drag and drop a Tab from a QtabBar to other QtabBar in a splitted Widget PyQt Qt

After many hours and have eaten many manyyyy pages of Qt today over the web, I did it in my way, now I can drag and drop tabs from one tabBar to the other and vice-versa and not just from selection the current tab, i could select every tab that I want in my tab bar and will show me the pixmap of the little tab while dragging...

Here is the code:

** EDITED **

I made it more bullet proof, I had a bug when I was using more than 2 tabs with the index, now is working better, and when I drop it in the same widget it return the event and not execute the code, plus the hovering tabs select with the right mouse button as well .. I hope this can help anybody in the future.

TABINDEX = int()

def getTabIndex(index):
    global TABINDEX
    if index == -1 or index == TABINDEX:
        return
    TABINDEX = index
    print (TABINDEX)
    return TABINDEX


class ColtTab(qg.QTabWidget):
    def __init__(self):
        super(ColtTab,self).__init__()
        self.setAcceptDrops(True)
        self.tabBar = self.tabBar()
        self.tabBar.setMouseTracking(True)
        self.setDocumentMode(True)
        self.indexTab = int()
        self.setMovable(True)
        self.setStyleSheet(style_sheet_file)


    # test for hovering and selecting tabs automatic while mouser over then - not working for now...
    def eventFilter(self, obj, event):
        if obj == self.tabBar:
            if event.type() == qc.QEvent.MouseMove:
                index=self.tabBar.tabAt(event.pos())
                self.tabBar.setCurrentIndex (index)
                return True
            else:
                return
        else:
            return

    ##################################
    # Events
    #
    def mouseMoveEvent(self, e):
        if e.buttons() != qc.Qt.MiddleButton:
            return

        globalPos = self.mapToGlobal(e.pos())
        #print(globalPos)
        tabBar = self.tabBar
        #print(tabBar)
        posInTab = tabBar.mapFromGlobal(globalPos)
        #print(posInTab)
        self.indexTab = tabBar.tabAt(e.pos())
        #print(self.indexTab)
        tabRect = tabBar.tabRect(self.indexTab)
        #print(tabRect)
        #print(tabRect.size())

        pixmap = qg.QPixmap(tabRect.size())
        tabBar.render(pixmap,qc.QPoint(),qg.QRegion(tabRect))
        mimeData = qc.QMimeData()
        drag = qg.QDrag(tabBar)
        drag.setMimeData(mimeData)
        drag.setPixmap(pixmap)
        cursor = qg.QCursor(qc.Qt.OpenHandCursor)
        drag.setHotSpot(e.pos() - posInTab)
        drag.setDragCursor(cursor.pixmap(),qc.Qt.MoveAction)
        dropAction = drag.exec_(qc.Qt.MoveAction)


    def mousePressEvent(self, e):
        if e.button() == qc.Qt.RightButton:
            self.tabBar.installEventFilter(self)
            print('Right button pressed')

        super(ColtTab, self).mousePressEvent(e)


    def dragEnterEvent(self, e):
        e.accept()
        if e.source().parentWidget() != self:
            return

        # Helper function for retrieving the Tab index into a global Var
        getTabIndex(self.indexOf(self.widget(self.indexTab)))


    def dragLeaveEvent(self,e):
        e.accept()


    def dropEvent(self, e):
        if e.source().parentWidget() == self:
            return

        e.setDropAction(qc.Qt.MoveAction)
        e.accept()
        counter = self.count()

        if counter == 0:
            self.addTab(e.source().parentWidget().widget(TABINDEX),e.source().tabText(TABINDEX))
        else:
            self.insertTab(counter + 1 ,e.source().parentWidget().widget(TABINDEX),e.source().tabText(TABINDEX))

        print ('Tab dropped')

    def mouseReleaseEvent(self, e):
        if e.button() == qc.Qt.RightButton:
            print('Right button released')
            self.tabBar.removeEventFilter(self)

        super(ColtTab, self).mouseReleaseEvent(e)


    #---------------------------------------------------------------------------------#

Pic ->

Found this thread useful. Used your solution to create a self contained generic example in PyQt5. May help someone in the future.

import sys

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

class Tabs(QTabWidget):
    def __init__(self, parent):
        super().__init__(parent)
        self.parent = parent
        self.setAcceptDrops(True)
        self.tabBar = self.tabBar()
        self.tabBar.setMouseTracking(True)
        self.indexTab = None
        self.setMovable(True)

        self.addTab(QWidget(self), 'Tab One')
        self.addTab(QWidget(self), 'Tab Two')

    def mouseMoveEvent(self, e):
        if e.buttons() != Qt.RightButton:
            return

        globalPos = self.mapToGlobal(e.pos())
        tabBar = self.tabBar
        posInTab = tabBar.mapFromGlobal(globalPos)
        self.indexTab = tabBar.tabAt(e.pos())
        tabRect = tabBar.tabRect(self.indexTab)

