[Python] Is it possible to drag a QTabWidget and open a new window containing what's in this...

I'm wondering if it is possible by clicking and dragging a Tab to open a new window with what was in that Tab. If it's possible, I would like to also do the reverse: dragging the new window inside the Tabs (where it was in the first place).

I don't know how should I start. I read in some forums that all must be coded but I don't know if Qt allows some facilities to do that?

Here a code as a starting point:

from PyQt5.QtGui import *
from PyQt5.QtCore import *
from PyQt5.QtWidgets import *
import sys


class SurfViewer(QMainWindow):
def __init__(self, parent=None):
super(SurfViewer, self).__init__()
self.parent = parent
self.centralTabs= QTabWidget()
self.setCentralWidget(self.centralTabs)
self.setFixedWidth(200)
self.setFixedHeight(200)

#tab 1
self.tab_1 = QWidget()
self.centralTabs.addTab(self.tab_1,"Label")
vbox = QVBoxLayout()
Label = QLabel('Tab1')
Label.setFixedWidth(180)
LineEdit = QLineEdit('Tab1')
LineEdit.setFixedWidth(180)
vbox.addWidget(Label)
vbox.addWidget(LineEdit)
vbox.setAlignment(Qt.AlignTop)
self.tab_1.setLayout(vbox)

#tab 2
self.tab_2 = QWidget()
self.centralTabs.addTab(self.tab_2,"Label")
vbox = QVBoxLayout()
Label = QLabel('Tab2')
Label.setFixedWidth(180)
LineEdit = QLineEdit('Tab2')
LineEdit.setFixedWidth(180)
vbox.addWidget(Label)
vbox.addWidget(LineEdit)
vbox.setAlignment(Qt.AlignTop)
self.tab_2.setLayout(vbox)

if __name__ == '__main__':
app = QApplication(sys.argv)
ex = SurfViewer(app)
ex.setWindowTitle('window')
ex.show()
sys.exit(app.exec_( ))


This is far from my Qt level, so I'm asking some help. If I well understood, I need to reimplement the mousePressEvent() and the dragMoveEvent() of the QTabWidget? Their is this topic: In PyQt4, is it possible to detach tabs from a QTabWidget? but it is with PYQT4 and I'm using PYQT5.

update


So, according to In PyQt4, is it possible to detach tabs from a QTabWidget? and after conversion toward pyqt5

from PyQt5.QtGui import *
from PyQt5.QtCore import *
from PyQt5.QtWidgets import *
import sys

class DetachableTabWidget(QTabWidget):
def __init__(self, parent=None):
QTabWidget.__init__(self, parent)

self.tabBar = self.TabBar(self)
self.tabBar.onDetachTabSignal.connect(self.detachTab)
self.tabBar.onMoveTabSignal.connect(self.moveTab)

self.setTabBar(self.tabBar)


##
# The default movable functionality of QTabWidget must remain disabled
# so as not to conflict with the added features
def setMovable(self, movable):
pass

##
# Move a tab from one position (index) to another
#
# @param fromIndex the original index location of the tab
# @param toIndex the new index location of the tab
@pyqtSlot(int, int)
def moveTab(self, fromIndex, toIndex):
widget = self.widget(fromIndex)
icon = self.tabIcon(fromIndex)
text = self.tabText(fromIndex)

self.removeTab(fromIndex)
self.insertTab(toIndex, widget, icon, text)
self.setCurrentIndex(toIndex)


##
# Detach the tab by removing it's contents and placing them in
# a DetachedTab dialog
#
# @param index the index location of the tab to be detached
# @param point the screen position for creating the new DetachedTab dialog
@pyqtSlot(int, QPoint)
def detachTab(self, index, point):

# Get the tab content
name = self.tabText(index)
icon = self.tabIcon(index)
if icon.isNull():
icon = self.window().windowIcon()
contentWidget = self.widget(index)
contentWidgetRect = contentWidget.frameGeometry()

# Create a new detached tab window
detachedTab = self.DetachedTab(contentWidget, self.parentWidget())
detachedTab.setWindowModality(Qt.NonModal)
detachedTab.setWindowTitle(name)
detachedTab.setWindowIcon(icon)
detachedTab.setObjectName(name)
detachedTab.setGeometry(contentWidgetRect)
detachedTab.onCloseSignal.connect(self.attachTab)
detachedTab.move(point)
detachedTab.show()


##
# Re-attach the tab by removing the content from the DetachedTab dialog,
# closing it, and placing the content back into the DetachableTabWidget
#
# @param contentWidget the content widget from the DetachedTab dialog
# @param name the name of the detached tab
# @param icon the window icon for the detached tab
@pyqtSlot(QWidget, type(''), QIcon)
def attachTab(self, contentWidget, name, icon):

