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The QWebPage class provides an object to view and edit web documents. More...
#include <QWebPage>
Inherits QObject.
This class was introduced in Qt 4.4.
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The QWebPage class provides an object to view and edit web documents.
QWebPage holds a main frame responsible for web content, settings, the history of navigated links and actions. This class can be used, together with QWebFrame, to provide functionality like QWebView in a widget-less environment.
QWebPage's API is very similar to QWebView, as you are still provided with common functions like action() (known as pageAction() in QWebView), triggerAction(), findText() and settings(). More QWebView-like functions can be found in the main frame of QWebPage, obtained via QWebPage::mainFrame(). For example, the load(), setUrl() and setHtml() unctions for QWebPage can be accessed using QWebFrame.
The loadStarted() signal is emitted when the page begins to load.The loadProgress() signal, on the other hand, is emitted whenever an element of the web page completes loading, such as an embedded image, a script, etc. Finally, the loadFinished() signal is emitted when the page has loaded completely. Its argument, either true or false, indicates whether or not the load operation succeeded.
Before you begin painting a QWebPage object, you need to set the size of the viewport by calling setViewportSize(). Then, you invoke the main frame's render function (QWebFrame::render()). An example of this is shown in the code snippet below.
Suppose we have a Thumbnail class as follows:
class Thumbnailer : public QObject
{
Q_OBJECT
public:
Thumbnailer(const QUrl &url);
signals:
void finished();
private slots:
void render();
private:
QWebPage page;
};
The Thumbnail's constructor takes in a url. We connect our QWebPage object's loadFinished() signal to our private slot, render().
Thumbnailer::Thumbnailer(const QUrl &url)
{
page.mainFrame()->load(url);
connect(&page, SIGNAL(loadFinished(bool)),
this, SLOT(render()));
}
The render() function shows how we can paint a thumbnail using a QWebPage object.
void Thumbnailer::render()
{
page.setViewportSize(page.mainFrame()->contentsSize());
QImage image(page.viewportSize(), QImage::Format_ARGB32);
QPainter painter(&image);
page.mainFrame()->render(&painter);
painter.end();
QImage thumbnail = image.scaled(400, 400);
thumbnail.save("thumbnail.png");
emit finished();
}
We begin by setting the viewportSize and then we instantiate a QImage object, image, with the same size as our viewportSize. This image is then sent as a parameter to painter. Next, we render the contents of the main frame and its subframes into painter. Finally, we save the scaled image.
See also QWebFrame.
This enum describes the types of extensions that the page can support. Before using these extensions, you should verify that the extension is supported by calling supportsExtension().
Currently there are no extensions.
This enum describes the options available to QWebPage's findText() function. The options can be OR-ed together from the following list:
| Constant | Value | Description |
|---|---|---|
| QWebPage::FindBackward | 1 | Searches backwards instead of forwards. |
| QWebPage::FindCaseSensitively | 2 | By default findText() works case insensitive. Specifying this option changes the behaviour to a case sensitive find operation. |
| QWebPage::FindWrapsAroundDocument | 4 | Makes findText() restart from the beginning of the document if the end was reached and the text was not found. |
The FindFlags type is a typedef for QFlags<FindFlag>. It stores an OR combination of FindFlag values.
This enum defines the delegation policies a webpage can have when activating links and emitting the linkClicked() signal.
| Constant | Value | Description |
|---|---|---|
| QWebPage::DontDelegateLinks | 0 | No links are delegated. Instead, QWebPage tries to handle them all. |
| QWebPage::DelegateExternalLinks | 1 | When activating links that point to documents not stored on the local filesystem or an equivalent - such as the Qt resource system - then linkClicked() is emitted. |
| QWebPage::DelegateAllLinks | 2 | Whenever a link is activated the linkClicked() signal is emitted. |
This enum describes the types of navigation available when browsing through hyperlinked documents.
