Fixed EditorBrush forgetting brushMode between Editor::reloadContent
Editor is now a EngineEventListener
Made EngineEventListener abstract pure
SelectionManager can get subscribers to notify them when the selection changes. Also, added SelectionManager::tagsUnion.
Fixed InputManager sending keyReleased event for unpressed keys
- Fixed Editor loosing Engine&Selection listener registrations upon content reloading
- Added model tags (de)serialization, though models only delegate their tags to their agent
- Switched selection based on tagging to selection based on memoing agents (less confusion with actual tags)
- Finished v0.5 of Editor selectionTagsInfoBox (still untagging to be done but this commit has already grown so much)
- Switched agent tag set to tag map with refcount (agents are un/tagged by their models upon un/linkage)
[minor]