Arguments: window buttons key-code
Called when a virtual-key-down event happens on window.
buttons is an integer that indicates the mouse buttons and shift keys
that are down, and is some logior'ed combination of the values of
these bit-flag constants: left-mouse-button,
middle-mouse-button,
right-mouse-button,
shift-key,
control-key, and
alt-key.
key-code is an integer representing the key that was pressed. If an
alphanumeric character appears on the key, then key-code is the
char-int of that character. Otherwise, key-code is the value of one of
the character name constants beginning with "vk-". The value of the
constant key-names is a list of all of the
"vk-" character names.
A note about virtual-key-down and character-message:
While a keypress will always cause virtual-key-down and virtual-key-up to be called, it will cause character-message to be called only under certain conditions. First, the keypress must indicate a graphical character. second, one of the following must be true:
1. The window in which the key was pressed is a dialog-mixin instance or a child or
other descendant of a dialog-mixin instance; or
2. The default virtual-key-down method must run (since this method tells the operating system to generate a character message from the virtual-key-down message).
Therefore, if an application adds a virtual-key-down method for a window that is not on a dialog, and this method does not call (call-next-method) for a particular keypress, then the default virtual-key-down method is not called, and therefore character-message will not be called for that keypress.
See About events in the IDE in cgide.htm.
Common Graphics and IDE documentation is described in About Common Graphics and IDE documentation in cgide.htm.
The documentation is described in introduction.htm and the index is in index.htm.
Copyright (c) 1998-2000, Franz Inc. Berkeley, CA., USA. All rights reserved.
Created 2000.10.5.