| Constant | Value | Description |
|---|---|---|
| QWebPage::NavigationTypeLinkClicked | 0 | The user clicked on a link or pressed return on a focused link. |
| QWebPage::NavigationTypeFormSubmitted | 1 | The user activated a submit button for an HTML form. |
| QWebPage::NavigationTypeBackOrForward | 2 | Navigation to a previously shown document in the back or forward history is requested. |
| QWebPage::NavigationTypeReload | 3 | The user activated the reload action. |
| QWebPage::NavigationTypeFormResubmitted | 4 | An HTML form was submitted a second time. |
| QWebPage::NavigationTypeOther | 5 | A navigation to another document using a method not listed above. |
| Constant | Value | Description |
|---|---|---|
| QWebPage::NoWebAction | -1 | No action is triggered. |
| QWebPage::OpenLink | 0 | Open the current link. |
| QWebPage::OpenLinkInNewWindow | 1 | Open the current link in a new window. |
| QWebPage::OpenFrameInNewWindow | 2 | Replicate the current frame in a new window. |
| QWebPage::DownloadLinkToDisk | 3 | Download the current link to the disk. |
| QWebPage::CopyLinkToClipboard | 4 | Copy the current link to the clipboard. |
| QWebPage::OpenImageInNewWindow | 5 | Open the highlighted image in a new window. |
| QWebPage::DownloadImageToDisk | 6 | Download the highlighted image to the disk. |
| QWebPage::CopyImageToClipboard | 7 | Copy the highlighted image to the clipboard. |
| QWebPage::Back | 8 | Navigate back in the history of navigated links. |
| QWebPage::Forward | 9 | Navigate forward in the history of navigated links. |
| QWebPage::Stop | 10 | Stop loading the current page. |
| QWebPage::Reload | 11 | Reload the current page. |
| QWebPage::Cut | 12 | Cut the content currently selected into the clipboard. |
| QWebPage::Copy | 13 | Copy the content currently selected into the clipboard. |
| QWebPage::Paste | 14 | Paste content from the clipboard. |
| QWebPage::Undo | 15 | Undo the last editing action. |
| QWebPage::Redo | 16 | Redo the last editing action. |
| QWebPage::MoveToNextChar | 17 | Move the cursor to the next character. |
| QWebPage::MoveToPreviousChar | 18 | Move the cursor to the previous character. |
| QWebPage::MoveToNextWord | 19 | Move the cursor to the next word. |
| QWebPage::MoveToPreviousWord | 20 | Move the cursor to the previous word. |
| QWebPage::MoveToNextLine | 21 | Move the cursor to the next line. |
| QWebPage::MoveToPreviousLine | 22 | Move the cursor to the previous line. |
| QWebPage::MoveToStartOfLine | 23 | Move the cursor to the start of the line. |
| QWebPage::MoveToEndOfLine | 24 | Move the cursor to the end of the line. |
| QWebPage::MoveToStartOfBlock | 25 | Move the cursor to the start of the block. |
| QWebPage::MoveToEndOfBlock | 26 | Move the cursor to the end of the block. |
| QWebPage::MoveToStartOfDocument | 27 | Move the cursor to the start of the document. |
| QWebPage::MoveToEndOfDocument | 28 | Move the cursor to the end of the document. |
| QWebPage::SelectNextChar | 29 | Select to the next character. |
| QWebPage::SelectPreviousChar | 30 | Select to the previous character. |
| QWebPage::SelectNextWord | 31 | Select to the next word. |
| QWebPage::SelectPreviousWord | 32 | Select to the previous word. |
| QWebPage::SelectNextLine | 33 | Select to the next line. |
| QWebPage::SelectPreviousLine | 34 | Select to the previous line. |
| QWebPage::SelectStartOfLine | 35 | Select to the start of the line. |
| QWebPage::SelectEndOfLine | 36 | Select to the end of the line. |
| QWebPage::SelectStartOfBlock | 37 | Select to the start of the block. |
| QWebPage::SelectEndOfBlock | 38 | Select to the end of the block. |
| QWebPage::SelectStartOfDocument | 39 | Select to the start of the document. |
| QWebPage::SelectEndOfDocument | 40 | Select to the end of the document. |
| QWebPage::DeleteStartOfWord | 41 | Delete to the start of the word. |
| QWebPage::DeleteEndOfWord | 42 | Delete to the end of the word. |
| QWebPage::SetTextDirectionDefault | 43 | Set the text direction to the default direction. |
| QWebPage::SetTextDirectionLeftToRight | 44 | Set the text direction to left-to-right. |
| QWebPage::SetTextDirectionRightToLeft | 45 | Set the text direction to right-to-left. |
| QWebPage::ToggleBold | 46 | Toggle the formatting between bold and normal weight. |
| QWebPage::ToggleItalic | 47 | Toggle the formatting between italic and normal style. |
| QWebPage::ToggleUnderline | 48 | Toggle underlining. |
| QWebPage::InspectElement | 49 | Show the Web Inspector with the currently highlighted HTML element. |
| Constant | Value | Description |
|---|---|---|
| QWebPage::WebBrowserWindow | 0 | The window is a regular web browser window. |
| QWebPage::WebModalDialog | 1 | The window acts as modal dialog. |
This property holds whether QWebPage should forward unsupported content through the unsupportedContent signal.
