(Solved) Custom control KeyDown event
lazarus / 31-LCL

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lainz · 2020-10-04 16:03

Hi, I'm making a ListBox with TCustomControl. What I need is when the
user press the keys down and up fire the code that I wrote.

I overrided KeyDown event, but it does nothing.

I've seen in other controls the use of UTF8KeyPress, but I need
KeyDown because I need the arrow keys, vk_up and vk_down.

Any help is appreciated.

Edit:

Here is the source code:
https://github.com/bgrabitmap/bgracontrols/blob/dev-
bgracontrols/bclistboxex.pas

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Blaazen · 2020-10-04 16:38

KeyDown should work in everything derived from TCustomControl. I can
only see that you don't call
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i inherited
KeyDown(Key, Shift);

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winni · 2020-10-04 16:44

Hi!

I just tested your BCListBoxEX.

If you set the initial value of ItemHeight to 20 (and not 150) then
you can see the Items.

Two Bugs:
* If you change the direction you have to type KeyUp or KeyDown twice
* You start at the first item, but you will never reach it again with
KeyUp.

Winni

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lainz · 2020-10-04 16:54

I'm using trunk. I first made the logic in a TForm, but then I'm
moving to TCustomControl to have it independently of the TForm. But in
trunk it doesn't works, I can't move with the keys, maybe it's my
trunk that doesn't works...

Winni you're using FPC release? or trunk?

Edit: using FPC 3.2.0 and Lazarus 2.0.10 doesn't works as well...

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lainz · 2020-10-04 16:58

Quote from: winni on October 04, 2020, 06:44:18 pmHi!

I just tested your BCListBoxEX.

If you set the initial value of ItemHeight to 20 (and not 150) then
you can see the Items.

Two Bugs:
* If you change the direction you have to type KeyUp or KeyDown twice
* You start at the first item, but you will never reach it again with
KeyUp.

Winni

The idea was not to see the items to force the need of changing the
scroll when moving with the keyboard.
I've not tested the code with keyboard since it doesn't works on my
setup

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lainz · 2020-10-04 17:00

Quote from: Blaazen on October 04, 2020, 06:38:28 pmKeyDown should
work in everything derived from TCustomControl. I can only see that
you don't call
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i inherited
KeyDown(Key, Shift);
Thanks, but adding that also doesn't works...

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Blaazen · 2020-10-04 17:17

Do you mean that KeyDown is not triggered at all or your code just
does not work?
Put there some DebugLn('KeyDown', inttostr(Key)); to see what happens.

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winni · 2020-10-04 17:26

Quote from: lainz on October 04, 2020, 06:54:23 pm
Winni you're using FPC release? or trunk?


Hi!

fpc 3.04, Laz 2.010

Screenshot attached.

Winni

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lainz · 2020-10-04 21:25

Quote from: Blaazen on October 04, 2020, 07:17:16 pmDo you mean that
KeyDown is not triggered at all or your code just does not work?
Put there some DebugLn('KeyDown', inttostr(Key)); to see what happens.

Added that in top of the event and doesn't fire. Also added a
breackpoint and doesn't fire as well.

Quote from: winni on October 04, 2020, 07:26:55 pmQuote from: lainz on
October 04, 2020, 06:54:23 pm
Winni you're using FPC release? or trunk?


Hi!

fpc 3.04, Laz 2.010

Screenshot attached.

Winni

Thanks winni, so it's an FPC bug, since with 3.2.0 doesn't works and
you confirm my code is buggy but at least fires on 3.0.4

I will report at the bugtracker
https://bugs.freepascal.org/view.php?id=37871

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lainz · 2020-10-04 22:02

Ok It works, the problem was I've not setup ActiveControl in the demo
form.