Global functions or macros to get Qt version in QML code - c++

How Can I get Qt version, for example 5.11.2 or similar, in my QML code. In my C++ code I have these options:
Method available on C++:
qVersion();
Macro available on C++:
QT_VERSION
But I couldn't find anything on QML?

You could use a Context Property, as explained here.
A simple example, given a simple qml file like this:
import QtQuick 2.9
import QtQuick.Window 2.2
Window {
Text {
text: qtversion
}
visible: true
width: 640
height: 480
title: qsTr("Hello World")
}
Set the qtversion property at startup, in main function:
#include <QGuiApplication>
#include <QQmlApplicationEngine>
#include <QQmlContext>
int main(int argc, char *argv[])
{
QCoreApplication::setAttribute(Qt::AA_EnableHighDpiScaling);
QGuiApplication app(argc, argv);
QQmlApplicationEngine engine;
engine.rootContext()->setContextProperty("qtversion", QString(qVersion()));
engine.load(QUrl(QStringLiteral("qrc:/main.qml")));
if (engine.rootObjects().isEmpty())
return -1;
return app.exec();
}

Related

Qt WebEngine url blocking

I would like to ask you a question, how to correctly block some url access. I would like to block access to URLs like "file:///" on QtWebEngine. I was searching something about WebUrlRequestInterceptor and QWebEngineUrlSchemeHandler but, did I find the right answer?
// main.qml
import QtQuick 2.0
import QtQuick.Window 2.0
import QtWebEngine 1.1
Window {
id: window
width: 800
height: 600
WebEngineView {
id: webView
anchors.fill: parent
url: "file:///"
}
}
// request.cpp
#include <QtCore/QRegExp>
#include "request.h"
WebUrlRequestInterceptor::WebUrlRequestInterceptor(QObject *p)
:QWebEngineUrlRequestInterceptor(p)
{
}
void WebUrlRequestInterceptor::interceptRequest(QWebEngineUrlRequestInfo &info) {
if(!info.requestUrl().toString().contains(QRegExp("(?:https?|ftp)://\\S+")))
info.block(true);
}
// main.cpp
#include <QtGui/QGuiApplication>
#include <QtCore/QCoreApplication>
#include <QtQml/QQmlApplicationEngine>
#include <QtWebEngine/QQuickWebEngineProfile>
#include <QtWebEngine/QtWebEngine>
#include <QtQuick/QQuickWindow>
#include "request.h"
int main(int argc, char **argv) {
QCoreApplication::setAttribute(Qt::AA_EnableHighDpiScaling);
QCoreApplication::setAttribute(Qt::AA_ShareOpenGLContexts);
QGuiApplication app(argc, argv);
WebUrlRequestInterceptor *wuri = new WebUrlRequestInterceptor;
QQuickWebEngineProfile::defaultProfile()->setUrlRequestInterceptor(wuri);
QQmlApplicationEngine engine;
engine.load(QStringLiteral("./main.qml"));
QQuickWindow *window = qobject_cast<QQuickWindow*>(engine.rootObjects().first());
QRect rectangle;
rectangle.setWidth(800);
rectangle.setHeight(600);
window->setGeometry(rectangle);
window->show();
return app.exec();
}
Is it the right way, how I made it? I founded some flags here https://doc.qt.io/qt-5/qwebengineurlscheme.html#Flag-enum like QWebEngineUrlScheme::LocalAccessAllowed, but not sure, if this will help me. Isn't possible to control this list somehow https://admx.help/?Category=Chrome&Policy=Google.Policies.Chrome::URLBlocklist ?
Thank you

How to choose the OpenGL context for QtQuick applications

I am writing an QtQuick application, mainly in QML, but I have some parts that use OpenGL more directly (an OpenSceneGraph scene). For some reasons, I want to use OpenGL version >= 3.3, but Qt only choose a 3.0 implementation. My code is:
main.cpp:
#include <QApplication>
#include <QQmlApplicationEngine>
int main(int argc, char *argv[])
{
// Create the app.
QApplication app(argc, argv);
// Start the UI.
QQmlApplicationEngine engine;
engine.load(QUrl("main.qml"));
return app.exec();
}
main.qml:
import QtQuick 2.7
import QtQuick.Controls 2.2
ApplicationWindow {
id: root
width: 800
height: 600
title: "App"
visible: true
Label {
text: "OpenGL: " + OpenGLInfo.majorVersion + ' ' + OpenGLInfo.minorVersion + OpenGLInfo.profile
}
}
One way of doing it is to set the default QSurfaceFormat before the app.exec().
#include <QSurfaceFormat>
...
QSurfaceFormat surfaceFormat;
surfaceFormat.setMajorVersion(3);
surfaceFormat.setMinorVersion(3);
surfaceFormat.setProfile(QSurfaceFormat::CoreProfile);
QSurfaceFormat::setDefaultFormat(surfaceFormat);

