How to use QRubberBand with QRect Class in PyQt? - python

I want to select or activate a bunch of buttons by marquee rectangle selection in a UI using QRubberBand and QRect in PyQt.
I would appreciate if anyone could tell me how to implement this functionality?

Here's a simple demo:
from PyQt4 import QtGui, QtCore
class Window(QtGui.QWidget):
def __init__(self):
QtGui.QWidget.__init__(self)
layout = QtGui.QVBoxLayout(self)
layout.setMargin(15)
layout.setSpacing(10)
for text in 'One Two Three Four Five'.split():
layout.addWidget(QtGui.QPushButton(text, self))
self.rubberband = QtGui.QRubberBand(
QtGui.QRubberBand.Rectangle, self)
self.setMouseTracking(True)
def mousePressEvent(self, event):
self.origin = event.pos()
self.rubberband.setGeometry(
QtCore.QRect(self.origin, QtCore.QSize()))
self.rubberband.show()
QtGui.QWidget.mousePressEvent(self, event)
def mouseMoveEvent(self, event):
if self.rubberband.isVisible():
self.rubberband.setGeometry(
QtCore.QRect(self.origin, event.pos()).normalized())
QtGui.QWidget.mouseMoveEvent(self, event)
def mouseReleaseEvent(self, event):
if self.rubberband.isVisible():
self.rubberband.hide()
selected = []
rect = self.rubberband.geometry()
for child in self.findChildren(QtGui.QPushButton):
if rect.intersects(child.geometry()):
selected.append(child)
print 'Selection Contains:\n ',
if selected:
print ' '.join(
'Button: %s\n' % child.text() for child in selected)
else:
print ' Nothing\n'
QtGui.QWidget.mouseReleaseEvent(self, event)
if __name__ == '__main__':
import sys
app = QtGui.QApplication(sys.argv)
window = Window()
window.show()
sys.exit(app.exec_())

Related

Drag-and-drop from button to button without subclass

I want to move color data from button to button.
Is there any other way to subclass pushbutton with eventfilter?
The event.pos() value was different when eventfilter was installEventFilter on pushbutton.
from PySide2 import QtWidgets, QtCore, QtGui
from functools import partial
class DragTest(QtWidgets.QMainWindow):
def __init__(self):
super(DragTest, self).__init__()
cent = QtWidgets.QWidget()
self.setCentralWidget(cent)
layout = QtWidgets.QHBoxLayout(cent)
self.color1_btn = QtWidgets.QPushButton()
self.color1_btn.clicked.connect(partial(self.color_btn_click, widget=self.color1_btn))
self.color2_btn = QtWidgets.QPushButton()
self.color2_btn.clicked.connect(partial(self.color_btn_click, widget=self.color2_btn))
layout.addWidget(self.color1_btn)
layout.addWidget(self.color2_btn)
self.btn1 = QtWidgets.QPushButton()
self.btn2 = QtWidgets.QPushButton()
layout.addWidget(self.btn1)
layout.addWidget(self.btn2)
def color_btn_click(self, widget):
color = QtWidgets.QColorDialog.getColor()
if color.isValid():
print "red: {0}, green: {1}, blue: {2}".format(*color.getRgb())
widget.setStyleSheet("background-color:rgb({0},{1},{2})".format(*color.getRgb()))
widget.setProperty("color", color.getRgb())
def eventFilter(self, obj, event):
super(DragTest, self).eventFilter(obj, event)
if __name__ == "__main__":
import sys
app = QtWidgets.QApplication(sys.argv)
win = DragTest()
win.show()
sys.exit(app.exec_())
You can set up the drag operation in eventFilter if that's your preference. Make sure acceptDrops is True for the buttons, and then catch the mouse move and drag events in the event filter. QMimeData has a colorData property to store the QColor object.
class DragTest(QtWidgets.QMainWindow):
def __init__(self):
super(DragTest, self).__init__()
cent = QtWidgets.QWidget()
self.setCentralWidget(cent)
layout = QtWidgets.QHBoxLayout(cent)
self.color1_btn = QtWidgets.QPushButton(acceptDrops=True)
self.color1_btn.clicked.connect(partial(self.color_btn_click, widget=self.color1_btn))
self.color2_btn = QtWidgets.QPushButton(acceptDrops=True)
self.color2_btn.clicked.connect(partial(self.color_btn_click, widget=self.color2_btn))
layout.addWidget(self.color1_btn)
layout.addWidget(self.color2_btn)
self.color1_btn.installEventFilter(self)
self.color2_btn.installEventFilter(self)
self.color1_btn.color = self.color2_btn.color = None
self.btn1 = QtWidgets.QPushButton()
self.btn2 = QtWidgets.QPushButton()
layout.addWidget(self.btn1)
layout.addWidget(self.btn2)
def color_btn_click(self, widget):
color = QtWidgets.QColorDialog.getColor()
if color.isValid():
self.set_color(widget, color)
def set_color(self, widget, color):
widget.setStyleSheet("background-color:rgb({0},{1},{2})".format(*color.getRgb()))
widget.color = color
def eventFilter(self, obj, event):
if obj in {self.color1_btn, self.color2_btn}:
if event.type() == QtCore.QEvent.MouseMove and obj.color:
mimedata = QtCore.QMimeData()
mimedata.setColorData(obj.color)
pixmap = QtGui.QPixmap(20, 20)
pixmap.fill(QtCore.Qt.transparent)
painter = QtGui.QPainter(pixmap)
painter.setRenderHint(QtGui.QPainter.Antialiasing)
painter.setBrush(obj.color)
painter.setPen(QtGui.QPen(obj.color.darker(150), 2))
painter.drawEllipse(pixmap.rect().center(), 8, 8)
painter.end()
drag = QtGui.QDrag(obj)
drag.setMimeData(mimedata)
drag.setPixmap(pixmap)
drag.setHotSpot(pixmap.rect().center())
drag.exec_(QtCore.Qt.CopyAction)
elif event.type() == QtCore.QEvent.DragEnter:
event.accept() if event.mimeData().hasColor() else event.ignore()
elif event.type() == QtCore.QEvent.Drop:
self.set_color(obj, event.mimeData().colorData())
event.accept()
return super(DragTest, self).eventFilter(obj, event)

