pyqt5: why the mimeData().text() returns nothing? - python-3.x

Question

learning PyQt5 recently, I've tried to drag a QPushButton learning this tutorial Drag & drop a button widget, and made some improvements to place the button more accurate, so I add
mime = e.mimeData().text()
x, y = mime.split(',')
according to #Avaris for this question, but I found e.mimeData().text() returned nothing which supposed to be the coordinate of local position of the cursor with respect to the button, i tried to print(mime), and got a blank line with nothing, then i print(mime.split(',')) and got ['']。
here's the code:
import sys
from PyQt5.QtWidgets import QPushButton, QWidget, QApplication, QLabel
from PyQt5.QtCore import Qt, QMimeData
from PyQt5.QtGui import QDrag
from PyQt5 import QtCore
class Button(QPushButton):
def __init__(self, title, parent):
super().__init__(title, parent)
def mouseMoveEvent(self, e):
if e.buttons() != Qt.RightButton:
return
mimeData = QMimeData()
drag = QDrag(self)
drag.setMimeData(mimeData)
dropAction = drag.exec_(Qt.MoveAction)
def mousePressEvent(self, e):
QPushButton.mousePressEvent(self, e)
if e.button() == Qt.LeftButton:
print('press')
class Example(QWidget):
def __init__(self):
super().__init__()
self.initUI()
def initUI(self):
self.setAcceptDrops(True)
self.button = Button('Button', self)
self.button.move(100, 65)
self.setWindowTitle('Click or Move')
self.setGeometry(300, 300, 280, 150)
def dragEnterEvent(self, e):
e.accept()
def dropEvent(self, e):
position = e.pos()
mime = e.mimeData().text()
x, y = mime.split(',')
#print(mime.split(','))
self.button.move(position - QtCore.QPoint(int(x), int(y)))
e.setDropAction(Qt.MoveAction)
e.accept()
if __name__ == '__main__':
app = QApplication(sys.argv)
ex = Example()
ex.show()
app.exec_()

Answer 1

In the answer of #Avaris, you will notice they set the mimedata with the button position in the mouseMoveEvent:
mimeData = QtCore.QMimeData()
# simple string with 'x,y'
mimeData.setText('%d,%d' % (e.x(), e.y()))
The mimedata does not contain anything by default. You have to set everything yourself! Have a look at the documentation for QMimeData to see what else you can do (other than setting arbitrary text)

Answer 2

Drag and Drop in Camera View
def dragEnterEvent(self, event): # Drag lines
mimeData = QtCore.QMimeData()
if mimeData.hasText:
event.accept()
else:
event.ignore()
def dropEvent(self, event): # Drop lines
mimeData = QtCore.QMimeData()
format = 'application/x-qabstractitemmodeldatalist'
data=event.mimeData().data(format) # Drag Drop get data's name
name_str = codecs.decode(data,'utf-8') # Convert byte to string
mimeData.setText(name_str)
# print(name_str[26:].replace('\x00','').strip("")) # remove white space
if mimeData.hasText:
print(name_str)
# write what you will do