My application has a dialog that asks the user via a QMessageBox whether he wants to discard all changes he made or wants to keep editing. I want this dialog to be modal to the whole application.
I read somewhere that this is the standard behavior for a QMessageBox, so I dont have to set it explicitly with something like:
mbox.setWindowModality(Qt::ApplicationModal);
I wonder why it behaves differently from other modal dialogs in the OS (Windows 7 in my case). On the one hand it functions like it should, i.e. all other input methods in the application are blocked until the user answeres the dialog. However, it doesn't 'blink'* if the user clicks any other window of the application. Is there any way to get Qt to behave like a native Windows dialog?
Thanks in advance!
*If you don't know what I mean with this 'blinking': Just open notepad on a Windows OS, type some text and try to close it. A dialog pops up that asks to save, discard or keep editing. Now click somewhere on the editor window -> the border and titlebar of the dialog flashes/blinks a few times.
The problem arises when the message box has no parent. This works fine for me:
QMessageBox box(this);
box.setStandardButtons(QMessageBox::Close);
box.exec();
But this does not:
QMessageBox box;
box.setStandardButtons(QMessageBox::Close);
box.exec();
This makes sense... the message box can't blink unless it knows that its parent was clicked on.
A simple solution that comes into my mind and if you want to deploy your application only on windows you should #include <windows.h> and use the MessageBoxA API.
Besides that this works great for me in Windows and ubuntu
if (QMessageBox::question(this,"Close?","Close this dialog?",QMessageBox::Yes,QMessageBox::No) == QMessageBox::Yes)
{
this->close();
}
Related
I have an application in which users, upon logging in, are prompted with a modal dialog where they must choose the facility they wish to work out of. At this stage, the application looks like this:
The modal dialog is shown by calling this method:
bool __fastcall ShowFacChoiceForm()
{
TFacChoiceForm *Form = new TFacChoiceForm( Application );
bool Result = ( Form->ShowModal() == mrOk );
delete Form;
return Result;
}
In this case, TFacChoiceForm inherits from TForm so the ShowFacChoiceForm() function is calling the standard TForm.ShowModal method documented here.
The issue I am running into is that if my application loses focus, it cannot become the active window again unless the modal dialog itself is clicked. To better illustrate this, I will present the following scenario:
Lets say its Friday afternoon and I decide to goof off a bit and read some web comics. With my application open, I open up another window on top of it, like so:
Then, out of nowhere my boss comes in for a performance review, and I attempt to refocus my application by clicking somewhere on the main form. For example, at the position of this red X in the next image.
In the above image, I have clicked at the location of the red X. Now, both the form containing the web comic, and my application are inactive. Thus, my application does not come to the front of the screen.
However, if I am able to click somewhere on the modal dialog, like the red X in the following image...
...then my application comes to the front like one would expect.
To solve this, I have looked at using something like SetForegroundWindow from the Windows API, but I have not been able to find a way to trigger the event, since my main form does not fire events while I have a modal dialog open.
My question is, how can I make sure that if the user clicks anywhere on my application that it is brought to the front? Is there a property I can edit in my form to do this?
If you set modalresult to mrcancel in the ondeactivate of the modal dialog then the main form will get focus when its clicked. You can then check if the user is logged in the mousedown event of the main form and if not, show the modal dialog again.
My application is a dialog shipped out as a dll. It can be launched in modal and modeless modes,from a bigger application that I have no control of. We use MFC library and follows COM architecture. For development purpose we have a tester application that launches my dialog.
The problem I face is that tab key do not work at all in both modal and modeless.
but, arrow keys work.
When observed through SPY++, I cannot see tabs coming to my dialog at all.
I am pretty confused on what's happening ?
For tabs to work in a modeless dialog, the application must call IsDialogMessage from its main message pump. But in your case, the application doesn't even know the dialog exists. I believe your only option is to install a Windows hook (see SetWindowsHookEx) and call IsDialogMessage yourself.
Modal dialog should work out of the box though - are you sure it doesn't?
I seem to have discovered an annoying issue with Qt 5.1.
Let's say for example you have a system tray icon (QSystemTrayIcon) and you hide your form (QDialog), so:
this->hide();
Then, while the form is hidden, your app displays a message box:
QMessageBox::information(0, "Test", "Test");
Once the user hits Ok to close the dialog, the program exits with exit code 0. So, it doesn't crash, but it politely exits.
The only work around that I know off is to use the WIN32 API on Windows and the MessageBox function. This is not what I want to do.
Is this a bug?
By default, a Qt application closes when the last window is closed (in your case, when you close the QMessageBox).
You can add this code to keep your application running:
qApp()->setQuitOnLastWindowClosed(false);
Right now I'm working on a real time software, but I got myself implementing forms - using C++Builder 2007 - for confirmation messages (you know, those dialog box with OK and Cancel or only OK if it's an error), and I read that there's a DialogBox class on Windows MFC. The problem is the calling interrupts the thread until some input is done on the dialog, which I can't afford because another things might be happening on the application.
I've read about Modeless Dialog Box, but I'm not sure it's what I need or how to implement. Is there a default assynchronous dialog box on Windows MFC and if there is, how do I call it?
You don't need threads for this, you need modeless dialog boxes... they end up being windows on the same dispatch thread.
I have a dialog (CDialog derived class) that can be used in two different ways (edition mode and programming mode).
When the dialog is open to be used in programming mode it is a modeless dialog that it is used for modifying the main view (kind of a toolbar). When it is open in edition mode the user can change the configuration of the dialog itself and in this case it is a modal dialog.
Right now they are two different dialogs with few differences and I would like to have just want dialog and let the user change between programming mode and edition mode just by pressing a button in the dialog.
So I need to convert the modeless dialog in a modal dialog and vice versa at runtime. Is there a way to achive that?
Thanks.
As maybe someone could be interested in doing something similar in the future, this is the way I eventually did it:
I use this two functions of main frame: CMainFrame::BeginModalState() and CMainFrame::EndModalState().
The problem with these functions is the same that with disabling the parent window. The window you want to make modal also gets disabled. But the solution is easy, just re-enable the window after calling BeginModalState.
void CMyDialog::MakeModal()
{
//disable all main window descendants
AfxGetMainWnd()->BeginModalState();
//re-enable this window
EnableWindow(TRUE);
}
void CMyDialog::MakeModeless()
{
//enable all main window descendants
AfxGetMainWnd()->EndModalState();
}
Thanks for your help.
That can't be done easily without closing and reopening the dialog. Then you can call ShowWindow or DoModal as appropriate.
That is not correct. This can be done, if you look at MFC's source you will realize that it's modal dialogs are not technically even modal. You will have to do a lot of mucking about to make this work properly, but basically you just have to disable the parent of the 'modal' window, and re-enable it when the 'modal' window closes.
I have done this personally so this may work for you, though I am not exactly sure what you are trying to do.