Re: How to create an NSEvent for Option-E?

FROM : Aki Inoue
DATE : Wed Aug 30 23:09:12 2006

> This isn't intended to be shipping code, just a test of a general 
> approach. On a US keyboard, Option-E is the beginning of a multi-
> keystroke char, like "é". If you override keyDown: in an NSView 
> subclass and type Option-E on a US keyboard, the event that you 
> receive has these exact parameters, including the empty string for 
> the characters: parameter. At this point I'm trying to understand 
> how the system could generate and send this NSEvent, but I can't.

The Cocoa's design principle in this area is to avoid the event model 
as much as possible and to offer higher-level abstractions.

When you need to post key events, you can directly create an NSEvent 
with the final Unicode string instead of relying on individual raw 
key event.  Note as Uli mentioned, the result of posting the low-
level raw key event is at most unpredictable because different 
keyboard layouts produce different character mappings.

Aki

On 2006/08/30, at 10:51, Glen Simmons wrote:

> On Aug 30, 2006, at 12:40 PM, Uli Kusterer wrote:
>

>> Am 29.08.2006 um 23:03 schrieb Glen Simmons:

>>>    NSEvent* fakeEvent = [NSEvent keyEventWithType:NSKeyDown
>>>                                          location:NSZeroPoint
>>>                                      modifierFlags:0x80120
>>>                                          timestamp:0
>>>                                      windowNumber:[[NSApp 
>>> mainWindow] windowNumber]
>>>                                            context:nil
>>>                                        characters:@""
>>>                        charactersIgnoringModifiers:@"e"
>>>                                          isARepeat:NO
>>>                                            keyCode:14];
>>>    [NSApp postEvent:fakeEvent atStart:NO];
>>>
>>> This throws an exception: *** -[NSCFString characterAtIndex:]: 
>>> Range or index out of bounds
>>>
>>> Why? What's wrong with this code? How can I send an event for 
>>> Option-E?

>>
>>  I guess AppKit isn't prepared to get an empty string for the 
>> characters: parameter? Why do you need to do this anyway? What is 
>> Option-E? On my keyboard, that's the Euro-sign, so you'd neither 
>> want to use this as a keyboard shortcut, not would you want to use 
>> a fake event to generate the character (Because it may be 
>> different depending on the keyboard, and NSEvent won't auto-fill 
>> the characters: param, which can cause application code to detect 
>> this as the wrong key...).
>>
>>  What are you trying to do?

>
> This isn't intended to be shipping code, just a test of a general 
> approach. On a US keyboard, Option-E is the beginning of a multi-
> keystroke char, like "é". If you override keyDown: in an NSView 
> subclass and type Option-E on a US keyboard, the event that you 
> receive has these exact parameters, including the empty string for 
> the characters: parameter. At this point I'm trying to understand 
> how the system could generate and send this NSEvent, but I can't.


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