<div dir="ltr"><div>That may depend on many aspects.<br><br></div><div>First of all, keep in mind that the QMenu implementation is quite complex, as it needs to consider lots of aspects, including the size hint (including that of each item, which may even recursively ask for the current size hint of the whole menu), the position relative to the screen (and, therefore, the screen it would eventually be shown), not to mention OS limitations, including screen size capabilities which would eventually cause scrolling or further menu columns, making event management even more complex. There's a lot of things going on before a menu is finally shown, and some of them may work unexpectedly under certain conditions.</div><div><br></div><div>Then, <span style="font-family:monospace">setActiveAction()</span> only sets the <i>highlighted</i> action at an arbitrary moment, and that may even change depending on platform aspects and their event management. Remember that context menus may be triggered differently depending on the OS: normally, on *nix it happens when the mouse button (or context menu key) is pressed, on Windows when it's released.<br></div><div>Things could also become even uglier when a QMenu has just been created (I'm not completely sure, but calling <span style="font-family:monospace">ensurePolished()</span> before doing anything else <i>may</i> help, especially if you're using a custom style/proxy or stylesheets, but parent/child relation may also come into play).</div><div><br></div><div>If you want to ensure that an item is highlighted, from the UX perspective, you should also ensure that that item is actually placed under the mouse (assuming that the menu is being shown after a <span style="font-family:monospace">ContextMenu</span> event) using <span style="font-family:monospace">popup(pos, action)</span> (see <a href="https://doc.qt.io/qt-5/qmenu.html#popup">the docs</a>), so that the user <i>does</i> know, intuitively, that the current item is the default selected one, as long as the menu geometry doesn't go beyond the current QScreen geometry.</div><div><br></div><div>This is also important for actions used for sub menus: QMenu automatically clears any active action whenever a further mouse event happens after showing, which brings back to what mentioned above: you need to be aware about what event triggers the popup, and also when/how it does that. Do further testing, as it's possible that you only made assumptions ignoring the difference between press and release events: the simple solution is to try to trigger the menu by pressing the mouse button and wait, <b>then</b> release that button.<br></div><div><br></div><div>Setting the "atAction" with popup() may not be appropriate, though, for instance when using QAbstractButton's menus. If that's the case, you may consider using possible work arounds, including "bad ones" (such as a singleShot QTimer) that delay the setActiveAction call, which can still be undone based on the aspect explained above: for instance, if moving the mouse right after that.<br><br></div><div>That said, I know it can be difficult to provide the actual reproducible code in large contexts, but that often means that you're possibly doing something wrong somewhere else, or that you're not calling the related functions properly (or in the proper order).</div><div>I strongly suggest you to put more efforts and try to create a reproducible example: with any luck, you'll be able to find out the issue on your own, otherwise we'll have more ways to understand where the problem is and eventually help you. Knowing more about your environment (PyQt/Qt versions, OS, and WM if using Linux) would certainly help. Note that if you're on Linux, such things easily become a nightmare to deal with. Most of the times, it's really not worth it.<br></div><div><br></div><div>Best regards,</div><div>MaurizioB<br></div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">Il giorno dom 3 mar 2024 alle ore 01:22 John F Sturtz <<a href="mailto:john@sturtz.org">john@sturtz.org</a>> ha scritto:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
<div style="color:rgb(25,72,105)">
Hello good folks.<br>
<br>
I think this is a relatively straightforward question. But the issue is
complicated by the fact that what I am trying to do works perfectly
well (seemingly) in my small test program. In my larger app, not so
much.<br>
<br>
I am creating a <span style="font-family:monospace">QMenu</span>
object on the fly and then using <span style="font-family:monospace">.exec()</span>
to
display it as a popup. What I would like to do is cause the first item
in the menu to be already selected when it pops up.<br>
<br>
I'd have thought this would be simple enough to accomplish, using
<span style="font-family:monospace">.setActiveAction()</span>. And
indeed, in the small test program I wrote
(which is in the zip file attached), it does seem to work as I expect.
The pertinent code is:<br>
<br>
<span style="font-family:monospace"> menu =
QtWidgets.QMenu()</span><span style="font-family:monospace"><br>
</span><span style="font-family:monospace"> for s in
('Foo', 'Bar', 'Baz'):</span><span style="font-family:monospace"><br>
</span><span style="font-family:monospace">
menu.addAction(QtGui.QIcon('account.png'), s)</span><span style="font-family:monospace"><br>
</span><span style="font-family:monospace">
menu.setActiveAction(menu.actions()[0])</span><span style="font-family:monospace"><br>
</span><span style="font-family:monospace">
menu.exec(self.mapToGlobal(QtCore.QPoint(20, 20)))</span><br>
<br>
In my smaller test program, this does just what I expect: When the menu
pops up, the first item is selected.<br>
<br>
Here's the rub: When I put essentially the exact same code into my
larger app, it behaves oddly. The <span style="font-style:italic">first</span>
time I display the popup menu, it doesn't work. The popup menu
displays, but it does not select the first item as I would expect. The <span style="font-style:italic">next</span> time I display the popup, it
does work. And every time thereafter, until the app shuts down.<br>
<br>
I realize this is a bit of a slippery question, because I can't post the
code that <span style="font-style:italic">doesn't</span> work -- only
the code that does. Apparently, something that is going on with the
larger app is messing with this. But I'm wondering if anyone has any
ideas as to why this might be the case, or what I might try to get
around it.<br>
<br>
Thanks!<br>
<br>
/John<span style="font-style:italic"></span><span style="font-style:italic"></span><br>
</div>
</blockquote></div><br clear="all"><br><span class="gmail_signature_prefix">-- </span><br><div dir="ltr" class="gmail_signature">È difficile avere una convinzione precisa quando si parla delle ragioni del cuore. - "Sostiene Pereira", Antonio Tabucchi<br><a href="http://www.jidesk.net" target="_blank">http://www.jidesk.net</a></div>