Qt 6

@Kais-Ahmad Are you by any chance mixing MSVC and MinGW? MinGW Qt build requires GLibC.

For those who are digging the depths of the internet to do this in Python, I figured out a way. It looks like the Python docs are wrong and/or ambiguous: "The video frame can then be used to read out the data of those frames and handle them further. When using QPainter, the QVideoFrame can be drawing using the paint() method in QVideoSink ."

I'm not a professional programmer so this may be ugly/non-conforming for some people but this works:

You can set the QMediaCaptureSession's video sink to your custom sink, and also make a QVideoWidget to display the frames. Then, take that custom sink, and connect some Slot method to the videoFrameChanged Signal, and inside that method do what you need to the frame, and then you can take that frame and use QVideoWidget.videoSink().setVideoFrame(the frame you just modified) and it works like a charm.

Please respond if this is unclear.

PS: mods/admins if this is in the wrong place please let me know.

@Damned-Ananas

The code you show does not work as the three QLabels are not part of any layout.
So setting

hLayout->setStretch(0, 1); hLayout->setStretch(1, 1); hLayout->setStretch(2, 4);

does not affect the labels, unless you are doing something else which you did not show.

And, as @JonB said above, until the layouts are applied and the widget is shown, you can't trust the widget's geometry you receive from geometry(), width() or height() as these values are generic/default values based on your settings and not how the widget actually looks when being rendered in some window or parent widget.

So please show your complete/actual code (and/or try what @JonB suggested)

Hello,
Unfortunately, there's no direct way to determine if your fragment shader is running within a Qt application or environment using built-in preprocessor directives or variables.
Understanding the Limitations
Shader Isolation: Shaders operate in a relatively isolated environment, with limited access to the surrounding application context.
Platform-Specific Information: Information about the application environment is typically handled at a higher level, outside the shader's scope.

I also have the same issue, and cannot find anyone else complaining. I don't have a solution for you though.

I recently transitioned from 6.6.1 to 6.7.2. And the "windows11" style in light mode looks hideous. There is less contrast throughout the application, making it difficult to navigate. Some bits are nice, but most are bad. The silver lining is that dark mode is better than the previous Fusion style, especially checkboxes. In light mode, I'm setting the style to "windowsvista" to achieve 6.6.1 look for now.

@Chakravarthi-N
Same as it has always been. Have you started by reading SQL Programming and Connecting to Databases?

@JonB @Q-Master @Qt-Enthusiast @Qt-embedded-developer I have this configuration use for msvc compiler and i have run different project that perfectly run with this configuration

image.png

because the qt.labs.platform has the Dialog as well, need to specifically use Dialog control in QtQuick.Controls

@Vishal-Kumar said in Is there any change in the licensing from qt5 to qt6?:

Is there any change happened to qt6 opensource licensing which might cause an issue later ?

As far as I know there are no changes since Qt 5.6 (where LGPL was changes to v3).

I am also having the same behavior:

If this is my custom widget that is derived from QWidget:

CCustomWidget.h namespace Ui { class CCustomWidget; } class CCustomWidget : public QWidget { Q_OBJECT public: explicit CCustomWidget(QWidget* pParent = nullptr); ~CCustomWidget(); private: Ui::CCustomWidget* ui; }; CCustomWidget.cpp #include "CCustomWidget.h" #include "ui_CCustomWidget.h" CCustomWidget::CCustomWidget(QWidget* pParent) : QWidget(pParent), ui(new Ui::CCustomWidget) { ui->setupUi(this); } CCustomWidget::~CCustomWidget() { delete ui; } main.cpp #include <QApplication> #include "CCustomWidget.h" int main(int argc, char* argv[]) { QApplication App(argc,argv); // this does not load the image CCustomWidget CW; CW.setStyleSheet(QStringLiteral("background-image: url(:/background.png);")); CW.show(); // this does load the image // QWidget W; // W.setStyleSheet(QStringLiteral("background-image: url(:/background.png);")); // W.show(); return App.exec(); }

When I am in the Designer tab of QtCreator, the background image for my custom widget displays correctly. But as soon as I compile/run the program. The custom widget no longer has a background image.

I have tried:

Programmatically setting the style sheet (as above) Setting the style sheet in the Designer of QtCreator Specifying my custom widget in the style sheet definition, where myCustomWidget is the QObject name that I set for my class in the constructor. CW.setStyleSheet("#myCustomWidget{ background-image: url(:/background.png); }");

I finally resorted to adding a QWidget on the Designer tab of QtCreator. Setting its style sheet to the background image by setting it in the properties section, and then moving the widget to the back so that it is behind everything else on the custom widget.

