在 QgraphicsView 中拖放不起作用（PyQt）
Drag n Drop inside QgraphicsView doesn't work (PyQt)
我为一些按钮创建了自定义 class。这些是 "draggable" 按钮，如其名称所示，是可以相互拖放的按钮（取决于是否设置了 allowDrag 属性），然后执行操作。
这些拖动按钮的代码已在此处 posted：
显然，按钮在 QWidget 中时效果很好，但是当它们被添加到 QGraphicsView 的场景中时（我还对其进行了自定义 class），放置事件不起作用。我收到了 QGraphicsItem::ungrabMouse: not a mouse grabber 警告。
这是自定义 GraphicsView 的代码：
from PyQt4 import QtGui, QtCore
class WiringGraphicsView(QtGui.QGraphicsView):
#Initializer method
def __init__(self, parent = None, scene=None):
QtGui.QGraphicsView.__init__(self, scene, parent)
#Set Accept Drops property true
self.setAcceptDrops(True)
#This method creates a line between two widgets
def paintWire(self, start_widget, end_widget):
#Size and Position of both widgets
_start = start_widget.geometry()
_end = end_widget.geometry()
#Creates a Brush object with Red color
brush = QtGui.QBrush(QtGui.QColor(255, 0, 0) )
#Creates Pen object with specified brush
pen = QtGui.QPen(brush, 2)
#Create a Line object between two widgets
line = QtGui.QGraphicsLineItem(_start.x() + _start.width() / 2, _start.y() + _start.height() / 2, _end.x() + _end.width() / 2, _end.y() + _end.height() / 2)
#Set the Pen for the Line
line.setPen(pen)
#Add this line item to the scene.
self.scene().addItem( line )
这里是自定义按钮和图形视图所在的代码：
from PyQt4.QtGui import *
from PyQt4.QtCore import *
from dragbutton import DragButton
from wiringgraphicsview import WiringGraphicsView
import icons_rc
app = QApplication([])
scene = QGraphicsScene()
menu = QMenu()
# put a button into the scene and move it
button1 = DragButton('Button 1')
button1.setText("")
button1.setDefault(False)
button1.setAutoDefault(True)
#button1.setMouseTracking(True)
button1.setAllowDrag(True) #Allow Drag n Drop of DragButton
button1.setGeometry(QRect(50, 50, 51, 31)) #Set dimensions of it
#Set icon of button1
icon = QIcon()
icon.addPixmap(QPixmap(":/audio-input-line.png"), QIcon.Normal, QIcon.Off)
button1.setIcon(icon)
button1.setFlat(True)
button1.setMenu(menu)
#Create a QGraphicsProxyWidget adding the widget to scene
scene_button1 = scene.addWidget(button1)
#move the button on the scene
r1 = scene_button1.geometry()
r1.moveTo(-100, -50)
# put another button into the scene
button2 = DragButton('Button 2')
button2.setText("")
#This button shoudn't be dragged, it is just for dropping.
button2.setAllowDrag(False)
button2.setAcceptDrops(True)
icon = QIcon()
icon.addPixmap(QPixmap(":/input_small.png"), QIcon.Normal, QIcon.Off)
button2.setIcon(icon)
#button2.setMouseTracking(True)
#button2.setGeometry(QRect(270, 150, 41, 31))
scene_button2 = scene.addWidget(button2)
scene_button2.setAcceptDrops(True)
r2 = scene_button2.geometry()
# Create the view using the scene
view = WiringGraphicsView(None, scene)
view.resize(300, 200)
view.show()
#and paint a wire between those buttons
view.paintWire(button1, button2)
app.exec_()
另外：如果我想先将按钮嵌入到水平或垂直布局中（让它们按顺序排列），然后再嵌入到 QgraphicsView 中，这可能吗？
编辑：我已经发现您可以像任何其他小部件一样将带有子按钮的布局添加到图形场景中。
我仍然不知道为什么在我的拖动按钮 class 中实现的拖放在 Qgraphicsscene/QgraphicsView 中时不起作用。
我阅读的大部分文档都在谈论实现拖放逻辑，但是在 QgraphicsItem class 中。
基于 QGraphicsItem 创建一个新的 class 是个好主意，但此时让我做以下问题：
- 我应该如何重新实现按钮行为？单击效果、属性和添加 QMenu 的可能性？当我使用
addWidget 将 QButton 或我的自定义 DragButton 添加到场景中时，这已经有效。
- 布局呢？我无法将 QgraphicsItem 添加到布局中，然后将布局添加到场景中！有没有办法让这些项目在 scene/view 中按顺序排列？
