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Python pyqt (gui) example 'borderlayout'
borderlayout
Python pyqt example: borderlayout
#!/usr/bin/env python
#############################################################################
##
## Copyright (C) 2013 Riverbank Computing Limited.
## Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).
## All rights reserved.
##
## This file is part of the examples of PyQt.
##
## $QT_BEGIN_LICENSE:BSD$
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## * Redistributions of source code must retain the above copyright
## notice, this list of conditions and the following disclaimer.
## * Redistributions in binary form must reproduce the above copyright
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## the documentation and/or other materials provided with the
## distribution.
## * Neither the name of Nokia Corporation and its Subsidiary(-ies) nor
## the names of its contributors may be used to endorse or promote
## products derived from this software without specific prior written
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## THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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## $QT_END_LICENSE$
##
#############################################################################
from PyQt5.QtCore import QRect, QSize, Qt
from PyQt5.QtWidgets import (QApplication, QFrame, QLabel, QLayout,
QTextBrowser, QWidget, QWidgetItem)
class ItemWrapper(object):
def __init__(self, i, p):
self.item = i
self.position = p
class BorderLayout(QLayout):
West, North, South, East, Center = range(5)
MinimumSize, SizeHint = range(2)
def __init__(self, parent=None, margin=None, spacing=-1):
super(BorderLayout, self).__init__(parent)
if margin is not None:
self.setContentsMargins(margin, margin, margin, margin)
self.setSpacing(spacing)
self.list = []
def __del__(self):
l = self.takeAt(0)
while l is not None:
l = self.takeAt(0)
def addItem(self, item):
self.add(item, self.West)
def addWidget(self, widget, position):
self.add(QWidgetItem(widget), position)
def expandingDirections(self):
return Qt.Horizontal | Qt.Vertical
def hasHeightForWidth(self):
return False
def count(self):
return len(self.list)
def itemAt(self, index):
if index < len(self.list):
return self.list[index].item
return None
def minimumSize(self):
return self.calculateSize(self.MinimumSize)
def setGeometry(self, rect):
center = None
eastWidth = 0
westWidth = 0
northHeight = 0
southHeight = 0
centerHeight = 0
super(BorderLayout, self).setGeometry(rect)
for wrapper in self.list:
item = wrapper.item
position = wrapper.position
if position == self.North:
item.setGeometry(QRect(rect.x(), northHeight,
rect.width(), item.sizeHint().height()))
northHeight += item.geometry().height() + self.spacing()
elif position == self.South:
item.setGeometry(QRect(item.geometry().x(),
item.geometry().y(), rect.width(),
item.sizeHint().height()))
southHeight += item.geometry().height() + self.spacing()
item.setGeometry(QRect(rect.x(),
rect.y() + rect.height() - southHeight + self.spacing(),
item.geometry().width(), item.geometry().height()))
elif position == self.Center:
center = wrapper
centerHeight = rect.height() - northHeight - southHeight
for wrapper in self.list:
item = wrapper.item
position = wrapper.position
if position == self.West:
item.setGeometry(QRect(rect.x() + westWidth,
northHeight, item.sizeHint().width(), centerHeight))
westWidth += item.geometry().width() + self.spacing()
elif position == self.East:
item.setGeometry(QRect(item.geometry().x(),
item.geometry().y(), item.sizeHint().width(),
centerHeight))
eastWidth += item.geometry().width() + self.spacing()
item.setGeometry(QRect(rect.x() + rect.width() - eastWidth + self.spacing(),
northHeight, item.geometry().width(),
item.geometry().height()))
if center:
center.item.setGeometry(QRect(westWidth, northHeight,
rect.width() - eastWidth - westWidth, centerHeight))
def sizeHint(self):
return self.calculateSize(self.SizeHint)
def takeAt(self, index):
if index >= 0 and index < len(self.list):
layoutStruct = self.list.pop(index)
return layoutStruct.item
return None
def add(self, item, position):
self.list.append(ItemWrapper(item, position))
def calculateSize(self, sizeType):
totalSize = QSize()
for wrapper in self.list:
position = wrapper.position
itemSize = QSize()
if sizeType == self.MinimumSize:
itemSize = wrapper.item.minimumSize()
else: # sizeType == self.SizeHint
itemSize = wrapper.item.sizeHint()
if position in (self.North, self.South, self.Center):
totalSize.setHeight(totalSize.height() + itemSize.height())
if position in (self.West, self.East, self.Center):
totalSize.setWidth(totalSize.width() + itemSize.width())
return totalSize
class Window(QWidget):
def __init__(self):
super(Window, self).__init__()
centralWidget = QTextBrowser()
centralWidget.setPlainText("Central widget")
layout = BorderLayout()
layout.addWidget(centralWidget, BorderLayout.Center)
# Because BorderLayout doesn't call its super-class addWidget() it
# doesn't take ownership of the widgets until setLayout() is called.
# Therefore we keep a local reference to each label to prevent it being
# garbage collected too soon.
label_n = self.createLabel("North")
layout.addWidget(label_n, BorderLayout.North)
label_w = self.createLabel("West")
layout.addWidget(label_w, BorderLayout.West)
label_e1 = self.createLabel("East 1")
layout.addWidget(label_e1, BorderLayout.East)
label_e2 = self.createLabel("East 2")
layout.addWidget(label_e2, BorderLayout.East)
label_s = self.createLabel("South")
layout.addWidget(label_s, BorderLayout.South)
self.setLayout(layout)
self.setWindowTitle("Border Layout")
def createLabel(self, text):
label = QLabel(text)
label.setFrameStyle(QFrame.Box | QFrame.Raised)
return label
if __name__ == '__main__':
import sys
app = QApplication(sys.argv)
window = Window()
window.show()
sys.exit(app.exec_())
Useful links
- Learn PyQt: https://pythonbasics.org/pyqt-hello-world/
- Install PyQt: https://pythonbasics.org/install-pyqt/