7.1 Tools

7.1.1 Card Viewer

Examine/edit a manual card

The Card Viewer allows you to read the textual contents of a card. It is normally started by double-clicking on a card in one of the summary lists (for example from the ClassBrowser).

Notation. The card editor may display multiple cards simultaneously Each card is started using by a bold-printed header-line. If multiple cards with the same description are displayed by the card viewer this tool will put a header for each displayed card above the actual description. The type-indicator of the header of the card the description originates from is underlined.

User interface:

Jumping around:

• double-clicking on a bold-printed button in the running-text jumps to the related card.
• META-p jumps to the previous card. Jumping to other already-visited cards is achieved using the history entry of the manual's menu bar.
• The popup menu of the card viewer defines the following options:

  Jump				As double-click (follow link)
  Previous			Jump back (META-p)
  Source				View related sourcecode
  Consult				Consult code fragment
  Describe			Describe *this* card (edit)
  Show Key Bindings	All keyboard accelerators

  The options Source and Describe are also active on the header lines and allow the user to specify a specific object if multiple cards with the same description are displayed.

  Tool name: card_viewer

  See also

  - Summary List
  - Topic Browser
  - Predicate Browser
  - Object Browser
  - Example Browser
  - ClassBrowser
  - class editor
  - Class Hierarchy
  - PCE Manual

7.1.2 Class Hierarchy

Overview PCE's class hierarchy

The Class Hierarchy browser provides a hierarchical overview of PCE's class inheritance hierarchy. Initially, it displays the root and first level of sub-classes.

Classes are represented by a small box-icon, followed by their name. The fron-side of the box-icon indicated whether the class is built-in (a house) or user-defined (a face).

The Classes Hierarchy browser automatically displays user-defined classes when they are created.

User interface:

The text-entry-field CLASS may be used to locate classes in the hierarchy. The argument is a pattern (see regex->file_pattern). All matching classes will be added to the hierarchy and selected.

LEFT-CLICKING a node will try to make that class the selection (i.e. it will show a description of the class in the Card Viewer. If the‘Card Viewer’is not yet opened, DOUBLE-LEFT-CLICK opens it.

RIGHT-DOWN on a node presents a POPUP-MENU, providing access to the ClassBrowser and source-code (if the class is user-defined).

Tool name: class_hierarchy

See also

- Topic Browser
- Card Viewer
- ClassBrowser
- PCE Manual

7.1.3 ClassBrowser

Examine/find class attributes

The ClassBrowser finds cards that are related in some way to the current class. It can be started from the PCE Manual window, or from any card that represents a PCE class by selecting the ClassBrowser option. Some of the runtime environment tools (Visual Hierarchy and Inspector) also allow you to jump to the ClassBrowser. Finally, the ClassBrowser may be started directly using the predicate manpce/1.

User interface:

7.1.4 Windows

This tool consists of three windows. The dialog at the left is used to specify a query for the types of cards you are interested in. The window at the top indicates the current class, the initialisation arguments and the inheritance- and delegation relations of the class. The browser shows all cards that match the query.

7.1.5 The dialog window

The primary goal of the dialog window is to specify a query for finding class related cards. As almost anything is an object, most cards can be found this way. Below is a specifiation of the entry fields,

• CLASS May be used to switch to another class. A partial class-name is completed by hitting the space-bar.
• FILTER Determines the class(es) of cards you are interrested in. Basic refers to the principal and most commonly used items, Advanced to less frequently used material,
• Rare* to rarely used items, Internal to items that should not be used by normal applications, Basic OO to methods that are commondly refined in subclasses or methods that are used in method definitions. Advanced OO are methods for less commonly used refinements of classes and Application refers to methods defined in the application language.
• DISPLAY Select those parts of the class definition you want to consider. Values are:

  SELF		The current class itself
  SUB-CLASS	All immediate sub-classes
  VARIABLE	Associated instance variables
  RESOURCE	Associated X-resources
  SEND-METHOD	Associated send behaviour
  GET-METHOD	Associated get behaviour

• SEARCH Specifies a string to search for. All candicate cards specified are searched for this string, and each card holding this string in on of the fields specified in’... In:’will be put in the browser at the right. Searching is not case sensitive.

  # ... IN This specifies the textual attributes that are searched if a search-string is specified in the SEARCH entry-field.

  Typing RETURN is equivalent to clicking APPLY; it starts the actual search.

