[Gambas-user] How do I directly access the child controls in a panel container.

[T Lee Davidson]

On 01/10/2015 01:37 PM, Tobias Boege wrote:
> On Sat, 10 Jan 2015, T Lee Davidson wrote:
>> On 01/10/2015 11:08 AM, J?rn Erik M?rne wrote:
>>>
>>>> Hello,
>>>>
>>>>
>>>>
>>>> One can address a control on another form with fMain.txtHello.Text. This
>>>> syntax also works for other container objects. I have a form with a panel
>>>> control. There are several controls within the panel. To avoid naming
>>>> conflicts I want to keep the panel controls separate from the parent form.
>>>> Something like panel.txtEdit.Text would be great but, it does not work. I
>>>> can get the "children" collection of the panel and get the control names.
>>>> That does not help. I need to get to the control and use its properties and
>>>> events. Is there a way to do this?
>>>>
>>>>
>>>>
>>>> Thanks
>>>>
>>> This is the way: Panel1.Children[1].Text
>>>
>>
>> The documentation for Container.Children says that it, "Returns a collection [...]" But it does not return a Collection (class).
>>
>> That's too bad. The ability to do Panel1.Children["TextBox1"].Text would be nice.
>>
>
> If Panel1's containing Form is FForm, then you can do
>
>    FForm.Controls["TextBox1"]
>
> to have this access pattern. Since for every non-Form control, there must be
> a Form somewhere up in the parent chain, it is always an option to go up
> Panel.Parent, Panel.Parent.Parent, etc. to find the *first* container which
> is a Form and then use its Controls property as shown above.
>
> Since all controls (recursively[*]) included in a form must have different
> names, there are no name clashes by design.
>
> [*] It is not so easy if your Form embeds other Forms. If you want to, say,
>      list all control names in your form, you descend recursively from the
>      Form through all containers and Print their children's names.
>
>      In this process, you may not descend into containers which happen to be
>      Forms because another Form is a brand new namespace and you don't want
>      the new names which are in there.
>
> To test whether a container is a form, you can use the Is operator[0].
>
> Regards,
> Tobi
>
> [0] http://gambaswiki.org/wiki/lang/is
>

Thanks for the elucidation, Tobi. But, I must be missing something.

FForm.Controls["TextBox1"] returns a Control which does not have a Text property.

.Parent ("Panel1.Parent") returns a Container which also does not have a Text property.

If we do something like

	Dim hForm As Form
	If Panel1.Parent Is Form Then hForm = Panel1.Parent

we would have hForm.Controls["TextBox1"], which returns a Control with no Text property.


So, we seem to be right back to needing to know the integer index of the control in the container:
Jørn Erik Mørne wrote, "This is the way: Panel1.Children[1].Text"


I did not realize that my little comment would elicit a response, and I do not wish to hijack Martin's thread.
So, unless there is a better way to access the properties of a Container's children, then it seems his question has been answered.


Lee
__________

"Artificial Intelligence is no match for natural stupidity."