Qt: Add option to disable the system tray icon #8006

My changes leave all tray icon and menu creation/initialization logic untouched. It only shows or hides the icon according to the setting.

A new checkbox was added to the OptionsDialog under the Window tab. A bool option named "disableTray" was added to OptionsModel. This checkbox was mapped like other all options to the OptionsModel.

A signal was added to the OptionsModel for broadcasting changes the the disableTray option. This signal was connected to a new slot added to BitcoinGUI named updateDisableTray(bool). The slot simply hides or shows the trayIcon in BitcoinGUI according to the parameter recieved.

The negative wording of "disableTray" instead of a positive wording ("enableTray") because enabled is the default. Perhaps "hideTray" would be better than disable.

This pull request intends to resolve this issue: #7160

Btw, this is my first pull request. Don't hurt me.

@jonasschnelli, yes, it was. I'll edit it back to zero.

Nice work! Concept ACK will test in detail soon.

Concept ACK.

Perhaps "hideTray" would be better than disable.

I'd prefer "setTrayVisible(bool)" - this is closer to Qt's own usage. I agree on the positive versus negative wording in principle, but on the other hand the default could change later, so may as well make it general.

@laanwj, since we're getting verbose anyway, would "setTrayIconVisible(bool)" be even better? Because, technically, I'm setting the visibility on the TrayIcon.

Btw, thanks for reminding me about the setVisible function. I had used an if(flag) tray->hide(); else tray->show() logic that I can simplify to a single line with setVisible.

setTrayIconVisible(bool)

Sure, even clearer.

@laanwj, fixed.

This currently results in a startup crash on OSX because trayIcon is NULL on OSX (see void BitcoinGUI::createTrayIcon(const NetworkStyle *networkStyle)).

IMO this PR should remove the #ifndef Q_OS_MAC for the tray-icon creation (so it also gets created on OSX) and disabled it by default on OSX (over platformstyle class).

@jonasschnelli I think the reason it's not created on OSX is because the menu items are added to some other menu (which effectively acts as a tray icon). It was non-trivial to get rid of the #ifdeffing there, at least it seemed back in the day when I implmemented platformstyle.

utACK (testes a bit but will test more in detail). I can fix the OSX tray-icon support later (if even possible).

Needs squashing.

@jonasschnelli, squashed.

Tested ACK a8abd45ec7ddb16d09f9abfd90b6eea722c55103

A little nit: If you have your tray icon disabled, it shortly flickers up during startup of Bitcoin-Qt.

A simple change can fix this:

--- a/src/qt/bitcoingui.cpp
+++ b/src/qt/bitcoingui.cpp
@@ -545,7 +545,7 @@ void BitcoinGUI::createTrayIcon(const NetworkStyle *networkStyle)
     QString toolTip = tr("%1 client").arg(tr(PACKAGE_NAME)) + " " + networkStyle->getTitleAddText();
     trayIcon->setToolTip(toolTip);
     trayIcon->setIcon(networkStyle->getTrayAndWindowIcon());
-    trayIcon->show();
+    trayIcon->hide();
 #endif

     notificator = new Notificator(QApplication::applicationName(), trayIcon, this);

@jonasschnelli, good catch. I added that edit.

Tested ACK 8b0e4970281de15472a93a529302f3de15163943

Tested ACK 8b0e497