编辑 2：我将 "DragButton" class post 的代码包含在我的其他 post 中，因为与这个问题相关。
from PyQt4 import QtGui, QtCore
class DragButton(QtGui.QPushButton):
def __init__(self, parent):
super(DragButton, self).__init__(parent)
self.allowDrag = True
def setAllowDrag(self, allowDrag):
if type(allowDrag) == bool:
self.allowDrag = allowDrag
else:
raise TypeError("You have to set a boolean type")
def mouseMoveEvent(self, e):
if e.buttons() != QtCore.Qt.RightButton:
return
if self.allowDrag == True:
# write the relative cursor position to mime data
mimeData = QtCore.QMimeData()
# simple string with 'x,y'
mimeData.setText('%d,%d' % (e.x(), e.y()))
print mimeData.text()
# let's make it fancy. we'll show a "ghost" of the button as we drag
# grab the button to a pixmap
pixmap = QtGui.QPixmap.grabWidget(self)
# below makes the pixmap half transparent
painter = QtGui.QPainter(pixmap)
painter.setCompositionMode(painter.CompositionMode_DestinationIn)
painter.fillRect(pixmap.rect(), QtGui.QColor(0, 0, 0, 127))
painter.end()
# make a QDrag
drag = QtGui.QDrag(self)
# put our MimeData
drag.setMimeData(mimeData)
# set its Pixmap
drag.setPixmap(pixmap)
# shift the Pixmap so that it coincides with the cursor position
drag.setHotSpot(e.pos())
# start the drag operation
# exec_ will return the accepted action from dropEvent
if drag.exec_(QtCore.Qt.LinkAction | QtCore.Qt.MoveAction) == QtCore.Qt.LinkAction:
print 'linked'
else:
print 'moved'
def mousePressEvent(self, e):
QtGui.QPushButton.mousePressEvent(self, e)
if e.button() == QtCore.Qt.LeftButton:
print 'press'
#AQUI DEBO IMPLEMENTAR EL MENU CONTEXTUAL
def dragEnterEvent(self, e):
e.accept()
def dropEvent(self, e):
# get the relative position from the mime data
mime = e.mimeData().text()
x, y = map(int, mime.split(','))
# move
# so move the dragged button (i.e. event.source())
print e.pos()
#e.source().move(e.pos()-QtCore.QPoint(x, y))
# set the drop action as LinkAction
e.setDropAction(QtCore.Qt.LinkAction)
# tell the QDrag we accepted it
e.accept()
该解决方案似乎要求您 subclass QGraphicsScene 明确地将放置事件传递给放置坐标处的 QGraphicsItem。此外，QGraphicsProxyWidget 似乎没有将放置事件传递给子小部件。因此，您再次需要 subclass QGraphicsProxyWidget 并手动实例化此 class，添加小部件，然后使用 scene.addItem().[=21= 手动将实例添加到场景中]
注意：您可能已经知道，但是 drag/drop 不会启动，除非您首先与小部件进行交互（例如单击它）。据推测，这也可以通过从场景到代理再到小部件的 mouseMoveEvent 传递来解决。
注2：我不知道为什么要花那么大的力气才能做到这一点。我确实觉得我可能会遗漏一些东西。 documentation 表示：
QGraphicsProxyWidget supports all core features of QWidget, including tab focus, keyboard input, Drag & Drop, and popups
但如果没有 subclassing，我无法让它工作。
相关子class实现：
class MyScene(QGraphicsScene):
def dragEnterEvent(self, e):
e.acceptProposedAction()
def dropEvent(self, e):
# find item at these coordinates
item = self.itemAt(e.scenePos())
if item.setAcceptDrops == True:
# pass on event to item at the coordinates
try:
item.dropEvent(e)
except RuntimeError:
pass #This will supress a Runtime Error generated when dropping into a widget with no MyProxy
def dragMoveEvent(self, e):
e.acceptProposedAction()
class MyProxy(QGraphicsProxyWidget):
def dragEnterEvent(self, e):
e.acceptProposedAction()
def dropEvent(self, e):
# pass drop event to child widget
return self.widget().dropEvent(e)
def dragMoveEvent(self, e):
e.acceptProposedAction()
修改后的应用程序代码：
scene = MyScene()
...
my_proxy = MyProxy()
my_proxy.setWidget(button2)
my_proxy.setAcceptDrops(True)
scene.addItem(my_proxy)
...
