[Solved] How to calc width of OS scrollbar

[AlexTP]

E.g. in Listview OS scrollbar added if needed. How to calc it's width (of vert var) on all WS'es?

[Blaazen]

I did a test on Linux+Qt (I hope it will work for other WS'es too).
ListBox.Width gives 100 (default).
Empty ListBox.ClientWIdth gives 96 (2px border on both sides).
ListBox.ClientWidth with vertical scrollbar gives 80 (2*2px border + 16px scrollbar).

Alternatively, create a TScrollBar (Standart palette). Its default height is also 16.

[wp]

Code: Pascal  [Select][+][-]

1. uses
2.   LCLIntf, LCLType;
3. var
4.   h, w: Integer;
5. ...
6.   h := GetSystemMetrics(SM_CYHSCROLL);
7.   w := GetSystemMetrics(SM_CXVSCROLL);

Looks like a Windows call, but is in LCLIntf and, therefore, should be cross-platform.

[Blaazen]

@ h := GetSystemMetrics(SM_CYHSCROLL);
  w := GetSystemMetrics(SM_CXVSCROLL);

I tried now, works well for Qt and GTk2. Also the trick with ClientWidth works with GTk2.