[news.eclipse.platform.swt] Re: KeyEvent.keyCode

["Steve Northover" <steve_northover@xxxxxxxxxx>]

The hex code are just \u0001 etc.
There was a bug in Motif that was fixed for 2.1.
The code below constucts an accelerator from a key event.

"Paul T. Keyser" <rolarenfan@xxxxxxxxxxxxx> wrote in message
news:3ECE7B4B.14F8D470@xxxxxxxxxxxxxxxx
> I'm having the same trouble (I think) trying to get a KeyListener to
respond to
> Ctrl-C/V/X in Text or StyledText.  I don't really understand the character
> arithmetic below, but it seems like it's specific for 'A' (or Ctrl-'A');
what
> would I do for Ctrl-C, Ctrl-V, and Ctrl-X (are the hex-codes just \u0001,
> \u0003, \u0016, and \u0018)?  I want to detect Ctrl + those four keys --
and
> come to think of it, I'm not even sure how the code below distinguishes
between
> the event "Ctrl-A" and any other event -- which output has which value in
which
> case?
>
> (I was trying to get this to work on 2.0.2, and Veronika Irvine, Lynne
Kues, and
> Knut Radloff finally concluded that there was a bug, allegedly fixed in
2.1: see
> the thread on the old newsgroup "cut, copy, paste in StyledText Widget";
now I'm
> on 2.1, and it still doesn't work, or else that global accelerator is
still set
> and I don't know how tto "unset" it.)
>
> Thanks,
> Paul K
>
> Steve Northover wrote:
>
> > We're not hiding any information but it's another field that has to be
> > available and right on every platform.  For example, when the user is
typing
> > in Japanese characters in the IME on Linux, the raw unaffected keycodes
are
> > simply not available.
> >
> > Try this:
> >
> >  int key = event.character;
> >  if (key == 0) {
> >   key = event.keyCode;
> >  } else {
> >   if (0 <= key && key <= 0x1F) {
> >    if ((event.stateMask & SWT.CTRL) != 0) {
> >     key += 0x40;
> >    }
> >   } else {
> >    if ('a' <= key && key <= 'z') {
> >     key -= 'a' - 'A';
> >    }
> >   }
> >  }
> >  int mods = event.stateMask & SWT.MODIFIER_MASK;
> >  int accelerator = mods + key;
> >
> > "Stephen" <stephen.goldbaum@xxxxxxxxxx> wrote in message
> > news:badr3l$pna$1@xxxxxxxxxxxxxxxx
> > > OK, that's a point.  However, I'm not concerned with international
> > > keyboards.  In any case, I don't see how providing the keyCode is in
any
> > > way dangerous.  It's just another bit of information that may or may
not
> > > be useful, depending on your application.  I certainly don't see why
you'd
> > > want to hide it from us.
> > >
> > > I'm trying to mimic JFace Action accelerator behavior for cases when
the
> > > menubar isn't present (and toolbar in the future).  Unfortunately,
setting
> > > the Action's accelerator to "Ctrl+T" (via the convert methods) gets a
> > > value of 262228 (SWT.CTRL|'t').  This value is in no way related to
the
> > > values in the fields of the associated KeyEvent.  In fact, the only
way I
> > > could get the Action accelerator to match the state of the KeyEvent
was to
> > > set the accelerator to (SWT.CTRL|'').  Unfortunately, this relies on
> > > checking the stateMask for SWT.CTRL, thus presenting the same problem
you
> > > mentioned previously.  Am I missing something?  Do you have any other
> > > suggestions for this?
> > >
> > > Thanks,
> > > -Stephen
> > >
> > >
> > > Steve Northover wrote:
> > >
> > > > Yes, this is portable and works the same on all platforms (please
enter
> > a
> > > > bug report when it doesn').
> > >
> > > > Looking for a state mask and key code combination does not work well
on
> > > > international keyboards.  For example, on German Windows, to type an
> > '@',
> > > > the user presses Strg+'Q' or Ctrl+Alt+'Q'.  The Ctrl key is down,
but no
> > > > control character is generated.
> > >
> > > >  /**
> > > >   * depending on the event, the character represented by the key
> > > >   * that was typed.  This is the final character that results
> > > >   * after all modifiers have been applied.  For example, when the
> > > >   * user types Ctrl+A, the character value is 0x01 (NUL).  It is
> > > >   * important that applications do not attempt to modify the
character
> > > >   * value based on a stateMask (such as SWT.CTRL) or the resulting
> > > >    * character will not be correct.
> > > >   */
> > > >  public char character;
> > >
> > >
> > >
> > > > "Stephen" <stephen.goldbaum@xxxxxxxxxx> wrote in message
> > > > news:ba3hrs$5r2$1@xxxxxxxxxxxxxxxx
> > > > > Why is KeyEvent.keyCode only used for modifiers?  Leaving this
field 0
> > for
> > > > > alpha keys makes it very difficult to detect key combinations.
For
> > > > > example Ctrl+a generates an event with
> > > > >
> > > > > event.character = 0x0001 (whereas 'a' is 0x0101)
> > > > > event.keyCode = 0x0
> > > > > event.stateMask = 0x1000000
> > > > >
> > > > > So the only way to detect a Ctrl+a is to map it to '^A' (at least
on
> > > > > Windows).  Beside being a lot of work, I doubt that this is
> > cross-platform
> > > > > compatible.  At least providing the keyCode gives us a fighting
> > chance.
> > > > >
> > >
> > >
> > >
> > >
> > >
>