完全正常工作（好吧，当拖放成功时它会打印出 "linked"...这是您之前编写的所有内容）应用程序：
from PyQt4 import QtGui, QtCore
class WiringGraphicsView(QtGui.QGraphicsView):
#Initializer method
def __init__(self, parent = None, scene=None):
QtGui.QGraphicsView.__init__(self, scene, parent)
#Set Accept Drops property true
self.setAcceptDrops(True)
#This method creates a line between two widgets
def paintWire(self, start_widget, end_widget):
#Size and Position of both widgets
_start = start_widget.geometry()
_end = end_widget.geometry()
#Creates a Brush object with Red color
brush = QtGui.QBrush(QtGui.QColor(255, 0, 0) )
#Creates Pen object with specified brush
pen = QtGui.QPen(brush, 2)
#Create a Line object between two widgets
line = QtGui.QGraphicsLineItem(_start.x() + _start.width() / 2, _start.y() + _start.height() / 2, _end.x() + _end.width() / 2, _end.y() + _end.height() / 2)
#Set the Pen for the Line
line.setPen(pen)
#Add this line item to the scene.
self.scene().addItem( line )
class DragButton(QtGui.QPushButton):
def __init__(self, parent):
super(DragButton, self).__init__(parent)
self.allowDrag = True
def setAllowDrag(self, allowDrag):
if type(allowDrag) == bool:
self.allowDrag = allowDrag
else:
raise TypeError("You have to set a boolean type")
def mouseMoveEvent(self, e):
if e.buttons() != QtCore.Qt.RightButton:
return QtGui.QPushButton.mouseMoveEvent(self, e)
if self.allowDrag == True:
# write the relative cursor position to mime data
mimeData = QtCore.QMimeData()
# simple string with 'x,y'
mimeData.setText('%d,%d' % (e.x(), e.y()))
# print mimeData.text()
# let's make it fancy. we'll show a "ghost" of the button as we drag
# grab the button to a pixmap
pixmap = QtGui.QPixmap.grabWidget(self)
# below makes the pixmap half transparent
painter = QtGui.QPainter(pixmap)
painter.setCompositionMode(painter.CompositionMode_DestinationIn)
painter.fillRect(pixmap.rect(), QtGui.QColor(0, 0, 0, 127))
painter.end()
# make a QDrag
drag = QtGui.QDrag(self)
# put our MimeData
drag.setMimeData(mimeData)
# set its Pixmap
drag.setPixmap(pixmap)
# shift the Pixmap so that it coincides with the cursor position
drag.setHotSpot(e.pos())
# start the drag operation
# exec_ will return the accepted action from dropEvent
if drag.exec_(QtCore.Qt.LinkAction | QtCore.Qt.MoveAction) == QtCore.Qt.LinkAction:
print 'linked'
else:
print 'moved'
return QtGui.QPushButton.mouseMoveEvent(self, e)
def mousePressEvent(self, e):
if e.button() == QtCore.Qt.LeftButton:
print 'press'
#AQUI DEBO IMPLEMENTAR EL MENU CONTEXTUAL
return QtGui.QPushButton.mousePressEvent(self, e)
def dragEnterEvent(self, e):
e.accept()
return QtGui.QPushButton.dragEnterEvent(self, e)
def dropEvent(self, e):
# get the relative position from the mime data
mime = e.mimeData().text()
x, y = map(int, mime.split(','))
# move
# so move the dragged button (i.e. event.source())
print e.pos()
# e.source().move(e.pos()-QtCore.QPoint(x, y))
# set the drop action as LinkAction
e.setDropAction(QtCore.Qt.LinkAction)
# tell the QDrag we accepted it
e.accept()
return QtGui.QPushButton.dropEvent(self, QDropEvent(QPoint(e.pos().x(), e.pos().y()), e.possibleActions(), e.mimeData(), e.buttons(), e.modifiers()))
from PyQt4.QtGui import *
from PyQt4.QtCore import *
class MyScene(QGraphicsScene):
def dragEnterEvent(self, e):
