QT QWebKit所属对象的事件

1. QWebView信号：

QWebView继承了QWidget的4个事件和QObject的2个事件。

void	iconChanged()
void	linkClicked(const QUrl & url)
void	loadFinished(bool ok)
void	loadProgress(int progress)
void	loadStarted()
void	selectionChanged()
void	statusBarMessage(const QString & text)
void	titleChanged(const QString & title)
void	urlChanged(const QUrl & url)

2. QWebPage信号：

QWebPage继承了QObject的2个事件

void	applicationCacheQuotaExceeded(QWebSecurityOrigin * origin, quint64 defaultOriginQuota, quint64 totalSpaceNeeded)
void	contentsChanged()
void	databaseQuotaExceeded(QWebFrame * frame, QString databaseName)
void	downloadRequested(const QNetworkRequest & request)
void	featurePermissionRequestCanceled(QWebFrame * frame, QWebPage::Feature feature)
void	featurePermissionRequested(QWebFrame * frame, QWebPage::Feature feature)
void	frameCreated(QWebFrame * frame)
void	geometryChangeRequested(const QRect & geom)
void	linkClicked(const QUrl & url)
void	linkHovered(const QString & link, const QString & title, const QString & textContent)
void	loadFinished(bool ok)
void	loadProgress(int progress)
void	loadStarted()
void	menuBarVisibilityChangeRequested(bool visible)
void	microFocusChanged()
void	printRequested(QWebFrame * frame)
void	repaintRequested(const QRect & dirtyRect)
void	restoreFrameStateRequested(QWebFrame * frame)
void	saveFrameStateRequested(QWebFrame * frame, QWebHistoryItem * item)
void	scrollRequested(int dx, int dy, const QRect & rectToScroll)
void	selectionChanged()
void	statusBarMessage(const QString & text)
void	statusBarVisibilityChangeRequested(bool visible)
void	toolBarVisibilityChangeRequested(bool visible)
void	unsupportedContent(QNetworkReply * reply)
void	viewportChangeRequested()
void	windowCloseRequested()

3. QWebFrame信号：

QWebFrame继承了QObject的2个事件

void	contentsSizeChanged(const QSize & size)
void	iconChanged()
void	initialLayoutCompleted()
void	javaScriptWindowObjectCleared()
void	loadFinished(bool ok)
void	loadStarted()
void	pageChanged()
void	titleChanged(const QString & title)
void	urlChanged(const QUrl & url)

4. 注册QT交互对象的时机

为了与HTML交互，我们需要调用

webView->page()->mainFrame()->addToJavaScriptWindowObject("Evnitem", envSce);

向DOM中注入一个交互对象。这个对象的加入时机需要把握。可通过对javaScriptWindowObjectCleared()信号进行处理，调用上面方法加入对象。javaScriptWindowObjectCleared()信号的解释如下：

This signal is emitted whenever the global window object of the JavaScript environment is cleared, e.g., before starting a new load.

If you intend to add QObjects to a QWebFrame using addToJavaScriptWindowObject(), you should add them in a slot connected to this signal. This ensures that your objects remain accessible when loading new URLs.

其方法是

（1）声明一个slot函数

private slots:

    void populateJavaScriptWindowObject();

并实现这个函数

void MainWindow::populateJavaScriptWindowObject()
{
    webView->page()->mainFrame()->addToJavaScriptWindowObject("Evnitem", envSce);
}

（2）将信号与槽连接

    connect(webView->page()->mainFrame(), SIGNAL(javaScriptWindowObjectCleared()),this, SLOT(populateJavaScriptWindowObject()));