@title{Helper}{Help Panel}

 The Help panel performs functions for navigating through help
 text contained in help files (*.HLP) and EASI procedures (*.EAS).

 The panel is composed of a main area which contains the actual text
 extracted from the help file or EASI procedure. A smaller area under
 the text block titled "Subtopics / See Also" contains a list of
 other topics associated with the text currently displayed in the main
 area.

 There is an option menu above the "Subtopics / See Also" list which 
 determines the sort order of the list. A sort order of "None" means
 that the subtopics are listed first (in the order they appear in the
 help file) followed by the See Alsos. A sort order of "Alphabetical"
 means that the subtopics and see also topics are sorted together
 in alphabetical order.

 The See Also topics can be distinguished in the list by the presence
 of "..." following the topic name.

 There are several buttons under the "Subtopics / See Also" list
 which facilitate the traversal of help topics. 

 The "Next" button displays the text for the next subtopic from 
 the current topic. It can be used to read the subtopics of a particular
 topic in order. 

 The help topics are organized into a tree where each topic is a node and 
 its children are subtopics. Essentially, this button performs a depth 
 first traversal of that tree. Note that this ordering is not necessarily
 the same as the listing in the "Subtopics / See Also". Those are 
 an alphabetical merger of the See Also topics and subtopics. Therefore,
 very rarely will the "Next" button show the topics in the order they
 appear in the list box.

 The "Top" button displays the text for the highest level in the
 hierarchy in the current file.

 The "Parent" button displays the text for the item of which the
 current text is a subtopic.

 The "Search" button activates a panel which allows topic or keyword
 searching. 

 The "History" button activates a panel which displays a list of the most
 recently selected help topics.

 The "Save" button allows the currently displayed help text to be saved
 into an ASCII text file.

 The "Snapshot" button activates a panel containing the text from
 the main area of the Help panel.  The contents of this panel do
 not change and several can be visible at once with different contents.

1	Functions

 The following topics outline some of the functions available from the
 help panel.

2	Search

 The search panel is used to find topics that contain a keyword or to
 search on a help topic. The string entered in the text field can either 
 be a simple keyword (i.e. airphoto) or a fully formed help topic string
 (i.e. Xpace|Digitizing). The search
 is activated by pressing enter in the "Keyword or Topic" textfield.
 The list of matching topics is shown in the list below the textfield.
 If the list is empty, this means that no matching topics were found.
 The help for that topic can be displayed by selecting that topic from
 the list. Pressing "Close" pops down the search panel.

 Note that the keywords and topics are case insensitive.

 See Also: {..|..|Concepts|}Topic Strings, KEYWORDS

2	History

 Each time a new help topic is displayed in the main panel, the topic
 is added to a history list. This topic history list can be viewed
 in the history panel which is activated by pressing "History" from
 the main panel. The help for a topic can be redisplayed by selecting 
 it from the list. Pressing "Close" pops down the history panel.

1	Concepts

 The following topics outline some of the concepts associated with PCI's
 help system.

2	Help Text Structure

 The help text in help files and EASI procedures is organized in
 a hierarchy.  For example, the help text for IVI is structured as
 follows:

@verbatim
                                  IVI
                                   |
                  +----------------+----------------+
                  |                |                |
              PARAMETERS        DETAILS          EXAMPLE
                  |
          +-------+-------+-------+-------+
          |       |       |       |       |
        FILE     DBIC    VDOC    DBIW    VDOW
@end

 Understanding this structure is important for forming topic strings
 effectively.

 See Also: {..|..|Concepts|}Topic Strings

2	Topic Strings

 The format of a topic string is:

  <topic>|<subtopic-1>|<subtopic-2>| ... |<subtopic-n>

 where <topic> is the name of a PACE task or EASI procedure (e.g. IVI
 or PROGNO) and each <subtopic-m> is the name of a subtopic at the
 m'th level in the help hierarchy. 

 For example, the search string "IVI|PARAMETERS|FILE" would specify
 the help text explaining the use of the FILE parameter for the PACE
 task IVI.  Note that subtopics in the string do not have
 to be specified completely so for the previous example, "IVI|PAR|FI"
 would achieve the same result.

 See Also: {..|}Help Text Structure

1	Helper

 The "helper" is a standalone program which activates a help panel
 from the system command prompt rather than from within a PCI application 
 such as ImageWorks. The syntax for the helper command is:

  % helper <topic> <subtopic-1> <subtopic-2> ... <subtopic-n>

 where <topic> and <subtopic-m> have the same meaning as they do
 in topic strings. 

 For example, the following command would display information on the 
 Albers Conical Equal Area projection:

  % helper proset proj acea

 The helper can also be invoked with no arguments, in which case the
 user can perform a search for an appropriate help topic.