e.acceptProposedAction()
def dropEvent(self, e):
# find item at these coordinates
item = self.itemAt(e.scenePos())
if item.setAcceptDrops == True:
# pass on event to item at the coordinates
try:
item.dropEvent(e)
except RuntimeError:
pass #This will supress a Runtime Error generated when dropping into a widget with no ProxyWidget
def dragMoveEvent(self, e):
e.acceptProposedAction()
class MyProxy(QGraphicsProxyWidget):
def dragEnterEvent(self, e):
e.acceptProposedAction()
def dropEvent(self, e):
# pass drop event to child widget
return self.widget().dropEvent(e)
def dragMoveEvent(self, e):
e.acceptProposedAction()
app = QApplication([])
scene = MyScene()
menu = QMenu()
# put a button into the scene and move it
button1 = DragButton('Button 1')
button1.setText("aaa")
button1.setDefault(False)
button1.setAutoDefault(True)
#button1.setMouseTracking(True)
button1.setAllowDrag(True) #Allow Drag n Drop of DragButton
button1.setGeometry(QRect(50, 50, 51, 31)) #Set dimensions of it
#Set icon of button1
icon = QIcon()
icon.addPixmap(QPixmap(":/audio-input-line.png"), QIcon.Normal, QIcon.Off)
button1.setIcon(icon)
button1.setFlat(True)
button1.setMenu(menu)
#Create a QGraphicsProxyWidget adding the widget to scene
scene_button1 = scene.addWidget(button1)
#move the button on the scene
r1 = scene_button1.geometry()
r1.moveTo(-100, -50)
# put another button into the scene
button2 = DragButton('Button 2')
button2.setText("bbb")
#This button shoudn't be dragged, it is just for dropping.
button2.setAllowDrag(False)
button2.setAcceptDrops(True)
icon = QIcon()
icon.addPixmap(QPixmap(":/input_small.png"), QIcon.Normal, QIcon.Off)
button2.setIcon(icon)
#button2.setMouseTracking(True)
#button2.setGeometry(QRect(270, 150, 41, 31))
# Instantiate our own proxy which forwars drag/drop events to the child widget
my_proxy = MyProxy()
my_proxy.setWidget(button2)
my_proxy.setAcceptDrops(True)
scene.addItem(my_proxy)
# Create the view using the scene
view = WiringGraphicsView(None, scene)
view.resize(300, 200)
view.show()
#and paint a wire between those buttons
view.paintWire(button1, button2)
app.exec_()
我为一些按钮创建了自定义 class。这些是 "draggable" 按钮，如其名称所示，是可以相互拖放的按钮（取决于是否设置了 allowDrag 属性），然后执行操作。
这些拖动按钮的代码已在此处 posted：
显然，按钮在 QWidget 中时效果很好，但是当它们被添加到 QGraphicsView 的场景中时（我还对其进行了自定义 class），放置事件不起作用。我收到了 QGraphicsItem::ungrabMouse: not a mouse grabber 警告。
这是自定义 GraphicsView 的代码：
from PyQt4 import QtGui, QtCore
class WiringGraphicsView(QtGui.QGraphicsView):
#Initializer method
def __init__(self, parent = None, scene=None):
QtGui.QGraphicsView.__init__(self, scene, parent)
#Set Accept Drops property true
self.setAcceptDrops(True)
#This method creates a line between two widgets
def paintWire(self, start_widget, end_widget):
#Size and Position of both widgets
_start = start_widget.geometry()
_end = end_widget.geometry()
#Creates a Brush object with Red color
brush = QtGui.QBrush(QtGui.QColor(255, 0, 0) )
#Creates Pen object with specified brush
pen = QtGui.QPen(brush, 2)
#Create a Line object between two widgets
line = QtGui.QGraphicsLineItem(_start.x() + _start.width() / 2, _start.y() + _start.height() / 2, _end.x() + _end.width() / 2, _end.y() + _end.height() / 2)
#Set the Pen for the Line
line.setPen(pen)
#Add this line item to the scene.
