[SOLVED]OnShowhint with dymanic hints
lazarus / 21-General

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torbente · 2021-01-17 12:00

I believe i solved this issue some time ago, but i searched the forums
and i do not found nothing.

I want be able to show a customized hint for a control, which may
include even global variables values.For this example lets use:

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 MyButton:=
TButton.Create(form1);MyButton.ShowHint := true;
I know i must declare a function to be called on show hint:

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
MyButton.OnShowHint := CheckForHint(MyButton);
and then...

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 Procedure
CheckForHint(Sender:TObject);Beginif Sender = MyButton then   begin 
 // do verifications and finally   MyButton.Hint := 'This is the
customized hint';   end;if Sender = AnotherControl // and so on...end;
But i got this error:
Quoteunit1.pas(37,21) Error: Incompatible types: got "untyped"
expected "<procedure variable type of procedure(TObject;PHintInfo) of
object;Register>
How i could solve this?

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wp · 2021-01-17 12:34

Quote from: torbente on January 17, 2021, 01:00:31 pmCode: Pascal
 [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i
MyButton.OnShowHint := CheckForHint(MyButton);
This is probably supposed to be
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 // if you
use {$mode objfpc}MyButton.OnShowHint := @CheckForHint; // or, if you
use {$mode Delphi}MyButton.OnShowHint := CheckForHint;

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lucamar · 2021-01-17 13:41

Besides what wp said, there are two other problems; the first is that
the signature of your procedure doesn't reflect the one of the event.
Note that the event is declared as a TControlShowHintEvent, which is:
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 type
TControlShowHintEvent = procedure(    Sender: TObject;    HintInfo:
PHintInfo) of object;so your procedure should be:
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 procedure
CheckForHint(Sender:TObject; HintInfo: PHintInfo);
The second is that it's declared "of object", so to be compatible your
procedure should be an object's method, for example:
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 procedure
TForm1.CheckForHint(Sender:TObject; HintInfo: PHintInfo);of course,
with the corresponding declaration inside the form's class, in the
interface section.

That's basically it. HTH!

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torbente · 2021-01-18 03:16

EDIT: Solved using onMouseEnter instead onShowHint

Ok, i did it way and everything is ok except that the assigned hint is
show the next time the cursor moves over the control.
This is what is doing:

first show the current hint
then run CheckForhint procedure
And finally assigns the new hints.

So i need something like "BeforeShowHint?

Quote from: lucamar on January 17, 2021, 02:41:09 pmBesides what wp
said, there are two other problems; the first is that the signature of
your procedure doesn't reflect the one of the event. Note that the
event is declared as a TControlShowHintEvent, which is:
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 type
TControlShowHintEvent = procedure(    Sender: TObject;    HintInfo:
PHintInfo) of object;so your procedure should be:
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 procedure
CheckForHint(Sender:TObject; HintInfo: PHintInfo);
The second is that it's declared "of object", so to be compatible your
procedure should be an object's method, for example:
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 procedure
TForm1.CheckForHint(Sender:TObject; HintInfo: PHintInfo);of course,
with the corresponding declaration inside the form's class, in the
interface section.

That's basically it. HTH!