Q: I've noticed that when I type certain key
combinations (particularly those involving the Shift and Option
keys), nothing comes through to my application's event loop. These
key combinations don't seem to be documented as reserved. What's
happening?
A: You're probably running your app while a
multi-byte script system's input method is active. It turns out that
certain key combinations are reserved as meta-keys for communication
with input methods, in addition to the usual assortment of reserved
keys.
No, these input method meta-keys have not been documented before
now.
So that the information will all be in one place, here is a
complete list of key combinations we know of which may require
avoidance or special handling on the part of an application:
|
key combination
|
reserved by/for
|
effect/purpose
|
notes
|
Option-Shift
and
Option-Control
|
multi-byte script system input methods
|
meta-communication between the user and the input
method
|
You can avoid conflicts with input methods by choosing
not to pass the relevant key combinations to
TSMEvent. However, this
means input method users may not be able to perform
essential tasks.
|
|
Option
|
some third-party input methods
|
meta-communication between the user and the input
method
|
This is not an error; some third-party input methods do
indeed use key combinations involving the Option key with no
other modifier key.
|
|
Option-Control-Shift-Tab
|
Kotoeri (Japanese) input method
|
shows About Box
|
This behavior will be removed in a future release.
|
|
Command-Tab
|
Mac OS 8.5
and later
|
switches to the next application
|
In Mac OS 8.5, the Application Switcher system extension
reserves this combination, but in the future it may be built
into the System file.
|
|
Command-Space
|
System 7.0
and later
|
rotates to the default keyboard layout or input
method in the next script
|
For details, see: Tech Info Library Articles 16481,
Keyboard
Layouts: Availability and Installation, and 16378,
Command-Option-Space bar
Application Conflict
|
|
Command-Option-Space
|
System 7.0
and later
|
rotates to the next keyboard layout or input method
in the active script
|
For details, see: Tech Info Library Articles 16481,
Keyboard
Layouts: Availability and Installation, and 16378,
Command-Option-Space bar
Application Conflict
|
|
Command-Option-Escape
|
System 7.0
and later
|
performs "force quit" on current
application
|
For details, see: Tech Info Library Article 7110,
How
to Quit from an Application That Hangs
|
|
Command-Shift-<digit>
|
Mac OS
(all versions)
|
invokes system function or Fkey code
resource
|
For details, see: Inside Macintosh / Macintosh Toolbox
Essentials / Chapter 2 - Event Manager / Using the Event
Manager / Responding
to Keyboard Events
|
Command-/
and
Command-?
|
System 7.0
and later
|
invokes Apple Guide
|
|
|
Control-[, ], @, \ or +
|
Kotoeri (Japanese) input method
|
none
|
Due to a problem with 'itlk' resources in Mac OS-J, these control key combinations do not always generate events. The 'itlk' resources will be fixed in a future release.
|
This document deliberately omits mention of the Power key
because:
- Third-party applications don't need or want to respond to it,
nor should they.
- Responding to it doesn't involve
keyDown
events.
[May 17 1999]
|