self.scene().addItem( line )
这里是自定义按钮和图形视图所在的代码：
from PyQt4.QtGui import *
from PyQt4.QtCore import *
from dragbutton import DragButton
from wiringgraphicsview import WiringGraphicsView
import icons_rc
app = QApplication([])
scene = QGraphicsScene()
menu = QMenu()
# put a button into the scene and move it
button1 = DragButton('Button 1')
button1.setText("")
button1.setDefault(False)
button1.setAutoDefault(True)
#button1.setMouseTracking(True)
button1.setAllowDrag(True) #Allow Drag n Drop of DragButton
button1.setGeometry(QRect(50, 50, 51, 31)) #Set dimensions of it
#Set icon of button1
icon = QIcon()
icon.addPixmap(QPixmap(":/audio-input-line.png"), QIcon.Normal, QIcon.Off)
button1.setIcon(icon)
button1.setFlat(True)
button1.setMenu(menu)
#Create a QGraphicsProxyWidget adding the widget to scene
scene_button1 = scene.addWidget(button1)
#move the button on the scene
r1 = scene_button1.geometry()
r1.moveTo(-100, -50)
# put another button into the scene
button2 = DragButton('Button 2')
button2.setText("")
#This button shoudn't be dragged, it is just for dropping.
button2.setAllowDrag(False)
button2.setAcceptDrops(True)
icon = QIcon()
icon.addPixmap(QPixmap(":/input_small.png"), QIcon.Normal, QIcon.Off)
button2.setIcon(icon)
#button2.setMouseTracking(True)
#button2.setGeometry(QRect(270, 150, 41, 31))
scene_button2 = scene.addWidget(button2)
scene_button2.setAcceptDrops(True)
r2 = scene_button2.geometry()
# Create the view using the scene
view = WiringGraphicsView(None, scene)
view.resize(300, 200)
view.show()
#and paint a wire between those buttons
view.paintWire(button1, button2)
app.exec_()
另外：如果我想先将按钮嵌入到水平或垂直布局中（让它们按顺序排列），然后再嵌入到 QgraphicsView 中，这可能吗？
编辑：我已经发现您可以像任何其他小部件一样将带有子按钮的布局添加到图形场景中。 我仍然不知道为什么在我的拖动按钮 class 中实现的拖放在 Qgraphicsscene/QgraphicsView 中时不起作用。 我阅读的大部分文档都在谈论实现拖放逻辑，但是在 QgraphicsItem class 中。 基于 QGraphicsItem 创建一个新的 class 是个好主意，但此时让我做以下问题：
- 我应该如何重新实现按钮行为？单击效果、属性和添加 QMenu 的可能性？当我使用
addWidget将 QButton 或我的自定义 DragButton 添加到场景中时，这已经有效。 - 布局呢？我无法将 QgraphicsItem 添加到布局中，然后将布局添加到场景中！有没有办法让这些项目在 scene/view 中按顺序排列？
编辑 2：我将 "DragButton" class post 的代码包含在我的其他 post 中，因为与这个问题相关。
from PyQt4 import QtGui, QtCore
class DragButton(QtGui.QPushButton):
def __init__(self, parent):
super(DragButton, self).__init__(parent)
self.allowDrag = True
def setAllowDrag(self, allowDrag):
if type(allowDrag) == bool:
self.allowDrag = allowDrag
else:
raise TypeError("You have to set a boolean type")
def mouseMoveEvent(self, e):
if e.buttons() != QtCore.Qt.RightButton:
return
if self.allowDrag == True:
# write the relative cursor position to mime data
mimeData = QtCore.QMimeData()
# simple string with 'x,y'
mimeData.setText('%d,%d' % (e.x(), e.y()))
print mimeData.text()
# let's make it fancy. we'll show a "ghost" of the button as we drag
# grab the button to a pixmap
pixmap = QtGui.QPixmap.grabWidget(self)
# below makes the pixmap half transparent
painter = QtGui.QPainter(pixmap)
painter.setCompositionMode(painter.CompositionMode_DestinationIn)
painter.fillRect(pixmap.rect(), QtGui.QColor(0, 0, 0, 127))
painter.end()
# make a QDrag
drag = QtGui.QDrag(self)
# put our MimeData
drag.setMimeData(mimeData)
