How to change the build/ window name of application?

himanshu chauhan

I had cloned a drone application's repository in Qtcreator and want to change the application's build or window name located on the top left corner of the window.

ChrisW67

I think you are talking about the title that appears on the application's main window title bar. You change that with QWidget::setWindowTitle(). If you are using Qt Creator or Designer to make the UI then the window title is accessible as a property of the main widget (and will generate code calling setWindowTitle).

himanshu chauhan

If I am trying to write this code following error is coming-

jsulm

@himanshu-chauhan Please post code and error messages as text.
You need to call that meathod on your top level widget. Usually it is a QMainWindow instance.

himanshu chauhan

@jsulm
Ther error is-
C:\Users\hc243\PROJECT_ASSIGNEMENT\Qgroundcontrol\src\main.cc:241: error: C2352: 'QWidget::setWindowTitle': a call of a non-static member function requires an object
D:\QT\5.15.2\msvc2019_64\include\QtWidgets/qwidget.h(365): note: see declaration of 'QWidget::setWindowTitle'

What do mean by "top level widget".

jsulm

@himanshu-chauhan said in How to change the build/ window name of application?:

What do mean by "top level widget".

I mean the widget representing your main window.
Please post the whole content of your main() function then I can tell you what exactly you need to do.

The error message tells you that setWindowTitle() is a non static method, so you need an object on which you call it (basic C++).

himanshu chauhan

@jsulm
this is the whole main.cc file-

#include <QtGlobal>
#include <QApplication>
#include <QIcon>
#include <QSslSocket>
#include <QMessageBox>
#include <QProcessEnvironment>
#include <QHostAddress>
#include <QUdpSocket>
#include <QtPlugin>
#include <QStringListModel>

#include "QGC.h"
#include "QGCApplication.h"
#include "AppMessages.h"
#include "SDL_video.h"

#ifndef NO_SERIAL_LINK
#include "SerialLink.h"
#endif

#ifndef mobile
#include "QGCSerialPortInfo.h"
#include "RunGuard.h"
#ifndef NO_SERIAL_LINK
#include <QSerialPort>
#endif
#endif

#ifdef UNITTEST_BUILD
#include "UnitTest.h"
#endif

#ifdef QT_DEBUG
#include "CmdLineOptParser.h"
#ifdef Q_OS_WIN
#include <crtdbg.h>
#endif
#endif

#ifdef QGC_ENABLE_BLUETOOTH
#include <QtBluetooth/QBluetoothSocket>
#endif

#include <iostream>
#include "QGCMapEngine.h"

/* SDL does ugly things to main() */
#ifdef main
#undef main
#endif

#ifndef mobile
#ifndef NO_SERIAL_LINK
Q_DECLARE_METATYPE(QGCSerialPortInfo)
#endif
#endif

#ifdef Q_OS_WIN

#include <windows.h>
/// @brief CRT Report Hook installed using _CrtSetReportHook. We install this hook when
/// we don't want asserts to pop a dialog on windows.
int WindowsCrtReportHook(int reportType, char* message, int* returnValue)
{
Q_UNUSED(reportType);

std::cerr << message << std::endl;  // Output message to stderr
*returnValue = 0;                   // Don't break into debugger
return true;                        // We handled this fully ourselves

}

#endif

#if defined(android)
#include <jni.h>
#include "JoystickAndroid.h"
#if defined(QGC_ENABLE_PAIRING)
#include "PairingManager.h"
#endif
#if !defined(NO_SERIAL_LINK)
#include "qserialport.h"
#endif

static jobject _class_loader = nullptr;
static jobject _context = nullptr;

//-----------------------------------------------------------------------------
extern "C" {
void gst_amc_jni_set_java_vm(JavaVM *java_vm);

jobject gst_android_get_application_class_loader(void)
{
    return _class_loader;
}

