I think this is my problem
3.4. Inheritance and constructor
Contrary to all the object language I know, each class in the
inheritance hierarchy consumes the parameters passed to the constructor.
Let's suppose we have the following inheritance tree:
|MyListBox ---inherits--> ListBox ---inherits---> Control |
*
Control <http://gambaswiki.org/wiki/comp/gb.gtk/control>._new() does
not exist.
*
ListBox <http://gambaswiki.org/wiki/comp/gb.qt4/listbox>._new()
takes one parameter: the parent control.
*
MyListBox._new() takes one parameter: a name - It is just an example.
So |NEW <http://gambaswiki.org/wiki/lang/new> MyListBox| will take two
parameters.
*
The first will be sent to ListBox
<http://gambaswiki.org/wiki/comp/gb.qt4/listbox>._new().
*
The second to MyListBox._new().
Be careful: the ListBox
<http://gambaswiki.org/wiki/comp/gb.qt4/listbox>._new() will be called
first, so that you are sure that the ListBox
<http://gambaswiki.org/wiki/comp/gb.qt4/listbox> control exists when you
are in MyListBox._new().
Then you will create a MyListBox control this way:
hMyListBox *=* *New* *MyListBox**(*hContainer*,* "Name"*)*
So the order of arguments is the following:
*
Mandatory arguments are consumed first, and then optional arguments
if they are available.
*
The arguments of elder classes are specified first.
In Gambas 2.0, the order or arguments were reversed!
For example, if you have the following inheritance:
|MyForm --> Form --> Window |
with the MyForm constructor being:
|Sub _new(FirstArg As String, SecondArg as Integer, Optional ThirdArg As
Integer) |
Note: the Form <http://gambaswiki.org/wiki/comp/gb.qt4/form> constructor
takes no argument, and the Window
<http://gambaswiki.org/wiki/comp/gb.qt4/window> constructor takes an
optional parent argument.
The signature of the final constructor will be:
|New MyForm(FirstArg As String, SecondArg As Integer, Optional Parent As
Control, Optional ThirdArg As Integer) |
In a more general way, the order of arguments for a three level
inheritance tree is:
*
Mandatory arguments of the grand-parent constructor.
*
Mandatory arguments of the parent constructor.
*
Mandatory arguments of the final constructor.
*
Optional arguments of the grand-parent constructor.
*
Optional arguments of the parent constructor.
*
Optional arguments of the final constructor.
On 17/02/17 13:55, Benoît Minisini wrote:
> Le 17/02/2017 à 03:08, Shane a écrit :
>> Looks Like Pic1
>>
>> and then pic2
>>
>>
>>
> Which version of Gambas do you use?
>
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