greg heil wrote:
>> If I remember correctly, there is a flag to enable or disable
>> keypreview. If it is enabled every keystroke event will be reported as
>> if for the parent form. Inside parent form's event, user can further
>> allow/disallow the same key event be sent to child control by
>> modifying an output parameter.
>
> Any citation?
>
It is a form property in VB3, but I've not used VB for 10 years. You may try the
all mighty google as usual for "visual basic keypreview event"
>> Since J event handling does not allow output parameter, there may be
>> difficulty to implement what you requested.
>
> i was taking what hints i could from the end of the 2D Graphics
> section of J4C chapter 34 on graphics (p205). Henry suggests getting
> "char Events" from a call like
>
char or mouse events is only available for isigraph. I guess the find dialog
does not contain any isigraph so that these events are not possible.
> formname_isigraphname_eventname_formlocale_ ''
>
> That event is supposed to populate "sysdata". Is that what you
> need/mean by an "output parameter"?
>
That will mean input parameter because usually input/output direction refer to
the callee. Output may means if you set a new value to sysdata and the caller (J
interpreter) will be able to use on returning.
> Also hoping to get/utilise "Mouse Events", but i need to first figure
> out the 4 locatives of that callback to get the data patched into my
> code when an event occurs. ... And possibly set the "flag" you speak
> of?
>
> As always documentation pointers appreciated.
>
The first thing is identify to isigraph in the form, eg. 2 isigraphs in a form
wd'pc myform;cc g isigraph;cc h isigraph;'
you get
myform_g_{event}
myform_h_{event}
where {event} are those given in isigraph event in wd documentation help pages.
The locale of these verbs is the locale (result of 18!:5 '') that your create
the form using wd'pc ...' as explained by Henry. The verb called by event is the
equivalent of
myform_h_{event}_(>18!:5 '')_
For all other child control classes, such as textbox or button, these events are
not available, nor there will be any event raised in parent form except those
assortment of function keys that you find in form editor.
Hope this help
regards,
bill
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