How to drag the icon when using drag and drop

Currently I have the following code that executes a drag and drop function and generates a new button by dragging and dropping another.
But what I would like to know is:
How can I make an image of him when I drag the mouse button?
something like this:
This is the code you used
In this I would like to obtain the same effect as in the gif previously shown but with the Qpushbutton
from PyQt5.QtWidgets import QPushButton, QWidget, QApplication
from PyQt5.QtCore import Qt, QMimeData
from PyQt5.QtGui import QDrag
import sys
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)
drag.setHotSpot(e.pos() - self.rect().topLeft())
dropAction = drag.exec_(Qt.MoveAction)
def mousePressEvent(self, e):
super().mousePressEvent(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()
self.button.move(position)
self.create(position)
e.setDropAction(Qt.MoveAction)
e.accept()
def create(self,position):
print(position)
self.position = position
self.newButton = QPushButton("new",self)
self.newButton.move(self.position)
self.newButton.resize(150,50)
self.newButton.show()
if __name__ == '__main__':
app = QApplication(sys.argv)
ex = Example()
ex.show()
app.exec_()
You have to take a widget image using the grab() method then set it to QDrag using the setPixmap() method. Also I have created a method that creates a widget of the same type of the source with the same q-properties (that does not imply that it is a copy of the widget since there are non copyable elements). On the other hand it is advisable to use the right click since the left click will interfere with the clicked signal
from PyQt5 import QtCore, QtGui, QtWidgets
def fake_copy_widget(widget, parent):
t = type(widget)
w = t(parent)
mo = widget.metaObject()
for i in range(mo.propertyCount()):
prop = mo.property(i)
if prop.isWritable() and prop.isReadable():
name = prop.name()
w.setProperty(name, widget.property(name))
return w
class Button(QtWidgets.QPushButton):
def mouseMoveEvent(self, e):
if e.buttons() & QtCore.Qt.RightButton:
pos = self.mapFromGlobal(QtGui.QCursor().pos())
ba = QtCore.QByteArray()
ds = QtCore.QDataStream(ba, QtCore.QIODevice.WriteOnly)
ds << pos
mimeData = QtCore.QMimeData()
mimeData.setData("application/x-pos", ba)
pixmap = self.grab()
drag = QtGui.QDrag(self)
drag.setHotSpot(pos)
drag.setPixmap(pixmap)
drag.setMimeData(mimeData)
drag.setHotSpot(e.pos() - self.rect().topLeft())
dropAction = drag.exec_(QtCore.Qt.MoveAction)
class Example(QtWidgets.QWidget):
def __init__(self):
super().__init__()
self.initUI()
def initUI(self):
self.setAcceptDrops(True)
button = Button('Button', self)
button.move(100, 65)
self.setWindowTitle('Click or Move')
self.setGeometry(300, 300, 280, 150)
def dragEnterEvent(self, e):
if e.mimeData().hasFormat("application/x-pos"):
e.accept()
def dropEvent(self, e):
position = e.pos()
button = e.source()
mimedata = e.mimeData()
p = QtCore.QPoint()
ba = mimedata.data("application/x-pos")
ds = QtCore.QDataStream(ba)
ds >> p
self.create(QtCore.QRect(position - p, button.size()), button, self)
e.accept()
def create(self, geometry, widget, parent):
button = fake_copy_widget(widget, parent)
button.setGeometry(geometry)
button.show()
if __name__ == '__main__':
import sys
app = QtWidgets.QApplication(sys.argv)
ex = Example()
ex.show()
sys.exit(app.exec_())

