pyqt : transparent background QGLWidget

Question

enter image description here

I hope to make a QGLWidget that has a transparent background, like a figure above.
It's a cpp code and I don't understand the some parts of it. As far as I know, it uses window handle, drawing context, and so on. But I'm poor at C and C++. I've used Python and PyQt, so it seems like a Atlantis for me. Is there any idea for QGLWidget that has a transparent background?

ADD

from PyQt4.QtCore import Qt
from PyQt4.QtGui import QApplication, QColor
from PyQt4.QtOpenGL import QGLWidget

from OpenGL import GL
import sys

class TransGLWidget(QGLWidget):
    def __init__(self, parent=None):
        QGLWidget.__init__(self, parent)
        self.setWindowFlags(Qt.FramelessWindowHint)
        self.setAttribute(Qt.WA_TranslucentBackground, True)
        self.setGeometry(200, 100, 640, 480)

    def initializeGL(self):
        self.qglClearColor(QColor(0, 0, 0, 0))

    def resizeGL(self, w, h):
        GL.glViewport(0, 0, w, h)
        GL.glMatrixMode(GL.GL_PROJECTION)
        GL.glLoadIdentity()
        x = float(w) / h
        GL.glFrustum(-x, x, -1.0, 1.0, 1.0, 10.0)
        GL.glMatrixMode(GL.GL_MODELVIEW)
        GL.glLoadIdentity()

    def paintGL(self):
        GL.glClear(GL.GL_COLOR_BUFFER_BIT | GL.GL_DEPTH_BUFFER_BIT)   

        GL.glBegin(GL.GL_TRIANGLES)
        GL.glColor3f(1.0, 0.0, 0.0)
        GL.glVertex3f(-1.0, 1.0, -3.0)
        GL.glColor3f(0.0, 1.0, 0.0)
        GL.glVertex3f(1.0, 1.0, -3.0)
        GL.glColor3f(0.0, 0.0, 1.0)
        GL.glVertex3f(0.0, -1.0, -3.0)
        GL.glEnd()

app = QApplication(sys.argv)
widget = TransGLWidget()    
widget.show()
app.exec_()

I try with above code, but it shows me nothing. (It seems a whole transparent widget.) If I get rid of "setAttribute", "setWindowFlags", is shows up a triangle. Is there any miss at the code?

possible duplicate of [Qt Widget with Transparent Background](http://stackoverflow.com/questions/7667552/qt-widget-with-transparent-background) — Ramchandra Apte, Nov 13 '13 at 04:01

Ramchandra Apte · Answer 1 · 2013-11-13T04:03:02.510

1

Translated into Python from this C++ solution. The semicolon at the end has been removed, :: has been replaced with ., and True has been capitalized. The main source of difficulty is that setAttribute and setWindowFlags are actually methods of the QGLWidget, so self. has been added. Just add this in the __init__() constructor of your QGLWidget`.

self.setAttribute(Qt.WA_TranslucentBackground, True)

You can add self.setWindowFlags(Qt.FramelessWindowHint | Qt.WindowStaysOnTopHint)

if you want the window to be on top of others and have no frame.

edited Nov 13 '13 at 04:03

answered Nov 13 '13 at 03:57

Ramchandra Apte

4,033
2
24
44

I tried as you suggested, but I failed. I wrote my code, so can you check my fault? – Hyun-geun Kim Nov 14 '13 at 04:24
@Hyun-geunKim It's working for me; which OS are you using? I think it won't work on Windows XP because it doesn't use a compositing window manager. – Ramchandra Apte Nov 14 '13 at 04:26
I'm using Windows 7. It means that in my system transparency is impossible? – Hyun-geun Kim Nov 14 '13 at 07:38
@Hyun-geunKim. It might be possible. See this [Windows Seven Forum thread](http://www.sevenforums.com/tutorials/283-transparency-enable-disable.html) for details. – ekhumoro Dec 04 '13 at 02:51
Hi, @Hyun-geun Kim Did you ever solved this transprency issue on a gL widget ? – MBV Apr 13 '23 at 23:13

pyqt : transparent background QGLWidget

ADD

1 Answers1