If disabled the download of such content is aborted immediately.
By default unsupported content is not forwarded.
Access functions:
This property holds how QWebPage should delegate the handling of links through the linkClicked() signal.
The default is to delegate no links.
Access functions:
This property holds whether the page contains unsubmitted form data.
By default, this property is false.
Access functions:
This property holds the page's palette.
The background brush of the palette is used to draw the background of the main frame.
By default, this property contains the application's default palette.
Access functions:
This property holds the text currently selected.
By default, this property contains an empty string.
Access functions:
See also selectionChanged().
This property holds the size of the viewport.
The size affects for example the visibility of scrollbars if the document is larger than the viewport.
By default, for a newly-created Web page, this property contains a size with zero width and height.
Access functions:
Constructs an empty QWebView with parent parent.
Destroys the web page.
This function is called whenever WebKit requests to navigate frame to the resource specified by request by means of the specified navigation type type.
If frame is a null pointer then navigation to a new window is requested. If the request is accepted createWindow() will be called.
The default implementation interprets the page's linkDelegationPolicy and emits linkClicked accordingly or returns true to let QWebPage handle the navigation itself.
See also createWindow().
Returns a QAction for the specified WebAction action.
The action is owned by the QWebPage but you can customize the look by changing its properties.
QWebPage also takes care of implementing the action, so that upon triggering the corresponding action is performed on the page.
See also triggerAction().
Returns the number of bytes that were received from the network to render the current page.
See also totalBytes().
This function is called when the web content requests a file name, for example as a result of the user clicking on a "file upload" button in a HTML form.
A suggested filename may be provided in suggestedFile. The frame originating the request is provided as parentFrame.
This function is called whenever WebKit encounters a HTML object element with type "application/x-qt-plugin". The classid, url, paramNames and paramValues correspond to the HTML object element attributes and child elements to configure the embeddable object.
This function is called whenever WebKit wants to create a new window of the given type, for example when a JavaScript program requests to open a document in a new window.
If the new window can be created, the new window's QWebPage is returned; otherwise a null pointer is returned.
If the view associated with the web page is a QWebView object, then the default implementation forwards the request to QWebView's createWindow() function; otherwise it returns a null pointer.
See also acceptNavigationRequest().
Returns the frame currently active.
See also mainFrame() and frameCreated().
This signal is emitted when the user decides to download a link. The url of the link as well as additional meta-information is contained in request.
See also unsupportedContent().
This virtual function can be reimplemented in a QWebPage subclass to provide support for extensions. The option argument is provided as input to the extension; the output results can be stored in output.
The behavior of this function is determined by extension.
You can call supportsExtension() to check if an extension is supported by the page.
By default, no extensions are supported, and this function returns false.
See also supportsExtension() and Extension.
Finds the next occurrence of the string, subString, in the page, using the given options. Returns true of subString was found and selects the match visually; otherwise returns false.
Similar to QWidget::focusNextPrevChild it focuses the next focusable web element if next is true; otherwise the previous element is focused.
Returns true if it can find a new focusable element, or false if it can't.
This signal is emitted whenever the page creates a new frame.
This signal is emitted whenever the document wants to change the position and size of the page to geom. This can happen for example through JavaScript.
Returns a pointer to the view's history of navigated web pages.
This method is used by the input method to query a set of properties of the page to be able to support complex input method operations as support for surrounding text and reconversions.
property specifies which property is queried.
See also QWidget::inputMethodEvent(), QInputMethodEvent, and QInputContext.
This function is called whenever a JavaScript program running inside frame calls the alert() function with the message msg.
The default implementation shows the message, msg, with QMessageBox::information.
This function is called whenever a JavaScript program running inside frame calls the confirm() function with the message, msg. Returns true if the user confirms the message; otherwise returns false.
The default implementation executes the query using QMessageBox::information with QMessageBox::Yes and QMessageBox::No buttons.
This function is called whenever a JavaScript program tries to print a message to the web browser's console.
For example in case of evaluation errors the source URL may be provided in sourceID as well as the lineNumber.
The default implementation prints nothing.
This function is called whenever a JavaScript program running inside frame tries to prompt the user for input. The program may provide an optional message, msg, as well as a default value for the input in defaultValue.
If the prompt was cancelled by the user the implementation should return false; otherwise the result should be written to result and true should be returned.
The default implementation uses QInputDialog::getText.
