Is there a key in the keyboard that is the opposite of an escape key? - windows

When you press the escape key, for example, in a YouTube video, it comes out. I recently saw someone press a button to put it in a video and not the other way around as opposed to esacpe, in the keyboard

If you mean putting the video full screen you just need to press the 'f' key. But there is no generic key that allows you to do something like this, it depends on the application.

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Standard (no third-party) way to get numeric keypad working as arrow keys on macOS (Xcode? hidutil?)

I always use numeric keypad as arrows, as I find it more convenient than using an separate arrow pad. Until recently I used a tool Karabiner Elements, but it stopped functionning at Big Sur.
Yes, The Karabiner developer is working on that issue, but it will be better to solve it without relying on a third-party tool.
It will be enough for me to either remap Xcode, or (which is preferred) to change key bindings in the system, using a tool like hidutil.
Xcode's Preferences - Key Binding has a section Text - Section. When I try to modify the binding for say Move Down by pressing Down arrow on numeric keypad it comes up as '2'. Now whereever I press '2', on keyboard or numeric keypad, it always works as Move Down which is certainly not what I am after.
About hidutil. I couldn't find a good manual or any example of keyboard mapping.
Any help?
Had another look at this article. Here is the answer:
hidutil property --set '{"UserKeyMapping":[{"HIDKeyboardModifierMappingSrc":0x70000005A,"HIDKeyboardModifierMappingDst":0x700000051},
{"HIDKeyboardModifierMappingSrc":0x700000060,"HIDKeyboardModifierMappingDst":0x700000052},
{"HIDKeyboardModifierMappingSrc":0x70000005C,"HIDKeyboardModifierMappingDst":0x700000050},
{"HIDKeyboardModifierMappingSrc":0x70000005E,"HIDKeyboardModifierMappingDst":0x70000004F},
{"HIDKeyboardModifierMappingSrc":0x70000005F,"HIDKeyboardModifierMappingDst":0x70000004A},
{"HIDKeyboardModifierMappingSrc":0x700000061,"HIDKeyboardModifierMappingDst":0x70000004B},
{"HIDKeyboardModifierMappingSrc":0x700000059,"HIDKeyboardModifierMappingDst":0x70000004D},
{"HIDKeyboardModifierMappingSrc":0x70000005B,"HIDKeyboardModifierMappingDst":0x70000004E},
{"HIDKeyboardModifierMappingSrc":0x700000062,"HIDKeyboardModifierMappingDst":0x700000049},
{"HIDKeyboardModifierMappingSrc":0x700000063,"HIDKeyboardModifierMappingDst":0x70000004C}]}'
Still can't fugure out, how to do (if possible) complex mapping with modifier keys (eg Ctrl+PgUp to Home), but that's another topic.

Hotkey field in XUL for Firefox

I have a Firefox extension written in XUL. It takes a hotkey. I want to have an input field where the user can press any key and I can programmatically determine what key was pressed.
I don't care about key combos which have meta meanings inside the OS (I don't need to capture Ctrl + Alt + Del).
If the key is already defined by Firefox, I'm OK with not capturing it (for instance, if the user presses F1 and help pops up instead of the key being captured, I'm fine).
I would also love to have some way to determine programmatically whether the key pressed already has some other meaning inside of Firefox, but that is likely out of scope for this request. I just mention it in case it's easy.
My current solution, which seems to have been adopted by a number of add-ons, is to provide a text box where the user can type a printable character and then a series of check boxes for modifier keys. This solution is barely workable but terrible for a number of reasons (it doesn't allow users to use non-printing keys such as function keys in their combos, it allows the user to input invalid characters (such as Unicode characters with no physical key on the keyboard), and it's just awkward to use).
Thanks!
You can use Inline Options
https://developer.mozilla.org/en-US/Add-ons/Inline_Options
You can detect the key pressed in the text input and write your modifiers like accel or alt.
Source example:
http://git.io/vez1o

Create a cocoa button that accepts keyboard input

Hey everyone, thanks for all your help so far, I've learned a whole lot in a short amount of time.
What I've done so far is to create a small calculator program and it works nicely. To complete this version of it, what I'd like to do is make my "keys" on the calculator interface accept input from my keyboard presses. So, for example, if I want to add 2 and 4, instead of clicking my "2" and "4" buttons, I can just press them on my numeric keypad instead.
I know it has something to do with giving my buttons focus but I can't figure out how to make them respond to keydown events.
I'm looking around on the apple developer documentation as well, so if I find the answers before you guys can then I'll try what I find out, and if it doesn't work I'll post with my progress.
Again, thanks everyone for your help!
You can set the key equivalent in interface builder. Click on the button in interface builder open the inspector and open it to the first tab. Under the first section there is a Key Equiv: and a gray box you can click on. Click on it and press the key you want to press it.
If you're using interface builder, just set the "Key Equivalent" field to be your number.

