This reverts commit 13a72114.

Applies #78522 to existing code, by replacing all occurrences of LogicalKeySet to SingleActivator or ShortcutActivator.

Co-authored-by: Shi-Hao Hong <shihaohong@google.com>
Adds a disable argument in DropdownMenuItem widget and added tests.
Design Doc: docs.google.com/document/d/13W6PupVZUt6TenoE3NaTP9OCYsKBIYg9YgdurKe1XKs

Update samples to use repo analysis options, Fix sample templates and a ton of analyzer issues (#77868)

Fix DropdownButton crash when viewport size is too small for the entirety of the menu's height (#76764)

Add fixes for autovalidate deprecation in Form, FormField, TextFormField, and DropdownButtonFormField (#73996)

* DropdownButton should display the value over hint and disabledHint if a DropdownButton.value is defined

This reverts commit 59cf0d22.

Adds Navigator.maybeOf to replace calling Navigator.of(context, nullOk: true), and removes the nullOk parameter. Also changes Navigator.of to return a non-nullable value, and removes many (120!) instances of the ! operator, reducing the possible places where a null dereference could occur.

This removes the nullOk parameter from Focus.of, FocusTraversalOrder.of and FocusTraversalGroup.of, and creates maybeOf equivalents for each. The of methods now return non-nullable values, and the maybeOf equivalents return nullable values.

Adds MediaQuery.maybeOf to replace calling MediaQuery.of(context, nullOk: true), and removes the nullOk parameter. Also changes MediaQuery.of to return a non-nullable value, and removes many instances of the ! operator, reducing the possible places where a null dereference could occur.