[Qt-interest] QTabWidget::currentWidget() problem

[Malyushytsky, Alex]

Mostly likely

textEditorArray[0] contains invalid pointer. Check it.

Alex




Alex Malyushytsky
Research Engineer - Weidlinger Associates Inc.
office: 650 230 0210,
direct: 650 230 0349
web: http://www.wai.com
________________________________________
From: Keshava Krishna [mailto:keshavkrishna88 at gmail.com]
Sent: Thursday, April 02, 2009 8:31 PM
To: Malyushytsky, Alex
Cc: qt-interest at trolltech.com
Subject: Re: [Qt-interest] QTabWidget::currentWidget() problem

Is this happening because i called    " textTab->setCurrentWidget(textEditorArray[0]);"
in a slot that has been connected to "textTab->currentChanged(int)" ??
Can anyone help me out?

Regards,
Keshava.
On Wed, Apr 1, 2009 at 10:50 AM, Keshava Krishna <keshavkrishna88 at gmail.com> wrote:
Thanks Alex, the code you gave worked...

But 'm facing a new problem now....
'm trying to give a fading effect while user clicks on a tab
i have used the following signal connection for this pupose

    connect(textTab,SIGNAL(currentChanged(int)),this,SLOT(tabTransformation()));

and the tabTransformation function is like this..

void Win::tabTransformation()
{

    QColor *color1 = new QColor(255,255,255,0);
    QTextEdit *ptr1 = qobject_cast< QTextEdit *>(textTab->currentWidget());
    textTab->setCurrentWidget(textEditorArray[0]);
    QPalette *palette = new QPalette();
    for(int i=0;i<10;i++)
    {
        *color1 = QColor::fromRgbF(1,1,1,1*(i+1)/10);
        palette->setColor(QPalette::Active,QPalette::Base,*color1);
        ptr1->setPalette(*palette);
        palette->setColor(QPalette::Inactive,QPalette::Base,*color1);
        ptr1->setPalette(*palette);
        textEditorArray[0]->show();
        QTest::qWait(100);
    }

}

but now when i open a new tab (in textTab), it is giving segmentation fault... by using qDebug(0 i discovered that the following line is giving the segmentation fault..
        ptr1->setPalette(*palette); this

Can anyone suggest me why is this happening, please suggest me a better way way acomplishing this task..

Regards,
Keshava.


On Wed, Apr 1, 2009 at 1:48 AM, Malyushytsky, Alex <alex at wai.com> wrote:
>> Before this used to be a warning and my program was working fine, but now it has become an error( 'm really surprised )
I guess you changed compiler.
Use a proper cast. I would recommend qobject_cast in this case:


QTextEdit *ptr1 = qobject_cast< QTextEdit *>(obj);

Regards,
 Alex

________________________________________
From: qt-interest-bounces at trolltech.com [mailto:qt-interest-bounces at trolltech.com] On Behalf Of Keshava Krishna
Sent: Tuesday, March 31, 2009 5:20 AM
To: qt-interest at trolltech.com
Subject: [Qt-interest] QTabWidget::currentWidget() problem

Hi,
'm using a tabwidget to which 'm adding many QTextEdit s...
now i want to get a pointer to the currently activated widget...
i used the following code

   QTextEdit *ptr1 = textTab->currentWidget();

but it is giving the following error

Win.cpp:846: error: invalid conversion from 'QWidget*' to 'QTextEdit*'

Before this used to be a warning and my program was working fine, but now it has become an error( 'm really surprised )

can anyone help me out to debug this ?

Regards ,
Keshava.

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