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"""
/*
* This file is part of PySide: Python for Qt
*
* Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
*
* Contact: PySide team <contact@pyside.org>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public License
* version 2.1 as published by the Free Software Foundation.
*
* This library is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA
*
*/
"""
from PySide2 import QtGui, QtCore
from kineticscroll import KineticScroll
#Ok I know, this class is not necessary in python
#but this will change the logic and this will bring more work
class ScrollAreaPrivate:
def __init__(self, parent):
self._offset = 0
self._maximumOffset = 0
self._widget = None
self._kinetic = None
self._isDragging = False
self._mouseDownPos = -1
self._moveConstant = 15
self._clickConstant = 25
self._scrollArea = parent
self._ignoreList = []
def smoothPos(self, y):
if abs(self._mouseDownPos - y) <= self._moveConstant:
return y
elif self._mouseDownPos - y < 0:
return y - self._moveConstant
else:
return y + self._moveConstant
def isClickPossible(self, y):
if self._isDragging or self._mouseDownPos < 0:
return False
else:
return abs(y - self._mouseDownPos) <= self._clickConstant
def updateMaximumOffset(self):
value = 0
if self._widget:
value = max(0, self._widget.size().height() - self._scrollArea.size().height())
if value != self._maximumOffset:
self._maximumOffset = value
self._scrollArea.emit(QtCore.SIGNAL("maximumOffsetChanged()"))
def reconfigure(self):
if self._widget:
self._widget.resize(self._scrollArea.size().width(), self._widget.size().height())
self.updateMaximumOffset()
self._scrollArea.setOffset(self._offset)
def sendClick(self, x, y):
if self._scrollArea.scene() == None:
return
event = QtGui.QGraphicsSceneMouseEvent(QtCore.QEvent.GraphicsSceneMousePress)
event.setButton(QtCore.Qt.LeftButton)
pos = QtCore.QPointF(x, y)
event.setScenePos(pos)
self._ignoreList.append(pos)
QtCore.QCoreApplication.postEvent(self._scrollArea.scene(), event)
event = QtGui.QGraphicsSceneMouseEvent(QtCore.QEvent.GraphicsSceneMouseRelease)
event.setButton(QtCore.Qt.LeftButton)
pos = QtCore.QPointF(x, y)
event.setScenePos(pos)
self._ignoreList.append(pos)
QtCore.QCoreApplication.postEvent(self._scrollArea.scene(), event)
class ScrollArea(QtGui.QGraphicsWidget):
def __init__(self, parent = None):
QtGui.QGraphicsWidget.__init__(self, parent)
self.setFlags(QtGui.QGraphicsItem.ItemHasNoContents)
self.setFlags(QtGui.QGraphicsItem.ItemClipsChildrenToShape)
self._d = ScrollAreaPrivate(self)
self._d._kinetic = KineticScroll(self)
self.connect(self._d._kinetic, QtCore.SIGNAL("signalMoveOffset(int)"), QtCore.SLOT("kineticMove(int)"))
def widget(self):
return self._d._widget
def setWidget(self, widget):
if self._d._widget:
self._d._widget.setParentItem(0)
self._d._widget.removeEventFilter(self)
self._d._widget = None
if widget:
self._d._widget = widget
self._d._widget.setParentItem(self)
self._d._widget.installEventFilter(self)
self._d._widget.setPos(0, 0)
self._d._widget.setFlag(QtGui.QGraphicsItem.ItemStacksBehindParent)
self._d.reconfigure()
def offset(self):
return self._d._offset
def setOffset(self, offset):
if self._d._widget:
value = max(min(offset, self._d._maximumOffset), 0)
if value != self._d._offset:
self._d._offset = value
self._d._widget.setY(-value)
self.emit(QtCore.SIGNAL("offsetChanged()"))
def maximumOffset(self):
return self._d._maximumOffset
def resizeEvent(self, event):
QtGui.QGraphicsWidget.resizeEvent(self, event)
self._d.reconfigure()
def eventFilter(self, object, event):
if object == self._d._widget and event.type() == QtCore.QEvent.GraphicsSceneResize:
self._d.reconfigure()
return False
def mousePressEvent(self, event):
pos = event.scenePos()
if pos in self._d._ignoreList:
self._d._ignoreList.remove(pos)
event.ignore()
return
y = event.pos().y()
self._d._mouseDownPos = y
self._d._isDragging = not self._d._kinetic.mouseDown(y)
def stopKinetic(self):
self._d._kinetic.kineticStop()
def mouseReleaseEvent(self, event):
pos = event.scenePos()
if pos in self._d._ignoreList:
self._d._ignoreList.remove(pos)
event.ignore()
return
if self._d._mouseDownPos >= 0:
y = event.pos().y()
if self._d.isClickPossible(y):
self._d.sendClick(event.scenePos().x(), event.scenePos().y())
self._d._kinetic.mouseCancel()
else:
self._d._kinetic.mouseUp(self._d.smoothPos(y))
self._d._mouseDownPos = -1
def mouseMoveEvent(self, event):
if self._d._mouseDownPos >= 0:
y = event.pos().y()
if not self._d.isClickPossible(y):
self._d._isDragging = True
if abs(self._d._mouseDownPos - y) > self._d._moveConstant:
self._d._kinetic.mouseMove(self._d.smoothPos(y))
def kineticMove(self, value):
finalOffset = self.offset() - value
self.setOffset(finalOffset)
if value == 0 or finalOffset != self.offset():
self._d._kinetic.kineticStop()
return False
return True
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