 都应该在其他项目的顶部。

下面是我想要的一个非常简单的例子。

import sys
from PySide import QtGui, QtCore


class Overlay(QtGui.QBoxLayout):
    """Overlay widgets on a parent widget."""

    def __init__(self, parent=None, location="left"):
        super().__init__(QtGui.QBoxLayout.TopToBottom, parent)

        if location == "left" or location == "right":
            self.setDirection(QtGui.QBoxLayout.TopToBottom)
            if location == "right":
                self.setAlignment(QtCore.Qt.AlignRight)
        elif location == "top" or location == "bottom":
            self.setDirection(QtGui.QBoxLayout.LeftToRight)
            if location == "bottom":
                self.setAlignment(QtCore.Qt.AlignBottom)

        self.css = "QWidget {background-color: lightskyblue; color: white}"
    # end Constructor

    def addWidget(self, widget):
        super().addWidget(widget)

        widget.setStyleSheet(self.css)
    # end addWidget
# end class Overlay

def main():
    app = QtGui.QApplication(sys.argv)

    window = QtGui.QMainWindow()
    window.show()

    widg = QtGui.QTreeView()
    window.setCentralWidget(widg)

    left = Overlay(widg, "left")
    left.addWidget(QtGui.QLabel("HELLO"))
    left.addWidget(QtGui.QLabel("WORLD!"))

    top = Overlay(widg, "top")
    top.addWidget(QtGui.QLabel("Hello"))
    top.addWidget(QtGui.QLabel("World!"))

    right = Overlay(location="right")
    right.setParent(widg)
    right.addWidget(QtGui.QLabel("hello"))
    right.addWidget(QtGui.QLabel("world!"))

    return app.exec_()
# end main

if __name__ == '__main__':
    sys.exit(main())

反正有同一个父级的多个布局吗？如果没有，是否有某种方法可以创建一个虚拟小部件，该小部件将与父小部件一起移动，并让叠加层使用多个虚拟小部件作为其父小部件？

还

layout = QtGui.QBoxLayout(QtGui.QBoxLayout.TopToBottom, parent_widget)

不做同样的事情

layout = QtGui.QBoxLayout(QtGui.QBoxLayout.TopToBottom)
layout.setParent(parent_widget)

初始化对不同的父级有什么作用？

Answer 1

我通过创建自己的主自定义布局解决了这个问题。 OverlayCenter 具有主小部件，因为它是父小部件，您只需将其他布局添加到此布局中。

import sys
from PySide import QtGui, QtCore


class OverlayCenter(QtGui.QLayout):
    """Layout for managing overlays."""

    def __init__(self, parent):
        super().__init__(parent)

        # Properties
        self.setContentsMargins(0, 0, 0, 0)

        self.items = []
    # end Constructor

    def addLayout(self, layout):
        """Add a new layout to overlay on top of the other layouts and widgets."""
        self.addChildLayout(layout)
        self.addItem(layout)
    # end addLayout

    def __del__(self):
        """Destructor for garbage collection."""
        item = self.takeAt(0)
        while item:
            item = self.takeAt(0)
    # end Destructor

    def addItem(self, item):
        """Add an item (widget/layout) to the list."""
        self.items.append(item)
    # end addItem

    def count(self):
        """Return the number of items."""
        return len(self.items)
    # end Count

    def itemAt(self, index):
        """Return the item at the given index."""
        if index >= 0 and index < len(self.items):
            return self.items[index]

        return None
    # end itemAt

    def takeAt(self, index):
        """Remove and return the item at the given index."""
        if index >= 0 and index < len(self.items):
            return self.items.pop(index)

        return None
    # end takeAt

    def setGeometry(self, rect):
        """Set the main geometry and the item geometry."""
        super().setGeometry(rect)

        for item in self.items:
            item.setGeometry(rect)
    # end setGeometry
# end class OverlayCenter


class Overlay(QtGui.QBoxLayout):
    """Overlay widgets on a parent widget."""

    def __init__(self, location="left", parent=None):
        super().__init__(QtGui.QBoxLayout.TopToBottom, parent)

        if location == "left":
            self.setDirection(QtGui.QBoxLayout.TopToBottom)
            self.setAlignment(QtCore.Qt.AlignLeft | QtCore.Qt.AlignVCenter)
        elif location == "right":
            self.setDirection(QtGui.QBoxLayout.TopToBottom)
            self.setAlignment(QtCore.Qt.AlignRight | QtCore.Qt.AlignVCenter)
        elif location == "top":
            self.setDirection(QtGui.QBoxLayout.LeftToRight)
            self.setAlignment(QtCore.Qt.AlignTop | QtCore.Qt.AlignHCenter)
        elif location == "bottom":
            self.setDirection(QtGui.QBoxLayout.LeftToRight)
            self.setAlignment(QtCore.Qt.AlignBottom | QtCore.Qt.AlignHCenter)


        self.css = "QWidget {background-color: lightskyblue; color: white}"
    # end Constructor

    def addWidget(self, widget):
        super().addWidget(widget)

        widget.setStyleSheet(self.css)
    # end addWidget
# end class Overlay

def main():
    app = QtGui.QApplication(sys.argv)

    window = QtGui.QMainWindow()
    window.show()

    widg = QtGui.QTreeView()
    window.setCentralWidget(widg)

    left = Overlay("left")
    lhlbl = QtGui.QLabel("Hello")
    lwlbl = QtGui.QLabel("World!")
    lhlbl.setSizePolicy(QtGui.QSizePolicy.Maximum, QtGui.QSizePolicy.Maximum)
    lwlbl.setSizePolicy(QtGui.QSizePolicy.Maximum, QtGui.QSizePolicy.Maximum)
    left.addWidget(lhlbl)
    left.addWidget(lwlbl)

    top = Overlay("top")
    lhlbl = QtGui.QLabel("HELLO")
    lwlbl = QtGui.QLabel("WORLD!")
    lhlbl.setSizePolicy(QtGui.QSizePolicy.Maximum, QtGui.QSizePolicy.Maximum)
    lwlbl.setSizePolicy(QtGui.QSizePolicy.Maximum, QtGui.QSizePolicy.Maximum)
    top.addWidget(lhlbl)
    top.addWidget(lwlbl)

    right = Overlay("right")
    lhlbl = QtGui.QLabel("hellO")
    lwlbl = QtGui.QLabel("worlD!")
    lhlbl.setSizePolicy(QtGui.QSizePolicy.Maximum, QtGui.QSizePolicy.Maximum)
    lwlbl.setSizePolicy(QtGui.QSizePolicy.Maximum, QtGui.QSizePolicy.Maximum)
    right.addWidget(lhlbl)
    right.addWidget(lwlbl)

    bottom = Overlay("bottom")
    lhlbl = QtGui.QLabel("hello")
    lwlbl = QtGui.QLabel("world!")
    lhlbl.setSizePolicy(QtGui.QSizePolicy.Maximum, QtGui.QSizePolicy.Maximum)
    lwlbl.setSizePolicy(QtGui.QSizePolicy.Maximum, QtGui.QSizePolicy.Maximum)
    bottom.addWidget(lhlbl)
    bottom.addWidget(lwlbl)

    center = OverlayCenter(widg)
    center.addLayout(left)
    center.addLayout(top)
    center.addLayout(right)
    center.addLayout(bottom)

    return app.exec_()
# end main

if __name__ == '__main__':
    sys.exit(main())