Here is an example of a moveable button that still supports the normal click signal properly:
from PyQt4 import QtCore, QtGui
class DragButton(QtGui.QPushButton):
def mousePressEvent(self, event):
self.__mousePressPos = None
self.__mouseMovePos = None
if event.button() == QtCore.Qt.LeftButton:
self.__mousePressPos = event.globalPos()
self.__mouseMovePos = event.globalPos()
super(DragButton, self).mousePressEvent(event)
def mouseMoveEvent(self, event):
if event.buttons() == QtCore.Qt.LeftButton:
# adjust offset from clicked point to origin of widget
currPos = self.mapToGlobal(self.pos())
globalPos = event.globalPos()
diff = globalPos - self.__mouseMovePos
newPos = self.mapFromGlobal(currPos + diff)
self.move(newPos)
self.__mouseMovePos = globalPos
super(DragButton, self).mouseMoveEvent(event)
def mouseReleaseEvent(self, event):
if self.__mousePressPos is not None:
moved = event.globalPos() - self.__mousePressPos
if moved.manhattanLength() > 3:
event.ignore()
return
super(DragButton, self).mouseReleaseEvent(event)
def clicked():
print "click as normal!"
if __name__ == "__main__":
app = QtGui.QApplication([])
w = QtGui.QWidget()
w.resize(800,600)
button = DragButton("Drag", w)
button.clicked.connect(clicked)
w.show()
app.exec_()
In the mousePressEvent
I record both the initial start position, and a position that will get updated throughout the drag.
In the mouseMoveEvent
, I get the proper offset of the widget from where it was clicked to where the actual origin is, so that the move is accurate.
In the mouseReleaseEvent
, I check to see if the overall move was greater than at least a tiny amount. If it was, then it was a drag and we ignore the normal event to not produce a "clicked" signal. Otherwise, we allow the normal event handler to produce the click.
与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…