i have flash player running on QWebkit , and on the flash player there are some web links
that needs to be open in external browser , what i did is :
m_webView->page()->setLinkDelegationPolicy(QWebPage::LinkDelegationPolicy::DelegateAllLinks);
connect(m_webView->page(),SIGNAL(linkClicked(const QUrl&)),
this,
SLOT(linkClickedHandler(const QUrl&)),Qt::DirectConnection);
void WebBroswerDeleget::linkClickedHandler(const QUrl& url)
{
QDesktopServices::openUrl(QUrl(url.toString(), QUrl::TolerantMode));
}
but its never triggered even of i change in the connect from m_webView->page() to m_webView
i overrided the QWebview::createWindow like this:
QWebView* MyAdWebview::createWindow (QWebPage::WebWindowType type)
{
QWebView* p = new QWebView(0);
connect(p->page()->networkAccessManager(), SIGNAL(finished(QNetworkReply*)), this, SLOT(newWindowLoadFinished(QNetworkReply*)), Qt::UniqueConnection);
return p;
}
void MyAdWebview::newWindowLoadFinished(QNetworkReply* reply) {
QDesktopServices::openUrl(reply->url().toString());
}
QDesktopServices::openUrl is a cutom function which opens the default system browser with this url
This is working for me on both 4.7.2 QtEmbedded and 4.8.1 on mac. What I don't understand is this:
m_webView->page()->setLinkDelegationPolicy(QWebPage::LinkDelegationPolicy::DelegateAllLinks);
Just do:
m_webView->page()->setLinkDelegationPolicy(QWebPage::DelegateAllLinks);
Something like this works for me:
#include <QWebPage>
#include <QWebView>
#include <QApplication>
#include "sigrec.h"
int main(int argc, char** argv)
{
QApplication a(argc, argv);
SigRec rec;
QWebView view;
view.page()->setLinkDelegationPolicy(QWebPage::DelegateAllLinks);
QObject::connect(view.page(), SIGNAL(linkClicked(const QUrl&)), &rec, SLOT(onLinkClicked(const QUrl&)),
Qt::DirectConnection);
view.show();
view.setUrl(QUrl("http://www.google.com"));
return a.exec();
}
Where SigRec is something like this:
#ifndef SIGREC_H
#define SIGREC_H
#include <QObject>
#include <QUrl>
class SigRec : public QObject
{
Q_OBJECT
public:
explicit SigRec(QObject *parent = 0);
public slots:
void onLinkClicked(const QUrl &url);
};
#endif // SIGREC_H
Related
I'm running QT 5.10.1 on Windows, the app is only made in QML. I'm trying to use the new retranslate() to change language during runtime. The current code is working fine with texts that use the getEmptyString() appended to it. But the rest of the text within qsTr() does not. TranslationHandler.cpp is empty and I haven't cleaned up the includes.
So I'm able to set a language from the QML using the context property. Also I checked so the engine is the same instance. Any ideas why the retranslate function is not working?
Thanks for the help!
main.cpp :
#include <QGuiApplication>
#include <QQmlApplicationEngine>
#include <QTranslator>
#include <QtGui>
#include <QQmlContext>
#include <QDebug>
#include <QQmlEngine>
#include "translationhandler.h"
int main(int argc, char *argv[])
{
QCoreApplication::setAttribute(Qt::AA_EnableHighDpiScaling);
QGuiApplication app(argc, argv);
QQmlApplicationEngine engine;
TranslationHandler transHndl(&engine);
engine.rootContext()->setContextProperty("translateHandler", &transHndl);
engine.load(QUrl(QStringLiteral("qrc:/main.qml")));
if (engine.rootObjects().isEmpty())
return -1;
return app.exec();
}
TranslationHandler.h :
#ifndef TRANSLATIONHANDLER_H
#define TRANSLATIONHANDLER_H
#include <QTranslator>
#include <QString>
#include <QGuiApplication>
#include <QObject>
#include <QDebug>
#include <QQmlEngine>
class TranslationHandler : public QObject
{
Q_OBJECT
Q_PROPERTY(QString emptyString READ getEmptyString NOTIFY languageChanged)
public:
explicit TranslationHandler(QQmlEngine *engine)
{
m_translator1 = new QTranslator(this);
m_currentLanguage = "en";
m_engine = engine;
}
QString getEmptyString()
{
return "";
}
Q_INVOKABLE QString getCurrentLanguage()
{
return m_currentLanguage;
}
Q_INVOKABLE void selectLanguage(QString language)
{
if(language == QString("jp"))
{
m_currentLanguage = language;
m_translator1->load(":/translation/qml_jp.qm");
qGuiApp->installTranslator(m_translator1);
m_engine->retranslate();
}
if(language == QString("en"))
{
m_currentLanguage = language;
qGuiApp->removeTranslator(m_translator1);
m_engine->retranslate();
}
emit languageChanged();
}
signals:
void languageChanged();
private:
QTranslator *m_translator1;
QString m_currentLanguage;
QQmlEngine *m_engine;
public slots:
};
#endif // TRANSLATIONHANDLER_H
This was confirmed as a bug and will be fixed in version 5.12. If you want to compile it yourself please check the bug report
https://bugreports.qt.io/browse/QTBUG-68350
I have the following Qt code that loads a local html file and prints it using the installed PDFCreator. When printing to PDFCreator the text is cut off at the right and only printed on the first page. Subsequent pages are without text just filled with the background color.
