[FIXED] How to stick widgets to dialog edges

Issue

How to make lineedit stick to the top and button to the lower edge of the dialog when it gets resized?

from PyQt5.QtWidgets import *

class Dialog(QDialog):
    def __init__(self, parent=None):
        super(Dialog, self).__init__(parent)
        self.setLayout(QVBoxLayout())

        layout = QHBoxLayout()
        self.layout().insertLayout(0, layout)
        lineedit = QLineEdit(self)
        layout.addWidget(lineedit)

        button = QPushButton(self)
        button.setText('ok')
        self.layout().addWidget(button)
        self.show()

app = QApplication(list())
dialog = Dialog()
app.exec_()

Solution

Add a vertical spacer to the layout:

from PyQt5.QtWidgets import *

class Dialog(QDialog):
    def __init__(self, parent=None):
        super(Dialog, self).__init__(parent)
        self.setLayout(QVBoxLayout())

        layout = QHBoxLayout()
        self.layout().insertLayout(0, layout)
        lineedit = QLineEdit(self)
        layout.addWidget(lineedit)

        # version (1): add vertical, expanding spacer item
        self.layout().addItem(
            QSpacerItem(0, 0, QSizePolicy.Minimum, QSizePolicy.Expanding))

        # version (2): use "addStretch"
        # self.layout().addStretch()

        button = QPushButton(self)
        button.setText('ok')
        self.layout().addWidget(button)
        self.show()

app = QApplication(list())
dialog = Dialog()
app.exec_()

A QSpacerItem is just an unstyled, blank space, that consumes horizontal and vertical space in the layout according to its size policies.

QSpacerItem's parameters:

• w - preferred width, 0
• h - preferred height, 0
• hPolicy - horizontal size policy, QSizePolicy.Minimum => the preferred width is sufficient, the item will not expand horizontally
• vPolicy - vertical size policy, QSizePolicy.Expanding => the item can make use of extra space, and thus will expand vertically and take all available space

See https://doc.qt.io/qt-5/qspaceritem.html#QSpacerItem and http://doc.qt.io/qt-5/qsizepolicy.html#Policy-enum for details.

Answered By - Flopp