# set its Pixmap
drag.setPixmap(pixmap)
# shift the Pixmap so that it coincides with the cursor position
drag.setHotSpot(e.pos())
# start the drag operation
# exec_ will return the accepted action from dropEvent
if drag.exec_(QtCore.Qt.LinkAction | QtCore.Qt.MoveAction) == QtCore.Qt.LinkAction:
print 'linked'
else:
print 'moved'
def mousePressEvent(self, e):
QtGui.QPushButton.mousePressEvent(self, e)
if e.button() == QtCore.Qt.LeftButton:
print 'press'
#AQUI DEBO IMPLEMENTAR EL MENU CONTEXTUAL
def dragEnterEvent(self, e):
e.accept()
def dropEvent(self, e):
# get the relative position from the mime data
mime = e.mimeData().text()
x, y = map(int, mime.split(','))
# move
# so move the dragged button (i.e. event.source())
print e.pos()
#e.source().move(e.pos()-QtCore.QPoint(x, y))
# set the drop action as LinkAction
e.setDropAction(QtCore.Qt.LinkAction)
# tell the QDrag we accepted it
e.accept()
该解决方案似乎要求您 subclass QGraphicsScene 明确地将放置事件传递给放置坐标处的 QGraphicsItem。此外，QGraphicsProxyWidget 似乎没有将放置事件传递给子小部件。因此，您再次需要 subclass QGraphicsProxyWidget 并手动实例化此 class，添加小部件，然后使用 scene.addItem().[=21= 手动将实例添加到场景中]
注意：您可能已经知道，但是 drag/drop 不会启动，除非您首先与小部件进行交互（例如单击它）。据推测，这也可以通过从场景到代理再到小部件的 mouseMoveEvent 传递来解决。
注2：我不知道为什么要花那么大的力气才能做到这一点。我确实觉得我可能会遗漏一些东西。 documentation 表示：
QGraphicsProxyWidget supports all core features of QWidget, including tab focus, keyboard input, Drag & Drop, and popups
但如果没有 subclassing，我无法让它工作。
相关子class实现：
class MyScene(QGraphicsScene):
def dragEnterEvent(self, e):
e.acceptProposedAction()
def dropEvent(self, e):
# find item at these coordinates
item = self.itemAt(e.scenePos())
if item.setAcceptDrops == True:
# pass on event to item at the coordinates
try:
item.dropEvent(e)
except RuntimeError:
pass #This will supress a Runtime Error generated when dropping into a widget with no MyProxy
def dragMoveEvent(self, e):
e.acceptProposedAction()
class MyProxy(QGraphicsProxyWidget):
def dragEnterEvent(self, e):
e.acceptProposedAction()
def dropEvent(self, e):
# pass drop event to child widget
return self.widget().dropEvent(e)
def dragMoveEvent(self, e):
e.acceptProposedAction()
修改后的应用程序代码：
scene = MyScene()
...
my_proxy = MyProxy()
my_proxy.setWidget(button2)
my_proxy.setAcceptDrops(True)
scene.addItem(my_proxy)
...
完全正常工作（好吧，当拖放成功时它会打印出 "linked"...这是您之前编写的所有内容）应用程序：
from PyQt4 import QtGui, QtCore
class WiringGraphicsView(QtGui.QGraphicsView):
#Initializer method
def __init__(self, parent = None, scene=None):
QtGui.QGraphicsView.__init__(self, scene, parent)
#Set Accept Drops property true
self.setAcceptDrops(True)
#This method creates a line between two widgets
def paintWire(self, start_widget, end_widget):
#Size and Position of both widgets
_start = start_widget.geometry()
_end = end_widget.geometry()
#Creates a Brush object with Red color
brush = QtGui.QBrush(QtGui.QColor(255, 0, 0) )
#Creates Pen object with specified brush
pen = QtGui.QPen(brush, 2)
#Create a Line object between two widgets
line = QtGui.QGraphicsLineItem(_start.x() + _start.width() / 2, _start.y() + _start.height() / 2, _end.x() + _end.width() / 2, _end.y() + _end.height() / 2)
#Set the Pen for the Line
line.setPen(pen)
#Add this line item to the scene.
