Icon disappears when clicked - How can I set multiple QIcon::Modes for an icon?

[skebanga]

@ambershark I have created a minimal example replicating the behaviour I see

<!DOCTYPE RCC><RCC version="1.0">
  <qresource prefix="icon">
    <file>play.png</file>
  </qresource>
</RCC>

#include <QApplication>
#include <QMainWindow>
#include <QMenuBar>

void initIcons()
{
	Q_INIT_RESOURCE(view);
}

int main(int argc, char** argv)
{
	QApplication* app = new QApplication(argc, argv);
	QMainWindow*  window = new QMainWindow();

	QMenuBar* menu = new QMenuBar();
	window->setMenuBar(menu);

	QIcon play;
	play.addFile(":icon/play.png", QSize(), QIcon::Normal);
	play.addFile(":icon/play.png", QSize(), QIcon::Active);

	QAction* action = new QAction(play, "", nullptr);
	menu->addAction(action);

	window->show();
	return app->exec();
}

Here is the icon unclicked

Here is the icon clicked

[ambershark]

@skebanga Cool, let me mess with this real quick and see if I can duplicate it and if so if I can find the problem. I'll let you know either later tonight or sometime tomorrow.

[ambershark]

@skebanga Ok so I played with it.. This seems like a bug in QMenuBar (maybe specific to linux).

Here's what I found... If you add text to your action, i.e. new QAction(play, "play") then when you click the play icon it will change to the text "play" as you hold the button down, highlighted with your selection color (in your case blackish gray, in mine blue).

So the reason you are seeing the blank is because it is showing text only and highlighted... so when your text is "" it basically shows a highlighted blank text/space.

That feels like it shouldn't be happening. It shouldn't be changing to the text mode for the highlight, it should highlight the icon as the QToolBar does.

So you could do a few things:

1. Override QMenuBar and handle that click highlight yourself.
2. Switch to a QToolBar - the highlighting of icons works properly on these, see the Qt example widgets/mainwindows/application.
3. Wait for a fix from Qt (assuming you report the bug and it is confirmed as a bug).

I don't see any function in QAction or QMenuBar that could change this behavior. It makes me think it was not intentional... Or I just missed the function that fixes it. ;)

[skebanga]

@ambershark Thanks for giving it a try! I've submitted a bug report

[SGaist]

I just realised one thing, you seem to be using Ubuntu. Are you using the Qt version from your distribution ? If not, then please try with it before opening a report. It might be related to their customisation.

[skebanga]

@SGaist I'm using Qt 5.5 downloaded from the Qt website. Is this not the correct way to obtain Qt?

[SGaist]

This is one way and usually the only one to get the latest version when it comes out.

However, most Linux distribution provide Qt and its development environment because it's a widely used framework and there are usually several system tools using it. This is not only valid for KDE which is based on Qt but also for example for WireShark and other tools which front end are written using Qt.

Thus depending on your target customer/user/etc. you might also want to use your distribution provided Qt to build packages that fits in. In the Ubuntu case, IIRC, there where some customisation done to integrate with their Window Manager.

[skebanga]

@SGaist Ok, thanks! I'll try it out

[ambershark]

@skebanga If it helps I was testing on Arch Linux running without KDE and no preinstalled system wide Qt.

So it's probably not a Ubuntu thing. However like @SGaist I thought that originally since Ubuntu does OSX style stuff with menu bars. I figured that was the issue but it turned out not to be.

[skebanga]

@ambershark Ok, thanks for confirming that