# Make the content widget a child of this widget
contentWidget.setParent(self)


# Create an image from the given icon
if not icon.isNull():
tabIconPixmap = icon.pixmap(icon.availableSizes()[0])
tabIconImage = tabIconPixmap.toImage()
else:
tabIconImage = None


# Create an image of the main window icon
if not icon.isNull():
windowIconPixmap = self.window().windowIcon().pixmap(icon.availableSizes()[0])
windowIconImage = windowIconPixmap.toImage()
else:
windowIconImage = None


# Determine if the given image and the main window icon are the same.
# If they are, then do not add the icon to the tab
if tabIconImage == windowIconImage:
index = self.addTab(contentWidget, name)
else:
index = self.addTab(contentWidget, icon, name)


# Make this tab the current tab
if index > -1:
self.setCurrentIndex(index)


##
# When a tab is detached, the contents are placed into this QDialog. The tab
# can be re-attached by closing the dialog or by double clicking on its
# window frame.
class DetachedTab(QDialog):
onCloseSignal = pyqtSignal(QWidget,type(''), QIcon)

def __init__(self, contentWidget, parent=None):
QDialog.__init__(self, parent)

layout = QVBoxLayout(self)
self.contentWidget = contentWidget
layout.addWidget(self.contentWidget)
self.contentWidget.show()
self.setWindowFlags(Qt.Window)


##
# Capture a double click event on the dialog's window frame
#
# @param event an event
#
# @return true if the event was recognized
def event(self, event):

# If the event type is QEvent.NonClientAreaMouseButtonDblClick then
# close the dialog
if event.type() == 176:
event.accept()
self.close()

return QDialog.event(self, event)


##
# If the dialog is closed, emit the onCloseSignal and give the
# content widget back to the DetachableTabWidget
#
# @param event a close event
def closeEvent(self, event):
self.onCloseSignal.emit(self.contentWidget, self.objectName(), self.windowIcon())


##
# The TabBar class re-implements some of the functionality of the QTabBar widget
class TabBar(QTabBar):
onDetachTabSignal = pyqtSignal(int, QPoint)
onMoveTabSignal = pyqtSignal(int, int)

def __init__(self, parent=None):
QTabBar.__init__(self, parent)

self.setAcceptDrops(True)
self.setElideMode(Qt.ElideRight)
self.setSelectionBehaviorOnRemove(QTabBar.SelectLeftTab)

self.dragStartPos = QPoint()
self.dragDropedPos = QPoint()
self.mouseCursor = QCursor()
self.dragInitiated = False


##
# Send the onDetachTabSignal when a tab is double clicked
#
# @param event a mouse double click event
def mouseDoubleClickEvent(self, event):
event.accept()
self.onDetachTabSignal.emit(self.tabAt(event.pos()), self.mouseCursor.pos())


##
# Set the starting position for a drag event when the mouse button is pressed
#
# @param event a mouse press event
def mousePressEvent(self, event):
if event.button() == Qt.LeftButton:
self.dragStartPos = event.pos()

self.dragDropedPos.setX(0)
self.dragDropedPos.setY(0)

self.dragInitiated = False

QTabBar.mousePressEvent(self, event)


##
# Determine if the current movement is a drag. If it is, convert it into a QDrag. If the
# drag ends inside the tab bar, emit an onMoveTabSignal. If the drag ends outside the tab
# bar, emit an onDetachTabSignal.
#
# @param event a mouse move event
def mouseMoveEvent(self, event):

# Determine if the current movement is detected as a drag
if not self.dragStartPos.isNull() and ((event.pos() - self.dragStartPos).manhattanLength() < QApplication.startDragDistance()):
self.dragInitiated = True

# If the current movement is a drag initiated by the left button
if (((event.buttons() & Qt.LeftButton)) and self.dragInitiated):

# Stop the move event
finishMoveEvent = QMouseEvent(QEvent.MouseMove, event.pos(), Qt.NoButton, Qt.NoButton, Qt.NoModifier)
QTabBar.mouseMoveEvent(self, finishMoveEvent)

# Convert the move event into a drag
drag = QDrag(self)
mimeData = QMimeData()
mimeData.setData('action', b'application/tab-detach')
drag.setMimeData(mimeData)

#Create the appearance of dragging the tab content
pixmap = self.parentWidget().grab()
targetPixmap = QPixmap(pixmap.size())
targetPixmap.fill(Qt.transparent)
painter = QPainter(targetPixmap)
painter.setOpacity(0.85)
painter.drawPixmap(0, 0, pixmap)
painter.end()
drag.setPixmap(targetPixmap)

