[lazarus] Programmatically showing the listbox of combobox

[Jesus Reyes]

----- Original Message -----
From: <hernan.et at pg.com>
To: <lazarus at miraclec.com>
Sent: Wednesday, June 11, 2003 5:51 PM
Subject: RE: [lazarus] Programmatically showing the listbox of combobox


> Hi Jesus,
>
> I have played around the combobox implementation and here is what I got.
>
> If you need to trap arrow keys, we need the attached patch. And as for the
> FDroppedDown not updated, I am still working on it. If I may ask, why
would you
> need to check the value of FDroppedDown.

I need the combobox to send the keyboard events to the parent grid in order
to allow
normal grid navigation

I will be happy if I could get the following::

    1. the combobox IS dropped down.

        1.1.    UP/DOWN key events    =>    Item focus
        1.2.    LEFT/RIGHT key events    =>    Item focus or Grid navigation
???
        1.3.    ENTER key event  =>    Focused item is now the selected
Item, hide listbox.
        1.4.    ESC key event    =>    Selected item remains without
changes, hide listbox
        1.5.    CTRL+DOWN    =>    Same as ESC
        1.6.    Typing Text    =>    Incremental search  (item focusing)

    2. the combobox IS NOT dropped down.

        2.1.    UP/DOWN key events    =>    Grid navigation
        2.2.    LEFT/RIGHT key events    =>    Grid navigation
        2.3.    ENTER key event  =>    unhandled or same as 2.5 ???
        2.4.    ESC key event    =>    unhandled
        2.5.    CTRL+DOWN    =>    drop down the listbox to allow 1.1,1.2 or
1.6
        2.6.    Typing Text =>{Dropdown the listbox ???,}Inc. search (item
selection)

The way is now, it sometimes does Item selection and sometimes Grid
navigation, depending on the current item selection! (2.1).

If the lcl combobox will get all key events (being the listbox droppedown or
not), I need a way to know when to do Item Selection or grid navigation and
this depends on DroppedDown Property, at least in the way I planned.

> In my program, when I set Style to
> csDroppedDown, AutoDropDown = True, and I type something on the entry box
I
> cannot get out of the listbox not unless I select an item from the list.
> Also,
> if you need to trap VK_UP or VK_DOWN, the attached file adds another
property
> for the combo box  name ArrowKeysTraverseList with a default value of
True. This
> is the defualt behaviour of the combo box(gtk widget default behaviour),
> especially if you set style to csdropdownlist. Now if you set
> ArrowKeysTraverseList to False and AutoDroppedDown to false and I am not
sure
> style to csdroppedownlist you should be able to trap VK_UP or VK_DOWN. And
also
> the patch implemented the key sequence Ctrl+Down to show the popup.
>
> Regards
>
> Yoyong
>

Thank you, It sounds nice I will update as soon the patches are in cvs ;)

What do you think, are we asking to much to gtk?. I'm asking this because
for example, if I need a multicolumn listbox, with headers, footers and
other goodies, does the underlaying gtkwidget provide such functionality or
we need to wrap another one. if this is the case, aren't we being too gtk
dependant? I mean what if others interfaces doesn't have a so-similar
widget?.

Thanks.

Jesus Reyes A.