WA_TranslucentBackground Frameless windows problem with WIN32 API SetParent

Emrecp

Hello,
Here is video: https://streamable.com/0a6q8r
When I use my custom Frameless and rounded form (I must use Qt.WA_TranslucentBackground for rounded form), WIN32API SetParent doesn't work.
But when normal window (no custom form or custom form WITHOUT WA_TranslucentBackground), SetParent API works fine.
I'm waiting for your help, Thanks!

Here is my code:

import sys,os, subprocess, psutil, time
import win32gui
from win32con import *
from PySide6 import QtCore, QtWidgets
from PySide6.QtWidgets import *
from PySide6.QtCore import *
from PySide6.QtGui import *


BORDERLESS_CUSTOM_FORM = True
class MACTema(QDialog):
    def __init__(self, w, parent=None):
        QDialog.__init__(self, parent)

        self.parent = parent
        self._w = w
        self.setupUi()
        contentLayout = QHBoxLayout()
        contentLayout.setContentsMargins(0, 3, 0, 3)
        contentLayout.addWidget(w)

        self.windowContent.setLayout(contentLayout)
        self.setWindowTitle(w.windowTitle())
        self.setGeometry(w.geometry())

        self._w.setAttribute(Qt.WA_DeleteOnClose, True)
        self._w.destroyed.connect(self.__child_was_closed)

    def setupUi(self):
        self.vboxWindow = QtWidgets.QVBoxLayout(self)
        self.vboxWindow.setContentsMargins(0, 0, 0, 0)

        self.windowFrame = QWidget(self)
        self.windowFrame.setObjectName('windowFrame')

        self.vboxFrame = QtWidgets.QVBoxLayout(self.windowFrame)
        self.vboxFrame.setContentsMargins(0, 0, 0, 0)

        self.titleBar = QWidget()
        self.titleBar.setContentsMargins(0, 0, 0, 0)
        self.titleBar.setSizePolicy(QSizePolicy(QSizePolicy.Preferred, QSizePolicy.Fixed))

        self.hboxTitle = QHBoxLayout(self.titleBar)
        self.hboxTitle.setContentsMargins(0, 0, 4, 0)
        self.hboxTitle.setSpacing(0)

        self.lblIcon = QLabel()
        if not self._w.windowIcon().isNull():
            self.lblIcon.setPixmap(self._w.windowIcon().pixmap(QSize(64, 64)))
        self.lblIcon.setAlignment(Qt.AlignLeft | Qt.AlignVCenter)
        self.lblIcon.setFixedSize(QSize(64 + 16, 32 + 2))
        self.lblIcon.setContentsMargins(5, 5, 0, 0)

        self.lblTitle = QLabel('Title')
        self.lblTitle.setObjectName('lblTitle')
        self.lblTitle.setAlignment(Qt.AlignBottom | Qt.AlignHCenter)
        self.lblTitle.setAttribute(Qt.WA_TransparentForMouseEvents, True)
        spButtons = QSizePolicy(QSizePolicy.Fixed, QSizePolicy.Expanding)

        self.btnMaximize = QPushButton()  # clicked pyqtSlot => on_btnMaximize_clicked
        self.btnMaximize.setObjectName('btnMaximize')
        self.btnMaximize.setSizePolicy(spButtons)

        self.btnClose = QPushButton()  # clicked pyqtSlot => on_btnClose_clicked
        self.btnClose.setObjectName("btnClose")
        self.btnClose.setContentsMargins(0, 0, 0, 0)
        self.btnClose.setSizePolicy(spButtons)

        self.btnMinimize = QPushButton()  # click => on_btnMinimize_clicked
        self.btnMinimize.setObjectName("btnMinimize")
        self.btnMinimize.setSizePolicy(spButtons)
        self.vboxFrame.addWidget(self.titleBar)
        self.windowContent = QWidget(self.windowFrame)
        self.vboxFrame.addWidget(self.windowContent)
        self.vboxWindow.addWidget(self.windowFrame)
        self.hboxTitle.addWidget(self.lblIcon)
        self.hboxTitle.addWidget(self.lblTitle)
        self.hboxTitle.addWidget(self.btnMinimize)
        self.hboxTitle.addWidget(self.btnMaximize)

        self.hboxTitle.addWidget(self.btnClose)
        self.CONTROLBOX_WIDTH = self.btnClose.width()
        self.setWindowFlags(Qt.WindowType.Window | Qt.FramelessWindowHint | Qt.WindowMinimizeButtonHint)








        if True: # Problem here
            self.setAttribute(Qt.WA_TranslucentBackground)





        COLOR_ACIK_MINIMIZE, COLOR_KAPALI_MINIMIZE = "rgb(0, 120, 0)", "rgb(0,200,0)"
        COLOR_ACIK_CLOSE, COLOR_KAPALI_CLOSE = "rgb(255, 0, 0)", "rgb(255, 50, 50)"
        COLOR_MINIMIZE = COLOR_ACIK_MINIMIZE
        COLOR_CLOSE = COLOR_ACIK_CLOSE


