Absolute positioning

The programmer specifies the position and the size of each widget in pixels. When you use absolute positioning, we have to understand the following limitations:

  • The size and the position of a widget do not change if we resize a window
  • Applications might look different on various platforms
  • Changing fonts in our application might spoil the layout
  • If we decide to change our layout, we must completely redo our layout, which is tedious and time consuming

The following example will position widgets in absolute coordinates.

#!/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):
        
        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()

We use the move() method to position our widgets. In our case these are labels. We position them by providing the x and y coordinates. The beginning of the coordinate system is at the left top corner. The x values grow from left to right. The y values grow from top to bottom.

lbl1 = QtGui.QLabel('Zetcode', self)
lbl1.move(15, 10)

The label widget is positioned at x=15 and y=10.

Absolute positioningFigure: Absolute positioning

posted on 2015-04-17 17:20  帅胡  阅读(318)  评论(0编辑  收藏  举报

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