This signal is emitted whenever the user clicks on a link and the page's linkDelegationPolicy property is set to delegate the link handling for the specified url.
By default no links are delegated and are handled by QWebPage instead.
See also linkHovered().
This signal is emitted when the mouse is hovering over a link. The first parameter is the link url, the second is the link title if any, and third textContent is the text content. Method is emitter with both empty parameters when the mouse isn't hovering over any link element.
See also linkClicked().
This signal is emitted when a load of the page is finished. ok will indicate whether the load was successful or any error occurred.
See also loadStarted().
This signal is emitted when the global progress status changes. The current value is provided by progress and scales from 0 to 100, which is the default range of QProgressBar. It accumulates changes from all the child frames.
See also bytesReceived().
This signal is emitted when a new load of the page is started.
See also loadFinished().
Returns the main frame of the page.
The main frame provides access to the hierarchy of sub-frames and is also needed if you want to explicitly render a web page into a given painter.
See also currentFrame().
This signal is emitted whenever the visibility of the menubar in a web browser window that hosts QWebPage should be changed to visible.
This signal is emitted when for example the position of the cursor in an editable form element changes. It is used inform input methods about the new on-screen position where the user is able to enter text. This signal is usually connected to QWidget's updateMicroFocus() slot.
Returns the QNetworkAccessManager that is responsible for serving network requests for this QWebPage.
See also setNetworkAccessManager().
Returns the QWebPluginFactory that is responsible for creating plugins embedded into this QWebPage. If no plugin factory is installed a null pointer is returned.
See also setPluginFactory().
This signal is emitted whenever the page requests the web browser to print frame, for example through the JavaScript window.print() call.
See also QWebFrame::print() and QPrintPreviewDialog.
This signal is emitted whenever this QWebPage should be updated and no view was set. dirtyRect contains the area that needs to be updated. To paint the QWebPage get the mainFrame() and call the render(QPainter*, const QRegion&) method with the dirtyRect as the second parameter.
See also mainFrame() and view().
This signal is emitted whenever the content given by rectToScroll needs to be scrolled dx and dy downwards and no view was set.
See also view().
This signal is emitted whenever the selection changes.
See also selectedText().
Sets the QNetworkAccessManager manager responsible for serving network requests for this QWebPage.
See also networkAccessManager().
Sets the QWebPluginFactory factory responsible for creating plugins embedded into this QWebPage.
Note: The plugin factory is only used if the QWebSettings::PluginsEnabled attribute is enabled.
See also pluginFactory().
Sets the view that is associated with the web page.
See also view().
Returns a pointer to the page's settings object.
See also QWebSettings::globalSettings().
This signal is emitted when the statusbar text is changed by the page.
This signal is emitted whenever the visibility of the statusbar in a web browser window that hosts QWebPage should be changed to visible.
This virtual function returns true if the web page supports extension; otherwise false is returned.
See also extension().
Filters the context menu event, event, through handlers for scrollbars and custom event handlers in the web page. Returns true if the event was handled; otherwise false.
A web page may swallow a context menu event through a custom event handler, allowing for context menus to be implemented in HTML/JavaScript. This is used by Google Maps, for example.
This signal is emitted whenever the visibility of the toolbar in a web browser window that hosts QWebPage should be changed to visible.
Returns the total number of bytes that were received from the network to render the current page, including extra content such as embedded images.
See also bytesReceived().
This function can be called to trigger the specified action. It is also called by QtWebKit if the user triggers the action, for example through a context menu item.
If action is a checkable action then checked specified whether the action is toggled or not.
See also action().
Returns a pointer to the undo stack used for editable content.
This signals is emitted when webkit cannot handle a link the user navigated to.
At signal emissions time the meta data of the QNetworkReply reply is available.
Note: This signal is only emitted if the forwardUnsupportedContent property is set to true.
See also downloadRequested().
Updates the page's actions depending on the position pos. For example if pos is over an image element the CopyImageToClipboard action is enabled.
This function is called when a user agent for HTTP requests is needed. You can re-implement this function to dynamically return different user agent's for different urls, based on the url parameter.
The default implementation returns the following value:
"Mozilla/5.0 (%Platform%; %Security%; %Subplatform%; %Locale%) AppleWebKit/%WebKitVersion% (KHTML, like Gecko, Safari/419.3) %AppVersion"
In this string the following values are replaced at run-time:
Returns the view widget that is associated with the web page.
See also setView().
This signal is emitted whenever the page requests the web browser window to be closed, for example through the JavaScript window.close() call.
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