When using QPrinter::PdfFormat as output Format and setting a file path a PDF file is successfully generated and the content is showing correctly. I'm using Qt 5.4.
Do I need to set special parameters for the printer or is this still a Qt bug (there was one reported for Qt 5.0).
#include <QApplication>
#include <QWebPage>
#include <QWebFrame>
#include <QTimer>
#include <QFileInfo>
#include <QPrinter>
class Task : public QObject {
Q_OBJECT
public:
Task(QObject *parent = 0) : QObject(parent) {}
public slots:
void run()
{
QFileInfo fileInfo("test.html");
QUrl url = QUrl::fromLocalFile(fileInfo.absoluteFilePath());
connect(&page, SIGNAL(loadFinished(bool)), this, SLOT(print()));
page.mainFrame()->load(url);
}
void print()
{
QPrinter printer;
printer.setPrinterName("PDFCreator");
printer.setPaperSize(QPrinter::A4);
#ifdef PRINT_TO_PDF
printer.setOutputFormat(QPrinter::PdfFormat);
printer.setOutputFileName("output.pdf");
#endif
page.mainFrame()->print(&printer);
emit finished();
}
signals:
void finished();
private:
QWebPage page;
};
#include "main.moc"
int main(int argc, char *argv[])
{
QApplication app(argc, argv);
// Task parented to the application so that it
// will be deleted by the application.
Task *task = new Task(&app);
// This will cause the application to exit when
// the task signals finished.
QObject::connect(task, SIGNAL(finished()), &app, SLOT(quit()));
// This will run the task from the application event loop.
QTimer::singleShot(0, task, SLOT(run()));
return app.exec();
}
i read other questions about the same issue but wasn't able to solve mine. When i run my code, the program starts, send QObject::connect: No such slot mywindow::changerLargeur(int) and then fails.
thanks you for your help
h file
#ifndef MYWINDOW_H
#define MYWINDOW_H
#include <QWidget>
#include <QSlider>
#include <QLCDNumber>
class mywindow : public QWidget
{
Q_OBJECT
public:
mywindow();
public slots:
void changerlargeur(int largeur);
private:
QSlider *glisseur;
QLCDNumber *afficheur;
};
#endif // MYWINDOW_H
cpp file
#include "mywindow.h"
mywindow::mywindow(): QWidget()
{
setFixedSize(200, 100);
glisseur = new QSlider(Qt::Horizontal,this);
glisseur->setRange(100,900);
glisseur->setGeometry(10, 60, 150, 20);
QObject::connect(glisseur, SIGNAL(valueChanged(int)), this, SLOT(changerLargeur(int)));
QObject::connect(glisseur, SIGNAL(valueChanged(int)), afficheur, SLOT(display(int)));
afficheur = new QLCDNumber(this);
afficheur->setSegmentStyle(QLCDNumber::Flat);
}
void mywindow::changerlargeur(intlargeur)
{
setFixedSize(largeur, 100);
}
main file
#include <QApplication>
#include "mywindow.h"
int main(int argc, char *argv[])
{
QApplication app(argc, argv);
mywindow fenetrep;
fenetrep.show();
return app.exec();
}
Like most other things in C++, Qt's signals and slots are case sensitive. So this won't work:
void changerlargeur(int largeur);
vs.
