Hi! The setResizable() method of AudioProcessorEditor has two arguments, of which the first one is described as follows:
allowHostToResize: whether the editor’s parent window can be resized by the host. Even if this is false, you can still resize your window yourself by calling setBounds (for example, when a user clicks on a button in your editor to drop out a panel) which will bypass any resizable/constraints checks.
May I know when and which host would resize the plugin parent window? I plan to set it to false to avoid some unexpected resizing, if there is any.
The main situation where a host will attempt to resize a plugin window is in response to the user dragging on the edge of the window displaying the plugin editor.
Most VST3 hosts support this feature. You can test this in DAWs like Cubase, REAPER, and the AudioPluginHost.
Some AUv2 hosts also support this feature, but notably not Logic or GarageBand.
AUv3 plugins only allow host-initiated resize, and Logic/GarageBand do support resizing hosted AUv3 plugins.
LV2 hosts are hit-and-miss: there are a couple of APIs that a host might use for resizing plugins, and support differs across hosts. Many hosts implement some kind of support for host-initiated resize.
VST2 and AAX do not have any support for host-initiated resize.
