[Lazarus] LCL don't paint to canvas if a key is holded

[Alexey]

Problem: CudaText editor opens 400K file at the end, syntax parser is 
slow, I hold "d" char. expected: "d" or "d"*n chars appears from time to 
time. Eg each 1-2 seconds. Seen: 
"ddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddd" 
chars appears each 5-6 seconds. Not ok.

Maybe LCL don't call Paint method during holding a key (if component 
paints slowly)? How to solve it? Or i must force repaint to canvas each 
1-2 seconds (not all platforms support it, Mac don't).

ps. Ubuntu x64 gtk2

-- 
Regards,
Alexey