Disable Close button (X) of a QDialog

[BrainB0ne]

Hello,

I want to know if it is possible to disable the close button (X) of a QDialog during a Process.
After my Process is finished i want to enable the close button (X) again.

Posted some screenshots of an example to show what i mean.





Any help is welcome

Greetz,

[marcel]

I didn't manage to do it by using the Qt window flags, but it is possible using winapi:

#ifdef Q_WS_WIN
   CMenu* menu = this->GetSystemMenu(FALSE);
   menu->ModifyMenu(SC_CLOSE, MF_BYCOMMAND | MF_GRAYED );
#endif

#ifdef Q_WS_WIN
   CMenu* menu = this->GetSystemMenu(FALSE);
   menu->ModifyMenu(SC_CLOSE, MF_BYCOMMAND | MF_GRAYED );
#endif

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[rajesh]

Marcel,
this is not a Qt code. it is VC++ code.

[marcel]

And what did I say?
It's not VC code, but it is winapi code. Please notice the ifdefs.

[rajesh]

BrainB0ne,

try this:
setWindowFlags(Qt::FramelessWindowHint);
setWindowFlags(Qt::WindowTitleHint);

[marcel]

The second setWindowFlags overrides the first.
And he said disable the button, not hide it. But I guess that's a solution too.

[rajesh]

the first flag reset all flag to 0, so,it is also required.

[marcel]

No.
Using the second flag only yields the same result.
setWindowFlags(Qt::WindowTitleHint) will result in the window flags to be JUST Qt::WindowTitleHint.

If you want to set more than one flag you have to OR them:
setWindowFlags(flag1 | flag2 | ... | flagn );

[BrainB0ne]

Damn i am really late with reacting.... sorry for that u guys.

I am gonna try some of the solutions mentioned... i will tell you about what i have done

[BrainB0ne]

hmmm... I dont get Marcel's solution to work with the Winapi code.

And the next solution with the windowflags also doesnt work at Qt 3, the mentioned defines do not exist.

Maybe i have to search trough the Qt 3 Assistent for appropriate window flags.

Thx for your help and till next time

[marcel]

hmmm... I dont get Marcel's solution to work with the Winapi code.

Do you get any errors or it just doesn't work?

Maybe i have to search trough the Qt 3 Assistent for appropriate window flags.

See http://doc.trolltech.com/3.3/qt.html#WidgetFlags-enum.
Play with different combinations until you get some result. But it really depends on the window manager to respect the flags.

[BrainB0ne]

Do you get any errors or it just doesn't work?

See http://doc.trolltech.com/3.3/qt.html#WidgetFlags-enum.
Play with different combinations until you get some result. But it really depends on the window manager to respect the flags.

With the Winapi code I first get the following errors:

#ifdef Q_WS_WIN
 
   CMenu* menu = m_pParent->GetSystemMenu(FALSE);
   menu->ModifyMenu(SC_CLOSE, MF_BYCOMMAND | MF_GRAYED );
 
#endif

#ifdef Q_WS_WIN

   CMenu* menu = m_pParent->GetSystemMenu(FALSE);
   menu->ModifyMenu(SC_CLOSE, MF_BYCOMMAND | MF_GRAYED );

#endif

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: error C2065: 'CMenu' : undeclared identifier
: error C2065: 'menu' : undeclared identifier
: error C2039: 'GetSystemMenu' : is not a member of 'QWidget'
: see declaration of 'QWidget'
: error C2227: left of '->ModifyMenu' must point to class/struct/union
: error C2065: 'SC_CLOSE' : undeclared identifier
: error C2065: 'MF_BYCOMMAND' : undeclared identifier
: error C2065: 'MF_GRAYED' : undeclared identifier


After that i include the <afxwin.h> include file (for CMenu class)
Then the following errors show up:
C:\Program Files\Microsoft Visual Studio\VC98\MFC\INCLUDE\afx.h(226) : warning C4005: 'ASSERT' : macro redefinition
C:\Qt\3.3.4\include\qglobal.h(1010) : see previous definition of 'ASSERT'
: error C2039: 'GetSystemMenu' : is not a member of 'QWidget'
C:\Qt\3.3.4\include\qwidget.h(60) : see declaration of 'QWidget'

[jpn]

That's MFC, not WinAPI...

