closing a dialog

[RSX]

I made a plasma app that opens a settings dialog
I'm trying to close a dialog with a close button
If I open it like this

void test::settings() { 
 myQtApp *dialog = new myQtApp;
 dialog->show();
}

void test::settings() { 
 myQtApp *dialog = new myQtApp;
 dialog->show();
}

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How can i close it like this

myQtApp::myQtApp(QWidget *parent)
{
    setupUi(this);
    connect( pushButton_close, SIGNAL( clicked() ), this, SLOT( close() ) ); 
}
void myQtApp::close() {
  QMessageBox::about(this,"close",
  "this shold close the dialog");
}

myQtApp::myQtApp(QWidget *parent)
{
    setupUi(this);
    connect( pushButton_close, SIGNAL( clicked() ), this, SLOT( close() ) ); 
}
void myQtApp::close() {
  QMessageBox::about(this,"close",
  "this shold close the dialog");
}

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Didn't read up all if you actually fixed your problem already but:

myQtApp *dialog = new myQtApp(this);
dialog->setAttribute(Qt::WA_DeleteOnClose);
dialog->show();

myQtApp *dialog = new myQtApp(this);
dialog->setAttribute(Qt::WA_DeleteOnClose);
dialog->show();

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this would solve your problem with deleting dialog.

[chrisb123]

Didn't read up all if you actually fixed your problem already but:

myQtApp *dialog = new myQtApp(this);
dialog->setAttribute(Qt::WA_DeleteOnClose);
dialog->show();

myQtApp *dialog = new myQtApp(this);
dialog->setAttribute(Qt::WA_DeleteOnClose);
dialog->show();

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this would solve your problem with deleting dialog.

That works but how do I test if dialog has been deleted or not, I only want to have one created at any one time

[jano_alex_es]

I think it's deleted when you close the dialog. Qt uses to do a lot of hard work for you

Well, if so, you can delete it manually.

myQtApp *dialog = new myQtApp(this);
dialog->setAttribute(Qt::WA_DeleteOnClose);
dialog->show();
delete dialog;
dialog = 0;

myQtApp *dialog = new myQtApp(this);
dialog->setAttribute(Qt::WA_DeleteOnClose);
dialog->show();
delete dialog;
dialog = 0;

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What I do is to create the dialog on the stack. So it will be deleted for sure when it's out of scope. But I do it with small and temporary dialogs.

myQtApp dialog(this);
dialog.setAttribute(Qt::WA_DeleteOnClose);
dialog.show();

myQtApp dialog(this);
dialog.setAttribute(Qt::WA_DeleteOnClose);
dialog.show();

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[chrisb123]

My application is a plasma widget so 99.99% of the time its just the one widget, there is no reason to have anything else just waiting, hidden, invisible or not shown.

When I use this code

m_setapp = new SetApp(this);

m_setapp = new SetApp(this);

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I get this error while compiling

mum.cpp: In member function 'void mum::settings()':
mum.cpp:75: error: no matching function for call to 'SetApp::SetApp(mum* const)'
myqtapp.h:34: note: candidates are: SetApp::SetApp(QWidget*)
myqtapp.h:29: note:                 SetApp::SetApp(const SetApp&)

mum.cpp: In member function 'void mum::settings()':
mum.cpp:75: error: no matching function for call to 'SetApp::SetApp(mum* const)'
myqtapp.h:34: note: candidates are: SetApp::SetApp(QWidget*)
myqtapp.h:29: note:                 SetApp::SetApp(const SetApp&)

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But this works ok

m_setapp = new SetApp(NULL);

m_setapp = new SetApp(NULL);

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From what I can tell it's not deleted when it's closed, I have to manually delete it when its closed, then create it again when required

[axeljaeger]

Right, you have to delete it yourself when you close the application.

But again: Dont try to be to clever. Get your application up and running and dont bother too much in saving memory when you are not know what you are actually doing. Keeping the dialog in memory will not hurt very much. I'd keep it there so it gets shown faster the second time I open it.

[chrisb123]

thanks for your help, its been useful
I still need to learn c++ as object oriented programming is new to me
As for my application, it does what is needed thats why Ive moved onto improving it