[Solved] ListBox OnMeasureItem call it OnResize

[lainz]

Hi, ListBox configured as lbOwnerDrawVariable can handle different item heights. However when I resize the form the items are not resized, and it's a common problem, like you can read here

https://social.msdn.microsoft.com/Forums/Windows/en-US/0dce187f-a5b7-47d9-8a3c-6fe4b5e40c6d/listbox-ownerdrawvariable-itemheight-not-set-on-resize?forum=winformsdesigner

In that post there's a solution but for C#.

Any ideas on how I can force internal OnMeasureItem call to resize each item?

Attached all the source code.

[esvignolo]

Hi Lainz!, on GTK2 works similar windows, (with the same problem), but in carbon doesn't work.

Thanks again for your time and work!

[balazsszekely]

That c# code translated looks like this(create OnResize event for ListBox1):

Code: Pascal  [Select][+][-]

1. procedure TForm1.ListBox1Resize(Sender: TObject);
2. const
3.   LB_SETITEMHEIGHT = $01A0;
4. var
5.   H: Integer;
6.   I: Integer;
7.   MeasureItemEvent: TMeasureItemEvent;
8. begin
9.   MeasureItemEvent := ListBox1.OnMeasureItem;
10.   if not Assigned(MeasureItemEvent) then
11.     Exit;
12.   for I := 0 to ListBox1.Count - 1 do
13.   begin
14.     MeasureItemEvent(TWinControl(ListBox1), I, H);
15.     LCLIntF.SendMessage(ListBox1.Handle, LB_SETITEMHEIGHT, I, H);
16.   end;
17. end;

Edit: SendMessage is declared in lclintf.

[lainz]

Hi Lainz!, on GTK2 works similar windows, (with the same problem), but in carbon doesn't work.

Thanks again for your time and work!

Maybe it's the

Code: Pascal  [Select][+][-]

1. LCLIntf.DrawText

that's not supported.

That c# code translated looks like this(create OnResize event for ListBox1):
...

Thanks GetMem, that works.

However seems that the height of the ListBox items has a limit or there's another bug in my code that limits the item height when the width is too small. But that's another problem, this one is solved.

[balazsszekely]

I would draw into each item a TRichMemo and that would take care of text alignment on resize. Actually I did something similar in OPM with VST. VST works great on every major platform.