Unreal - UI and Widgets

• Simple Tutorial
  • https://www.youtube.com/watch?v=lYfXkxlInVIuuukjA

• Unreal has a built in system that can handle basic navigation types.
  • These types are defined in EUINavigation and are. Up Down Left Right Next Previous
  • Most of the Widgets, will use the EVisibilty type and code for each of the widgets to determine which items should be navigated to next
  • Each EUINavigation Type can have some behaviour associated with it. These are:
    • Escape - Navigation is a allow to leave the bounds of the widget
    • Stop - Navigation stops at the bounds of the widget
    • Wrap - Navigation will wrap to the opposite bounds of the widget
    • Explicit - Navigation will travel to a specified widget
    • Custom - Navigation will be decided by calling a function
    • Custom Boundary - Navigation will travel to the boundry decided by this Function
  • If NativeOnKeyDown is not handeled by the focused widget, Unreal will check the Visibilty and Navigation rules for that in put before.

• The above works well for most simple cases howerer there are times where there is a more complicated setup that it can’t handle. In these cases you can provide either a Native or BP function that can return the correct widget that should be focused.
  • An example decleration :
  • UFUNCTION(BlueprintCallabe) UWidget* Class::FunctionName(EUINavigation Nav)
  • Here you can write the logic to determin the next focuasable widget and return a pointer to it or nullptr
    • #TODO what happens in the nullptr case?