PyQt - Custom scrolling with QListWidget

I am trying to figure out a way to customize the scrollbars for QListWidget to have the scrollbars above and below the QListWidget instead of the normal vertical and horizontal scrollbars.
Please check out my example below if you don't understand what I mean.
In the example below I use QPushButtons with QTimers controlling the scrolling in place of the scrollbars but what I am looking for are scrollbars like the ones in QMenu when menu scrolling is enabled.
If that is not an option, I am wondering if there is a scrollbar signal or something that I could try to use to know when the scrollbars are normally activated? That way I can show/hide the buttons as needed. Thanks.
import sys
from PyQt5.QtCore import pyqtSignal, QTimer, Qt
from PyQt5.QtGui import QPainter
from PyQt5.QtWidgets import QWidget, QPushButton, QVBoxLayout, \
QApplication, QStyle, QListWidget, QStyleOptionButton, QListWidgetItem
class UpBtn(QPushButton):
mouseHover = pyqtSignal()
def __init__(self):
QPushButton.__init__(self)
self.setMouseTracking(True)
self.timer = QTimer()
def paintEvent(self, event):
painter = QPainter()
painter.begin(self)
opt = QStyleOptionButton()
self.initStyleOption(opt)
self.style().drawControl(QStyle.CE_ScrollBarSubLine, opt, painter, self)
painter.end()
def startScroll(self):
self.mouseHover.emit()
def enterEvent(self, event):
self.timer.timeout.connect(self.startScroll)
self.timer.start(120)
def leaveEvent(self, event):
self.timer.stop()
class DwnBtn(QPushButton):
mouseHover = pyqtSignal()
def __init__(self):
QPushButton.__init__(self)
self.setMouseTracking(True)
self.timer = QTimer()
def paintEvent(self, event):
painter = QPainter()
painter.begin(self)
opt = QStyleOptionButton()
self.initStyleOption(opt)
self.style().drawControl(QStyle.CE_ScrollBarAddLine, opt, painter, self)
painter.end()
def startScroll(self):
self.mouseHover.emit()
def enterEvent(self, event):
self.timer.timeout.connect(self.startScroll)
self.timer.start(120)
def leaveEvent(self, event):
self.timer.stop()
class Window(QWidget):
def __init__(self):
super(Window, self).__init__()
self.layout = QVBoxLayout()
self.layout.setContentsMargins(0, 0, 0, 0)
self.layout.setSpacing(0)
self.upBtn = UpBtn()
self.upBtn.setFixedWidth(230)
self.layout.addWidget(self.upBtn)
self.listWidget = QListWidget()
self.listWidget.setFixedWidth(230)
self.listWidget.setHorizontalScrollBarPolicy(Qt.ScrollBarAlwaysOff)
self.listWidget.setVerticalScrollBarPolicy(Qt.ScrollBarAlwaysOff)
self.layout.addWidget(self.listWidget)
self.downBtn = DwnBtn()
self.downBtn.setFixedWidth(230)
self.layout.addWidget(self.downBtn)
self.setLayout(self.layout)
self.upBtn.clicked.connect(self.upBtnClicked)
self.upBtn.mouseHover.connect(self.upBtnClicked)
self.downBtn.clicked.connect(self.downBtnClicked)
self.downBtn.mouseHover.connect(self.downBtnClicked)
for i in range(100):
item = QListWidgetItem()
item.setText("list item " + str(i))
self.listWidget.addItem(item)
def upBtnClicked(self):
cur = self.listWidget.currentRow()
self.listWidget.setCurrentRow(cur - 1)
def downBtnClicked(self):
cur = self.listWidget.currentRow()
self.listWidget.setCurrentRow(cur + 1)
if __name__ == '__main__':
app = QApplication(sys.argv)
window = Window()
window.show()
sys.exit(app.exec_())
EDIT:
Here is an example image for what I am talking about. This is a scrollable QMenu.
EDIT:
Scrollable QMenu code.
Uncomment the commented parts to get a fixed size like in the image. Normally Qmenu scrolling only works when the menu items exceed the screen height. I am just looking for the top and bottom hover style scrolling but to be used in QListWidget.
import sys
from PyQt5.QtCore import QPoint, QEvent
from PyQt5.QtWidgets import QWidget, QPushButton, QVBoxLayout, \
QApplication, QAction, QMenu, QProxyStyle, QStyle
class MyMenu(QMenu):
def event(self, event):
if event.type() == QEvent.Show:
self.move(self.parent().mapToGlobal(QPoint(-108, 0)))
return super(MyMenu, self).event(event)
