How to control subform: Show vs ShowModal et al

[Wilko500]

MacOs Sequoia Laz 4.1 FPC 2.3.3
Scenario: Main form contains active component eg TTimer.  Button on main form runs a process but first requires user input of two dates.

I created a small subform, added two DateTimePickers, user can select date.  It would be desirable to prevent user selecting items on main form until date selection completed along with secondary process.

If I call subform with .ShowModal main form timer process is stopped.
If I call subform with .Show main form timer process continuers but main form can be selected by user

Setting FormStyle to "StayOnTop" looked like a solution but it is not.  Two things, it still allows access to main form  and the DateTimePicker calendar is hidden under the subform.  This may be by design  but I would have expected that the form stays on top but behaves in the standard way ie any clicks on it are still visible.

I would like suggestions as how to prevent user interaction with main form while subform is in operation. Secondly is it right that calendar dialog on DateTimePicker is behind form when StayOnTop is the chosen form style.

[jamie]

I think the timer should remain running while there is a model mode. It must be something different on the target?

Anyways, you can try setting the Enable property to false, that should reject mouse and keyboard input.

[madref]

Take a look at this post. Because I had the same problem.


It also has an example in it.

[Wilko500]

Thank you for responding and sorry for delay answering.

@jamie I have done some more checking and you are correct. Timer does indeed continue during Modal mode.  My program did have ShowModal and then it was changed to Show.  My new understanding is that ShowModal freezes the main thread but the timers running from the main form are in their own threads so they continue running.  Also any code called by the Timer fire event also runs in Modal mode.  I think there must have been something else on the main form that froze when I used ShowModal.  I cannot duplicate that now

@madref Thank you for ref to your post.  An interesting solution.  Looks like my post was referring to a problem that didn't exist, or at least I can't recreate it now, so for now ShowModal is working for me.  I have bookmarked your post and will go through it in more detail when I have more time.  I really enjoy learning new stuff from posts like yours.  Thank you