Bring window to front -> raise(),show(),activateWindow() don't work on Windows

Hedge

I open a URL in the default-browser.
Afterwards I want to bring the main-window of my application to the front again.

I tried all approaches I could find but none worked. All it does is blink in the taskbar (of Window 7)
Here's an example:

@this->viewer->show();
this->viewer->raise();
this->viewer->activateWindow();@

Peppy

Why do you call viewer, not window instance?

Hedge

I forgot to mention *viewer is a pointer to a QmlApplicationViewer which is derived from QDeclarativeView

Chuck Gao

Is the viewer a top-level window? Make sure it has no parent window.

Hedge

It's the only window my program has.

giesbert

In windows, an application can't rais itself in front of the currently active window and it can't pull the focus to itself :-(
What you can do is make it topmost (--> brings it to front) and remove tompost flag afterwards. But it will not get the input focus.

Hedge

I don't care about input-focus as I only want to know my user to see that amazing QML-animation I crafted (and see that they succeeded to authorize my application to use Twitter).

How do I make it topmost?

giesbert

You should try:

@
Qt::WindowFlags eFlags = windowFlags ();
eFlags |= Qt::WindowStaysOnTopHint;
setWindowFlags(eFlags);
@

and then remove it again

Hedge

Ah thanks. That works.

One general question though.
How do I remove the flag? I'm not much familiar with bit by bit manipulation.

DenisKormalev

@
eFlags &= ~Qt::WindowStaysOnTopHint;
@

Hedge

Thank you but there must be something wrong with this code.
The window comes to the front and instantly gets hidden completely. It doesn't even show up in the taskbar anymore.

@ Qt::WindowFlags eFlags = this->viewer->windowFlags();
eFlags |= Qt::WindowStaysOnTopHint;
this->viewer->setWindowFlags(eFlags);
this->viewer->show();
eFlags &= ~Qt::WindowStaysOnTopHint;
this->viewer->setWindowFlags(eFlags);@

DenisKormalev

If you will look into assistant you will find there next info
"Note: This function calls setParent() when changing the flags for a window, causing the widget to be hidden. You must call show() to make the widget visible again."

So you need to call show() again after second setWindowFlags()

Hedge

Ah, sorry.

The problem is that the window is behind the browser again after calling show() so if there isn't another solution I can only keep the window topmost (not really an option).

giesbert

you can do it with windows API:

@
::SetWindowPos(winID(), HWND_TOP, 0, 0, 0, 0, SWP_DRAWFRAME | SWP_NOMOVE | SWP_NOSIZE | SWP_SHOWWINDOW)
@

If this does not work, first call it with HWND_TOPMOST, and then this one.

Hedge

Do I need to trigger something else as well?

I tried:

but nothing happened.

giesbert

Hi Hege,

I digged a bit, this is what I did:

@
// HACK: bringing window to top
// from QT documentation:
// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
// void QWidget::activateWindow ()
// ...
// On Windows, if you are calling this when the application is not currently
// the active one then it will not make it the active window. It will change
// the color of the taskbar entry to indicate that the window has changed in
// some way. This is because Microsoft do not allow an application to
// interrupt what the user is currently doing in another application.
// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
// This hack does not give the focus to the app but brings it to front so
// the user sees it.
::SetWindowPos(effectiveWinId(), HWND_TOPMOST, 0, 0, 0, 0, SWP_NOMOVE | SWP_NOSIZE | SWP_SHOWWINDOW);
::SetWindowPos(effectiveWinId(), HWND_NOTOPMOST, 0, 0, 0, 0, SWP_NOMOVE | SWP_NOSIZE | SWP_SHOWWINDOW);
// HACK END

    raise();
    show();
    activateWindow();

@

This brings the window to front. Is your browser perhaps a topmost window? Or a child of yours?

Hedge

Hmm that doesn't work either.

My browser is opened via QDesktopServices like this:

@QDesktopServices::openUrl(openWebPageUrl);@

giesbert

perhaps that makes it a child of your window and therefore on top of your app.
Can you bring your window to front by mouse?

Hedge

If the browser is not maximized, yes.

goetz

I would kick out the native browser and put everything in a "QWebView":http://doc.qt.nokia.com/4.7/qwebview.html. You have control of the window then.

Is there anything that hinders you from doing it this way (despite having to pack QtWebkit.dll and bloating the package)?