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Programming Interfaces
Input/Output Processes : Handling User Input : Monitoring keystrokes during data entry : User interface triggers
User interface triggers
ABL allows you to access all keystrokes as events. You can intercept these events using the ON statement or the trigger phrase of any statement that declares a user interface widget. For each intercepted event, you can provide a user interface trigger to implement any ABL action. This action can add to, and often replace, the default action associated with the event.
All ABL key labels and key functions are valid events. You can specify a keyboard event in the ON statement or trigger phrase by:
*Using the key label name, such as F2
*Using the key function name, such as GO
Key label events take priority over corresponding key function events. For example, if you specify a trigger for the TAB key function event and another trigger on the same widget for the CTRL+I key label event, only the CTRL+I trigger executes.
Where a key label event corresponds to a key function, use the key function event whenever possible. Key functions are more portable. If you must reference key label events, be sure not to also reference corresponding key function events for the same widget.