Desktop UniPageControl - Event Required BEFORE Activating Page Change (with option to prevent) - How ?

[andyhill]

We need the provision for a Desktop UniPageControl Event to advise the program of a user ChangePage Request with the option in code to prevent/cancel the page change (not show the specified TabSheet).

The only event that is fired (none of the Uni/Ext Events fire)  is 'tabchange' but as you can see it is after the event, also there is no way to prevent the change. 

Please advise - thanks

[Sherzod]

14 minutes ago, andyhill said:

We need the provision for a Desktop UniPageControl Event to advise the program of a user ChangePage Request with the option in code to prevent/cancel the page change (not show the specified TabSheet).

The only event that is fired (none of the Uni/Ext Events fire)  is 'tabchange' but as you can see it is after the event, also there is no way to prevent the change. 

Please advise - thanks

\FMSoft\Framework\uniGUI\Demos\Desktop\PageControl - BeforeActivate

?

[andyhill]

Thanks Sherzod, I was viewing the problem from a DevExpress point of view.

[andyhill]

My work around is still messy (lots of flag switching and re-activating).

The problem for me is you have a Sheet Activate Event that expects either a True / False result (BeforeActivate(Sender: TObject; var AllowActivate: Boolean);) which is not ideal if one needs to carry out some dynamic interaction with the user before allowing:-

1) Catch the Activating Request

2) Solicit Password from user

3) If valid password then Activate Sheet else deny

 

[Hayri ASLAN]

On 9/4/2020 at 7:18 PM, andyhill said:

My work around is still messy (lots of flag switching and re-activating).

The problem for me is you have a Sheet Activate Event that expects either a True / False result (BeforeActivate(Sender: TObject; var AllowActivate: Boolean);) which is not ideal if one needs to carry out some dynamic interaction with the user before allowing:-

1) Catch the Activating Request

2) Solicit Password from user

3) If valid password then Activate Sheet else deny

 

Do you need OnChanging(Accept:Boolean) event?

[andyhill]

I need intent to change, then Prompt for Password, validate password and if correct then change to Sheet else not change (as stated 1, 2, 3 above).

[Sherzod]

3 hours ago, andyhill said:

I need intent to change, then Prompt for Password, validate password and if correct then change to Sheet else not change (as stated 1, 2, 3 above).

The first option for your case is using MainModule.EnableSynchronousOperations = True

For example:

procedure TMainForm.UniTabSheet3BeforeActivate(Sender: TObject;
  var AllowActivate: Boolean);
begin
  if UniForm3.ShowModal = mrOk then
    AllowActivate := True
  else
    AllowActivate := False;

  if not AllowActivate then
    ShowMessage('You can not see this TabSheet!');
end;

 

[andyhill]

I appreciate your help Sherzod but my understanding is that the BeforeActivate event is lost once I prompt the user for a password, as mentioned before I have managed a work around.

Ideally the BeforeActivate should have a CallBack so I can further interact with user, then if happy with the challenge response continue with the event allowing activation or denying.

[Sherzod]

6 hours ago, Sherzod said:

MainModule.EnableSynchronousOperations = True

Are you using it?

[andyhill]

Yes, I am away for a week, will touch base on return.

[Sherzod]

OK.

[andyhill]

What I do need desperately is the Desktop PopUpMenu Y Overflow (cater for hundreds of items) that I have raised a ticket for plus of course the Mobile DBListGrid DoubleTap (also ticketed a long time ago), hopefully when I am back they will be resolved. 

[Sherzod]

12 minutes ago, andyhill said:

What I do need desperately is the Desktop PopUpMenu Y Overflow (cater for hundreds of items) that I have raised a ticket for plus of course the Mobile DBListGrid DoubleTap (also ticketed a long time ago), hopefully when I am back they will be resolved. 

Remind us again please, we'll check. But, preferably, always attach test cases so we can reproduce and see the problem.