Detecting if a form of a given type is already open in Firemonkey application


I am trying to come up with a way to tell if a given type of form is open in my application, before opening a new one. The reason for this, is that there are certain forms in the application which only make sense to have one instance of them open at a time, but I would rather not make them strictly modal.

To solve this I have implemented the following method, which iterates through Screen->Forms and attempts to cast each form to the type of form provided. I figured if the cast was made, I have discovered that type of form is already open.

template <typename T>
bool __fastcall FormOfTypeExists( T * Form )
for( int i = 0; i < Screen->FormCount; i++ )
T * CurrentForm = (T*)Screen->Forms[i];

if( CurrentForm != 0 )
return true;

return false;

Then I call the method wherever I am attempting to create a form, like so:

TFormA *Form;

if( FormOfTypeExists( Form ) )

Form = new TFormA( Owner );


The problem that I am running into is that it seems I am always able to successfully cast the TCommonCustomForm objects in Screen->Forms to whatever type of form I have passed in.

Is there a way I can alter my logic to successfully detect if a form of a certain type already exists in the application? Is there a better approach to this problem I should be looking at?

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