convoluted GUI

Got a problem; look:

main.cpp

Code:

---

#include <QApplication>
 
#include "usc_sip_api.h"
#include "usc_gui.h"
#include "usc_gateway.h"
 
GatewayUnit *uscGatewayUnit = new GatewayUnit(0);
 
int main(int argc, char *argv[])
{
	init_sip();
 
	QApplication uscApp(argc, argv);	
	UscGuiES1 uscGui;
	uscGui.show();
 
	return uscApp.exec();

---

}

usc_gui.cpp

Code:

---

#include <QPalette>
#include <QtGui>
 
#include "usc_gui.h"
#include "usc_radio_element.h"
#include "usc_gateway.h"
 
UscGuiES1::UscGuiES1(QWidget *parent)
	: QWidget(parent)
{
	UscRadioElement uscRadioElement;
	uscRadioElement.show();	
 
	setWindowTitle(tr("Universal SIP Client"));
}

---

usc_radio_element.cpp

Code:

---

#include <QPalette>
#include <QtGui>
 
#include "usc_gui.h"
#include "usc_radio_element.h"
 
UscRadioElement::UscRadioElement(QWidget *parent)
	: QWidget(parent)
{
	radioButton	= new QPushButton(tr("R1"));
	rxButton	= new QPushButton(tr("Rx"));
	txButton	= new QPushButton(tr("Tx"));
	pttButton	= new QPushButton(tr("PTT"));
 
	QVBoxLayout *rxtxLayout	= new QVBoxLayout;
	rxtxLayout->addWidget(rxButton);
	rxtxLayout->addWidget(txButton);
 
	QHBoxLayout *topLayout	= new QHBoxLayout;
	topLayout->addWidget(radioButton);
	topLayout->addLayout(rxtxLayout);
 
	QVBoxLayout *mainLayout	= new QVBoxLayout;
	mainLayout->addLayout(topLayout);
	mainLayout->addWidget(pttButton);
 
	setLayout(mainLayout);
}

---

I got no exception at compiling but my window is empty when I start the application.

What is my mistake, what can I do to solve this problem?


Yours Sincerely
Walsi

After setlayout( mainLayout ), try setting setFixedSize( sizeHint() );
Just for curiosity, to see if this is the reason - the widget doesn't get resized yet.

Then you'll know what the problem is.

Regards

No, forget that :)
You create your buttons without a parent.
Pass the "this" pointer as parent and everything will be OK.

Regards

Layouts handle reparenting so it should be fine.

The reason is likely this:

Code:

---

UscGuiES1::UscGuiES1(QWidget *parent)
    : QWidget(parent)
{
    UscRadioElement uscRadioElement; // a local variable is destroyed when going out of scope
    uscRadioElement.show(); 
 
    setWindowTitle(tr("Universal SIP Client"));
}

---

@ marcel: please explain a little bit more detaled what you are meaning

@ jpn: yes and how can I handle my problem that it works???

Best Regards,...

It depends how you want it to be. Here's one way:

Code:

---

UscGuiES1::UscGuiES1(QWidget *parent)
    : QWidget(parent)
{
    UscRadioElement* uscRadioElement = new UscRadioElement(this);
    QVBoxLayout* layout = new QVBoxLayout(this);
    layout->addWidget(uscRadioElement);
 
    setWindowTitle(tr("Universal SIP Client"));
}

---

That's exactly the solution I want. Many thanks to you!

But my further questions, ... to come away from my newbie status, ... are following:

Can you explain this 3 little code lines a liitle bit so that I understand it???

Why do you define uscRadioElement as a Pointer and not like this?

Code:

---

UscRadioElement uscRadioElement:

---

What means (this) at the uscRadioElement Definition and also at the QVBoxLayout definition??

Best Regards!

Quote:

---

Originally Posted by Walsi

Can you explain this 3 little code lines a liitle bit so that I understand it???

Why do you define uscRadioElement as a Pointer and not like this?

Code:

---

UscRadioElement uscRadioElement:

---

---

A local variable allocated on the stack no more exists after the block finishes:

Code:

---

[...]
{
    UscRadioElement uscRadioElement;
    [...]
} // object "uscRadioElement" no more exists

---

However,

Code:

---

[...]
{
    UscRadioElement* uscRadioElement = new UscRadioElement(this);
    [...]
} // the pointer "uscRadioElement" no more exists, but the actual object remains alive

---

Quote:

---

Originally Posted by Walsi

What means (this) at the uscRadioElement Definition and also at the QVBoxLayout definition??

---

It passes "this" as a parent for the layout. Refer to docs about QObject's parent-child relationship. When a layout is in question, it also has a special meaning that it basically calls setLayout() on the passed parent for you.

thanks, that is enough explanation for me! :rolleyes:

Best Regards!