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Python pyqt (gui) example 'guide'
guide
Python pyqt example: guide
#############################################################################
##
## 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.
##
## $QT_BEGIN_LICENSE:LGPL$
## Commercial Usage
## Licensees holding valid Qt Commercial licenses may use this file in
## accordance with the Qt Commercial License Agreement provided with the
## Software or, alternatively, in accordance with the terms contained in
## a written agreement between you and Nokia.
##
## GNU Lesser General Public License Usage
## Alternatively, this file may be used under the terms of the GNU Lesser
## General Public License version 2.1 as published by the Free Software
## Foundation and appearing in the file LICENSE.LGPL included in the
## packaging of this file. Please review the following information to
## ensure the GNU Lesser General Public License version 2.1 requirements
## will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
##
## In addition, as a special exception, Nokia gives you certain additional
## rights. These rights are described in the Nokia Qt LGPL Exception
## version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
##
## GNU General Public License Usage
## Alternatively, this file may be used under the terms of the GNU
## General Public License version 3.0 as published by the Free Software
## Foundation and appearing in the file LICENSE.GPL included in the
## packaging of this file. Please review the following information to
## ensure the GNU General Public License version 3.0 requirements will be
## met: http://www.gnu.org/copyleft/gpl.html.
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## If you have questions regarding the use of this file, please contact
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## $QT_END_LICENSE$
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#############################################################################
from PyQt5.QtCore import QLineF, QPointF
class Guide(object):
def __init__(self, follows=None):
self.scaleX = 1.0
self.scaleY = 1.0
if follows is not None:
while follows.nextGuide is not follows.firstGuide:
follows = follows.nextGuide
follows.nextGuide = self
self.prevGuide = follows
self.firstGuide = follows.firstGuide
self.nextGuide = follows.firstGuide
self.startLength = int(follows.startLength + follows.length()) + 1
else:
self.prevGuide = self
self.firstGuide = self
self.nextGuide = self
self.startLength = 0
def setScale(self, scaleX, scaleY, all=True):
self.scaleX = scaleX
self.scaleY = scaleY
if all:
next = self.nextGuide
while next is not self:
next.scaleX = scaleX
next.scaleY = scaleY
next = next.nextGuide
def setFence(self, fence, all=True):
self.fence = fence
if all:
next = self.nextGuide
while next is not self:
next.fence = fence
next = next.nextGuide
def lengthAll(self):
len = self.length()
next = self.nextGuide
while next is not self:
len += next.length()
next = next.nextGuide
return len
def move(self, item, dest, moveSpeed):
walkLine = QLineF(item.getGuidedPos(), dest)
if moveSpeed >= 0 and walkLine.length() > moveSpeed:
# The item is too far away from it's destination point so we move
# it towards it instead.
dx = walkLine.dx()
dy = walkLine.dy()
if abs(dx) > abs(dy):
# Walk along x-axis.
if dx != 0:
d = moveSpeed * dy / abs(dx)
if dx > 0:
s = moveSpeed
else:
s = -moveSpeed
dest.setX(item.getGuidedPos().x() + s)
dest.setY(item.getGuidedPos().y() + d)
else:
# Walk along y-axis.
if dy != 0:
d = moveSpeed * dx / abs(dy)
if dy > 0:
s = moveSpeed
else:
s = -moveSpeed
dest.setX(item.getGuidedPos().x() + d)
dest.setY(item.getGuidedPos().y() + s)
item.setGuidedPos(dest)
def startPos(self):
return QPointF(0, 0)
def endPos(self):
return QPointF(0, 0)
def length(self):
return 1.0
def guide(self, item, moveSpeed):
raise NotImplementedError
Useful links
- Learn PyQt: https://pythonbasics.org/pyqt-hello-world/
- Install PyQt: https://pythonbasics.org/install-pyqt/