QMenu: Mac style inverts selected item's text, but not its icon

[barbicels]

The current Mac style for QMenu follows macOS's habit of inverting the text of the selected item (e.g., to light-gray-on-accent from black-on-light-gray), but how can I prevent my monochrome SVG icon from disappearing into the dark accent color when its menu item is selected?

I have tried setting the QAction's icon to a QIcon that has a different SVG file added for the QIcon::Selected mode, but that appears to have no effect.

[zvoopz]

Invert colors of an icon if selected
example for button icon

void MainWindow::invertButtonIcon(QPushButton *button)
{
   
    QPixmap pixmap = button->icon().pixmap(button->iconSize()); // Get icon as pixmap
    QImage img = pixmap.toImage();
    img.invertPixels(QImage::InvertRgb); // Invert colors
    button->setIcon(QIcon(QPixmap::fromImage(img))); // Apply new inverted icon
}

[barbicels]

@zvoopz That definitely works for a case where your code has control, but I was referring to a QMenu that the user is picking from, where my code is not in control. To stand out from the highlight color, the menu item's icon would need to render one way when the user mouses over the item and another way when mousing off it.

Currently, I've put a half-opaque "rim" on the SVGs so that the monochrome icon stands out a little bit against the highlight color. What I really need is for that (rimless) icon to switch completely from dark to light when the user mouses over, in the same way as the menu item text and shortcut do.

This ought to be easy, considering that a QIcon can have multiple modes including Selected, but nothing seems to work, and I can't find any working examples online. My suspicion is that Qt's "native Mac style" doesn't inform the icon-element renderer that it should use the "selected" mode in this situation. (Notice that it doesn't "disable" the cancel icon, either, even though the same QAction object shows a grayed-out icon when it's added to a QToolBar.)

Considering that we have to force the application's Qt::AA_DontShowIconsInMenus attribute to false even to see icons in menu items, Qt's answer might be that what I want is beyond consideration.

[IgKh]

On Cocoa QMenu objects are thin wrappers of AppKit NSMenu objects. You can get access to the underlying NSMenu Objective-C object with QMenu::toNSMenu and patch out the icons, probably with something like the onStateImage and offStateImage properties. You could probably write a workaround of sorts using that.

That said, no native macOS application I've seen recently has icons on menu items, despite AppKit supporting them. There doesn't seem to be any wording in Apple's HIG that discourages their use, but I guess the best way to blend in is to not have them as well...

[barbicels]

@IgKh I agree; my impression is that Apple disfavors the practice and Qt has adapted its default to follow that. I just think it's odd that the optional with-icons treatment is inconsistent — for example, icons on disabled menu items are dimmed if they're pixmaps but not if they're SVG.

As long as Qt intends to be a toolkit that minimizes the need for platform-specific code, I think it should try to support things like this in the name of cross-platform consistency, even if devs whose app is Mac-only should be happy with iconless menu items as you described.

[barbicels]

One data point about Apple's preference: Safari's Bookmarks menu uses a "globe" icon for pages that lack their own icon, and that monochrome globe icon does switch between light and dark when selected.