Need help with QStyle states of QToolButton when disabling the "State_Sunken"-flag

qwasder85

I have a QToolBar that only shows icons instead of whole buttons. In order to complete the look, I tried to disable the "sunken" look of a QToolButton when in its "checked"-state.
I removed State_Sunken from the QStyle-flags when the QToolButton is in its On-state, which works correctly and the button did not appear "sunken" anymore:

void MyToolButton::paintEvent(QPaintEvent* /*in_p_event*/)
{
    QStylePainter painter(this);

    QStyleOptionToolButton opt;
    initStyleOption(&opt);

    if (opt.state.testFlag(QStyle::State_On))
    {
        opt.state = opt.state & QStyle::State_Sunken;
    }

    painter.drawComplexControl(QStyle::CC_ToolButton, opt);
}

But then it also appeared deactivated (greyed out) in its On-state. So I added the State_Enabled-flag:

...
opt.state = opt.state & QStyle::State_Sunken | QStyle::State_Enabled;
...

After this, the icon didn't appear deactivated anymore. But it still didn't show the icon variation I set for "On" (checked). I tried also setting the State_On-flag, but that brought the old behavior back, including the "sunken" look.
I guess my question now is: Which QStyle-flag only sets the "On"-icon of the QToolButton?

Christian Ehrlicher

See the code in qcommonstyle.cpp:1702 ff:

...
QIcon::State state = toolbutton->state & State_On ? QIcon::On : QIcon::Off;
QIcon::Mode mode;
if (!(toolbutton->state & State_Enabled))
    mode = QIcon::Disabled;
...
pm = toolbutton->icon.pixmap(qt_getWindow(widget), toolbutton->rect.size().boundedTo(toolbutton->iconSize), mode, state);

qwasder85

@Christian-Ehrlicher Thank you so much, that did the trick!

Here's my code now:

void MyToolButton::paintEvent(QPaintEvent* /*in_p_event*/)
{
    QStylePainter painter(this);

    QStyleOptionToolButton opt;
    initStyleOption(&opt);

    if (opt.state.testFlag(QStyle::State_On))
    {
        opt.state = opt.state & QStyle::State_Sunken | QStyle::State_Enabled;

        QIcon::Mode icon_mode = QIcon::Normal;

        if (opt.state.testFlag(QStyle::State_Active))
            icon_mode = QIcon::Active;
        else if (opt.state.testFlag(QStyle::State_Selected))
            icon_mode = QIcon::Selected;
        else if (false == opt.state.testFlag(QStyle::State_Enabled))
            icon_mode = QIcon::Disabled;

        opt.icon = QIcon(this->icon().pixmap(rect().size(), icon_mode, QIcon::On));
    }

    painter.drawComplexControl(QStyle::CC_ToolButton, opt);
}

Christian Ehrlicher

Wouldn't it be better to set the correct icons for the different states than re-setting the icon every time?

qwasder85

@Christian-Ehrlicher They are set, but the whole thing ceases to work when I unset the QStyle::State_Sunken-flag.

Christian Ehrlicher

Since the code I posted above doesn't touch Sunken at all I wonder why it should not work

Bonnie

@qwasder85
I'm not sure how to archive what you want, but you are wrong at the very beginning.

opt.state = opt.state & QStyle::State_Sunken;

This means : clear all the other states, only leave State_Sunken as it was...

qwasder85

@Bonnie How would I unset just this one flag and not change anything else (bitwise operations and me do not see eye to eye)?

Christian Ehrlicher

~~Since it's an enum encapsulated in a QFlag you don't have to worry about bit-setting: https://doc.qt.io/qt-5/qflags.html#setFlag~~

Bonnie

@qwasder85
From qtoolbutton.cpp:

    if (d->down)
        option->state |= QStyle::State_Sunken;

And from the QAbstractButton doc:

down : bool
This property holds whether the button is pressed down

So I don't think this state is what you want...

qwasder85

@Christian-Ehrlicher Using just opt.state.setFlag(QStyle::State_Sunken, false) does not work. The button remains sunken when checked.

@Bonnie It has to be. I tried pretty much every other flag that sounded appropriate.

Christian Ehrlicher

@qwasder85 I don't see a reason why this should be the case. Please provide a minimal, reproducible example.

Bonnie

@qwasder85
I tried to print the state when a toolbutton is checked

if (opt.state.testFlag(QStyle::State_On))
{
    qDebug() << opt.state.testFlag(QStyle::State_Sunken);
    qDebug() << QString("0x%1").arg(opt.state, 8, 16, QChar('0'));
}

The result is:

false
"0x00011021"

Apparently State_Sunken(0x00000004) is not set by default unless it is being pressed down.

Christian Ehrlicher

Which bits are set when can also be seen in the code: https://code.woboq.org/qt5/qtbase/src/widgets/widgets/qtoolbutton.cpp.html#261

qwasder85

@Christian-Ehrlicher I'm creating a small example right now.