        CONTROL_BOX_MAC = f"""
        #windowFrame {{      
          border-top-left-radius:10px;border-top-right-radius:10px;
          border-bottom-left-radius:5px;border-bottom-right-radius:5px;  
          background-color: palette(Window);}}        
#btnClose, #btnMaximize, #btnMinimize {{ 
    margin: 4px;  
	border: none;
	border-radius: 8px;	
	width:17px;
	height:17px;
	max-height:17px; 
	max-width:17px;


}}
#btnMaximize {{
  	border: none;
	border-radius: 8px;	
	background-color: rgb(255, 170, 0);
}}
#btnMaximize::hover {{
  	background-color: rgba(255, 170, 0, 175);
}}
#btnMinimize {{
 	border: none;
	border-radius: 8px;		

	background-color: {COLOR_MINIMIZE};
}}
#btnMinimize::hover {{
    background-color: rgba(0, 120, 0, 175);

}}
#btnClose {{
	border: none;
	border-radius: 8px;		
	background-color: {COLOR_CLOSE};
}}
#btnClose::hover {{
  background-color: rgba(255, 0, 0, 175);
}}
#btnClose::disabled, #btnMaximize::disabled, #btnMinimize::disabled {{
  background-color: palette(midlight);
}}
"""
        self.setStyleSheet(CONTROL_BOX_MAC)


        QtCore.QMetaObject.connectSlotsByName(self)
        self.effect = QtWidgets.QGraphicsDropShadowEffect()
        self.effect.setBlurRadius(10)
        self.effect.setXOffset(0)
        self.effect.setYOffset(0)
        self.effect.setColor(QColor(0, 0, 0, 150))
        self.windowFrame.setGraphicsEffect(self.effect)
        self.setContentsMargins(8, 8, 8,8)

    @Slot()
    def on_btnClose_clicked(self):
        self.close()

    def __child_was_closed(self):
        self._w = None  # The child was deleted, remove the reference to it and close the parent window
        self.close()

    def setWindowTitle(self, title):
        super(MACTema, self).setWindowTitle(title)
        self.lblTitle.setText(title)



class MyForm(QMainWindow):
    def __init__(self):
        super(MyForm, self).__init__()
        self.setupUi()
        if BORDERLESS_CUSTOM_FORM:
            self.mac = MACTema(w=self)
            self.mac.setGeometry(QRect(350,200,1280,720))
            self.mac.show()
        else:
            self.setGeometry(QRect(350, 200, 1280, 720))
            self.show()
        QApplication.processEvents()
        self.CalcSetParentFunction()


    def setupUi(self):
        widCenter = QWidget()
        qv= QVBoxLayout(widCenter)
        self.frame = QFrame()
        qv.addWidget(self.frame)
        self.setCentralWidget(widCenter)

    def CalcSetParentFunction(self):
        psutil.Popen("notepad.exe", stdout=subprocess.DEVNULL, stderr=subprocess.DEVNULL, shell=True) # starts notepad
        time.sleep(2)
        self.hwnd = win32gui.FindWindow(None, "Untitled - Notepad") # Untitled - Notepad
        print("Notepad Hwnd: 0x%X"% self.hwnd)
        if not self.hwnd:
            return
        lStyle = win32gui.GetWindowLong(self.hwnd, GWL_STYLE);
        lStyle &= ~(WS_POPUP | WS_CHILD)
        #lStyle |= WS_CHILD
        win32gui.SetWindowLong(self.hwnd, GWL_STYLE, lStyle);


        win32gui.SetParent(self.hwnd, self.frame.winId())
        self.tmr = QTimer(self)
        self.tmr.timeout.connect(self.UpdateGUI)
        self.tmr.setInterval(100)
        self.tmr.start()

    def UpdateGUI(self):
        win32gui.RedrawWindow(self.hwnd, None, None, RDW_INVALIDATE | RDW_FRAME | RDW_ERASE | RDW_ALLCHILDREN)




if __name__ == "__main__":
    app = QApplication(sys.argv)
    os.system("taskkill /f /im notepad.exe")
    Form = MyForm()
    sys.exit(app.exec_())

Thank you very much!

Emrecp

Any idea? Maybe @SGaist can help me?

SGaist

Hi,

@Emrecp said in WA_TranslucentBackground Frameless windows problem with WIN32 API SetParent:

self.parent = parent

You are nuking the original property with this one. I am not saying that this is the cause of your issue but it may have some influence.

Why are you mixing super calls and base class method invocation ?

That said, when calling winId, your widget will get a native handle like explained in the method documentation. So I wonder if this triggers the effect you are seeing.

Try reordering that stuff, and start by making the parenting and only then finish the custom setup.

Emrecp

@SGaist
removing self.parent = parent did not help. Problem still continues.