# Initiate the drag
dropAction = drag.exec_(Qt.MoveAction | Qt.CopyAction)

# If the drag completed outside of the tab bar, detach the tab and move
# the content to the current cursor position
if dropAction == Qt.IgnoreAction:
event.accept()
self.onDetachTabSignal.emit(self.tabAt(self.dragStartPos), self.mouseCursor.pos())

# Else if the drag completed inside the tab bar, move the selected tab to the new position
elif dropAction == Qt.MoveAction:
if not self.dragDropedPos.isNull():
event.accept()
self.onMoveTabSignal.emit(self.tabAt(self.dragStartPos), self.tabAt(self.dragDropedPos))
else:
QTabBar.mouseMoveEvent(self, event)


##
# Determine if the drag has entered a tab position from another tab position
#
# @param event a drag enter event
def dragEnterEvent(self, event):
mimeData = event.mimeData()
formats = mimeData.formats()

if 'action' in formats and mimeData.data('action') == 'application/tab-detach':
event.acceptProposedAction()

QTabBar.dragMoveEvent(self, event)


##
# Get the position of the end of the drag
#
# @param event a drop event
def dropEvent(self, event):
self.dragDropedPos = event.pos()
QTabBar.dropEvent(self, event)

class SurfViewer(QMainWindow):
def __init__(self, parent=None):
super(SurfViewer, self).__init__()
self.parent = parent
self.centralTabs= DetachableTabWidget()
self.setCentralWidget(self.centralTabs)
self.setFixedWidth(200)
self.setFixedHeight(200)

#tab 1
self.tab_1 = QWidget()
self.centralTabs.addTab(self.tab_1,"Label")
vbox = QVBoxLayout()
Label = QLabel('Tab1')
Label.setFixedWidth(180)
LineEdit = QLineEdit('Tab1')
LineEdit.setFixedWidth(180)
vbox.addWidget(Label)
vbox.addWidget(LineEdit)
vbox.setAlignment(Qt.AlignTop)
self.tab_1.setLayout(vbox)

#tab 2
self.tab_2 = QWidget()
self.centralTabs.addTab(self.tab_2,"Label")
vbox = QVBoxLayout()
Label = QLabel('Tab2')
Label.setFixedWidth(180)
LineEdit = QLineEdit('Tab2')
LineEdit.setFixedWidth(180)
vbox.addWidget(Label)
vbox.addWidget(LineEdit)
vbox.setAlignment(Qt.AlignTop)
self.tab_2.setLayout(vbox)

if __name__ == '__main__':
app = QApplication(sys.argv)
ex = SurfViewer(app)
ex.setWindowTitle('window')
ex.show()
sys.exit(app.exec_( ))


It stil have one issue with that code. When several Tabs are detatched and when I close them in the wrong order, the Tabs are going in the wrong order in the main window. I would like to have them in the same order as originally

Update 2


So I rewrite the attachTabfunction in order to put back the Tab where they were before detachment:

def attachTab(self, contentWidget, name, icon):

# Make the content widget a child of this widget
contentWidget.setParent(self)


# Create an image from the given icon
if not icon.isNull():
tabIconPixmap = icon.pixmap(icon.availableSizes()[0])
tabIconImage = tabIconPixmap.toImage()
else:
tabIconImage = None


# Create an image of the main window icon
if not icon.isNull():
windowIconPixmap = self.window().windowIcon().pixmap(icon.availableSizes()[0])
windowIconImage = windowIconPixmap.toImage()
else:
windowIconImage = None


# Determine if the given image and the main window icon are the same.
# If they are, then do not add the icon to the tab
if name == 'Model Selection':
index = 0
elif name == "Model' Parameters":
index = 1
elif name == 'Stim settings':
index = 2
elif name == 'Parameter evolution settings':
index = 3
elif name == 'LambdaE':
index = 4
elif name == 'Simulation settings':
index = 5
elif name == 'LFP + PPS + Pulse Results':
index = 6
if tabIconImage == windowIconImage:
index = self.insertTab(index,contentWidget, name)
# index = self.addTab(contentWidget, name)
else:
# index = self.addTab(contentWidget, icon, name)
index = self.insertTab(index,contentWidget, icon, name)



# Make this tab the current tab
if index > -1:
self.setCurrentIndex(index)


So every Tab is insert according to the starting position, but everything is done by hand. Maybe it exists an automatic way to do that.

I also increase the drag minimal distance because it seems too short too me ni the mouseMoveEventfunction :

if not self.dragStartPos.isNull() and ((event.pos() - self.dragStartPos).manhattanLength() > QApplication.startDragDistance()*2):


Ialso modify the < to > to initiate the drag only if the distance is greater than startDragDistance()

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