Pre-Form trigger in Oracle Forms fires during the form start-up, before forms navigates to the first navigable data block of that form.
Use a Pre-Form trigger to perform the tasks such as maximize the forms_mdi_window, initialize some Global variables or set some properties of the form or data blocks etc. and if form gets failed to load (On Failure) Oracle Forms leaves the current form and fires no other trigger.
The following is an example of Pre-Form trigger:
Create the pre-form trigger as shown in below screen shot:
And write the following code in code editor to maximize the parent form window (forms_mdi_window) of Oracle Forms