This document summarises the points at which you can easily customise gui
There are a number of protected virtual methods provided in the helper
classes. Simply override these methods to provide your own processing.
CLASS dbEditHelper User Hook Methods
- Called just before copying record values into controls. Controls should be
fully constructed at this point, by the mechanism specific to the particular
GUI, and probably initialised to default values.
- Called after record values are loaded into controls. If you have any
unlinked controls which have values derived from the database values, this
is where you'd set them. (Alternatively, once we implement virtual fields,
you could have a virtual field linked to the control.)
- Called by all movement buttons and OK button. Default allows departure
from record but you can override for complex validation.
- Called to provide user interaction to confirm a save, typically if record
is dirty. Returns a tri-state YNCancelT.
CLASS dbEditHelper Messages - alternative way to react
Some people may not want to subclass dbEditHelper and override the above
messages. You can also set messages of type unsigned long which will be
broadcast along the normal message handling for your framework.
The accessor functions for the optional GUI messages are the public methods
with the same names as the above hook methods, with the prefix msg. eg:
- sets the message broadcast by the default EnteringAboutToLoad
- unsigned long getMsg = msgEnteringAboutToLoad()
- gets the message broadcast by the default EnteringAboutToLoad
Note that if you override the user hooks, the above messages won't be
broadcast unless you do so, or call the dbEditHelper original method.
(c) Copyright A.D. Software 1994-2000 (All Rights Reserved).
Last Updated: 9th September 2001