Some plugin UIs, particularly those that cannot be resized
unset `autoresizesSubviews`. Since the plugin-view is re-parented,
the host has to directly set the view's size.
However some plugins have multiple child views, apparently
for off-screen pixmaps (e.g. UAD plugins). Those additional
should not be resized (or re-stacked).
e.g.
Reason-Rack
view 0x7fe27e44e570 @ 0, 33 834 x 804
view 0x7fe288aa3770 @ 278, 268 278 x 268
UAD Tube-tech
view 0x7fe270a9cbf0 @ 0, 33 1160 x 374
view 0x7fe28883d030 @ 0, 0 1160 x 374
view 0x7fe2888546e0 @ 0, 0 1160 x 24
see also aef366c156https://discourse.ardour.org/t/uad-plugin-will-not-load-shows-as-expired-when-its-not/105756/5?u=x42
We have to call close_view(), which calls IPlugView::removed()
before destroying the parent widget.
Previously ~VST3PluginUI() was called after the derived class
destroyed the owned private `_gui_widget`, `_ns_view` or x11 parent.
On windows that may lead to the hwnd of the window becoming invalid
before the call to ::removed().
Some plugins correct their own size when resized which can lead
to endlessly growing GUIs. In particular this issue exists
if Ardour's plugin-toolbar forces a plugin to grow in size to fill
the allocated space. While the plugin aims for fixed aspect-ratio.
This will need a proper solution involving VST's checkSizeConstraint,
however GTK+2 does not have an appropriate API...
Robin Gareus