        pixmap = QPixmap(tabRect.size())
        tabBar.render(pixmap,QPoint(),QRegion(tabRect))
        mimeData = QMimeData()
        drag = QDrag(tabBar)
        drag.setMimeData(mimeData)
        drag.setPixmap(pixmap)
        cursor = QCursor(Qt.OpenHandCursor)
        drag.setHotSpot(e.pos() - posInTab)
        drag.setDragCursor(cursor.pixmap(),Qt.MoveAction)
        dropAction = drag.exec_(Qt.MoveAction)


    def dragEnterEvent(self, e):
        e.accept()
        if e.source().parentWidget() != self:
            return

        print(self.indexOf(self.widget(self.indexTab)))
        self.parent.TABINDEX = self.indexOf(self.widget(self.indexTab))


    def dragLeaveEvent(self,e):
        e.accept()


    def dropEvent(self, e):
        print(self.parent.TABINDEX)
        if e.source().parentWidget() == self:
            return

        e.setDropAction(Qt.MoveAction)
        e.accept()
        counter = self.count()

        if counter == 0:
            self.addTab(e.source().parentWidget().widget(self.parent.TABINDEX),e.source().tabText(self.parent.TABINDEX))
        else:
            self.insertTab(counter + 1 ,e.source().parentWidget().widget(self.parent.TABINDEX),e.source().tabText(self.parent.TABINDEX))


class Window(QWidget):
    def __init__(self):

        super().__init__()

        self.TABINDEX = 0
        tabWidgetOne = Tabs(self)
        tabWidgetTwo = Tabs(self)

        layout = QHBoxLayout()

        self.moveWidget = None

        layout.addWidget(tabWidgetOne)
        layout.addWidget(tabWidgetTwo)

        self.setLayout(layout)

if __name__ == '__main__':

    app = QApplication(sys.argv)
    window = Window()
    window.show()
    sys.exit(app.exec_())

This is modified from someone elses code, perhaps one of the examples above.

Anyhow, it's a minimal code for tab-to-tab or tab-to-window drag / droping of tab's contents.

from PyQt5.QtWidgets import QTabWidget
from PyQt5.QtCore import Qt, QPoint, QMimeData
from PyQt5.QtGui import QPixmap, QRegion, QDrag, QCursor

class TabWidget(QTabWidget):
   def __init__(self, parent=None, new=None):
      super().__init__(parent)
      self.setAcceptDrops(True)
      self.tabBar().setMouseTracking(True)
      self.setMovable(True)
      if new:
         TabWidget.setup(self)

   def __setstate__(self, data):
      self.__init__(new=False)
      self.setParent(data['parent'])
      for widget, tabname in data['tabs']:
         self.addTab(widget, tabname)
      TabWidget.setup(self)

   def __getstate__(self):
      data = {
         'parent' : self.parent(),
         'tabs' : [],
      }
      tab_list = data['tabs']
      for k in range(self.count()):
         tab_name = self.tabText(k)
         widget = self.widget(k)
         tab_list.append((widget, tab_name))
      return data

   def setup(self):
      pass

   def mouseMoveEvent(self, e):
      if e.buttons() != Qt.RightButton:
         return

      globalPos = self.mapToGlobal(e.pos())
      tabBar = self.tabBar()
      posInTab = tabBar.mapFromGlobal(globalPos)
      index = tabBar.tabAt(e.pos())
      tabBar.dragged_content = self.widget(index)
      tabBar.dragged_tabname = self.tabText(index)
      tabRect = tabBar.tabRect(index)

      pixmap = QPixmap(tabRect.size())
      tabBar.render(pixmap,QPoint(),QRegion(tabRect))
      mimeData = QMimeData()

      drag = QDrag(tabBar)
      drag.setMimeData(mimeData)
      drag.setPixmap(pixmap)

      cursor = QCursor(Qt.OpenHandCursor)

      drag.setHotSpot(e.pos() - posInTab)
      drag.setDragCursor(cursor.pixmap(),Qt.MoveAction)
      drag.exec_(Qt.MoveAction)

   def dragEnterEvent(self, e):
      e.accept()
      #self.parent().dragged_index = self.indexOf(self.widget(self.dragged_index))

   def dragLeaveEvent(self,e):
      e.accept()

   def dropEvent(self, e):
      if e.source().parentWidget() == self:
         return

      e.setDropAction(Qt.MoveAction)
      e.accept()
      tabBar = e.source()
      self.addTab(tabBar.dragged_content, tabBar.dragged_tabname)


if __name__ == '__main__':
   from PyQt5.QtWidgets import QWidget, QApplication, QHBoxLayout
   import sys

   class Window(QWidget):
      def __init__(self):

         super().__init__()

         self.dragged_index = None
         tabWidgetOne = TabWidget(self)
         tabWidgetTwo = TabWidget(self)
         tabWidgetOne.addTab(QWidget(), "tab1")
         tabWidgetTwo.addTab(QWidget(), "tab2")

         layout = QHBoxLayout()

         self.moveWidget = None

         layout.addWidget(tabWidgetOne)
         layout.addWidget(tabWidgetTwo)

         self.setLayout(layout)

   app = QApplication(sys.argv)
   window = Window()
   window1 = Window()
   window.show()
   window1.show()
   sys.exit(app.exec_())