The Calendar Tool provides cross-user access to the calendars it manages. It also provides access to the group calendars that contain the meetings scheduled for user groups.

2.3.5.1. Viewing Other User`s Calendars

To gain access to the calendar of another registered user, the current user selects `Other User ...' from the `View' menu. In response, the system displays the dialog shown in Figure 57.

The scrolling area at the top of the dialog lists all existing users by name and Calendar Tool ID. The default sorting order of the user list is case- insensitive by name. Since names are listed with last name first, the sorting order is primarily by last name. Secondary, tertiary, and quaternary orders are first name, middle name, and ID, respectively. The sorting order can be changed to ID by pressing the `ID' column heading. The order for the `ID' column is alphabetic, case-insensitive. Since IDs are unique, no secondary order is necessary when ID is the primary sort key.

To select a user for viewing, the current user clicks on the name or ID in any row of the display. The `Search by' field allows the current user to type a name or ID to be searched for. As characters are typed, the list scrolls to the earliest listed name or ID with a leading prefix that matches the typed characters. Whether the search is by name or ID is based on the selected sorting order. When the list is sorted by the `Name' field, the search field is labeled "Search by name". The search field is labeled "Search by ID" when the list is sorted by `ID'. The current user can enter a regular expression in the search field. Details of regular expression search and syntax are covered in Section 2.11.9.

Figure 58 shows the user having selected user James L. Brandon for viewing.

Exeuction of the `View Other User' command is independent of the windowing mode in that the system always opens a new window for each different user being viewed. Once the initial window for another user is open, the windowing mode affects subsequent viewing commands in the normal way, as described in Section 2.3.6.1

The visibility of items in other users' calendars is controlled by the security settings established by each user. As introduced originally in Section 2.2, the four security levels are the following:

• public -- other users can see all details of a scheduled item
• title only -- other users can see the title, time, date, and duration of the item, but no other information
• confidential -- other users can see the time, date, and duration of the item, but no other information; the item title shows as "Unavailable" to other users
• private -- other users can see no information at all about the item

To the current user, public items appear in displays as they appear to the other user, except:

1. The other user's items are not editable in item-level views. This means that the change, delete, and clear buttons that normally appear in an item-level view are absent when viewing another user at the item level.

2. All display option settings are those of the current user; the other user's option settings have no effect from the current user's perspective. This means that the initial view of the other user's calendar is based on the setting of the current user's initial view option (see Section 2.7.3.1).

3. Filtering is based on the current user's filter settings, if any; the filter definitions of the other user have no effect from the current user's perspective.

The category definitions of public items, including their coloring, are those of the other user. The current user's category definitions have no effect when viewing another user's calendar.

`Title only' and `confidential' security apply only to appointments and meetings, not to tasks or events. Other users' appointments and meetings with either of these securities are viewable at the month, week, and day levels, not at the item level. For `title only' security, the title of the item appears at its scheduled date, time, and duration. For confidential security, the title "Unavailable" appears. Since the category is not visible for `title only' and `confidential' items, the text of their titles appear in black type only. At the item level of calendar viewing, `title only' and `confidential' items are skipped in the next/previous traversal (see Section 2.3.2.1 ).

To the current user, the precise effect of `private' security in another user's item is to filter the item out of view, in exactly the same manner as if it had been filtered out with a custom filter definition. At the day, week, and month level, this means that private items are not visible at all. At the item viewing level, private items are not visible and are skipped in the next/previous traversal.

Per the operational details just described, the contents of Figures 59 , 60, and 61 reflect the following settings in the calendar of James L. Brandon:

1. There is a category named "school" colored red.

2. There is a category named "industry" colored blue.

3. There are public recurring appointments titled "101 lecture" and "101 lab", scheduled MWF 3-4 and 4-5, starting September 21, of the "school" category.

4. There is a public recurring appointment titled "grad seminar", scheduled weekly Tu 11-12, starting September 22, of the "school" category.

5. There is a non-recurring public appointment titled "Microsoft lunch", scheduled 12-1:30 September 23, category "industry".

6. There is a public recurring meeting titled "Computer Science Faculty Meeting", scheduled biweekly M 1-2, starting September 21 (appearing penciled-in because it is not yet accepted by the other user)

7. There is a title-only meeting "Microsoft rep", scheduled 1:30-2:30 September 23, category "industry" (but appears in black type because it is title-only).

8. There is a recurring confidential appointment titled "racket ball", scheduled TuTh 8-9 AM, starting September 1 (but appears as "Unavailable" because it is confidential).

9. There is a public recurring task titled "prepare for faculty meeting as necessary", scheduled biweekly Mon 9 AM, category "school".

10. There is a public recurring task titled "review lecture notes", scheduled Mon 11 AM, category "school".

11. There is a public recurring task titled "prepare for grad seminar", scheduled weekly Tu 10 AM, category "school".

12. There is a public non-recurring task titled "prepare for Microsoft visit", Tu, no due time, September 22, category "industry".

13. There is a private event titled "my birthday", scheduled September 24 (but does not appear because it is private).

The figures show how the banner of the display window is altered to indicate that the calendar of another user is displayed. The format of the banner is the following:

-- USER: full-user-name

When the user selects the `Group ...' item in the `View menu', the system displays the dialog shown in Figure 62.

To choose a group for viewing, the user selects its name or ID in the group list and presses `View ...'. In response, the system displays the monthy calendar for the selected group, for the month containing today's date. For example, Figure 63 shows the response to the user selecting the csfac group for viewing.

All of the rules described in the preceding section for viewing other users' calendars apply to viewing group calendars. In addition, the following rules apply specifically to viewing group calendars:

1. only meetings appear in a group calendar;

2. the only meetings that appear are those scheduled by a leader of the group

Figure 63 shows how the banner of the display window is altered to indicate that the calendar of a group is displayed. The format of the banner is the following:

-- GROUP: full-group-name