Stronger way to render a QQuickItem (WebView) into an Image

[mperrinel]

Hi,

Using the WebKit version of the Qt 5.4.0, I need to be able to print the content of a WebView :

MenuItem {
text: qsTr("&Print")
onTriggered: {
qmlPrinter.print(webView)
}
}

WebView {
id: webView
objectName: "view"
anchors.fill: parent
url: "myHtmlPage.htm"
}

Because I can't see any answer from the QML part, I have tried with the C++ part:

QmlItemPrinter::print(const QVariant &qmlItem)
{
QQuickItem *item = qobject_cast<QQuickItem >( qmlItem.value<QObject>() );
}

By googling, I have already tried different solution:

1. The GrabWindow: -> Only works for the visible part of the WebView. But My webView have a contentHeigh of 23000.

2. The grabToImage + ShaderEffectSource -> Image have the good size, but its contents is like the content of the resized grabWindow:
   ShaderEffectSource {
   id: webWiewShader
   height: webView.contentHeight
   width: webView.contentWidth
   live: false
   sourceItem: webView
   }

3. The QQuickPaintedImage: Yes but how can I implement its paint method ?

4. The QSGTextureProvider seems to not work with big WebView content:
   QSGTextureProvider *textureProvider = item->textureProvider();
   QSGTexture *texture = textureProvider->texture();
   texture->bind();
   GLint internalFormat;
   glGetTexLevelParameteriv(GL_TEXTURE_2D, 0, GL_TEXTURE_COMPONENTS, &internalFormat); // get internal format type of GL texture
   QImage image(texture->textureSize(), QImage::Format_RGBX8888);
   glGetTexImage(GL_TEXTURE_2D, 0, internalFormat, GL_UNSIGNED_BYTE, image.bits());
   image.save("D:/myHtmlImage.jpg");

5. The QGraphicsObject: It seems that the WebView cannot be cast to the QGraphicsObject.

My goal is to print the html content. I thank that a first way was to create a QImage from the WebView but maybe there is a simplest way.

Does anyone have a suggestion ?

Thanks in advance,

[jalomic]

You can cast your webview to QQuickPaintedItem ( because QQuickWebView iherits it), it has paint(QPainter *) method. Just replace QPainter and call this function !

[mperrinel]

Hi Jalomic and thanks for you reply.
I have tried your way but without sucess.

1. The webview cannot be cast to QQuickPaintedItem
2. The webvies can be cast to QQuickWebView but:

• I need then to include webkit-private and qquick-private to my .pro
• the QQuickWebView inherit from QQuickFlickable then QQuickItem but no QQuickPaintedItem
• There is no paint method for QQuickWebView

[jalomic]

@mperrinel Oh sorry. I used https://github.com/mardy/qt5webkit1 =) and forgot about webkit2

[jalomic]

@mperrinel It is very ruefully :(
http://www.kdab.com/creating-pdf-qtquick-2-scene-slideviewer/

[mperrinel]

Thanks for the link. I have read it.

It's very nice and can probably answer most of the case. But because it only works with a subset of QtQuickItem like image or text, I think that will not be enough for the webview. The biggest problem of the webview is it content height that can be very huge.
The grabImage was a nice way, but I was blocked by a problem of memory. only about the first 2000 height was painted...