}

//-----------------------------------------------------------------------------
static void
gst_android_init(JNIEnv* env, jobject context)
{
jobject class_loader = nullptr;

jclass context_cls = env->GetObjectClass(context);
if (!context_cls) {
    return;
}

jmethodID get_class_loader_id = env->GetMethodID(context_cls, "getClassLoader", "()Ljava/lang/ClassLoader;");
if (env->ExceptionCheck()) {
    env->ExceptionDescribe();
    env->ExceptionClear();
    return;
}

class_loader = env->CallObjectMethod(context, get_class_loader_id);
if (env->ExceptionCheck()) {
    env->ExceptionDescribe();
    env->ExceptionClear();
    return;
}

_context = env->NewGlobalRef(context);
_class_loader = env->NewGlobalRef (class_loader);

}

//-----------------------------------------------------------------------------
static const char kJniClassName[] {"org/mavlink/qgroundcontrol/QGCActivity"};

void setNativeMethods(void)
{
JNINativeMethod javaMethods[] {
{"nativeInit", "()V", reinterpret_cast<void *>(gst_android_init)}
};

QAndroidJniEnvironment jniEnv;
if (jniEnv->ExceptionCheck()) {
    jniEnv->ExceptionDescribe();
    jniEnv->ExceptionClear();
}

jclass objectClass = jniEnv->FindClass(kJniClassName);
if(!objectClass) {
    qWarning() << "Couldn't find class:" << kJniClassName;
    return;
}

jint val = jniEnv->RegisterNatives(objectClass, javaMethods, sizeof(javaMethods) / sizeof(javaMethods[0]));

if (val < 0) {
    qWarning() << "Error registering methods: " << val;
} else {
    qDebug() << "Main Native Functions Registered";
}

if (jniEnv->ExceptionCheck()) {
    jniEnv->ExceptionDescribe();
    jniEnv->ExceptionClear();
}

}

//-----------------------------------------------------------------------------
jint JNI_OnLoad(JavaVM* vm, void* reserved)
{
Q_UNUSED(reserved);

JNIEnv* env;
if (vm->GetEnv(reinterpret_cast<void**>(&env), JNI_VERSION_1_6) != JNI_OK) {
    return -1;
}

setNativeMethods();

#if defined(QGC_GST_STREAMING)
// Tell the androidmedia plugin about the Java VM
gst_amc_jni_set_java_vm(vm);
#endif

#if !defined(NO_SERIAL_LINK)
QSerialPort::setNativeMethods();
#endif

JoystickAndroid::setNativeMethods();

#if defined(QGC_ENABLE_PAIRING)
PairingManager::setNativeMethods();
#endif

return JNI_VERSION_1_6;

}
#endif

//-----------------------------------------------------------------------------
#ifdef android
#include <QtAndroid>
bool checkAndroidWritePermission() {
QtAndroid::PermissionResult r = QtAndroid::checkPermission("android.permission.WRITE_EXTERNAL_STORAGE");
if(r == QtAndroid::PermissionResult::Denied) {
QtAndroid::requestPermissionsSync( QStringList() << "android.permission.WRITE_EXTERNAL_STORAGE" );
r = QtAndroid::checkPermission("android.permission.WRITE_EXTERNAL_STORAGE");
if(r == QtAndroid::PermissionResult::Denied) {
return false;
}
}
return true;
}
#endif

// To shut down QGC on Ctrl+C on Linux
#ifdef Q_OS_LINUX
#include <csignal>

void sigHandler(int s)
{
std::signal(s, SIG_DFL);
QApplication::instance()->quit();
}

#endif /* Q_OS_LINUX */

//-----------------------------------------------------------------------------
/**
@brief Starts the application

@param argc Number of commandline arguments
@param argv Commandline arguments
@return exit code, 0 for normal exit and !=0 for error cases
*/

int main(int argc, char *argv[])
{
QWidget::setWindowTitle("Title1");
#ifndef mobile
// We make the runguard key different for custom and non custom
// builds, so they can be executed together in the same device.
// Stable and Daily have same QGC_APPLICATION_NAME so they would
// not be able to run at the same time
QString runguardString(QGC_APPLICATION_NAME);
runguardString.append("RunGuardKey");

