[Pythoncard-users] keyDown, keyUp, and keyPress events

Based on a recent discussion on the wx-dev mailing list, the addition of the
key handlers may cause a problem under wxGTK. There may be additional issues
with differences in key codes generated. Please report any issues you find
to the list.

The key events which were defined back in July and added to spec.py, never
got added to the TextField, PasswordField, and TextArea class event
bindings. There was a problem with passing the event on (wxPython
Event.Skip()) if the user code didn't process the event. Anyway, I want to
finally solve the issue, so I've checked in changes to:
  event.py, widget.py, and wxPython_binding.py

There will probably be a change to dispatch.py as well. The current changes
don't do much except allow the user code to handle the event and display the
event in the Message Watcher. I still need to add support for not passing on
the keyPress event, which will be necessary to limit the valid keystrokes
for a field. For example, if you only wanted a user to enter numbers you
would define a on_fieldName_keyPress handler that only called skip() when
the key code was 0 through 9.

The order of events:
  keyDown, keyPress, textUpdate, keyUp

Adding these events exposed some problems with the handling of tabs and the
return/enter key which I also need to investigate. However, it doesn't
appear that any of the samples have been broken by adding the key events. As
an example of handling each event, the following code could be added to
minimal.py:

    def on_field1_keyDown(self, target, event):
        print 'field1_keyDown'

    def on_field1_keyPress(self, target, event):
        print 'field1_keyPressed'
        #event.skip()

    def on_field1_keyUp(self, target, event):
        print 'field1_keyUp'

Note that the 'event.skip()' line commented out above will need to be
uncommented in the future or the keyPress handler above would keep the
characters from showing up in the field as user typed them.

In order to do anything with the event right now you need to get the native
wxPython event and then use wxPython methods.

    def on_field1_keyPress(self, target, event):
        print 'field1_keyPressed'
        nEvent = event.getNativeEvent()
        print nEvent.GetKeyCode()
        #event.skip()

See wxKeyEvent and the Keycodes topics in the wxWindows/wxPython
documentation for more info; I've included the Keycodes topic below. We'll
have to define our own method wrappers and keycode constants in order to
duplicate the wxPython functionality.

I am thinking about just duplicating the codes below, but using a KEY_
prefix instead of WXK_ prefix; the constants will be put in a separate
module file to make it easy to reference them. I'll need some suggestions
for whether we need to do anything specific for supporting Unicode or
keyboards outside the USA generating different 8-bit ASCII key codes
(Russian, Swedish, etc.)

It would be helpful to have some suggestions for a sample or two that need
to do key processing to get a better idea of the functionality we need to
support.

ka
---

Keycodes
Keypresses are represented by an enumerated type, wxKeyCode. The possible
values are the ASCII character codes, plus the following:


 WXK_BACK    = 8
 WXK_TAB     = 9
 WXK_RETURN  = 13
 WXK_ESCAPE  = 27
 WXK_SPACE   = 32
 WXK_DELETE  = 127

 WXK_START   = 300
 WXK_LBUTTON
 WXK_RBUTTON
 WXK_CANCEL
 WXK_MBUTTON
 WXK_CLEAR
 WXK_SHIFT
 WXK_CONTROL
 WXK_MENU
 WXK_PAUSE
 WXK_CAPITAL
 WXK_PRIOR
 WXK_NEXT
 WXK_END
 WXK_HOME
 WXK_LEFT
 WXK_UP
 WXK_RIGHT
 WXK_DOWN
 WXK_SELECT
 WXK_PRINT
 WXK_EXECUTE
 WXK_SNAPSHOT
 WXK_INSERT
 WXK_HELP
 WXK_NUMPAD0
 WXK_NUMPAD1
 WXK_NUMPAD2
 WXK_NUMPAD3
 WXK_NUMPAD4
 WXK_NUMPAD5
 WXK_NUMPAD6
 WXK_NUMPAD7
 WXK_NUMPAD8
 WXK_NUMPAD9
 WXK_MULTIPLY
 WXK_ADD
 WXK_SEPARATOR
 WXK_SUBTRACT
 WXK_DECIMAL
 WXK_DIVIDE
 WXK_F1
 WXK_F2
 WXK_F3
 WXK_F4
 WXK_F5
 WXK_F6
 WXK_F7
 WXK_F8
 WXK_F9
 WXK_F10
 WXK_F11
 WXK_F12
 WXK_F13
 WXK_F14
 WXK_F15
 WXK_F16
 WXK_F17
 WXK_F18
 WXK_F19
 WXK_F20
 WXK_F21
 WXK_F22
 WXK_F23
 WXK_F24
 WXK_NUMLOCK
 WXK_SCROLL