# class CustomStyle(QProxyStyle):
# def pixelMetric(self, QStyle_PixelMetric, option=None, widget=None):
# if QStyle_PixelMetric == QStyle.PM_MenuScrollerHeight:
# return 15
# if QStyle_PixelMetric == QStyle.PM_MenuDesktopFrameWidth:
# return 290
# else:
# return QProxyStyle.pixelMetric(self, QStyle_PixelMetric, option, widget)
class MainWindow(QWidget):
def __init__(self, parent=None):
super(MainWindow, self).__init__(parent)
self.layout = QVBoxLayout()
self.btn = QPushButton("Button")
self.btn.setFixedHeight(30)
self.btn.setFixedWidth(100)
self.myMenu = MyMenu("Menu", self.btn)
self.btn.setMenu(self.myMenu)
self.layout.addWidget(self.btn)
self.setLayout(self.layout)
menus = []
for _ in range(5):
myMenus = QMenu("Menu"+str(_+1), self.btn)
# myMenus.setFixedHeight(120)
myMenus.setStyleSheet("QMenu{menu-scrollable: 1; }")
menus.append(myMenus)
for i in menus:
self.btn.menu().addMenu(i)
for item in range(100):
action = QAction("item" + str(item), self)
i.addAction(action)
if __name__ == '__main__':
app = QApplication(sys.argv)
# app.setStyle(CustomStyle())
w = MainWindow()
w.show()
app.exec_()
The idea is to obtain the row of the upper and lower element that will decide whether the buttons are hidden or not, for that we use the method itemAt () that returns the item given the geometrical coordinates. On the other hand I have improved this calculation has to do every time they change the number of items in the QListView for that we use the signals of the internal model.
import sys
from PyQt5 import QtCore, QtGui, QtWidgets
class Button(QtWidgets.QPushButton):
moveSignal = QtCore.pyqtSignal()
def __init__(self, *args, **kwargs):
super(Button, self).__init__(*args, **kwargs)
self.m_timer = QtCore.QTimer(self, interval=120)
self.m_timer.timeout.connect(self.moveSignal)
self.setMouseTracking(True)
self.setFixedHeight(20)
def mouseReleaseEvent(self, e):
super(Button, self).mousePressEvent(e)
self.setDown(True)
def enterEvent(self, e):
self.setDown(True)
self.m_timer.start()
super(Button, self).enterEvent(e)
def leaveEvent(self, e):
self.setDown(False)
self.m_timer.stop()
super(Button, self).leaveEvent(e)
class Window(QtWidgets.QWidget):
def __init__(self):
super(Window, self).__init__()
self.setFixedWidth(230)
icon = self.style().standardIcon(QtWidgets.QStyle.SP_ArrowUp)
self.upBtn = Button(icon=icon)
self.upBtn.moveSignal.connect(self.moveUp)
icon = self.style().standardIcon(QtWidgets.QStyle.SP_ArrowDown)
self.downBtn = Button(icon=icon)
self.downBtn.moveSignal.connect(self.moveDown)
self.listWidget = QtWidgets.QListWidget()
self.listWidget.setHorizontalScrollBarPolicy(QtCore.Qt.ScrollBarAlwaysOff)
self.listWidget.setVerticalScrollBarPolicy(QtCore.Qt.ScrollBarAlwaysOff)
layout = QtWidgets.QVBoxLayout(self)
layout.setContentsMargins(0, 0, 0, 0)
layout.setSpacing(0)
layout.addWidget(self.upBtn)
layout.addWidget(self.listWidget)
layout.addWidget(self.downBtn)
self.adjust_buttons()
self.create_connections()
def create_connections(self):
self.listWidget.currentItemChanged.connect(self.adjust_buttons)
model = self.listWidget.model()
model.rowsInserted.connect(self.adjust_buttons)
model.rowsRemoved.connect(self.adjust_buttons)
model.rowsMoved.connect(self.adjust_buttons)
model.modelReset.connect(self.adjust_buttons)
model.layoutChanged.connect(self.adjust_buttons)
#QtCore.pyqtSlot()
def adjust_buttons(self):
first = self.listWidget.itemAt(QtCore.QPoint())
r = self.listWidget.row(first)
self.upBtn.setVisible(r != 0 and r!= -1)
last = self.listWidget.itemAt(self.listWidget.viewport().rect().bottomRight())
r = self.listWidget.row(last)
self.downBtn.setVisible( r != (self.listWidget.count() -1) and r != -1)
#QtCore.pyqtSlot()
def moveUp(self):
ix = self.listWidget.moveCursor(QtWidgets.QAbstractItemView.MoveUp, QtCore.Qt.NoModifier)
self.listWidget.setCurrentIndex(ix)
#QtCore.pyqtSlot()
def moveDown(self):
ix = self.listWidget.moveCursor(QtWidgets.QAbstractItemView.MoveDown, QtCore.Qt.NoModifier)
self.listWidget.setCurrentIndex(ix)
#QtCore.pyqtSlot(str)
def add_item(self, text):
item = QtWidgets.QListWidgetItem(text)
self.listWidget.addItem(item)
if __name__ == '__main__':
app = QtWidgets.QApplication(sys.argv)
window = Window()
for i in range(100):
window.add_item("item {}".format(i))
window.show()
sys.exit(app.exec_())