There is clearly something fundamental that I am missing but I do know know what it is or what even to ask. If someone could point me in the right direction, I would greatly appreciate it. It seems like setting a custom background image for your custom widget should be something that is very easy to do, but it is eluding me.

Thanks

Hi,

The answer is pretty simple: only use the templates for property declaration. If you don't, you may get the incompatible type error. The templates are also used to implement themes like Material or Universal theme.

Instead of doing

import QtQuick import QtQuick.Controls Item { id: root property Button myButton: Button {} }

You must use the Button type provided by the Templates

import QtQuick import QtQuick.Controls import QtQuick.Templates as T Item { id: root property T.Button myButton: Button {}

And they're used to defining the visual types

// Copyright (C) 2017 The Qt Company Ltd. // SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only import QtQuick import QtQuick.Templates as T import QtQuick.Controls.impl import QtQuick.Controls.Material import QtQuick.Controls.Material.impl T.Button { id: control implicitWidth: Math.max(implicitBackgroundWidth + leftInset + rightInset, implicitContentWidth + leftPadding + rightPadding) implicitHeight: Math.max(implicitBackgroundHeight + topInset + bottomInset, implicitContentHeight + topPadding + bottomPadding) topInset: 6 bottomInset: 6 verticalPadding: Material.buttonVerticalPadding leftPadding: Material.buttonLeftPadding(flat, hasIcon && (display !== AbstractButton.TextOnly)) rightPadding: Material.buttonRightPadding(flat, hasIcon && (display !== AbstractButton.TextOnly), (text !== "") && (display !== AbstractButton.IconOnly)) spacing: 8 icon.width: 24 icon.height: 24 icon.color: !enabled ? Material.hintTextColor : (control.flat && control.highlighted) || (control.checked && !control.highlighted) ? Material.accentColor : highlighted ? Material.primaryHighlightedTextColor : Material.foreground ...

https://github.com/qt/qtdeclarative/blob/dev/src/quickcontrols/material/Button.qml

And make sure to read this section. It explains why you must use templates when declaring properties: https://doc.qt.io/qt-6/qtquick-controls-qmlmodule.html#using-qt-quick-controls-types-in-property-declarations

You could write a feature request for that. CMake has a limited support for handling that file but AFAIK, nothing as complete as you would need.
Thanks for your kind words.

@jsulm

Hi. Could you please name the specific one in that list of Qt Quick? :)
Or I need to turn on all of them?

@TrahdBoy hi,

It's all explained here.

Hello,
Here I answer this question by myself, hope my answer can help someone who also meets this issue.

Set QMAKE_INFO_PLIST in your pro file.
Please refer https://doc.qt.io/qt-6/ios-platform-notes.html#info-plist-with-qmake

Make one function to check camera permission.
For example,
void MainWindow::checkCameraPermission(void)
{ // please refer https://code.qt.io/cgit/qt/qtmultimedia.git/tree/examples/multimedia/camera?h=6.7
#if QT_CONFIG(permissions)

QCameraPermission cameraPermission;
switch (qApp->checkPermission(cameraPermission)) {
case Qt::PermissionStatus::Undetermined:
qApp->requestPermission(cameraPermission, this, &MainWindow::checkCameraPermission);
return;
case Qt::PermissionStatus::Denied:
std::cout << "Camera permission is not granted!" << std::endl;
return;
case Qt::PermissionStatus::Granted:
std::cout << "Camera permission is granted!" << std::endl;
break;
}

#endif
}

Make one function to check camera permission status.
For example,
void MainWindow::checkAuthorizationStatus(void)
{
#if QT_CONFIG(permissions)

QCameraPermission cameraPermission;
Qt::PermissionStatus auth_status = Qt::PermissionStatus::Undetermined;
while(true)
{
QThread::msleep(1);
auth_status = qApp->checkPermission(cameraPermission);

if(auth_status == Qt::PermissionStatus::Undetermined) continue; break;

}

#endif // if QT_CONFIG
}

Before searching your camera, call the following functions,
checkCameraPermission();
checkAuthorizationStatus();

At my side, this issue had been solved.

Thanks.
Have a nice day.

@SimonSchroeder

This is a good idea.
I will try it.
Thanks.
Have a nice day.

@Ash-V What is your Linux distribution?

@Mihil-Ranasinghe said in How can I connect my QT cmake project to LibXL:

was using QXlsx library it was shown in project tree.

You did not - you just added the sources to your project instead linking to an external library - these are two completely different things.

Start the application with the QT_DEBUG_PLUGINS environment variable set to 1 to see why it fails to load.

Delete the qbs build directory in your project after exiting QtCreator and build it again