self.scene().addItem( line )
class DragButton(QtGui.QPushButton):
def __init__(self, parent):
super(DragButton, self).__init__(parent)
self.allowDrag = True
def setAllowDrag(self, allowDrag):
if type(allowDrag) == bool:
self.allowDrag = allowDrag
else:
raise TypeError("You have to set a boolean type")
def mouseMoveEvent(self, e):
if e.buttons() != QtCore.Qt.RightButton:
return QtGui.QPushButton.mouseMoveEvent(self, e)
if self.allowDrag == True:
# write the relative cursor position to mime data
mimeData = QtCore.QMimeData()
# simple string with 'x,y'
mimeData.setText('%d,%d' % (e.x(), e.y()))
# print mimeData.text()
# let's make it fancy. we'll show a "ghost" of the button as we drag
# grab the button to a pixmap
pixmap = QtGui.QPixmap.grabWidget(self)
# below makes the pixmap half transparent
painter = QtGui.QPainter(pixmap)
painter.setCompositionMode(painter.CompositionMode_DestinationIn)
painter.fillRect(pixmap.rect(), QtGui.QColor(0, 0, 0, 127))
painter.end()
# make a QDrag
drag = QtGui.QDrag(self)
# put our MimeData
drag.setMimeData(mimeData)
# set its Pixmap
drag.setPixmap(pixmap)
# shift the Pixmap so that it coincides with the cursor position
drag.setHotSpot(e.pos())
# start the drag operation
# exec_ will return the accepted action from dropEvent
if drag.exec_(QtCore.Qt.LinkAction | QtCore.Qt.MoveAction) == QtCore.Qt.LinkAction:
print 'linked'
else:
print 'moved'
return QtGui.QPushButton.mouseMoveEvent(self, e)
def mousePressEvent(self, e):
if e.button() == QtCore.Qt.LeftButton:
print 'press'
#AQUI DEBO IMPLEMENTAR EL MENU CONTEXTUAL
return QtGui.QPushButton.mousePressEvent(self, e)
def dragEnterEvent(self, e):
e.accept()
return QtGui.QPushButton.dragEnterEvent(self, e)
def dropEvent(self, e):
# get the relative position from the mime data
mime = e.mimeData().text()
x, y = map(int, mime.split(','))
# move
# so move the dragged button (i.e. event.source())
print e.pos()
# e.source().move(e.pos()-QtCore.QPoint(x, y))
# set the drop action as LinkAction
e.setDropAction(QtCore.Qt.LinkAction)
# tell the QDrag we accepted it
e.accept()
return QtGui.QPushButton.dropEvent(self, QDropEvent(QPoint(e.pos().x(), e.pos().y()), e.possibleActions(), e.mimeData(), e.buttons(), e.modifiers()))
from PyQt4.QtGui import *
from PyQt4.QtCore import *
class MyScene(QGraphicsScene):
def dragEnterEvent(self, e):
e.acceptProposedAction()
def dropEvent(self, e):
# find item at these coordinates
item = self.itemAt(e.scenePos())
if item.setAcceptDrops == True:
# pass on event to item at the coordinates
try:
item.dropEvent(e)
except RuntimeError:
pass #This will supress a Runtime Error generated when dropping into a widget with no ProxyWidget
def dragMoveEvent(self, e):
e.acceptProposedAction()
class MyProxy(QGraphicsProxyWidget):
def dragEnterEvent(self, e):
e.acceptProposedAction()
def dropEvent(self, e):
# pass drop event to child widget
return self.widget().dropEvent(e)
def dragMoveEvent(self, e):
e.acceptProposedAction()
app = QApplication([])
scene = MyScene()
menu = QMenu()
# put a button into the scene and move it
button1 = DragButton('Button 1')
button1.setText("aaa")
button1.setDefault(False)
button1.setAutoDefault(True)
#button1.setMouseTracking(True)
button1.setAllowDrag(True) #Allow Drag n Drop of DragButton
button1.setGeometry(QRect(50, 50, 51, 31)) #Set dimensions of it
#Set icon of button1
icon = QIcon()
icon.addPixmap(QPixmap(":/audio-input-line.png"), QIcon.Normal, QIcon.Off)
button1.setIcon(icon)
button1.setFlat(True)
button1.setMenu(menu)
#Create a QGraphicsProxyWidget adding the widget to scene
scene_button1 = scene.addWidget(button1)
#move the button on the scene
r1 = scene_button1.geometry()
r1.moveTo(-100, -50)
# put another button into the scene
button2 = DragButton('Button 2')
button2.setText("bbb")
#This button shoudn't be dragged, it is just for dropping.
button2.setAllowDrag(False)
button2.setAcceptDrops(True)
icon = QIcon()
icon.addPixmap(QPixmap(":/input_small.png"), QIcon.Normal, QIcon.Off)
button2.setIcon(icon)
#button2.setMouseTracking(True)
#button2.setGeometry(QRect(270, 150, 41, 31))
# Instantiate our own proxy which forwars drag/drop events to the child widget
my_proxy = MyProxy()
my_proxy.setWidget(button2)
my_proxy.setAcceptDrops(True)
scene.addItem(my_proxy)
# Create the view using the scene
view = WiringGraphicsView(None, scene)
view.resize(300, 200)
view.show()
#and paint a wire between those buttons
view.paintWire(button1, button2)
app.exec_()