A text view handled undo: and redo: and registered its changes even when allowsUndo was NO, so Edit > Undo stayed enabled and did nothing.
Behaviour now follows canonical Cocoa: a text view that does not allow undo registers nothing and passes undo: and redo: on to the window, and Undo and Redo are enabled only when there is a change to undo or redo.
* CPTextView/CPTextView.j: Register changes only when undo is allowed, stop responding to undo: and redo: when it is not, and validate the Undo and Redo items against the undo manager.
* CPWindow/CPWindow.j: Validate the Undo and Redo items against the window's undo manager.
* Tests/AppKit/CPTextViewTest.j: Add tests for responding to undo:, registering changes and validating the Undo item.
* Tests/Manual/TextEditor/DocumentWindowController.j: Add toggleAllowsUndo: and validateMenuItem:, so that undo can be turned on and off for the active document.
* Tests/Manual/TextEditor/Resources/MainMenu.xib, Resources/MainMenu.cib: Add Edit > Allow Undo.
* Tests/Manual/TextEditor/WORKLIST.md: Remove the entry for this gap, record Allow Undo as tested, and add the key equivalent behaviour of disabled menu items for discussion.
Stop document windows from shrinking below a usable size, and record the AppKit gaps that TextEditor has found.
* DocumentWindowController.j: Implement windowWillResize:toSize: to keep the window at or above provisional minimum dimensions.
* WORKLIST.md: Add a work list of the AppKit gaps found by TextEditor, the planned additions to the app and the tests done.
Turn on the text view's horizontal ruler in code, because nib2cib does not carry the Interface Builder ruler settings into the cib.
* DocumentWindowController.j: Enable the horizontal ruler on the text view's enclosing scroll view in windowDidLoad, with a comment explaining why it is set up in code.
* Resources/MainMenu.xib, Resources/MainMenu.cib: Remove the Insert Lorem Ipsum key equivalent, which duplicated File > New.
Give the document window a scrolling text view and a toolbar, and add an Edit menu item that inserts placeholder text into the active document.
* LoremIpsum.j: Add a class that supplies the traditional Lorem ipsum passage as static text.
* DocumentWindowController.j: Add a textView outlet and an insertLoremIpsum: action that inserts the placeholder text at the selection through insertText:, so the document's undo manager records it.
* Resources/DocumentWindow.xib, Resources/DocumentWindow.cib: Add a text view in a scroll view that resizes with the window, a toolbar with the default items, and the textView outlet connection.
* Resources/MainMenu.xib, Resources/MainMenu.cib: Add an Insert Lorem Ipsum item to the Edit menu that sends insertLoremIpsum: to First Responder.
Move the main window out of MainMenu.xib into a document window owned by a window controller, so that each document opens in its own window.
* Document.j: Add a CPDocument subclass that creates a DocumentWindowController for each document.
* DocumentWindowController.j: Add a CPWindowController subclass that loads DocumentWindow.cib and sets itself as the window's delegate.
* Resources/DocumentWindow.xib, Resources/DocumentWindow.cib: Add the document window, with DocumentWindowController as File's Owner.
* Resources/MainMenu.xib, Resources/MainMenu.cib: Remove the window, name the application menu Text Editor, rename Preferences to Settings, and remove Quit.
* AppController.j: Remove the window outlet and the code that made the window fill the browser.
* main.j: Import Document.j.
* Info.plist: Declare the Document type with Document as its document class.
David Richardson