SLOT(changerLargeur(int))
You need to decide whether you want the L to be upper or lower case and stick with it.
Another issue is this:
QObject::connect(glisseur, SIGNAL(valueChanged(int)), afficheur, SLOT(display(int)));
afficheur = new QLCDNumber(this);
You can't connect to a slot on an object that doesn't exist yet.
I am trying to program an App that fetches files from a server.
I have a 'Window' class(mainwindow.cpp, which is a widget class that would be the UI) and then I have a 'Backend' class(Backend.cpp).
The GUI has a push button and two radio buttons. If the radio button "remote" is seleted, then upon clicking the push button will lead to fetching files from server.
However, there is some problem in the 'connect' call in Backend.cpp which I can't figure out. The error I get is: no matching function call to 'QObject::connect(QNetworkReply*&), const char[13], Backend* const, const char[20])'
Here are the codes:
ANSWER: Avoid circular inclusions!!!!
Here are the updated codes:
mainwindow.h
#ifndef WINDOW_H
#define WINDOW_H
#include <QWidget>
#include <QRadioButton>
#include <QtNetwork/QTcpSocket>
#include <QtNetwork/QHostAddress>
#include <QFile>
#include <QUrl>
#include "Backend.h"
class QGroupBox;
class Window : public QWidget
{
Q_OBJECT
public:
Window(QWidget *parent = 0);
QTcpSocket *conn;
QFile *file;
QUrl url;
Backend backend_inst;
private:
QRadioButton *button_local;
QRadioButton *button_remote;
QGroupBox *createPushButtonGroup();
private slots:
void onClick_button1();
void onCheck_local();
void onCheck_remote();
};
#endif
mainwindow.c
#include <QtGui>
#include "mainwindow.h"
Window::Window(QWidget *parent)
: QWidget(parent)
{
QGridLayout *grid = new QGridLayout;
grid->addWidget(createPushButtonGroup(), 1, 1);
setLayout(grid);
setWindowTitle(tr("File-Fetch App"));
resize(480, 420);
}
QGroupBox *Window::createPushButtonGroup()
{
QGroupBox *groupBox = new QGroupBox();
QPushButton *pushButton1 = new QPushButton(tr("Fetch Files!!"));
button_local = new QRadioButton(tr("&Download Files from Local Storage"));
button_remote = new QRadioButton(tr("&Download Files from a Web-Server"));
button_local->setChecked(1);
connect(pushButton1,SIGNAL(clicked()), this, SLOT(onClick_button1()));
QVBoxLayout *vbox = new QVBoxLayout;
vbox->addWidget(pushButton1);
vbox->addSpacing(50);
vbox->addWidget(button_local);
vbox->addWidget(button_remote);
vbox->addStretch(1);
groupBox->setLayout(vbox);
return groupBox;
}
void Window::onClick_button1()
{
QTextStream out(stdout);
out << "fetch button clicked\n";
if (button_local->isChecked()){
onCheck_local();
}
else if (button_remote->isChecked()){
onCheck_remote();
}
}
void Window::onCheck_local()
{
QTextStream out(stdout);
out << "local update button checked\n";
}
void Window::onCheck_remote()
{
QTextStream out(stdout);
out << "remote update button checked\n";
QString pathname= "http://192.168.1.1:8000/example.txt";
QUrl webaddr = pathname;
backend_inst.FetchFile(webaddr);
}
Backend.h
#ifndef BACKEND_H
#define BACKEND_H
#include <QObject>
#include <QNetworkReply>
#include <QNetworkAccessManager>
#include <QUrl>
#include <QTextStream>
class Backend : public QObject
{
Q_OBJECT
public:
Backend(QObject* parent=0);
void FetchFile(QUrl fpath);
public slots:
void getBytesFromFile();
private:
QNetworkReply *reply;
QNetworkAccessManager qnam;
};
#endif // BACKEND_H
Backend.cpp
#include "Backend.h"
Backend::Backend(QObject* parent)
: QObject(parent)
{
}
void Backend::FetchFile(QUrl fpath)
{
reply = qnam.get(QNetworkRequest(fpath));
QObject::connect(reply, SIGNAL(readyRead()),this, SLOT(getBytesFromFile()));
//qnam = new QNetworkAccessManager;
//QObject::connect(&qnam, SIGNAL(finished(QNetworkReply*)), this, SLOT(getBytesFromFile()));
}
void Backend::getBytesFromFile(){
QByteArray downloadedData;
QTextStream out(stdout);
out << "we are loading data from URL\n";
downloadedData =reply->readAll();
out << downloadedData;
delete reply;
}
main.cpp
#include <QApplication>
#include "mainwindow.h"
int main(int argc, char *argv[])
{
QApplication app(argc, argv);
Window window;
window.show();
return app.exec();
}
To use signals and slots, your classes (both signaling and slotting) must derive from QObject, i.e.
