The dockpanel was reduced to the right when I set vcl style

The Capital Group

Hi,

I set the vcl style in 10.4(LMD version 2020.4), but I placed a dockpanel to the right of the docksite. 

After the program starts, I maximize the form, then minimize it to the taskbar, and finally restore it.

The dockpanel space will be reduced to the right.

Do you have any suggestions? Thanks.

Eugene Balabuev (LMD)

I've:

- started the app

- maximized the form

- minimized to taskbar

- activated back from taskbar (form now in maximized state)

- restore to original state

and.. nothing bad happens. The form looks originally (like after app starting). Following is a comparison of two layouts:

The Capital Group

Hi Eugene Balabuev,

The problem still exist in my test environment which C++ Builder 10.4 with patch 1 and set vcl style.

I found it will trigger event twice on LMDDockSite OnCanResize() when activated back from taskbar.

It got the unnormal width and height in first trigger event that cause dockpanel was reduced.

Check it was the same sitaution on TFrom's OnCanResize() and WindowProc which received twice.

Did you have any suggestion to avoid this bug?

Thank you.

Eugene Balabuev (LMD)

I can confirm several Form.OnResize events with strange size values. This is a bug of Delphi 10.4. I cannot imagine how we can workaround it. So, you are welcome to tell Embarcadero about this issue.