Fix Bug w/re to Keyboard Events in MouseBox

[ErraticAttack]

Consider the below code:

Names Default To Here( 1 );
New Window( "SetKey Example", mb = MouseBox( tb = Text Box( "Press a key." ) ) );
mb << setkey( Function( {this, key}, show( key ) ) );
mb << setkeyenable( 1 );
mb << setfocus;

Pressing a button, such as K, causes the attached function to run twice.  Clearly one can produce a work-around with timing and such, but I think that even the JMP developers would consider such user-based work-arounds to be unfortunate.

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[hogi]

Wow, what a cool functionality: setkey!

Thanks for mentioning ...

Nevertheless, really strange issue!
surprisingly, the function is not always triggered twice (see a,b,r,t,z) and for Return (and Enter), one gets an additional  End":

Jmp17 with german Keyboard:

[hogi]

I wondered if it's due to pressing the key and relasing it again.
But  when you keep the key presses, the function is triggered again and again.

The result is particularly interesting when pressing return. Then it is:

[hogi]

I wondered which time it takes between the two triggers of the command - and by doing so, I found an easy solution: 
just make the command slightly longer than show(key) - and it's just triggered 1x

The first function is triggerd twice:

uncommenting the second (slightly longer) function solves the problem:

Names Default To Here( 1 );
time0 = 0;

doSomething = Function( {this, key},
	time = HP Time();
	Write("\!n v1: ",key," ", time);
);

doSomething2 = Function( {this, key},
	time = HP Time();
	dt =  (time - time0)/1000000;
	Write ( "\!n v2: ", key," ", dt);
	time0 = time;
);


New Window( "SetKey Example",
	H List box(mb = MouseBox( tb = Text Box( "Press a key." )), Button Box ("save", onSave()))
);
mb << setkey( Function( {this, key}, doSomething( this, key ) ) );
//mb << setkey( Function( {this, key}, doSomething2( this, key ) ) );
mb << setkeyenable( 1 );
mb << setfocus;

[mia_stephens]

Hi @ErraticAttack, and everyone who has commented. This sounds like a bug. We're sharing with our technical support. 

[Jasean]

Unfortunately the Mouse Box documentation is not quite complete.  We are aware, and it is on the list to be corrected.  In the meantime, please know that the << Set Key message is designed to respond to a "boolean" return value from the enclosed function.  If the function returns "true" (like 1), it indicates to Set Key that the key press was processed, and you will not get the apparent second function call.  If the function returns "false" (like 0), you get the behavior illustrated by the OP example.  Here is a modification of the OP example that writes a single statement to the log for each key press.

Names Default To Here( 1 );
New Window( "SetKey Example", mb = MouseBox( tb = Text Box( "Press a key." ) ) );
mb << setkey( Function( {this, key}, 
	show( key );
	1; // return "boolean" to indicate if the key press was processed.
) );
mb << setkeyenable( 1 );
mb << setfocus;

[ErraticAttack]

Thanks @Jasean, this makes total sense -- just like Qt events.