[SOLVED] How to create WebView in QML from C++ code?

shav

Hi guys!

I have a question with QtWebKit. I want to create a WebView element in side my QML file using C++ plugin. As I known fro now in Qt 5.0.0 exist QGraphicsWebView class. But When I try use it to add in QML contents I have crash on call methods load(QUrl()). The code look like this:

@#include <QtGui/QGuiApplication>
#include "qtquick2applicationviewer.h"
#include <QtWebKit/QtWebKit>
#include <QtWebKitWidgets/QtWebKitWidgets>
#include <QDebug>

int main(int argc, char *argv[])
{
QGuiApplication app(argc, argv);

QtQuick2ApplicationViewer viewer;
viewer.setMainQmlFile&#40;QStringLiteral("qml/AppsnackSDKTest/main.qml"&#41;&#41;;
viewer.showExpanded();

QQuickItem* wnd = (QQuickItem*)qApp->allWindows().last();
QGraphicsWebView* view = new QGraphicsWebView();
view->setProperty("width", QVariant(300));
view->setProperty("height", QVariant(200));
view->setProperty("id", QVariant("webViewTemp"));
view->setProperty("objectName", QVariant("webViewTemp"));
view->setProperty("color", QVariant(QColor("red")));
//wnd->parentItem()->childItems().last()->childItems().append((QQuickItem*)view); <-- Try to add a element to QML elements tree
QQuickItem* rootItem = wnd->parentItem()->childItems().last();
QQuickView* rootComponent = (QQuickView*)rootItem;
if(rootComponent != NULL)
{
    rootComponent->rootContext()->setContextProperty("webViewTmp", view); //<-- crash here.
}
else
{
    qDebug()<<"ERROR: object not created: "<<rootComponent;
}

return app.exec&#40;&#41;;

}
@

What I do wrong? Thanks for any help!

Also I try this code:
@#include <QtGui/QGuiApplication>
#include "qtquick2applicationviewer.h"
#include <QtWebKit/QtWebKit>
#include <QtWebKitWidgets/QtWebKitWidgets>
#include <QDebug>

int main(int argc, char *argv[])
{
QGuiApplication app(argc, argv);

QtQuick2ApplicationViewer viewer;
viewer.setMainQmlFile&#40;QStringLiteral("qml/AppsnackSDKTest/main.qml"&#41;&#41;;
viewer.showExpanded();

//QQuickItem* wnd = (QQuickItem*)qApp->allWindows().last();
QGraphicsWebView* view = new QGraphicsWebView();
view->setProperty("width", QVariant(300));
view->setProperty("height", QVariant(200));
view->setProperty("id", QVariant("webViewTemp"));
view->setProperty("objectName", QVariant("webViewTemp"));
view->setProperty("color", QVariant(QColor("red")));
view->load(QUrl("http://appsnack.com"));
viewer.rootContext()->setContextProperty("webViewTmp", view);

return app.exec&#40;&#41;;

}
@

sierdzio

QGraphicsWebView is QtWidget-based. You cannot use QWidget children in QML2 QWindows.

Also, in order for a componen created in c++ be visible in QML, you need to properly reparent it.

shav

[quote author="sierdzio" date="1356529337"]QGraphicsWebView is QtWidget-based. You cannot use QWidget children in QML2 QWindows.

Also, in order for a componen created in c++ be visible in QML, you need to properly reparent it.[/quote]

Thanks for the quickly reply. How I can create QML WebView in C++ code? Or it's impossible for now? Where I can find some examples for it? In documentation I can't find any information about it. Thanks!

sierdzio

I have only tried it with custom files, not built-in ones, but here you go:
@
myComp = new QQmlComponent(engine, parent);
myComp->setData("import Whatever 1.0"
"WebView { height: 500; width: 500 //etc. }");
if (myComp->isReady()) {
QObject *obj = myComp->create();
obj->setProperty("parent", QVariant::fromValue(parent));
}
@

Brain-to-terminal, not tested. In my code, I don't use ::setData(), so I'm not sure it would work.

shav

[quote author="sierdzio" date="1356531410"]I have only tried it with custom files, not built-in ones, but here you go:
@
myComp = new QQmlComponent(engine, parent);
myComp->setData("import Whatever 1.0"
"WebView { height: 500; width: 500 //etc. }");
if (myComp->isReady()) {
QObject *obj = myComp->create();
obj->setProperty("parent", QVariant::fromValue(parent));
}
@

Brain-to-terminal, not tested. In my code, I don't use ::setData(), so I'm not sure it would work.[/quote]

Thanks for the code! I have try it and found the small problem. I was modify it to this version:
@
QQuickView* wnd = (QQuickView*)qApp->allWindows().last();
QQuickItem* wndContentItem = wnd->contentItem();
rootItem = wndContentItem->childItems().last();
QQmlEngine* engine = wnd->engine();

myComp = new QQmlComponent(engine, rootItem);
QString component("import QtQuick 2.0 \n import QtWebKit 3.0 \n WebView {anchors.top: parent.top; height: 300; width: 200; url:\"http://google.com\" }");
connect(myComp, SIGNAL(statusChanged(QQmlComponent::Status)), SLOT(sss(QQmlComponent::Status)));
myComp->setData(component.toUtf8(), QStringLiteral("qml/AppsnackSDKTest/main.qml"));

@

Because I need get 'engine' and 'parent' objects. So, I try get it from qApp window. And I have received the error like this:
@
QML debugging is enabled. Only use this in a safe environment.
ASSERT: "!isEmpty()" in file ../../../../Applications/Qt5.0.0/5.0.0/clang_64/include/QtCore/qlist.h, line 290
The program has unexpectedly finished.
@

Can you check my code and tell me what I do wrong? Thanks!

I known the problem in this few line of code:
@
QQuickView* wnd = (QQuickView*)qApp->allWindows().last(); //Try gett a main window of app
QQuickItem* wndContentItem = wnd->contentItem(); //Try QML content
rootItem = wndContentItem->childItems().last(); //Try get a last parent object (it's always one, so it's must be parent, but it's NULL !!!!!)
@

Thanks for the help!

sierdzio

@
QtQuick2ApplicationViewer viewer;
viewer.setMainQmlFile(QStringLiteral("qml/AppsnackSDKTest/main.qml"));
viewer.showExpanded();

// ...

myComp = new QQmlComponent(viewer.engine(), viewer.rootObject());
@

shav

[quote author="sierdzio" date="1356538127"]@
QtQuick2ApplicationViewer viewer;
viewer.setMainQmlFile(QStringLiteral("qml/AppsnackSDKTest/main.qml"));
viewer.showExpanded();

// ...

myComp = new QQmlComponent(viewer.engine(), viewer.rootObject());
@[/quote]

Thank for the help! It's works! I create a new component before app loading QML file. :-) Now all works fine! Thanks!

sierdzio

Pleasure :-)

I was afraid my last post could be a bit too enigmatic, but had no time to write more. Anyway, it works for you, so we're all happy.