#include <QtGui>
#ifdef Q_WS_WIN
#include <qt_windows.h>
#endif // Q_WS_WIN
 
int main(int argc, char *argv[])
{
	QApplication app(argc, argv);
	QWidget window;
 
#ifdef Q_WS_WIN
	HMENU menu = ::GetSystemMenu(window.winId(), FALSE);
	::DeleteMenu(menu, SC_CLOSE, MF_BYCOMMAND);
	::EnableMenuItem(menu, SC_CLOSE, MF_BYCOMMAND | MF_GRAYED);
	// or (removes the item in of system menu)
	// ::DeleteMenu(menu, SC_CLOSE, MF_BYCOMMAND);
#endif // Q_WS_WIN
 
	window.show();
	return app.exec();
}

#include <QtGui>
#ifdef Q_WS_WIN
#include <qt_windows.h>
#endif // Q_WS_WIN

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

#ifdef Q_WS_WIN
	HMENU menu = ::GetSystemMenu(window.winId(), FALSE);
	::DeleteMenu(menu, SC_CLOSE, MF_BYCOMMAND);
	::EnableMenuItem(menu, SC_CLOSE, MF_BYCOMMAND | MF_GRAYED);
	// or (removes the item in of system menu)
	// ::DeleteMenu(menu, SC_CLOSE, MF_BYCOMMAND);
#endif // Q_WS_WIN

	window.show();
	return app.exec();
}

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[BrainB0ne]

That's MFC, not WinAPI...

#include <QtGui>
#ifdef Q_WS_WIN
#include <qt_windows.h>
#endif // Q_WS_WIN
 
int main(int argc, char *argv[])
{
	QApplication app(argc, argv);
	QWidget window;
 
#ifdef Q_WS_WIN
	HMENU menu = ::GetSystemMenu(window.winId(), FALSE);
	::DeleteMenu(menu, SC_CLOSE, MF_BYCOMMAND);
	::EnableMenuItem(menu, SC_CLOSE, MF_BYCOMMAND | MF_GRAYED);
	// or (removes the item in of system menu)
	// ::DeleteMenu(menu, SC_CLOSE, MF_BYCOMMAND);
#endif // Q_WS_WIN
 
	window.show();
	return app.exec();
}

#include <QtGui>
#ifdef Q_WS_WIN
#include <qt_windows.h>
#endif // Q_WS_WIN

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

#ifdef Q_WS_WIN
	HMENU menu = ::GetSystemMenu(window.winId(), FALSE);
	::DeleteMenu(menu, SC_CLOSE, MF_BYCOMMAND);
	::EnableMenuItem(menu, SC_CLOSE, MF_BYCOMMAND | MF_GRAYED);
	// or (removes the item in of system menu)
	// ::DeleteMenu(menu, SC_CLOSE, MF_BYCOMMAND);
#endif // Q_WS_WIN

	window.show();
	return app.exec();
}

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Woooow! That did the job! I'm really happy with this solution

[blue.death]

Hi guys,
I'm quite late on this thread but I had the same problem :-)

Anybody knows how to disable that nasty little button on X11 and Mac OS X??

In case you need it, here is a nice macro I am using on Win32 - it's pretty similar to the latest post of course and it works fine:

# ifdef Q_OS_WIN
#  include <windows.h>
#  define ENABLE_CLOSE_BTN(Enable) \
	{ QWidget* tlw = this; \
	while (tlw && !tlw->isWindow() && tlw->windowType() != Qt::SubWindow) \
		tlw = tlw->parentWidget(); \
	HMENU hMenu = GetSystemMenu((HWND) tlw->winId(), FALSE); \
	EnableMenuItem(hMenu, SC_CLOSE, Enable ? (MF_BYCOMMAND | MF_ENABLED) : (MF_BYCOMMAND | MF_GRAYED)); }
# endif // Q_OS_WIN

# ifdef Q_OS_WIN
#  include <windows.h>
#  define ENABLE_CLOSE_BTN(Enable) \
	{ QWidget* tlw = this; \
	while (tlw && !tlw->isWindow() && tlw->windowType() != Qt::SubWindow) \
		tlw = tlw->parentWidget(); \
	HMENU hMenu = GetSystemMenu((HWND) tlw->winId(), FALSE); \
	EnableMenuItem(hMenu, SC_CLOSE, Enable ? (MF_BYCOMMAND | MF_ENABLED) : (MF_BYCOMMAND | MF_GRAYED)); }
# endif // Q_OS_WIN

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Now just use ENABLE_CLOSE_BTN(true) or ENABLE_CLOSE_BTN(false).

