edit

Class Edit

java.lang.Object

edit.Edit

abstract class Edit
extends java.lang.Object

Class Edit is derived from 2.9 of the requirements, which in turn derives from the commands on the 'Edit' menu. In this abstract model, most of the generic editing functionality is modeled as operations. As with the file methods described in file.File.java, the edit methods take user workspace inputs and return a workspace if the method changes any workspace values.

Field Summary

Fields

Modifier and Type	Field and Description
(package private) UserOptions	preferences

Constructor Summary

Constructors

Constructor and Description
Edit()

Method Summary

Methods

Modifier and Type	Method and Description
(package private) abstract UserWorkSpace	copy(UserWorkSpace uws) Copy the currently selected text segment into the clipboard.
(package private) abstract UserWorkSpace	cut(UserWorkSpace uws) Move the currently selected text segment into the clipboard and remove the segment from its context.
(package private) abstract UserWorkSpace	delete(UserWorkSpace uws) Remove the currently selected text from the context.
(package private) abstract UserWorkSpace	paste(UserWorkSpace uws) Paste the contents of the clipboard into the currently selected start position, replacing any selected text from start to end position.
(package private) abstract UserWorkSpace	undo(UserWorkSpace uws) Undo the most recent scheduling operation.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

preferences

UserOptions preferences

Constructor Detail

Edit

Edit()

Method Detail

undo

abstract UserWorkSpace undo(UserWorkSpace uws)

Undo the most recent scheduling operation. Only one level of undo/redo is specified here. Successive invocations of undo toggle between the current and previous states of the calendar. Note that the calendar editing operations support undo by saving a snapshot of the input calendar in the previous_state component of the workspace.

      pre:
        //
        // The previous saved calendar state is not null.
        //
        (uws.previous_state != null);

      post:
        //
        // The state of the current calendar is the previous state, and vice
        // versa.
        //
        (return.previous_state = uws.calendars[1].items) &&
        (uws.calendars[1].items = uws.previous_state);

cut

abstract UserWorkSpace cut(UserWorkSpace uws)

Move the currently selected text segment into the clipboard and remove the segment from its context. Set the workspace selection to empty.

      pre:
        //
        // The selection is not empty.
        //
        uws.selection != null;

      post:
        //
        // The clipboard of the output workspace equals the selection.  The
        // selection context of the output workspace has the selection removed.
        // The selection of the output workspace is null.
        //
        (return.clipboard = uws.context.substring(
            uws.selection.startPosition, uws.selection.endPosition)

             &&

        (return.context.equals(
                uws.context.substring(1,uws.selection.start_position-1) +
                        uws.context.substring(uws.selection.startPosition+1,
                                    uws.context.size())))

             &&

        (return.selection == null);

copy

abstract UserWorkSpace copy(UserWorkSpace uws)

Copy the currently selected text segment into the clipboard.

      pre: 
        //
        // The selection is not empty.
        //
        uws.selection != null;

      post:
        //
        // The clipboard of the output workspace equals the selection.  The
        // context and selection of the output workspace are unchanged.
        //
        (return.context.equals(
                uws.context.substring(1,uws.selection.start_position-1) +
                        uws.context.substring(uws.selection.startPosition+1,
                                    uws.context.size())))

             &&

        (return.context.equals(uws.context))

             &&

        (return.selection.equals(uws.selection));

paste

abstract UserWorkSpace paste(UserWorkSpace uws)

Paste the contents of the clipboard into the currently selected start position, replacing any selected text from start to end position.

      pre:
        //
        // The clipboard is not empty.
        //
        uws.clipboard != null;

      post:
        //
        // The context in the output workspace is the string consiting of
        // everything up to the selection, followed by the clipboard, followed
        // by everything after the selection.  The selection of the output
        // workspace is null and the clipboard is unchanged.
        //
        (return.context.equals(
                uws.context.substring(1,uws.selection.start_position-1) +
                        uws.clipboard +
                        uws.context.substring(uws.selection.start_position+1,
                                    uws.context.size)))

             &&

        (return.selection == null)

             &&

        (return.clipboard.equals(uws.clipboard));

delete

abstract UserWorkSpace delete(UserWorkSpace uws)

Remove the currently selected text from the context. Set the workspace selection to empty.

      pre: 
        //
        // The selection is not empty.
        //
        uws.selection != null;

    postcondition:
        //
        // The selection context of the output workspace has the selection
        // removed.  The selection of the output workspace is null.
        //
        (return.context.equals(
                uws.context.substring(1,uws.selection.start_position-1) +
                        uws.context.substring(uws.selection.start_position+1,
                                    (uws.context.size()))))

             &&

        (return.selection == null);