[qt5] Transparent (windows 7 aero) widget

billouparis

Ok apparently my code is OK
@#include <QtGui/QGuiApplication>
#include "qtquick2applicationviewer.h"
#include <QSurface>
#include <QSurfaceFormat>
#include <QDebug>

int main(int argc, char *argv[])
{
QGuiApplication app(argc, argv);

QtQuick2ApplicationViewer viewer;

viewer.setSurfaceType(QSurface::OpenGLSurface);

QSurfaceFormat format;
format.setAlphaBufferSize(8);
format.setRenderableType(QSurfaceFormat::OpenGL);
qDebug() <&lt; format.hasAlpha();
viewer.setFormat(format);

QColor color;
color.setRedF(0.0);
color.setGreenF(0.0);
color.setBlueF(0.0);
color.setAlphaF(0.0);
viewer.setColor(color);

viewer.setClearBeforeRendering(true);

//viewer.setFlags(Qt::FramelessWindowHint);
viewer.setMainQmlFile&#40;QStringLiteral("qml/myProject/main.qml"&#41;);
viewer.showExpanded();


return app.exec();

}
@

from my investigation on the Qt5 side in
void QSGDefaultRenderer::render() and then in
void QSGBindable::clear(QSGRenderer::ClearMode mode) const,
the glClear call is performed correctly, but sadly and this is my
conclusion, Windows is doing something under Qt that can not be directly/easily controlled from within Qt.

What do you think?
Bill

Itehnological

The solution is perfect! +1 from me!
P.S. Thanks a lot!

billouparis

Found something in the end.
First activate the aero feature, second use my test application (source code: http://dl.free.fr/nZHhZVRui),
finally you will get something that will look like this:

!http://i48.tinypic.com/35bcxmh.png()!

Enjoy,
Bill

Itehnological

There is a problem with your solution in Windows, when setting:

@format.setRenderableType(QSurfaceFormat::OpenGL);@

Which results in the output:
@Cant find EGLConfig, returning null config
QQuickWindow: makeCurrent() failed...
ASSERT: "context" in file opengl\qopenglfunctions.cpp, line 194@

elpuri

You get that error, because you're asking for an OpenGL surface and your Qt is configured to use ANGLE which provides an OpenGL ES2 interface using DirectX. If you change the parameter to QSurfaceFormat::OpenGLES it'll make the error go away, but I doubt it will make the transparency work as a QQuickWindow is always OpenGL anyway.

Itehnological

@billouparis How did you achieved transparency in windows having in mind what was said by elpuri?

billouparis

I must have a build with openGL flag for sure! I compiled Qt libraries myself!

diorahman

Hi @billouparis how to build the Qt Lib, without ANGLE? Thanks!

zhaoweiwei

Who know why QMainWindow are completely invisible whenever TranslucentBackground is set?
as fallow:
@int main(int argc, char *argv[])
{
QApplication::setStyle("cleanlooks");
QApplication a(argc, argv);
login w; // class login : public QMainWindow
w.setWindowTitle("ClientLogin");

w.setWindowOpacity(1);
w.setWindowFlags(Qt::FramelessWindowHint);

#ifndef NEWQT //I define this micro for Qt5, because in qt5 WA_TranslucentBackground will cause window invisible
w.setAttribute(Qt::WA_TranslucentBackground);
#endif

w.show();
w.move(200,100);
return a.exec&#40;&#41;;

}@

zhaoweiwei

I have find the resolution in http://qt-project.org/forums/viewthread/24344 Now I have get transparent dialog!