activateWindow() doesn't work

[roxton]

Hello!
I have two windows - the main one and the secondary window (an image viewer). Here is a code demostrating how I show the image viewer window:

if (! img_viewer->window.isVisible()) //if the viewer is not visible
   {
     img_viewer->window.show();
     activateWindow(); //trying to set focus back to the main window
     }
img_viewer->set_image (full_path); //just show an image
//at the QLabel

if (! img_viewer->window.isVisible()) //if the viewer is not visible
   {
     img_viewer->window.show();
     activateWindow(); //trying to set focus back to the main window
     }
img_viewer->set_image (full_path); //just show an image
//at the QLabel

To copy to clipboard, switch view to plain text mode 

So the focus works in the following way:
1. When the image viewer window became visible (after the show() method), the focus moves to this image viewer window.
2. But I want to get the focus back into the main window. So I call activateWindow().
3. Nothing happens. The focus stays on the image viewer window.

[drhex]

What if you also call QWidget::setFocus() on a widget in your main window?

[spirit]

try to do like this

...
raise();
activateWindow();
...

...
raise();
activateWindow();
...

To copy to clipboard, switch view to plain text mode 

[roxton]

Yes, I've tried raise(), and setFocus for the widget, etc - nothing changed, focus stays on the secondary window until I click on the main window.
Now I have found a bad solution:

img_viewer->window.show();
hide();
show();

img_viewer->window.show();
hide();
show();

To copy to clipboard, switch view to plain text mode 

After that, the focus moves to the main window. But I want to move the focus without any window disappearing

[drhex]

Are you testing this on Linux? I've seen cases were raise() did not have any effect. Does it help if you turn "desktop effects" off?

[roxton]

Yes, I'm on Linux, Qt 4.4.3. Desktop effect are turned off. Soon I'll test this focusing problem on Windows XP.

[roxton]

Update.
When I'm calling hide() and show() for the main window (after the image viewer window becomes active), I get those errors at console output:

X Error: BadWindow (invalid Window parameter) 3
Major opcode: 20 (X_GetProperty)
Resource id: 0x16055ff
X Error: BadWindow (invalid Window parameter) 3
Major opcode: 15 (X_QueryTree)
Resource id: 0x16055ff
X Error: BadWindow (invalid Window parameter) 3
Major opcode: 40 (X_TranslateCoords)
Resource id: 0x16055ff

So the problem is in the X-system?

[drhex]

Could you make a minimal compilable example-program demonstrating the problem and post it here?

[roxton]

I'll post an example a bit later. Currently I've solved the problem calling setWindowFlags (Qt::Tool) for the secondary window.