• APPLY This button is activated whenever one of the above describes specification fields is changed. Pressing it will start the search and display the found cards in the browser.

7.1.6 Top-right window

The first line indicates the class name and initialisation arguments (see object->initialise). Double-clicking this field shows the card belonging to the ->initialise method.

The second graphical object is a tree object that indicates the location in inheritance tree of the current class, as well as delegation performed by this class. All classes in the primary inheritance path are displayed in bold font. Classes to which delegation takes place are added in the default font. Dotted (on colour displays: green) lines indicate delegation relations.

Notes in this tree may be selected to indicate the scope of the search. All classes below selected nodes are considered when searching for methods to display. Double clicking selects the class clicked upon and activates the Apply button.

7.1.7 Bottom-left browser

This is a standard list of cards. LEFT-CLICK shows the card, the menu associated with the right-button gives the usual further options.

Tool name: class_browser

See also

- Visual Hierarchy
- Summary List
- class resource
- class class
- class send_method
- class get_method
- class variable
- topic Object -> Term
- Card Viewer
- Class Hierarchy
- PCE Manual

7.1.8 Errors

Examine errors/warnings

The Errors Browser visualises all defined error objects. It may be used to examine defined errors, get an extensive description of an error or change the kind of an error. The variable error<-kind describes how the system reacts when such an error is encountered:

ignored

The action fails silently

status

The user is informed without attracting attention (see object->report. If there is no place to display the message without attracting attention it is ignored.

inform

The user is informed while attracting attention. This kind of message is always displayed.

warning

The user is informed of a warning. Attracts attention.

error

As a warning, but the PCE tracer is started to allow for debugging.

fatal

A message is printed, the stacks are printed (see also pce->catch_error_signals, pce->print_c_stack). PCE attempts to abort back to the host-language toplevel

It is not advised to change fatal messages into another kind.

User interface:

The user interface of this tool is similar to the other overview tools.

If a search string is specified only cards that match the regular expression entered will be shown.

If an error is selected, the kind menu is activated. It may be used to change the kind of the error. For example the error no_behaviour is generated if a message is send to an object and the object has no method implementing this message. Setting kind to ignored will make the message silently fail; message will print it, but continue execution and warning will trap the tracer. The latter allows you to inspect PCE's goal-stack.

Tool name: errors

See also

@errors

7.1.9 Example Browser

Overview of examples

This tools displays an overview of all examples. Currently the examples themselves are displayed using the Card Viewer. A more dedicated visualisation that allows the user to run the code is planned.

User interface:

Standard card summary browser. After opening a card which is viewed by the normal card viewer tool a section called code is available. This code may be consulted in the Prolog process using the option Consult from the popup menu in the code section of the card.

After consulting, you may normally run the example by typing a relevant query in the Prolog window.

Copy and Paste may be used to copy (fragments) of the examples into your application.

Tool name: examples

See also

- Summary List
- Card Viewer

7.1.10 Group Overview

Overview of Functional Groups

The Group Overview tool allows the user to browse through the defined functional groups. A functional group is a collection of methods and variables that perform a similar or related action.

The window to the left displays the defined functional groups in the same order as they appear in the card summary overviews. This order is based on the notion of common use. Typing in this window starts incremental search. Hitting RETURN or double-clicking will display all related methods and variables in the summary window at the right-side of the tool.

The window to the right is a standard card summary window and may be used to start the card viewer on a specific card or all cards by selecting the (top) group-header-line.

Tool name: group_overview

7.1.11 Inspector

Analyse the structure of objects

The Inspector allows the user to inspect runtime-objects by showing their attributes. This tool is first of all a debugging tool.

There are three common ways to get a starting object. If you know the reference it may be typed in the Inspect entry-field, you can select an object from the screen after pressing the pointing-hand icon and finally various other tools provide Inspect Object or similar that activate this tool, in particular the Visual Hierarchy tool.

Selecting a card will FLASH the associated graphical if this is visible.

7.1.12 An object card

Each object is displayed on its own card, which consists of a two-column table. At the top-left is the displayed object and its class. At the top-right are the memory-management flags (see object <-_flags) and the reference count (see object <-references).

Below that follows an alphabetically ordered list of attribute-names and their current value.