RunGuard guard(runguardString);
if (!guard.tryToRun()) {
    // QApplication is necessary to use QMessageBox
    QApplication errorApp(argc, argv);
    QMessageBox::critical(nullptr, QObject::tr("Error"),
        QObject::tr("A second instance of %1 is already running. Please close the other instance and try again.").arg(QGC_APPLICATION_NAME)
    );
    return -1;
}

#endif

//-- Record boot time
QGC::initTimer();

#ifdef Q_OS_UNIX
//Force writing to the console on UNIX/BSD devices
if (!qEnvironmentVariableIsSet("QT_LOGGING_TO_CONSOLE"))
qputenv("QT_LOGGING_TO_CONSOLE", "1");
#endif

// install the message handler
AppMessages::installHandler();

#ifdef Q_OS_MAC
#ifndef ios
// Prevent Apple's app nap from screwing us over
// tip: the domain can be cross-checked on the command line with <defaults domains>
QProcess::execute("defaults", {"write org.qgroundcontrol.qgroundcontrol NSAppSleepDisabled -bool YES"});
#endif
#endif

#ifdef Q_OS_WIN
// Set our own OpenGL buglist
qputenv("QT_OPENGL_BUGLIST", ":/opengl/resources/opengl/buglist.json");

// Allow for command line override of renderer
for (int i = 0; i < argc; i++) {
    const QString arg(argv[i]);
    if (arg == QStringLiteral("-angle")) {
        QCoreApplication::setAttribute(Qt::AA_UseOpenGLES);
        break;
    } else if (arg == QStringLiteral("-swrast")) {
        QCoreApplication::setAttribute(Qt::AA_UseSoftwareOpenGL);
        break;
    }
}

#endif

#ifdef Q_OS_LINUX
std::signal(SIGINT, sigHandler);
std::signal(SIGTERM, sigHandler);
#endif /* Q_OS_LINUX */

// The following calls to qRegisterMetaType are done to silence debug output which warns
// that we use these types in signals, and without calling qRegisterMetaType we can't queue
// these signals. In general we don't queue these signals, but we do what the warning says
// anyway to silence the debug output.

#ifndef NO_SERIAL_LINK
qRegisterMetaTypeQSerialPort::SerialPortError();
#endif
#ifdef QGC_ENABLE_BLUETOOTH
qRegisterMetaTypeQBluetoothSocket::SocketError();
qRegisterMetaType<QBluetoothServiceInfo>();
#endif
qRegisterMetaTypeQAbstractSocket::SocketError();
#ifndef mobile
#ifndef NO_SERIAL_LINK
qRegisterMetaType<QGCSerialPortInfo>();
#endif
#endif

qRegisterMetaType<Vehicle::MavCmdResultFailureCode_t>("Vehicle::MavCmdResultFailureCode_t");

// We statically link our own QtLocation plugin

#ifdef Q_OS_WIN
// In Windows, the compiler doesn't see the use of the class created by Q_IMPORT_PLUGIN
#pragma warning( disable : 4930 4101 )
#endif

Q_IMPORT_PLUGIN(QGeoServiceProviderFactoryQGC)

bool runUnitTests = false;          // Run unit tests

#ifdef QT_DEBUG
// We parse a small set of command line options here prior to QGCApplication in order to handle the ones
// which need to be handled before a QApplication object is started.

bool stressUnitTests = false;       // Stress test unit tests
bool quietWindowsAsserts = false;   // Don't let asserts pop dialog boxes

QString unitTestOptions;
CmdLineOpt_t rgCmdLineOptions[] = {
    { "--unittest",             &runUnitTests,          &unitTestOptions },
    { "--unittest-stress",      &stressUnitTests,       &unitTestOptions },
    { "--no-windows-assert-ui", &quietWindowsAsserts,   nullptr },
    // Add additional command line option flags here
};