Drag and Drop QLabels with PyQt5

I'm trying to drag and drop a Qlabel on another Qlabel with PyQt5:
from PyQt5.QtWidgets import QApplication, QWidget, QToolTip, QPushButton, QMessageBox, QHBoxLayout, QVBoxLayout, QGridLayout,QFrame, QComboBox, QLabel, QLineEdit
from PyQt5.QtGui import QIcon, QFont, QPixmap, QImage
import sys
class my_label(QLabel):
def __init__(self,title,parent):
super().__init__(title,parent)
self.setAcceptDrops(True)
def dragEnterEvent(self,event):
if event.mimeData().hasFormat("text/plain"):
event.accept()
else:
event.ignore()
def dropEvent(self,event):
self.setText(event.mimeData().text())
class application(QWidget):
def __init__(self):
super().__init__()
self.initUI()
def initUI(self):
label = my_label("drop there",self)
label.resize(100,100)
label.move(190,65)
label_to_drag = QLabel("drag this",self)
#label_to_drag.setDragEnabled(True) #doesn't work with QLabel
self.show()
def closeEvent(self,event):
message = QMessageBox.question(self,"Message","Quit ?",QMessageBox.Yes | QMessageBox.No,QMessageBox.No)
if message == QMessageBox.Yes:
event.accept()
else:
event.ignore()
app = QApplication(sys.argv)
fenetre = application()
sys.exit(app.exec_())
I wanted to make my first label "draggable",by calling the setDragEnabled(True) method (as i was doing for QLineEdit),and drop it on the second label to change his text. Dropping text from another app is working fine,but I can't find how to drag the QLabel inside my own app...
What did I miss ?
EDIT : modified the code to try to Drag&Drop Images :
class DraggableLabel(QLabel):
def __init__(self,parent,image):
super(QLabel,self).__init__(parent)
self.setPixmap(QPixmap(image))
self.show()
def mousePressEvent(self, event):
if event.button() == Qt.LeftButton:
self.drag_start_position = event.pos()
def mouseMoveEvent(self, event):
if not (event.buttons() & Qt.LeftButton):
return
if (event.pos() - self.drag_start_position).manhattanLength() < QApplication.startDragDistance():
return
drag = QDrag(self)
mimedata = QMimeData()
mimedata.setText(self.text())
drag.setMimeData(mimedata)
pixmap = QPixmap(self.size())
painter = QPainter(pixmap)
painter.drawPixmap(self.rect(), self.grab())
painter.end()
drag.setPixmap(pixmap)
drag.setHotSpot(event.pos())
drag.exec_(Qt.CopyAction | Qt.MoveAction)
class my_label(QLabel):
def __init__(self,title,parent):
super().__init__(title,parent)
self.setAcceptDrops(True)
def dragEnterEvent(self,event):
if event.mimeData().hasFormat("text/plain"):
print("event accepted")
event.accept()
else:
print("event rejected")
event.ignore()
def dropEvent(self,event):
if event.mimeData().hasImage():
self.setPixmap(QPixmap.fromImage(QImage(event.mimeData().imageData())))
class application(QWidget):
def __init__(self):
super().__init__()
self.initUI()
def initUI(self):
label_to_drag = DraggableLabel(self,"index.jpg")
label = my_label("drop there",self)
label.resize(100,100)
label.move(190,65)
self.show()
When I drop the DraggableLabel (displaying the image) on my_label,the event is accepted, but hasImage() always returns false...Is the way I set the image up wrong ?