It will detect the top level widget of the widget containing the code, so you can use it inside of a child widget (eg. a wizard page in my case) without having to change the macro
Feel free to replace that "while" loop if you are always going to use it inside of a top level window.

And now on with your suggestions for X11/MAC

[MarkoSan]

How do I hide close, resize and minimize featuers in QGLWidget??

setWindowFlags(Qt::FramelessWindowHint);

setWindowFlags(Qt::FramelessWindowHint);

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does not work!!

[jpn]

How do I hide close, resize and minimize featuers in QGLWidget??

setWindowFlags(Qt::FramelessWindowHint);

setWindowFlags(Qt::FramelessWindowHint);

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does not work!!

What do you mean? Are you showing QGLWidget as a top level window? QGLWidget is a QWidget so when it comes to adjusting window flags, anything that works for a plain QWidget should work with QGLWidget as well.

[GokuH12]

Hi guys,
I'm quite late on this thread but I had the same problem :-)

Anybody knows how to disable that nasty little button on X11 and Mac OS X??

In case you need it, here is a nice macro I am using on Win32 - it's pretty similar to the latest post of course and it works fine:

# ifdef Q_OS_WIN
#  include <windows.h>
#  define ENABLE_CLOSE_BTN(Enable) \
	{ QWidget* tlw = this; \
	while (tlw && !tlw->isWindow() && tlw->windowType() != Qt::SubWindow) \
		tlw = tlw->parentWidget(); \
	HMENU hMenu = GetSystemMenu((HWND) tlw->winId(), FALSE); \
	EnableMenuItem(hMenu, SC_CLOSE, Enable ? (MF_BYCOMMAND | MF_ENABLED) : (MF_BYCOMMAND | MF_GRAYED)); }
# endif // Q_OS_WIN

# ifdef Q_OS_WIN
#  include <windows.h>
#  define ENABLE_CLOSE_BTN(Enable) \
	{ QWidget* tlw = this; \
	while (tlw && !tlw->isWindow() && tlw->windowType() != Qt::SubWindow) \
		tlw = tlw->parentWidget(); \
	HMENU hMenu = GetSystemMenu((HWND) tlw->winId(), FALSE); \
	EnableMenuItem(hMenu, SC_CLOSE, Enable ? (MF_BYCOMMAND | MF_ENABLED) : (MF_BYCOMMAND | MF_GRAYED)); }
# endif // Q_OS_WIN

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Now just use ENABLE_CLOSE_BTN(true) or ENABLE_CLOSE_BTN(false).

It will detect the top level widget of the widget containing the code, so you can use it inside of a child widget (eg. a wizard page in my case) without having to change the macro
Feel free to replace that "while" loop if you are always going to use it inside of a top level window.

And now on with your suggestions for X11/MAC

Woo so good! thx for the nice macro! its works just nice

[shad]

Starting with Qt 4.5 there is a new window hint for controlling close button Qt::WindowCloseButtonHint:

QWidget w;
w.setWindowFlags(Qt::Window | Qt::CustomizeWindowHint | Qt::WindowTitleHint| Qt::WindowSystemMenuHint | Qt::WindowMinMaxButtonHint);

QWidget w;
w.setWindowFlags(Qt::Window | Qt::CustomizeWindowHint | Qt::WindowTitleHint| Qt::WindowSystemMenuHint | Qt::WindowMinMaxButtonHint);

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[BrainB0ne]

Starting with Qt 4.5 there is a new window hint for controlling close button Qt::WindowCloseButtonHint:

QWidget w;
w.setWindowFlags(Qt::Window | Qt::CustomizeWindowHint | Qt::WindowTitleHint| Qt::WindowSystemMenuHint | Qt::WindowMinMaxButtonHint);

QWidget w;
w.setWindowFlags(Qt::Window | Qt::CustomizeWindowHint | Qt::WindowTitleHint| Qt::WindowSystemMenuHint | Qt::WindowMinMaxButtonHint);

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That's very nice to hear/know when i'm going to use Qt 4.5 or higher in the future!