[PyQt] Show tooltip onto QLabel

[Maurizio Berti]

Glad I could help!
I've never used HoverEvents, but if it suits your needs, that's ok :-)

Yes, another issue with QToolTip is the delay after their event is called.
Since Qt5 it can be customized, though, by setting a QProxyStyle that
returns the timeout in milliseconds when SH_ToolTip_WakeUpDelay styleHint
is requested.
This is a small example that allows you to set a 0 timeout for specific
widgets:

class MyStyle(QtWidgets.QProxyStyle):
    toolTipTimeouts = {}
    def styleHint(self, hint, option, widget, returnData):
        if hint == QtWidgets.QStyle.SH_ToolTip_WakeUpDelay:
            try:
                return self.toolTipTimeouts[widget]
            except:
                pass
        return QtWidgets.QProxyStyle.styleHint(self, hint, option, widget,
returnData)

class MyWindow(QtWidgets.QMainWindow):
    def __init__(self):
        [...]
        self.widget = SomeWidget()
        self.style().toolTipTimeouts[self.widget] = 0
        #optional, if you need to remove widgets at a certain point,
        #allowing the garbage collector to free up memory
        self.widget.destroyed.connect(self.style().toolTipTimeouts.pop)

app = QtWidgets.QApplication(sys.argv)
app.setStyle(MyStyle())

In this way the QProxyStyle will immediately call the QEvent.ToolTip for
the specified widgets.

Maurizio

Il giorno mar 22 gen 2019 alle ore 16:21 Tong Zhang <warriorlance at gmail.com>
ha scritto:

> Thanks, Maurizio! I've got what I want from your message, BTW, I used
> hover event to trig the help message to show on a textedit, since I
> found tooltip event responses a little bit slower than I want, maybe
> there is someway to speed up.
>
> Tong
>
> On 1/21/19 6:40 PM, Maurizio Berti wrote:
> > Using standard tooltips might be an issue in some (not so special)
> > cases, as QToolTip events are strictly related to the widget events, so
> > you'll need to install an eventFilter on every single widget you'll want
> > the behavior you ask about.
> > A simple implementation would be something like this:
> >
> >      def __init__(self, *args, **kwargs):
> >          [...]
> >          self.toolTipWidget = QtWidgets.QLabel()
> >          [...]
> >          self.someWidget = SomeWidget()
> >          self.someWidget.setToolTip('I am a tooltip!')
> >          self.someWidget.installEventFilter(self)
> >          [...]
> >
> >      def eventFilter(self, source, event):
> >          if event.type() == QtCore.QEvent.ToolTip:
> >              self.toolTipWidget.setText(source.toolTip())
> >          return QtWidgets.QWidget.eventFilter(self, source, event)
> >
> > On the other hand, I'd suggest to use the StatusTip instead of the
> > ToolTip: it's something I've successfully used for something similar to
> > your needs: in this way you can keep the StatusTip for "simple" tooltip
> > text and the ToolTips for further customized messages, as they also
> > allow rich text content.
> > Here's a small example:
> >
> >      def __init__(self, *args, **kwargs):
> >          [...]
> >          self.toolTipWidget = QtWidgets.QLabel()
> >          [...]
> >          self.someWidget = SomeWidget()
> >          self.someWidget.setStatusTip('I am a statustip!')
> >          [...]
> >
> >      def event(self, event):
> >          if event.type() == QtCore.QEvent.StatusTip and event.tip():
> >              self.toolTipWidget.setText(event.tip())
> >          return QtWidgets.QWidget.event(self, event)
> >
> > Note that here I used the setStatusTip() method instead of the
> > setToolTip() one.
> > Obviously, if you're using Designer you'll set the StatusTip property
> > from there, instead of the ToolTip property.
> >
> > How does it work?
> > Usually the StatusTip is only used on a QMainWindow with a QStatusBar
> > installed, but, interestingly enough, the event() method of *any* widget
> > can be used to catch /any/ StatusTip event called from both that widget
> > /and/ its children.
> >
> > In both cases you'd better think about a way to "clear" the tool/status
> > tip, as leaving it there might be confusing.
> > If you don't have too many widgets, the eventFilter way might be a good
> > solution, as you can also catch the QEvent.Leave event type to hide the
> > "tooltip" by clearing the label text, otherwise it's probably
> > better using a QTimer on the parent widget or the label, and set it as
> > singleShot (don't use the static method, as it could hide a new
> > statustip activated in the meantime), then connect it to something like
> > lambda: self.toolTipWidget.setText('')whenever you catch the StatusTip
> > event.
> >
> > If for some reason you'll need to stick with ToolTips, there's a
> > solution anyway.
> > If all widgets already have their tooltips, and the layout is static and
> > permanent once the main parent widget is being instantiated, just use
> > the children() iterator and check for both isWidgetType() and toolTip()
> > contents: if those condition match, install the eventFilter; if the
> > layout is dynamic instead, use the childEvent method on the parent and
> > check for QEvent.childAdded and QEvent.childRemoved events, then use
> > installEventFilter or removeEventFilter respectively.
> >
> > Regards,
> > Maurizio
> >
> >
> > Il giorno lun 21 gen 2019 alle ore 23:22 Tong Zhang
> > <warriorlance at gmail.com <mailto:warriorlance at gmail.com>> ha scritto:
> >
> >     Hello,
> >
> >     Can I show the tooltip of some widget onto a QLabel? e.g. Tooltip
> >     will show when I move the mouse onto the pushbutton, how about show
> >     the tooltip on another widget, say label?
> >
> >     Thanks,
> >     Tong
> >     _______________________________________________
> >     PyQt mailing list PyQt at riverbankcomputing.com
> >     <mailto:PyQt at riverbankcomputing.com>
> >     https://www.riverbankcomputing.com/mailman/listinfo/pyqt
> >
> >
> >
> > --
> > È difficile avere una convinzione precisa quando si parla delle ragioni
> > del cuore. - "Sostiene Pereira", Antonio Tabucchi
> > http://www.jidesk.net
>


-- 
È difficile avere una convinzione precisa quando si parla delle ragioni del
cuore. - "Sostiene Pereira", Antonio Tabucchi
http://www.jidesk.net
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://www.riverbankcomputing.com/pipermail/pyqt/attachments/20190122/214cd10a/attachment-0001.html>