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I'm trying to create a hybrid QML/C++ application, where the logic
is written in C++ and the interface is QML/Sailfish Silica based.<br>
<br>
I'm currently playing around with the different ways to let QML/C++
communicate with each other. I currently have this code:<br>
<br>
<code><br>
#include <QApplication><br>
#include <QGraphicsObject><br>
#include <QDir><br>
#include <QDeclarativeView><br>
#include <QDeclarativeContext><br>
#include <QDeclarativeEngine><br>
#include <QDeclarativeComponent><br>
#include <QDebug><br>
#include <QDeclarativePropertyMap><br>
<br>
#ifdef HAS_BOOSTER<br>
#include <MDeclarativeCache><br>
#endif<br>
<br>
Q_DECL_EXPORT int main(int argc, char *argv[])<br>
{<br>
#ifdef HAS_BOOSTER<br>
QScopedPointer<QApplication>
myapp(MDeclarativeCache::qApplication(argc, argv));<br>
#else<br>
QScopedPointer<QApplication> myapp = new
QApplication(argc, argv);<br>
#endif<br>
<br>
<br>
#ifdef HAS_BOOSTER<br>
QScopedPointer<QDeclarativeView>
appview(MDeclarativeCache::qDeclarativeView());<br>
#else<br>
QScopedPointer<QDeclarativeView>(new
QDeclarativeView);<br>
#endif<br>
<br>
QDeclarativePropertyMap binding_map;<br>
binding_map.insert("question_txt", QVariant(QString("5 * 5
=")));<br>
binding_map.insert("color", QVariant(QString("dark red")));<br>
QScopedPointer<QDeclarativeContext>
binding_context(appview->rootContext());<br>
binding_context->setContextProperty("binding_map",
&binding_map);<br>
QString file = "main.qml";<br>
QString path = QString(DEPLOYMENT_PATH);<br>
appview->setSource(QUrl::fromLocalFile(path + file));<br>
appview->setResizeMode(QDeclarativeView::SizeRootObjectToView);<br>
appview->setAttribute(Qt::WA_OpaquePaintEvent);<br>
appview->setAttribute(Qt::WA_NoSystemBackground);<br>
appview->viewport()->setAttribute(Qt::WA_OpaquePaintEvent);<br>
appview->viewport()->setAttribute(Qt::WA_NoSystemBackground);<br>
appview->showFullScreen();<br>
binding_map["question_txt"] = QVariant(QString("overwritten 5 *
5 ="));<br>
return myapp->exec();<br>
}<br>
</code><br>
I need to let C++ print text in the QML interface (the question) and
C++ has to obtain the<br>
answer the user has answered in the QML interface (TextField Silica
component). That's basically<br>
the needed communication between C++ and QML.<br>
<br>
So I thought that I'd create a QDeclarativePropertyMap in C++. This
propertymap will contain the question.<br>
My program has a while loop that asks the user new questions each
time the loop runs(the logic code can be found <a
href="https://bitbucket.org/Superpelican/clamshell_cli">here</a>,
<br>
but it hasn't been adjusted for use with a GUI, it's currently a CLI
application). So I need to constantly update the QML UI from C++<br>
while the programs running, after I've setup the QDeclarativeView
etc.<br>
<br>
However I noticed that if you change a value in the propertymap
after initializing and showing the QDeclarativeView, the UI won't be
updated!<br>
I thought the QDeclarativePropertyMap was dynamic! <a
href="http://qt-project.org/doc/qt-4.8/qdeclarativepropertymap.html#details">http://qt-project.org/doc/qt-4.8/qdeclarativepropertymap.html#details</a>:
"The binding is dynamic - whenever a key's value is updated,
anything bound to that key will be updated as well."<br>
<br>
Kind Regards,<br>
<br>
Superpelican<br>
<br>
<br>
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