"This plug-in will make contributions to the UI" option - behavior and explanation

Question

Does the option "This plug-in will make contributions to the UI" essentially get ignored if the previous option "Generate an activator, a Java class that controls the plug-in's life cycle" is NOT selected" ?

Answer 1

As far as I can tell, yes - it is ignored in that circumstance.

The "This plug-in will make contributions to the UI" toggle controls two things:

1) Which class the auto generated Activator class extends (see further explanation below).

2) The list of available templates to choose from on the "Next>" page of the wizard.

But if the first option isn't selected, neither of these are applicable. Almost seems like a bit of a form logic bug. The UI should ideally conditionally enable/disable the second toggle. Oh well...

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If set to ON, Activator extends org.eclipse.ui.plugin.AbstractUIPlugin

if set to OFF, Activator extends org.eclipse.core.runtime.Plugin

Answer 2

It is ignored.
This is a vestige from the pre-OSGi area, where you could develop a plugin making contribution to Eclipse UI without needing an Activator: see Eclipse Extension vs. OSGi services.

(No Activator there)