(solved) Screenshot in qml

Peppy

I would suggest you to look firstly at pure C++ basics of OOP, because this is not good way how to teach you, how to use C++ neither Qt/QML...

We could teach you here basics of language C++, but it's not good idea, because there are tons of tutorials and basics of C++ on the Internet...you should google it first.

I think, tutorials will be better than "try and hope" programming.

The whole function written above is logically wrong... that's all what I would say to that. And to that error. You can not use QDeclarativeView as stand-alone name for something - that's the reason why it was expecting something more (name of variable) - that is one of the basics for C++.

Best regards,
Peppy.

daljit97

I was trying it because i need it in qml app, but thanks anyhow.

daljit97

--Update: I’ve corrected some errors but doesn’t work yet.

Peppy

how does it look like after you have rewritten it?

DigitalPioneer

I wrote a class to acquire a screenshot in QML once. It's designed for QtQuick 1.1, I haven't updated it for 2.0. Here's the code:

screensnapper.h
@
#ifndef SCREENSNAPPER_H
#define SCREENSNAPPER_H

#include <QDeclarativeImageProvider>

class ScreenSnapper : public QDeclarativeImageProvider
{
public:
ScreenSnapper();

QPixmap requestPixmap(const QString &id, QSize *size, const QSize &requestedSize);

};

#endif // SCREENSNAPPER_H
@

screensnapper.cpp
@

#include "screensnapper.h"

#include "QApplication"
#include "QDesktopWidget"

ScreenSnapper::ScreenSnapper()
: QDeclarativeImageProvider(QDeclarativeImageProvider::Pixmap)
{
}

QPixmap ScreenSnapper::requestPixmap(const QString &id, QSize *size, const QSize &requestedSize)
{
*size = QApplication::desktop()->size();
return QPixmap::grabWindow(QApplication::desktop()->winId());
}
@

Use it in QML like so:
@
Image {
id: desktopSnapshot
source: "image://snapper/snapshot"
anchors.fill: parent
}
@

See how that does for you. :)

EDIT: Oops, I forgot the code to register it... Assuming your QDeclarativeView is called view, you'll need to do this before you load the QML:
@view->engine()->addImageProvider(QString("snapper"), new ScreenSnapper());@

daljit97

thank you very much, but i'm getting this little error(I'm getting errors and errors also with little things these days): base operand of '->' has non-pointer type 'QDeclarativeView'
Here's code.

@#include <QtGui/QApplication>
#include "qmlapplicationviewer.h"
#include "screensnapper.h"
Q_DECL_EXPORT int main(int argc, char *argv[])
{
QScopedPointer<QApplication> app(createApplication(argc, argv));

QmlApplicationViewer viewer;
viewer.setMainQmlFile&#40;QLatin1String("qml/untitled18/main.qml"&#41;);
viewer.showExpanded();
QDeclarativeView view;
view->engine()->addImageProvider(QString("snapper"), new ScreenSnapper());
return app->exec&#40;&#41;;

}@

DigitalPioneer

OK, that's not going to work; you're creating a worthless QDeclarativeView. You need to get the engine from the actual QML viewer and set the image provider before loading the QML, like so:

@
#include <QtGui/QApplication>
#include "qmlapplicationviewer.h"
#include "screensnapper.h"
Q_DECL_EXPORT int main(int argc, char *argv[])
{
QScopedPointer<QApplication> app(createApplication(argc, argv));

QmlApplicationViewer viewer;
viewer.engine()->addImageProvider(QString("snapper"), new ScreenSnapper());
viewer.setMainQmlFile&#40;QLatin1String("qml/untitled18/main.qml"&#41;);
viewer.showExpanded();

return app->exec&#40;&#41;;

}
@

The error you received was simply pointing out that you were using the dereferencing member selection operator (->) when you didn't have a pointer to an object, you just had the object. In that case, you would need to use the normal member selection operator, which is a dot.

daljit97

I've already tried it before your post but it was showing this errors(it's a malediction): -invalid use of incomplete type 'structQDeclarativeEngine'(line 9) & -forward declaration of 'structQDeclarativeEngine'

DigitalPioneer

Now it's angry because the compiler doesn't actually know what QDeclarativeEngine is -- you need to include the header for it:

@#include <QDeclarativeEngine>@

daljit97

Error: QML Image: Failed to get image from provider: image://snapper/snapshot.
P.S. : thanks to be so patient.
EDIT: It works perfectly on a symbian phone. It doesn't work in Qtsimulator.

daljit97

Any way to save it to the phone memory?

DigitalPioneer

You can look into the QtMobility stuff, but I would just write that in C++ personally.

Djay96

this is simple code from which i get snapshot

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

QDeclarativeView *view = new QDeclarativeView();

view->setSource(QUrl::fromLocalFile("inputQMLFile.qml")); //inputQMLFile.qml instead your QML file that will generate Image

QPixmap::grabWidget(view).save("outputFile.png"); //Output file where you want to store the image
}