User interface:

7.1.13 Object cards

• LEFT-CLICK on OBJECT INDICATOR in the top-left If the object is a graphical, send a ->flash message to it. Put the reference (e.g. @pce) on the clipboard.
• LEFT-CLICK on an VALUE (entry at right column) puts the reference or contents on the clipboard and shows a description in the status window.
• DOUBLE LEFT-CLICK on a value opens or exposes the referenced object (if any).
• MIDDLE-DRAG on CARD's BACKGROUND Move the card over the window.
• RIGHT-DOWN on a CARD Show a POPUP MENU to HIDE, EXPOSE or QUIT the card.

7.1.14 Bugs

This tool sometimes appears to miss changes.

Tool name: inspector

See also

- Visual Hierarchy
- display-inspect_handlers
- topic Object -> Term
- display->cut_buffer
- topic Garbage collection
- object<-references
- topic Debugging
- object<-_flags

7.1.15 Manual Tools

Overview of defined manual tools

The Manual Tools browser provides cards (i.e. the manual) for each of the manual tools. When the help-button of some tool is pressed, the corresponding card from this list is shown in the card-viewer.

Tool name: manual_tools

See also

Summary List

7.1.16 Object Browser

Overview of predefined global objects

The Object Browser displays a list of documented global objects provided by PCE. Examples are @pce to control the environment and @prolog to interface to Prolog.

User interface: Standard

Tool name: global_objects

See also

- Summary List
- Card Viewer

7.1.17 PCE Changes

Overview of changes to PCE

The PCE Changes tool allows for browsing changes that have been made to the PCE system itself. Normally, the description of the change will be related to the affected classes/behaviours of the PCE system.

User interface: The user interface is standard.

Tool name: changes_browser

Bugs:

A specialised visualisation is necessary that allows you to sort by name and find changes by searching for strings.

It should also be possible to get all changes made after a certain date.

See also

Summary List

7.1.18 PCE Manual

Overall manual/environment control

You are probably viewing the first card of the PCE online documentation system. This card is exceptionally long as we expect you to read it all and in the order presented. Once you understand the principles of this manual we hope you find it a handy tool to find your way in the mysterious world called PCE.

The manual is organised in Cards. This example contains an overview of the manual itself. It describes the main window and the overall organisation of tools. Read it carefully before you go on. The scrollbar allows you to scroll through the entire card.

7.1.19 The manual window

The window labeled PCE Manual is the graphical gateway to the PCE environment and and the PCE manual. It contains four pulldown menus and a field for (short) general feedback messages.

You managed to find the HELP option, so probably you'll know how to operate the menu bar.

The FILE menu provides overall operations; the BROWSERS menu provides access to various entry-points of the reference manual material, the TOOLS menu provides access to some tools to monitor runtime environment of PCE. Finally, the HISTORY menu provides access to places where you have been in this manual. At the bottom of this card is an overview of the options in these menu's.

Below follows a description of the general principles and style used by the online manual. To get a detailed overview of the existing tools, open the MANUAL BROWSERS window from the BROWSERS pulldown.

7.1.20 General principles

7.1.21 Cards

The manual is divided into cards, each describing some specific issue of PCE. The cards are typed; each specific kind of topic is described on a card of a specific kind. Each card has the following general attributes:

Type 			A single capital indicating the type
Name			Short meaningful name
Last Modified	Time-stamp for last modification
Summary			About 40 characters summary
Description		Arbitrary length contents of the card
See also		Related cards.

The available types and their identifiers are:

B	Browser (manual) tool
C	PCE Class
E	Example
K	Keyword entry
M	Method of a class
O	Global PCE object (@prolog, @pce, ...)
P	(Prolog) predicate
T	Topic
V	Variable

Currently, you are reading the DESCRIPTION of a card. In the window at the bottom-right are some cards that are related to this card. Note the first letter that serves as a type indicator.

7.1.22 Browsers

The entire online help system consists of three different type of tools. First of all the main window (called PCE manual), which allows the user to start a browser.

Each BROWSER provides access to a GROUP of CARDS, starting from a specific ORGANISATION. The manual is organised around a class-oriented hierarchy (ClassHierarchy and ClassBrowser), a keyword-based index (Keyword Browser) and some special browsers listing cards of one specific type (predicates, global XPCE objects, examples and manual tools).

Most Browsers present a list of CARDS, displaying only the name and possibly the summary of the card. From there, the user may select a card to view the contents in the CARD VIEWER. When the card viewer is opened, a SINGLE-LEFT-CLICK on the object will open the card. Otherwise DOUBLE-LEFT-CLICK will start the card-viewer.

