How to query and change the time it takes for a QToolTip to appear?

Question

Is it possible to change the time delay between the mouse being still in a window, and the tooltip's show event?

Is there a Qt wrapper for something like TTM_SETDELAYTIME? According to the Windows documentation, the default value depends on the double-click interval.

Answer 1

You'll have to set a custom QProxyStyle that overrides styleHint() and returns your preferred value for QStyle::SH_ToolTip_WakeUpDelay. Sample code below.

class CustomStyle : public QProxyStyle
{
Q_OBJECT
\\...
public:
    int styleHint(StyleHint hint, const QStyleOption *option = nullptr,
                  const QWidget *widget = nullptr, QStyleHintReturn *returnData = nullptr) const override
    {
        if (hint == SH_ToolTip_WakeUpDelay)
            return someCustomValue;
        else
            return QProxyStyle::styleHint(hint, option, widget, returnData);
    }
}

Answer 2

Apparently that's not possible with the built-in Qt Tooltips. In 4.8 qapplication.cpp they use magic numbers:

d->toolTipWakeUp.start(d->toolTipFallAsleep.isActive()?20:700, this);

So the default behavior is to show a tooltip after 700 ms, and start a 2000 ms fall-asleep timer. If we hover over another window(widget) with the fall-asleep timer still active, the delay will be reduced to 20 ms, probably under the assumption that the first tooltip was not the one the user wanted.