ParseCmdLineOptions(argc, argv, rgCmdLineOptions, sizeof(rgCmdLineOptions)/sizeof(rgCmdLineOptions[0]), false);
if (stressUnitTests) {
    runUnitTests = true;
}

if (quietWindowsAsserts) {

#ifdef Q_OS_WIN
_CrtSetReportHook(WindowsCrtReportHook);
#endif
}

#ifdef Q_OS_WIN
if (runUnitTests) {
// Don't pop up Windows Error Reporting dialog when app crashes. This prevents TeamCity from
// hanging.
DWORD dwMode = SetErrorMode(SEM_NOGPFAULTERRORBOX);
SetErrorMode(dwMode | SEM_NOGPFAULTERRORBOX);
}
#endif
#endif // QT_DEBUG

QCoreApplication::setAttribute(Qt::AA_UseHighDpiPixmaps);
QGCApplication* app = new QGCApplication(argc, argv, runUnitTests);
Q_CHECK_PTR(app);
if(app->isErrorState()) {
    app->exec();
    return -1;
}

#ifdef Q_OS_LINUX
QApplication::setWindowIcon(QIcon(":/res/resources/icons/qgroundcontrol.ico"));
#endif /* Q_OS_LINUX */

// There appears to be a threading issue in qRegisterMetaType which can cause it to throw a qWarning
// about duplicate type converters. This is caused by a race condition in the Qt code. Still working
// with them on tracking down the bug. For now we register the type which is giving us problems here
// while we only have the main thread. That should prevent it from hitting the race condition later
// on in the code.
qRegisterMetaType<QList<QPair<QByteArray,QByteArray> > >();

app->_initCommon();
//-- Initialize Cache System
getQGCMapEngine()->init();

int exitCode = 0;

#ifdef UNITTEST_BUILD
if (runUnitTests) {
for (int i=0; i < (stressUnitTests ? 20 : 1); i++) {
if (!app->_initForUnitTests()) {
return -1;
}

        // Run the test
        int failures = UnitTest::run(unitTestOptions);
        if (failures == 0) {
            qDebug() << "ALL TESTS PASSED";
            exitCode = 0;
        } else {
            qDebug() << failures << " TESTS FAILED!";
            exitCode = -failures;
            break;
        }
    }
} else

#endif
{

#ifdef android
checkAndroidWritePermission();
#endif
if (!app->_initForNormalAppBoot()) {
return -1;
}
exitCode = app->exec();
}

app->_shutdown();
delete app;
//-- Shutdown Cache System
destroyMapEngine();

qDebug() << "After app delete";

return exitCode;

}

jsulm

This is a lot of code and I can't see where you're creating any windows?
Does QGCApplication create the window?
Does your application have a QMainWindow instance?

himanshu chauhan

I am new to the platform so I can't really say where the window is been created but it seems that QGCApplication is doing that work. I found following code in it-

bool QGCApplication::_initForNormalAppBoot()
{
QSettings settings;

_qmlAppEngine = toolbox()->corePlugin()->createQmlApplicationEngine(this);
toolbox()->corePlugin()->createRootWindow(_qmlAppEngine);

// Image provider for PX4 Flow
QQuickImageProvider* pImgProvider = dynamic_cast<QQuickImageProvider*>(qgcApp()->toolbox()->imageProvider());
_qmlAppEngine->addImageProvider(QStringLiteral("QGCImages"), pImgProvider);

QQuickWindow* rootWindow = qgcApp()->mainRootWindow();

if (rootWindow) {
    rootWindow->scheduleRenderJob (new FinishVideoInitialization (toolbox()->videoManager()),
            QQuickWindow::BeforeSynchronizingStage);
}

}

jsulm

@himanshu-chauhan

QQuickWindow* rootWindow = qgcApp()->mainRootWindow();

if (rootWindow) {
    rootWindow->setTitle("YOUR TITLE HERE");

See https://doc.qt.io/qt-6/qwindow.html#title-prop

himanshu chauhan

Thank you very much, it is working now.

DevJhones

I have a similar problem, I wanted to change the name when installing and installing, I have an idea how to change this, I thought it was in the "Deploy" folder but I had no result

DevJhones

I managed to change it, it's inside the "qgroundcontrol.pro" file. This is for anyone who wants to change the name of the desktop application