I came across this problem a while ago, but did not press on it because I thought it was a Windows 2000 issue only.

When the application' screen is minimized and restored many elements are not redrawn so the contents of the previous windows show through some parts of the screen.

It happens on Windows 2000, Windows XP Classic theme and Windows 2003 (nobody bothers with downloading themes).

Is that a known bug, surely others must have observed it by now. I initially thought it was a Windows 2000 driver issue until I realized that Windows 2003 and Windows XP Classic displayed the same bug.

It is present in 0.9.26 and 0.9.28

What controls for example does not redraw themself (so I can test them)? I have windows xp and can test although I never noticed this problem.

Best regards,
Paul Ishenin.

It happens a lot with grids and some areas of the panel, and in the Windows Classic theme, which you probably have no cause to use. It is as though the lower layers of the Windows are not drawn, ie the brushes etc. Text comes up, but underneath the next is are the contents of the previous screen.

I will construct a quick demo to display it soon.

Paul Ishenin wrote

What controls for example does not redraw themself (so I can test them)? I have windows xp and can test although I never noticed this problem.

This is not related to WinXP/2003, but could be also a problem with painting handling.

Paul Ishenin please test on Win 7 with Aero enabled (if possible).

- create a form and put a combo box on it.
- make sure the application uses themes manifest. compile and run
- move the mouse to the right part of the combo box (drop-down arrow).

combo-box changes its view to "hot" state in one frame (while it should be fade in a several frames). The same happens if you move the mouse away. ComboBox changes its view to "normal" state in one frame, though animation should be used.

You can see ComboBox animation in non LCL applications (Windows, VCL etc).

The bug is minor, so i did create the bug report.

thanks,
dmitry

dmitry boyarintsev wrote

Paul Ishenin please test on Win 7 with Aero enabled (if possible).

This is unrelated problem. Double buffering can't be applied if you want the correct fade effects. I already removed the double buffering for buttons before.

Best regards,
Paul Ishenin.

After further tests it appears the problem arises when I use the OnDrawColumnCell event to draw the grid. When I disable the code the problem goes away, but I don't understand why it affects objects which are not part of the grid.

I'll will test the problem with another dataset and report my findings.