Ctrl+- (Ctrl+Hyphen-Minus) as ShortCut Key?

Question

It might seem natural to use Ctrl + +, Ctrl + -, and Ctrl + 0 as shortcuts for an application's zoom in, zoom out, and restore default zoom (typically 100 %) actions. Now, in Delphi, I am able to assign Ctrl + + and Ctrl + 0 as shortcuts. The former, though, requires that the plus sign of the main part of the keyboard is used; the plus sign of the numerical keypad cannot be used.

Problem arises, however, when I want to assign Ctrl + - as a shortcut. It simply doesn't work. If I assign "Ctrl+-" in the IDE, the value stored in the ShortCut property is 16495. If we subtract ssCtrl from this, we obtain 111. A work-around, one would believe, would be to assign ShortCut := 45 + ssCtrl, or, equivalently, ShortCut := Menus.ShortCut(45, [ssCtrl]), because ord('-') = 45. But that doesn't work.

However, I have found a working solution: ShortCut := 189 + ssCtrl. I choose 189 because that is the number I receive when I depress the "-" key and listen to the KeyDown event.

So, why am I not happy with this? Well, I am afraid that the constant 189 only is valid on Swedish keyboards. I have tried to read about this, and, as usual, the MSDN documentation is rather clear, but then, who knows how Delphi handles things.

Answer 1

The key code 189 is VK_OEM_MINUS in Windows.pas, so your solution isn't just for Swedes.

Answer 2

the correct to use menu shortcut on the numeric pad is
CtrlNum + for the [+]
CtrlNum - for the [-]

there is a space between Num + and Num -

Answer 3

I'm not sure why you're getting 16495 for Ctrl + -. When I add that shortcut to an action, it gives me 16573, and it does show up on the menu as Ctrl + -, and that shortcut does work.

However, you are correct that Menus.ShortCut(ord('-', [ssCtrl]) does not work. It gives the value 16429 and shows up on the menu as Ctrl + Ins, and Ctrl + Ins works as the shortcut.

Maybe this is a problem with Delphi 2009 and later since they added Unicode.