I have the following Qt webview:
QWebView *view = new QWebView();
view->load(QUrl("http://example.com"));
I want to get the title of document when load is finished, and use it to set the main window title.
From what I suppose view->loadFinished() returns true if page was loaded or not.
For setting the window title I use webView->setWindowTitle(newTitle). So, I need that newTitle variable that I want to be the document title.
How can I do this?
QWebView::loadFinished is a signal. You can subscribe to it to know when the page is loaded:
connect(view, SIGNAL(loadFinished(bool)), this, SLOT(onLoaded()));
To access HTML title you can use QWebView::title property.
void onLoaded()
{
window->setWindowTitle(view->title());
}
Rather then using loadFinished it may be more appropriate to use signal titleChanged(const QString& title) to apply a new title to the window:
connect(view, SIGNAL(titleChanged(QString)), this, SLOT(setWindowTitle(QString)));
EDIT:
Example:
QWebView* webView = new QWebView();
connect(webView, SIGNAL(titleChanged(QString)), webView, SLOT(setWindowTitle(QString)));
webView->load(QUrl("http://yahoo.com"));
webView->show();
Related
For example, I have a simple HTML page with button and label (or something else). How can I change the text in label (or something else) and catch the button click use QT.
I try to use QWebEngineView to show html, but I don`t know how to interact with elements from QT modul, just change the url, but I dont think its a better way
To be able to interact with HTML rendered with QWebEngine you need to use QWebChannel. You can find the basic guidelines at Qt WebChannel JavaScript API page.
To implement intercommunication with JavaScript in your HTML page you need:
Add Qt += webchannel in your project file
Implement a QObject derived class that should be a proxy between C++ and JavaScript. The simpliest way to make it usable in JavaScript is to create getters, setters and signals for the values you intend to use in JavaScript, and expose them as Q_PROPERTY.
Example:
class ProxyClass: public QObject
{
Q_OBJECT
Q_PROPERTY(QString value READ value WRITE setValue NOTIFY valueChanged)
public:
explicit ProxyClass(QObject *parent = nullptr);
QString value() const;
void setValue(const QString &aValue);
signals:
void valueChanged(const QString &aValue);
};
Set HTML to QWebEngineView with QWebEngineView::setHtml, instantiate your "proxy" class and create QWebChannel for the page (note that you can register multiple objects in QWebChannel). Example:
//create QWebEngineView and set HTML from resources
auto webView = new QWebEngineView;
QFile htmlFile(":/page.html");
htmlFile.open(QIODevice::ReadOnly);
QString html = htmlFile.readAll();
webView->setHtml(html);
//create and set up the instance of your "proxy" class
auto proxy = new ProxyClass;
//create QWebChannel and set it for the page
QWebChannel *webChannel = new QWebChannel(webView->page());
webChannel->registerObject(QStringLiteral("proxy"), proxy);
webView->page()->setWebChannel(webChannel);
Embed qwebchannel.js file in HTML. File is located at <Qt installation directory>/Examples/Qt-<version>/webchannel/shared directory. You can include it in application resources and embed in HTML with <script type="text/javascript" src="qrc:/qwebchannel.js"></script>
Create onload event handler in HTML and initialize QWebChannel in it. Example:
function loaded() {
new QWebChannel(qt.webChannelTransport, function (channel) {
<!--get and assign "proxy"-->
window.proxy = channel.objects.proxy;
<!--now you can-->
<!--get values-->
let proxyValue = proxy.value;
<!--connect signals-->
proxy.valueChanged.connect(() => {
...
});
});
}
function someFunction(newValue) {
<!--set values-->
proxy.value = newValue;
}
...
<body onload="loaded()">...</body>
Once you initialized a web channel and assigned "proxy" object to the window object, you are free to use it everywhere in JavaScript.
I've created a custom widget plugin that is a container( it overloads the qframe). In this container i would like to add children through the code. I've succeeded in doing this. However the children aren't editable or clickable in the designer. I know for children to be editable through the designer, they should be added as code to the XML, but i don't know how to do this.
Would anybody know if it's at all possible to do this?
The code I have, with arrowedFrame as my custom widget plugin class:
arrowedFrame::arrowedFrame(QWidget *parent, Qt::WindowFlags f) : (parent, f)
{
QLabel* testLabel = new QLabel(this);
}
this adds a new Label, as member (sorry i can't yet post pictures, but imagine a box with a label in it). But as i said this label isn't at all editable through the designer.
The solution I found to this is by taking this guide. And adding some things in the initialize function:
void PlotContainerPlugin::initialize(QDesignerFormEditorInterface *formEditor)
{
if (initialized)
return;
QExtensionManager *manager = formEditor->extensionManager();
myFormEditor = formEditor;
Q_ASSERT(manager != 0);
manager->registerExtensions(factory, Q_TYPEID(QDesignerContainerExtension));
initialized = true;
}
The first part just gets a manager:
QExtensionManager *manager = formEditor->extensionManager();
And then we use this manager to,
manager->registerExtensions(factory, Q_TYPEID(QDesignerContainerExtension));
register the plugin(a plotter I my case) with the designer.
Hope this helps:)
I have a text field and a button purely designed in c++(without importing a qml doc). How do i read the text from the text field when I click the buton.
I am unable to find a function associated for that.
To hook up the button to a method, use the following code:
button = new Button();
texField = new TextField();
connect(button, SIGNAL(clicked()), this, SLOT(onClicked());
Then define the onClicked slot as so:
void ClassName::onClicked() {
qDebug() << textField->text(); //print the textField's text
}
For this to work, this method has to be marked in the class as a Q_SLOT and the object itself must be marked as a Q_OBJECT.
I am trying to display a web page using the below code
QWebView *view = new QWebView();
view->load(QUrl("qrc://images//sample page.html/"));
view->show();
sample page.html is added to project resources/Images. The web page frame is loading, but I can't see any html data.
I tested with the below web url and it loaded the page
view->load(QUrl("http://www.google.com/"));
You will have to go through a few steps as follows:
1) Get the QWebPage object:
QWebPage *page = view->page();
2) Get the QWebFrame object:
QWebFrame *frame = page->currentFrame();
3) Call the toHtml member function on the current frame:
QString html = frame->toHtml();
Of course, you will need to add appropriate error checks in between.
the following code plays the song while a button is pressed (onclick). I have created a horizontalSlider UI but it is not sliding. I got the document from http://wiki.forum.nokia.com/index.php/Streaming_Audio_with_Qt
Please help me to make the slider work.
Phonon::MediaObject *mediaObject = new Phonon::MediaObject(this);
Phonon::AudioOutput *audioOutput =
new Phonon::AudioOutput(Phonon::MusicCategory, this);
Phonon::createPath(mediaObject, audioOutput);
const QString url("c://example.mp3");
mediaObject->setCurrentSource(url);
mediaObject->play();
volumeSlider = new Phonon::VolumeSlider(ui->horizontalSlider);
volumeSlider->setAudioOutput(audioOutput);
volumeSlider->setSizePolicy(QSizePolicy::Maximum, QSizePolicy::Maximum);
Probably you didn't bind the corresponding media object to the slider.
See a small example here.