delphi - TPanel does not AutoSize when containing a TPanel -

i have panel inside another:

the inner panel aligned altop:

and outer panel set autosize=true:

and sizes. if changes height of inner panel @ design time, outer panel auto sizes accommodate it:

and runtime

now need change height of inner panel @ runtime:

procedure tform2.button1click(sender: tobject); begin     pnlinner.height := pnlinner.height + 50;     lblpointer.top := pnlouter.top + pnlinner.height; end; 

except when change height of inner panel @ runtime, autosize panel not autosize:

this of course worked in delphi 5, 7, , probably xe2 - xe5.

what's fix?

the workaround is, of course, bypass alignment/autosize , during various onresize events. that's distinctly not rad. i'm sure it's small bug in vcl somewhere. , since have two-dozen xe6 vcl bugs we've patched, better fix nobody else has think it.

bonus chatter

i love line:

and, please attach sample project?

it's if nobody bothered try reproduce it.

the issue regression in twincontrol.aligncontrols:

procedure twincontrol.aligncontrols(acontrol: tcontrol; var rect: trect); begin    //...snip     // apply constraints    if showing , ((sfwidth in fscalingflags) or (sfheight in fscalingflags))       doadjustsize;     //...snip end; 

the bug here not call doadjustsize unless either sfwidth or sfheight scaling flags present.

the fix not try outsmart yourself, , doadjustsize regardless:

procedure twincontrol.aligncontrols(acontrol: tcontrol; var rect: trect); begin    //...snip     // apply constraints    //qc125995: don't scaling flags decide if should adjust size    if showing {and ((sfwidth in fscalingflags) or (sfheight in fscalingflags))}       doadjustsize;     //...snip end; 

with fix found, we're halfway solving the similar issue except tolecontrol (e.g. twebbrowser) rather tpanel.

note: code released public domain. no attribution required.