In the case of QLabel you must create everything from the beginning, for this you can follow the examples of the docs.
In the following example I have placed an example where one class only accepts the drop and the other the drag so that you can see each part and understand better.
import sys
from PyQt5.QtWidgets import QApplication, QLabel, QWidget
from PyQt5.QtGui import QDrag, QPixmap, QPainter, QCursor
from PyQt5.QtCore import QMimeData, Qt
class DraggableLabel(QLabel):
def mousePressEvent(self, event):
if event.button() == Qt.LeftButton:
self.drag_start_position = event.pos()
def mouseMoveEvent(self, event):
if not (event.buttons() & Qt.LeftButton):
return
if (event.pos() - self.drag_start_position).manhattanLength() < QApplication.startDragDistance():
return
drag = QDrag(self)
mimedata = QMimeData()
mimedata.setText(self.text())
drag.setMimeData(mimedata)
pixmap = QPixmap(self.size())
painter = QPainter(pixmap)
painter.drawPixmap(self.rect(), self.grab())
painter.end()
drag.setPixmap(pixmap)
drag.setHotSpot(event.pos())
drag.exec_(Qt.CopyAction | Qt.MoveAction)
class DropLabel(QLabel):
def __init__(self, *args, **kwargs):
QLabel.__init__(self, *args, **kwargs)
self.setAcceptDrops(True)
def dragEnterEvent(self, event):
if event.mimeData().hasText():
event.acceptProposedAction()
def dropEvent(self, event):
pos = event.pos()
text = event.mimeData().text()
self.setText(text)
event.acceptProposedAction()
class Widget(QWidget):
def __init__(self):
super().__init__()
self.initUI()
def initUI(self):
label = DropLabel("drop there",self)
label.setGeometry(190, 65, 100,100)
label_to_drag = DraggableLabel("drag this",self)
self.show()
if __name__ == '__main__':
app = QApplication(sys.argv)
w = Widget()
w.show()
sys.exit(app.exec_())
Update:
Do not confuse the QDrag with the QMimeData, if you want to use imageData() you must set it with setImageData() as indicated by the docs:
class DraggableLabel(QLabel):
def __init__(self,parent,image):
super(QLabel,self).__init__(parent)
self.setPixmap(QPixmap(image))
self.show()
def mousePressEvent(self, event):
if event.button() == Qt.LeftButton:
self.drag_start_position = event.pos()
def mouseMoveEvent(self, event):
if not (event.buttons() & Qt.LeftButton):
return
if (event.pos() - self.drag_start_position).manhattanLength() < QApplication.startDragDistance():
return
drag = QDrag(self)
mimedata = QMimeData()
mimedata.setText(self.text())
mimedata.setImageData(self.pixmap().toImage())
drag.setMimeData(mimedata)
pixmap = QPixmap(self.size())
painter = QPainter(pixmap)
painter.drawPixmap(self.rect(), self.grab())
painter.end()
drag.setPixmap(pixmap)
drag.setHotSpot(event.pos())
drag.exec_(Qt.CopyAction | Qt.MoveAction)
class my_label(QLabel):
def __init__(self,title,parent):
super().__init__(title,parent)
self.setAcceptDrops(True)
def dragEnterEvent(self,event):
if event.mimeData().hasImage():
print("event accepted")
event.accept()
else:
print("event rejected")
event.ignore()
def dropEvent(self,event):
if event.mimeData().hasImage():
self.setPixmap(QPixmap.fromImage(QImage(event.mimeData().imageData())))

