Weird QMenu behavior on Mac

[munna]

Hi!

When I set palette on QMenu it doesn't seem to be working. The following is the code

Selector_Menu::Selector_Menu(QWidget *parent) : QMenu(parent)
{
    setMinimumWidth(52);
 
    setAutoFillBackground(true);
 
    QPalette p = palette();
    p.setColor(QPalette::Window, QColor(5, 5, 5));
    setPalette(p);
}

Selector_Menu::Selector_Menu(QWidget *parent) : QMenu(parent)
{
    setMinimumWidth(52);

    setAutoFillBackground(true);

    QPalette p = palette();
    p.setColor(QPalette::Window, QColor(5, 5, 5));
    setPalette(p);
}

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I add actions to this menu from the function where I create this object. Something like this

menu = new Selector_Menu(this);
currentAction = menu->addAction("A");
menu->addSeparator();
menu->addAction("B");
menu->addSeparator();
menu->addAction("C");

menu = new Selector_Menu(this);
currentAction = menu->addAction("A");
menu->addSeparator();
menu->addAction("B");
menu->addSeparator();
menu->addAction("C");

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Output looks like the Picture1 attached

When I use stylesheets I get the output which looks like the Picture2 attached

RMS_Output_Assignment_Selector_Menu::RMS_Output_Assignment_Selector_Menu(QWidget *parent) : QMenu(parent)
{
    setMinimumWidth(52);
 
    setAutoFillBackground(true);
 
    QString menu_ss = "QMenu { color: white; background-color: black; }" +
                        QString("QMenu::item:selected { color: grey; background-color: black; }");
    setStyleSheet(menu_ss);
}

RMS_Output_Assignment_Selector_Menu::RMS_Output_Assignment_Selector_Menu(QWidget *parent) : QMenu(parent)
{
    setMinimumWidth(52);

    setAutoFillBackground(true);

    QString menu_ss = "QMenu { color: white; background-color: black; }" +
                        QString("QMenu::item:selected { color: grey; background-color: black; }");
    setStyleSheet(menu_ss);
}

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Any idea on why is the background not being set properly in the menu. I am using Qt 4.3.1

Thanks a lot for the help

[tinsuke]

Hey Munna!

I've already implemented applications both StyleSheet and Palette based for Mac OS X.

The truth is: they're both (speacially the Palette approach) buggy on (specially, again) Mac.

Up to Qt 4.4.3, some QWidgets properties (including palette) propagation has erronous behaviours. This issue seem to be addressed on Qt 4.5. But, as a workaround, you could implement some function like this:

void applyPaletteTo(const QPalette &palette, QWidget *widget)
{
    widget->setPalette(palette);
    foreach (QObject *object, widget->children())
        if (QWidget *child = (object->isWidgetType() ? dynamic_cast<QWidget *>(object) : NULL))
            applyPaletteTo(palette, child);
}

void applyPaletteTo(const QPalette &palette, QWidget *widget)
{
    widget->setPalette(palette);
    foreach (QObject *object, widget->children())
        if (QWidget *child = (object->isWidgetType() ? dynamic_cast<QWidget *>(object) : NULL))
            applyPaletteTo(palette, child);
}

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and call

applyPaletteTo(yourCustomPalette, yourCustomMenu);

applyPaletteTo(yourCustomPalette, yourCustomMenu);

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Note that, for this to have effect, it must be done AFTER the widget construction (not the constructor, but the whole 'addSomething' stuff).

Now for your StyleSheet problem, try the following:

QString menu_ss = "QMenu { color: white; background-color: black; }"
    "QMenu::item { background-color: black; }"
    "QMenu::item:selected { color: grey; background-color: black; }";

QString menu_ss = "QMenu { color: white; background-color: black; }"
    "QMenu::item { background-color: black; }"
    "QMenu::item:selected { color: grey; background-color: black; }";

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Best regards,
tinsukE