custom shaped buttons

[jsabater]

Hi all,

I know similar topics have been addressed in the forum but I was not able to found a solution to my problem.

I want to implement a non-squared button (that emits clicked signals only when the visible part is pressed)

I subclass from QAbstractButton.

This is how my constructor looks like.

GuiButton::GuiButton(QWidget *parent)
     : QAbstractButton(parent)
{
    setAttribute(Qt::WA_TranslucentBackground);
    setAttribute(Qt::WA_NoSystemBackground);
}

GuiButton::GuiButton(QWidget *parent)
     : QAbstractButton(parent)
{
    setAttribute(Qt::WA_TranslucentBackground);
    setAttribute(Qt::WA_NoSystemBackground);
}

To copy to clipboard, switch view to plain text mode 

My PaintEvent looks like:

void GuiButton::paintEvent ( QPaintEvent * event)
{
    Q_UNUSED(event);
 
    QPainter painter(this);
 
    if ( this->isEnabled() )
        painter.drawPixmap(0,0,icon().pixmap(iconSize(),QIcon::Normal));
    else
        painter.drawPixmap(0,0,icon().pixmap(iconSize(),QIcon::Disabled));
}

void GuiButton::paintEvent ( QPaintEvent * event)
{
    Q_UNUSED(event);

    QPainter painter(this);

    if ( this->isEnabled() )
        painter.drawPixmap(0,0,icon().pixmap(iconSize(),QIcon::Normal));
    else
        painter.drawPixmap(0,0,icon().pixmap(iconSize(),QIcon::Disabled));
}

To copy to clipboard, switch view to plain text mode 

My Icon is a PNG with transparent regions (round button).


The widget displays well (transparency...). However, when I click in the transparent region it emits signals.


According to the documentation, reimplementing "hitButton" should do the trick, but I do not get it working...

This is my code:

bool GuiButton::hitButton ( const QPoint & pos ) const
{
    QColor mcolor = icon().pixmap(iconSize()).alphaChannel().toImage().pixel(pos);
 
    if ( mcolor.alpha() == 0)
        return false;
    else
        return true;
 
}

bool GuiButton::hitButton ( const QPoint & pos ) const
{
    QColor mcolor = icon().pixmap(iconSize()).alphaChannel().toImage().pixel(pos);

    if ( mcolor.alpha() == 0)
        return false;
    else
        return true;

}

To copy to clipboard, switch view to plain text mode 

mcolor.alpha() is always 255 (independently) of the coordinate.


In addition, I have problems with the "clicked" signal. "pressed" works fine, but not "clicked".


I am using Qt 4.5 under Linux.


Thank you