How does QGraphicsView receive mouse move events?

Briefly I want to track mouse coordinate over a QGraphicsView.
This answer works well for a QLabel object, but not works as expected when I switch to QGraphicsView as follows:
from PyQt4 import QtGui, QtCore
class Window(QtGui.QWidget):
def __init__(self):
QtGui.QWidget.__init__(self)
self.graphicsView = QtGui.QGraphicsView(self)
self.graphicsView.setMouseTracking(True)
self.graphicsView.installEventFilter(self)
layout = QtGui.QVBoxLayout(self)
layout.addWidget(self.graphicsView)
def eventFilter(self, source, event):
if (event.type() == QtCore.QEvent.MouseMove and
source is self.graphicsView):
pos = event.pos()
print('mouse move: (%d, %d)' % (pos.x(), pos.y()))
return QtGui.QWidget.eventFilter(self, source, event)
if __name__ == '__main__':
import sys
app = QtGui.QApplication(sys.argv)
window = Window()
window.show()
window.resize(200, 100)
sys.exit(app.exec_())
Specifically, it seems like that the event is caught only when my cursor moves accross the border of the QGraphicsView (the black lines).
Could anyone tell me why and is there any better solutions?
For certain widgets, you need to use its viewport instead:
self.graphicsView.viewport().installEventFilter(self)
...
def eventFilter(self, source, event):
if (event.type() == QtCore.QEvent.MouseMove and
source is self.graphicsView.viewport()):
...
An alternative is to override mouseMoveEvent(event) of QGraphicsView directly.
Example:
from PySide import QtGui
class MyGraphicsView(QtGui.QGraphicsView):
def __init__(self, parent):
QtGui.QGraphicsView.__init__(self, parent)
self.setMouseTracking(True)
def mouseMoveEvent(self, event):
print('mouseMoveEvent: pos {}'.format(event.pos()))
class Window(QtGui.QWidget):
def __init__(self):
QtGui.QWidget.__init__(self)
self.graphicsView = MyGraphicsView(self)
layout = QtGui.QVBoxLayout(self)
layout.addWidget(self.graphicsView)
app = QtGui.QApplication([])
window = Window()
window.show()
window.resize(200, 100)
app.exec_()

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