How to determine if a certain key is pressed, knowing only its position on U.S. keyboards?

Consider that, for a Windows video game, I need to determine if the key which generates the ` and ~ characters on the U.S. English keyboard layout (which is usually below the Escape key and left to 1) has been pressed. This may sound like a trivial question, but it doesn't seem like one to me.
When Windows sends keyboard messages, it specifies the virtual key code and the OEM scan code. We can't rely on the OEM scan code, because "the value depends on the OEM" - and nor can we depend on the virtual key code, because it depends on the currently active keyboard layout.
Our current "solution" is to use LoadKeyboardLayout and MapVirtualKeyEx to find the OEM scan code of the key that generates the ` character on the U.S. English keyboard layout, then just listen for that OEM scan code. The problem is that this doesn't work if the user doesn't have the U.S. English layout installed.
Is there a real way to do this on Windows?
The OEM scancode does not change from keyboard to keyboard. No reason not to use it.
Back in the DOS-days the same scancodes have been used for games because it has been the only way to detect key-up and key-down events. Noone had problems with it and I doubt it will change in the future.
If you want another option you may want to give DirectInput-API a try. It gives you the raw scancodes as well and if I'm not mistaken you can also query the physical position, dimension and whatnot of each key.
Tie the game action to the character, not the position of the key. Otherwise, how do you tell the user which key to press? "under the escape key"? They may not have anything there, but if you tell them "the ^ key", they can look for it.
You'll probably also want to make it configurable to accomodate exotic keyboard layouts and user preferences.

Using Numpad with Modifier Keys exhibits curious behavior

I have a keyboard event listener, and I am listening for the number pad key codes (1 through 9) for when number lock is activated; this works fine. However, in my app I also want to allow usage of a modifier key (CTRL) along with the number pad keys. The strange thing is that when holding CTRL, pressing 1 or 3 does not generate any keyboard event whatsoever, whereas 2 and 4 - 9 do generate the expected events. I have seen other references to this issue after some Googling, so I do not believe this is necessarily Flash-specific, but I have yet to find any answers.
I tried using SHIFT as a modifier, but that just results in generating the key codes from the number pad as if number lock was off (eg, SHIFT+Numpad1 returns the End keycode, regardless of number lock state) - apparently this is intentional Windows behavior. ALT is not an option with the numpad due to altcodes.
Any ideas on how to get CTRL+Numpad1 and CTRL+Numpad3 to generate the keyboard events? Or any explanation as to why they don't?
Edit: I tried out using these key combinations in Firefox as enriquein suggests below, and all the key combinations work A-OK, leading me to believe that this is likely a Flash-specific issue, or at least not a hardware issue.
I have run into issues in the past with numpad keys on specific keyboards. Various key combinations fail to register on specific keyboards, and it is possible that the keyboard you are using may just not be generating any event in that case. It's not guaranteed to work, but I would recommend trying out a different keyboard (different vendor, etc) and see if that works. It also might be an issue with localized keyboards, if you are using a non-english keyboard.
I'm almost certain it's not Flash related because I had similar problems with a localized keyboard and could not get it to generate events at all for certain keys or key combinations.
Try enumerating all key events and searching trough what they're mapped to, or google evtest.c, compile it and run it and see what it has to say.
Indeed it looks like its keyboard specific. I tried the key combinations as I read this question in Firefox and they triggered the same event as pressing Ctrl+Number (which is switch to tab #Number).
This was using a standard US/101-key english keyboard (no extra media buttons or anything).
Some keyboards don't register certain key combinations. I think that this is down to how they are put together. For example some may register left hand Ctrl + key combination but not right Ctrl + same key!
A work around would be to detect the key down and key up events for the Ctrl key.
You could then raise a custom event for Ctrl + numpad key or work with a volatile flag to show the Ctrl key state.

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