ZetCode PyQt4 tutorial layout management

!/usr/bin/python
 -*- coding: utf-8 -*-

"""
ZetCode PyQt4 tutorial 

This example shows three labels on a window
using absolute positioning. 

author: Jan Bodnar
website: zetcode.com
last edited: October 2011
"""

import sys
from PyQt4 import QtGui

class Example(QtGui.QWidget):

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

        self.initUI()

    def initUI(self):

        # The label widget is positioned at x=15 and y=10.
        lbl1 = QtGui.QLabel('ZetCode', self)
        lbl1.move(15, 10)

        lbl2 = QtGui.QLabel('tutorials', self)
        lbl2.move(35, 40)

        lbl3 = QtGui.QLabel('for programmers', self)
        lbl3.move(55, 70)        

        self.setGeometry(300, 300, 250, 150)
        self.setWindowTitle('Absolute')
        self.show()

def main():

    app = QtGui.QApplication(sys.argv)
    ex = Example()
    sys.exit(app.exec_())

if __name__ == '__main__':
    main()

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#!/usr/bin/python
# -*- coding: utf-8 -*-

"""
ZetCode PyQt4 tutorial 

In this example, we position two push
buttons in the bottom-right corner
of the window. 

author: Jan Bodnar
website: zetcode.com
last edited: October 2011
"""

import sys
from PyQt4 import QtGui

class Example(QtGui.QWidget):

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

        self.initUI()

    def initUI(self):

        # Here we create two push buttons.
        okButton = QtGui.QPushButton("OK")
        cancelButton = QtGui.QPushButton("Cancel")

        # We create a horizontal box layout and add a stretch factor and both buttons. The stretch adds a stretchable space before the two buttons. This will push them to the right of the window.
        hbox = QtGui.QHBoxLayout()
        # Adds a stretchable space (a QSpacerItem) with zero minimum size and stretch factor stretch to the end of this box layout.
        # 添加一个弹簧，填充空间
        hbox.addStretch(1)
        hbox.addWidget(okButton)
        hbox.addWidget(cancelButton)

        # To create the necessary layout, we put a horizontal layout into a vertical one. The stretch factor in the vertical box will push the horizontal box with the buttons to the bottom of the window.
        vbox = QtGui.QVBoxLayout()
        # 添加一个弹簧，填充空间
        vbox.addStretch(1)
        vbox.addLayout(hbox)

        # Finally, we set the main layout of the window.
        self.setLayout(vbox)    

        self.setGeometry(300, 300, 300, 150)
        self.setWindowTitle('Buttons')
        self.show()

def main():

    app = QtGui.QApplication(sys.argv)
    ex = Example()
    sys.exit(app.exec_())

if __name__ == '__main__':
    main()

--------------------------------------------------------------------------------

#!/usr/bin/python
# -*- coding: utf-8 -*-

import sys
from PyQt4 import QtGui

"""
ZetCode PyQt4 tutorial 

In this example, we create a skeleton
of a calculator using a QtGui.QGridLayout.

author: Jan Bodnar
website: zetcode.com
last edited: July 2014
"""

class Example(QtGui.QWidget):

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

        self.initUI()

    def initUI(self):

        # The instance of a QtGui.QGridLayout is created and set to be the layout for the application window.
        grid = QtGui.QGridLayout()
        self.setLayout(grid)

        # These are the labels used later for buttons.
        names = ['Cls', 'Bck', '', 'Close',
                 '', '', '', '/',
                '', '', '', '*',
                 '', '', '', '-',
                '', '.', '=', '+']

        # We create a list of positions in the grid.
        positions = [(i,j) for i in range(5) for j in range(4)]

        # Buttons are created and added to the layout with the addWidget() method.
        for position, name in zip(positions, names):

            if name == '':
                continue
            button = QtGui.QPushButton(name)
            grid.addWidget(button, *position)

        self.move(300, 150)
        self.setWindowTitle('Calculator')
        self.show()

def main():
    app = QtGui.QApplication(sys.argv)
    ex = Example()
    sys.exit(app.exec_())

if __name__ == '__main__':
    main()

--------------------------------------------------------------------------------

#!/usr/bin/python
# -*- coding: utf-8 -*-

"""
ZetCode PyQt4 tutorial 

In this example, we create a bit
more complicated window layout using
the QtGui.QGridLayout manager. 

author: Jan Bodnar
website: zetcode.com
last edited: October 2011
"""

import sys
from PyQt4 import QtGui

class Example(QtGui.QWidget):

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

        self.initUI()

    def initUI(self):

        title = QtGui.QLabel('Title')
        author = QtGui.QLabel('Author')
        review = QtGui.QLabel('Review')

        titleEdit = QtGui.QLineEdit()
        authorEdit = QtGui.QLineEdit()
        reviewEdit = QtGui.QTextEdit()

        # We create a grid layout and set spacing between widgets.
        grid = QtGui.QGridLayout()
        grid.setSpacing(10)

        grid.addWidget(title, 1, 0)
        grid.addWidget(titleEdit, 1, 1)

        grid.addWidget(author, 2, 0)
        grid.addWidget(authorEdit, 2, 1)

        grid.addWidget(review, 3, 0)
        # If we add a widget to a grid, we can provide row span and column span of the widget. In our case, we make the reviewEdit widget span 5 rows.
        grid.addWidget(reviewEdit, 3, 1, 5, 1)

        self.setLayout(grid) 

        self.setGeometry(300, 300, 350, 300)
        self.setWindowTitle('Review')
        self.show()

def main():

    app = QtGui.QApplication(sys.argv)
    ex = Example()
    sys.exit(app.exec_())

if __name__ == '__main__':
    main()