Const parameters in TElXTree event functions.

Rascular Technology

I'm using BCB2010, so I'm not sure if this impacts Delphi users. In TElXTree, the "CanDrag" event has this signatore:-

  TElXCanDragEvent = procedure(Sender: TObject; const Item: TElXTreeItem; var CanDrag: Boolean) of object;

The C++ function for this is...

void __fastcall TMainForm::xCanDrag(TObject */*Sender*/,

    const TElXTreeItem *Item, bool &CanDrag)

{

  CanDrag = (Item->Text == "Hello");

}

But, because property access functions like GetText are not const functions, I get the following compiler error:

[BCC32 Error] pdesign.cpp(877): E2522 Non-const function _fastcall TElXTreeItem::GetText() called for const object

Obviously I can use a cast to fix this, but it shouldn't be necessary.

Rafael Maricca (LMD)

>>so I'm not sure if this impacts Delphi users<<

No, it does not.

>>Obviously I can use a cast to fix this, but it shouldn't be necessary.<<

We'll discuss this. In no case this change would affect Delphi users, because the negative side effect would be. that all existing event handlers would be invalid.