Is it possible to display the current state of modifier keys

keyboard

I have a keyboard which is a little flaky, and occasionally one of the modifier keys becomes stuck. Realizing I’ve entered this state often takes a while. Is it possible to display — e.g., in the menu bar or in the style of Sticky Keys — which modifier keys are currently down?

I don’t need the Sticky Keys functionality, so turning that on wouldn’t seem to be a solution.

Best Answer

There is one native solution I can think of, and that's to show the Keyboard Layout window. This can be accessed through the input menu in the menu bar*, and will show you all keys and their current states. A bonus to this for normal circumstances is that you can see where option and shift-option special characters are mapped.

Another possible solution involves a third-party app such as Keyboard Maestro. If you create a macro triggered by the press of a modifier key, you can tell it to, say, display a Growl notification with a relevant message. I'm not exactly sure how you'd want to do this, or what exactly you'd want it to do in the first place, but many of these programs have tons of options.

*To enable this, go to System Preferences > Keyboard > "Show Keyboard and Character Viewers in menu bar"

Related Solutions

Changing modifier keys from the command line

Changing preferences and running, defaults -currentHost read -g shows you what changes are being written. I was going to write up a short bash script to automate it, but it looks like I was beaten to the punch:

#!/bin/bash                                                                      

mappingplist=com.apple.keyboard.modifiermapping

if [ $1 == "emacs" ]; then
    echo "Switching to emacs modifiers"
    defaults -currentHost write -g $mappingplist '(                              
                {                                                                
            HIDKeyboardModifierMappingDst = 4;                                   
            HIDKeyboardModifierMappingSrc = 2; },                                
                {                                                                
            HIDKeyboardModifierMappingDst = 12;                                  
            HIDKeyboardModifierMappingSrc = 10;                                  
        },                                                                       
                {                                                                
            HIDKeyboardModifierMappingDst = 2;                                   
            HIDKeyboardModifierMappingSrc = 4;                                   
        },                                                                       
                {                                                                
            HIDKeyboardModifierMappingDst = 10;                                  
            HIDKeyboardModifierMappingSrc = 12;                                  
        })'


else
    echo "Switching to default modifiers"
    defaults -currentHost delete -g $mappingplist
fi

The script takes one argument, if the argument is emacs, then it swaps command and control, if the argument is anything else it restores the defaults.

http://forums.macrumors.com/showthread.php?t=949280

How to disable visual display of modifier keys

It sounds like you have the “Sticky Keys” feature enabled.

To control the setting, open the System Preferences application ( > System Preferences…), load the Universal Access preference pane, goto the Keyboard tab. You can turn “Sticky Keys” Off (or On) there. You may also want to disable the “Press the Shift key five times to turn Sticky Keys on or off” feature. Or, if you want the sticky feature without the display, just disable “Display pressed keys on screen” and leave it enabled.

Best Answer

Related Solutions

Changing modifier keys from the command line

How to disable visual display of modifier keys

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