QQuickView window freezes upon mouse resize

I have problem resizing the window using this example. It works, but unpredictable when it becomes unresponsive. Window minimization and maximization works every time, but resizing with the mouse causes weird, frozen behavior. Happens on Windows 10 using Qt 5.12.0. What I do wrong here?
Thanks!
#include <QGuiApplication>
#include <QQuickView>
int main(int argc, char *argv[])
{
QGuiApplication app(argc, argv);
QQuickView view;
view.setSource(QUrl(QStringLiteral("qrc:/main.qml")));
view.show();
return app.exec();
}
And this is the main QML code:
import QtQuick 2.10
Rectangle {
anchors.fill: parent
color: "red"
}
Ok, I have figured out the solution:
anchors.fill: parent should not be used in the root element, but instead we have to tell to the view in C++ the following:
view.setResizeMode(QQuickView::SizeRootObjectToView);

How to use GrabWindow?

I have found a class GrabWindow but I am a noobie in Qt Quick 2 and can't get how to use it.
Can a someone explain how can I use this view?
At this moment I added in my main function:
#include <QGuiApplication>
#include <QQmlApplicationEngine>
#include <QtQml>
#include "grabwindow.h"
int main(int argc, char *argv[]) {
QCoreApplication::setAttribute(Qt::AA_EnableHighDpiScaling);
QGuiApplication app(argc, argv);
qmlRegisterType<GrabWindow>("test", 1, 0, "GrabWindow");
QQmlApplicationEngine engine;
engine.load(QUrl(QStringLiteral("qrc:/qml/SystemTray.qml")));
if (engine.rootObjects().isEmpty()) {
return -1;
}
GrabWindow grabWnd;
grabWnd.setResizeMode(QQuickView::SizeViewToRootObject);
grabWnd.setSource(QUrl(QStringLiteral("qrc:/qml/main.qml")));
grabWnd.setFlags(Qt::Popup);
grabWnd.show();
return app.exec();
}
And my main.qml:
import QtQuick 2.9
import QtQuick.Controls 2.2
ApplicationWindow {
id: window
visible: true
width: 320
height: 480
title: qsTr("test")
}
But on start I get that only:
How to get a screenshot using that class and remove a square at the left top corner of the screen?
ADDED
I use Ubuntu 17.10

Run QtVirtualKeyboard using QQuickWidget

I am trying to make the QtVirtualKeyboard example work with QQuickWidget instead of QQuickView. For QuickView, I use the following main.cpp code, which works fine for me:
#include <QQuickView>
#include <QGuiApplication>
#include <QQmlEngine>
int main(int argc, char *argv[])
{
qputenv("QT_IM_MODULE", QByteArray("qtvirtualkeyboard"));
QGuiApplication app(argc, argv);
QQuickView view(QString("qrc:/%2").arg(MAIN_QML));
view.setResizeMode(QQuickView::SizeRootObjectToView);
view.show();
return app.exec();
}
I run into problems, when changing to QQuickWidgets with the following implementation of main.cpp:
#include <QQuickWidget>
#include <QApplication>
#include <QQmlEngine>
int main(int argc, char *argv[])
{
qputenv("QT_IM_MODULE", QByteArray("qtvirtualkeyboard"));
QApplication app(argc, argv);
QQuickWidget w(QString("qrc:/%2").arg(MAIN_QML));
w.setResizeMode(QQuickWidget::SizeRootObjectToView);
w.show();
return app.exec();
}
When I hit the input fields, the virtual keyboard shows up, but when I start typing at the keyboard, I get the message "input method is not set", which seems to be related to the input method plugin. No chars appear in the input fields.
Any ideas? The QML-code didn't change between the above variants of main.cpp
BTW: I am using Linux, gcc, Qt 5.9.0, EGLFS plugin
Thanks for any suggestions!
Regards,
Patrick
Found the solution for QML looking through inputMethod documentation. Following workaround works for me:
TextArea {
...
onActiveFocusChanged: {
if(activeFocus) {
Qt.inputMethod.update(Qt.ImQueryInput)
}
}
}
Works with other controls as well.
Of course InputPanel should be defined in ApplicationWindow like this:
ApplicationWindow {
...
InputPanel {
id: inputPanel
...
}
}