Third-party plugins create multiple-choice parameters via PF_ADD_POPUP. If you add a new option (menu item) to such a parameter, Premiere Pro will display it, but disallow users from selecting it on existing instances of the plugin on the timeline. This creates a confusing situtation for users, who can readily see the new option, but are unable to select it.
Steps to reproduce:
- Create a new visual effect plugin based on the AE SDK.
- Have the plugin add a popup-based parameter with three choices.
- Launch Premiere Pro, add an instance of this plugin to a clip, and select the second option in the menu:
- Save this project and quit Premiere Pro
- Back in your IDE, tweak the code that creates the parameter by adding a fourth item to the popup menu.
- Build the plugin again with this change, and launch Premiere Pro
- As you reopen the existing timeline, click on the instance of your plugin that you had previously saved.
- Notice that if you click on the same popup menu, you will see four choices:
- Try selecting that fourth choice. You will be unable to do so.
- Instead, when you select the fourth choice, Premiere Pro will select the third choice. It is clamping your selection to the last-known maximum value.
Expected results:
Premiere Pro should allow users to select new items, rather than displaying the choice but then disallowing selection.
Why is this important?
It is common for products to receive new features over their lifetime. This includes adding new parameters (sliders, checkboxes, etc) but often times it involves adding new options under existing popup menus. It is crucial that this remains a viable strategy. Should a change be more extensive (potentially breaking compatibility) developers still have the option to use plugin versioning anyway.
Secondary reasons:
After Effects does not have this bug. It is always possible to select any new menu items added to a popup parameter.
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