How to grab current qt application Window

jhovarie

Hello guys I am trying to screenshot my own qt application window.
I tried this code but I know there are some better way.

void Test::capture(const QString &path) const
{
    QPixmap originalPixmap;
    QScreen *screen = QGuiApplication::primaryScreen();
    int y = 100;
    int w = 1600;
    int h = 450;
    originalPixmap = screen->grabWindow(0,x,y,w,h);
    originalPixmap.save(path);
}

is there another way to screenshot or grab current qt application?

jsulm

@jhovarie Use http://doc.qt.io/qt-5/qwidget.html#winId to get WId and don't pass x, y, w, h to grab the whole window.

jhovarie

How to use it? sorry I am a beginner

VRonin

void Test::capture(const QString &path) const
{
QWidget* parentWid = this; // Current widget
while(parentWid->parent()) parentWid = parentWid->parent(); // climb up utill you reach the widget that's the parent of everything
    parentWid->grab().save(path); // save it
}

JonB

@VRonin
Your method relies on starting from a widget. To find the app's main window I use this standalone approach:

def findMainWindow() -> typing.Union[QMainWindow, None]:
    # Global function to find the (open) QMainWindow in application
    app = QApplication.instance()
    for widget in app.topLevelWidgets():
        if isinstance(widget, QMainWindow):
            return widget
    return None

As I respect your expertise, if you have any comment on this it would be welcome?

VRonin

As @JonB suggested, (i'm just translating in C++ are removing the QMainWindow assumption), if Test is not a widget inside the area you want to grab

const QWidgetList topWidg = QApplication::topLevelWidgets();
for(int i=0;i<topWidg.size();++i){
widget->grab().save("GrabImage" + QString::number(i+1) + ".png");
}

DungeonLords

@VRonin said in How to grab current qt application Window:

parentWid

Your code doesn't work on Qt 5.15 (but thanks for your job). I fix it.

QWidget* parentWid = this; // Current widget
while(parentWid->parent()) parentWid = parentWid->parentWidget(); // climb up utill you reach the widget that's the parent of everything
    parentWid->grab().save("path.png"); // save it