When the user selects Undo from the Edit menu, the system undoes the effect of the most recently confirmed updating command, or the effect of a previously executed Undo command. An updating command is any Grader Tool command that changes information in the spreadsheet. For any of these actions, the precise definition of Undo is that the Grader Tool workspace is restored to the state that existed immediately prior to the confirmed execution of the action. If no confirmed updating command has been executed since the Grader Tool was invoked, Undo has no effect.

If Undo is executed twice in succession, with no intervening confirmed update between the two executions, the effect of the first of the two Undo executions is undone. That is, the state of the workspace is restored to the state that existed immediately prior to the first Undo. Third and further successive executions of Undo, without an intervening updating command, cause the system to toggle between the state of the workspace with and without the effect of the most recently confirmed update. This behavior means that only a single level of undo is available. That is, only the single most recently executed updating command can be undone.

Undo only applies to the updating commands and itself, not to any other commands such as Publishing Grades. Redo has the same functionality and restrictions as Undo only it restores the state of the Grader Tool workspace to one that existed preceding the confirmed execution of an updating command.

Cut, Copy, and Paste

Operating systems typically provide a "clipboard" area through which cut and paste editing commands operate. This clipboard holds values that are cut, copied, and pasted in tools such as the Grader. Hence, the Grader Cut, Copy, and Paste commands operate through such a clipboard.

To execute the Cut or Copy command, the user must first select a segment of text in a text box or row of student data. Text selection is performed using click and drag with the mouse, or by other environment-specific means such as double or triple clicking in a text box.

After text selection, when the user selects the Cut command from the Edit menu, the system removes the selected text from the edit box and copies the text into the clipboard. When the user selects the Copy command, the selected text is copied to the clipboard, but is not removed from the display in which it is selected and the text remains selected. A particular segment of selected text is unselected by selecting another text segment or by single-clicking the mouse anywhere in the Grader display. Other environment-specific means of unselecting text may be available.

The Cut command can only be executed in the context of a display where the text boxes are editable, i.e., where the user may type in the text boxes. In contrast to Cut, the Copy command can be executed in any dialog in which text boxes appear, including read-only text boxes.

To execute the Paste command, the user must first execute a Cut or Copy and then place the typing cursor within some editable text box. After these steps, when the user selects the Paste command from the Edit menu, the text stored in the clipboard is inserted at the point of the typing cursor, as if it had been entered by the user from the keyboard. Pasted text appears in normal font, i.e., it is not highlighted as selected text.

If the user attempts to execute a Cut or Copy command without first selecting text, the commands have no effect. If the user attempts to execute a Paste command without having executed either a Cut or Copy, the Paste command has no effect. The Cut, Copy, and Paste commands operate only on plain text strings within a single displayed text box.

The use of the clipboard for communication between the Grader Tool and the outside operating environment depends on the capabilities of the environment. Specifically, the environment must support the insertion and removal of plain text to and from the clipboard. If this requirement is met, and the operating environment permits inter-tool clipboard communication, then plain text copied to the clipboard from a another tool can be pasted in the Grader using Paste. Similarly, plain text cut or copied in the Grader Tool can be pasted or otherwise accessed as plain text in another tool, via the clipboard.

Delete

When the user selects Delete from the Edit menu, the system deletes a field or cell from the spreadsheet.

Find

When the user selects Find from the Edit menu, the system initiates a standard operating system "Finder" window to search for specific strings within the spreadsheet's data.

Matching strings will be highlighted and a count will be displayed, similar to using a "Command-F" command on a webpage. The user can toggle through them with arrows next to the string matcher, and the finder bar is removed when the user clicks any other part of the Grader display.

If the Find command is closed and used again, the previous string pattern that was searched for remains, and progress is kept until the user deletes the string from the search bar.

Clear

When the user selects Clear from the Edit menu, the system removes all information from a selected field. When paired with the "Shift" key to select multiple items, the user may clear multiple items of data, such as category inputs or whole rows of student data.

If nothing is selected and the Clear command is selected, there is no effect. On the contrary, the user may use "Shift" to select the whole spreadsheet and clear all fields of information with the command.

Filter

When the user selects Filter from the Edit menu, the system brings up a dialog for the user to select which items they want to view in the spreadsheet. See Section 2.5.5 for more details and specifics.

Preferences

Preferences currently has no implementation details.