#include "mainwindow.h"
#include <QObject>
class Backend : public QObject
{
Q_OBJECT
public:
Backend(QObject* parent=0);
[...]
Backend::Backend(QObject* parent)
: QObject(parent)
{
}
You posted this:
class Backend
{
// Q_OBJECT
public:
Backend();
void FetchFile(QUrl fpath);
public slots:
void getBytesFromFile();
private:
QNetworkReply *reply;
QNetworkAccessManager qnam;
};
Q_OBJECT is still commented if yes remove it.. you are using signal and slots..
EDIT :
try to avoid circular inclusion:
you included Backend in mainwindow and viceversa..
The commented out lines:
qnam = new QNetworkAccessManager;
QObject::connect(&qnam, SIGNAL(finished(QNetworkReply*)), this, SLOT(getBytesFromFile()));
Were what's causing your issue. Connect excepts a pointer, not a pointer-to-pointer. qnam is a pointer was a pointer in the previous version of the code and using the address-of operator on it would turn it into a pointer-to-pointer. Second mistake is that you need to have the same signature for your signal and slot in order to get it called (otherwise you get a runtime error). So, correctly:
connect(qnam, SIGNAL(finished(QNetworkReply*)), this, SLOT(getBytesFromFile(QNetworkReply*)));
(and obviously, change the actual signature of the getBytesFromFile method).
As to why your error persists despite commenting the code out: I think you are running an old build and the new one is failing to build due to the vtable issue (as you described in the comment thread). My guess is that qmake is glitching out, which I have experienced when adding the Q_OBJECT macro to already existing classes. Go to your build folders and delete Makefile* everywhere. Then go back to Qt creator and rebuild the project, that should force qmake to generate the Makefiles again.
It seems you have some problems with build mechanism. With posted code and un-commented
QObject::connect(&qnam, SIGNAL(finished(QNetworkReply*)), this, SLOT(getBytesFromFile())); in Backend::FetchFile function, all your code works. Running and with checked "Download Files from Web-Server" it prints the "we are loading data from URL" from getBytesFromFile - isn't this the slot you want to be called ?
I'm trying to write an application using QNetworkManager. I have simplified the code down to the problem. The following code hangs, and I have no idea why:
main.cpp:
#include <QApplication>
#include "post.h"
int main(int argc, char *argv[]) {
QApplication app(argc, argv);
post("http://google.com/search", "q=test");
return app.exec();
}
post.h:
#ifndef _H_POST
#define _H_POST
#include <QNetworkAccessManager>
#include <QNetworkRequest>
class post : public QObject {
Q_OBJECT
public:
post(QString URL, QString data);
public slots:
void postFinished(QNetworkReply* reply);
protected:
QNetworkAccessManager *connection;
};
#endif
post.cpp:
#include <QApplication>
#include <QUrl>
#include "post.h"
post::post(QString URL, QString data) {
connection = new QNetworkAccessManager(this);
connect(connection, SIGNAL(finished(QNetworkReply*)), this, SLOT(postFinished(QNetworkReply*)));
connection->post(QNetworkRequest(QUrl(URL)), data.toAscii());
}
void post::postFinished(QNetworkReply*) {
qApp->exit(0);
}
Some Googling shows it may be because I have everything on one thread, but I have no idea how to change that in Qt... none of the network examples show this.
I just tried it with the same results. The problem is that you are creating the post object by only calling the constructor. Since you are not specifying an object it is getting destroyed right away (to check this create a destructor and see when it gets called.)
try:
post p("http://google.com/search","q=test");
Then your slot gets called.