Since commit a7e9edb, creating multiple standalone windows is no longer allowed. While this change might seem straightforward, it affects an in-house test setup I use for a project where I’m spawning multiple standalone windows. With the recent update, this is no longer possible without getting asserts. What is the reasoning behind adding this restriction?
The existence of the function static StandalonePluginHolder* getInstance() implied that the intention was for there only to be a single holder at a time. Additionally, the old implementation of this function would fail in the case that the standalone was running headlessly. The new implementation fixes these issues.
It’s possible to supply your own standalone window if the built-in one isn’t sufficient (see the JUCE_USE_CUSTOM_PLUGIN_STANDALONE_APP preprocessor definition). Perhaps that would be a good path forwards.