The CARD VIEWER displays the textual attributes of the card and allows you to jump to RELATED cards.

7.1.23 Selection and focus

The online manual tools use two mechanisms to communicate. First of all, a CARD may be SELECTED. All other manual tools will highlight the currently selected card. The CARD VIEWER will show the textual contents and relations of the selected card. Selecting a card is done by LEFT-CLICKING on the card, or by selecting the SELECT option from the POPUP MENU associated with most representations of a card.

The manual can be requested to FOCUS on a specific card. The general intention is that each tool is given the opportunity to focus on that card. In practice, the current implementation makes this feature only handy for cards representing a CLASS: requesting it to become the focus makes the Class browser jump to the associated class.

7.1.24 Popup menus

From the POPUP MENU associated with a visualisation of a card, a number of other options are available. These are:

SELECT			Select the card and view its contents
FOCUS			Make card the focus (see above)
SOURCE			Start an editor on the source code
RELATE			Relate the card to the selection
UNRELATE		Unrelate the card from the selection

7.1.25 Menu overview

Menu BROWSERS MANUAL BROWSERS Overview of available manual tools ======================================== CLASS HIERARCHY Overview of the PCE class hierarchy CLASS BROWSER Examine definition of a class GlOBAL OBJECTS Overview of predefined objects ERRORS Define errors (may be catched) PROLOG PREDICATES Overview of PCE/Prolog predicates ======================================== KEYWORD BROWSER Keyword-based access GROUP OVERVIEW Overview of related methods EXAMPLES Overview of examples

Tool name: manual

Bugs:

Various things are still incomplete or buggy to these manual tools. A short list:

• Many cards need to be filled
• Errors (diagnostics) need to be related to PCE error objects
• The Visual Hierarchy browser cannot be quit'ed. @see Summary List @see Topic Browser @see ClassBrowser @see Class Hierarchy @see Card Viewer @see topic Manual

7.1.26 Predicate Browser

Overview of PCE related Prolog predicates

The Predicate Browser provides an overview of the Prolog predicates related to the PCE/Prolog interface and the PCE/Prolog libraries.

User interface: Standard

Tool name: predicate_browser

See also

- Summary List
- Card Viewer

7.1.27 Search Tool

Search for combination of words in manual

The Search Tool is located in the Browsers/Search menu of the online manual tools.

This tool consists of a browser containing all words extracted from the manual, a summary window with the same user-interface as all other summary windows and a dialog containing a‘Search For’button and associated text entry field. A search specification can by typed in this field and all cards matching this specification will be shown on the upper summary browser.

If the user pauses typing for one second, the tool will evaluate the current expression and indicate the number of matches if the expression is syntactically correct.

The expression syntax contains the following keywords and special symbols:

• Expr1 and Expr2 Search for cards satisfying both the left-hand and right-hand expression
• word Expr Treated as word and Expr. Simply typing a list of words thus specifies cards containing all specified words.
• Expr1 or Expr2 Search for cards satisfying either the left-hand or the right-hand expression
• not Expr Succeeds if Expr does not hold. Can only be used in combination with and.
• <word> Succeeds if card contains the indicated word. Only matches entire words.
• word Succeeds if card contains a word that starts with the indicated word.

  # ( Expr ) Brackets may be used to specify association. There is no ordering in the operators. not matches the smallest expression. A and B or C is read as A and ( B or C).

  Below are some valid expressions:

  frame and displayed
  (file or directory) and absolute
  graphical and move and user

7.1.28 Database

The database is maintained in the file

pce('man/reference/index.obj')

This file is a chain_table object, mapping words in the cards on their card identifier. The system will prompt to create a new index if the index cannot be found.

Tool name: search

7.1.29 Statistics

Resource usage by PCE/Prolog

The Statistics Tool provides an overview of the memory usage by PCE. The values are updated every 5 seconds.

The values have the following meaning:

• Core In Use (pce<-core_usage) The total amount of core PCE has requested itself explicitly via the system's malloc() function. Note that core requested by libraries is not included.
• Core Wasted (pce<-core_wasted) PCE defines it's own memory allocation schema. This value indicates the total amount of memory allocated and later freed, but not (yet) reused.
• Objects in Use (pce<-objects_allocated - pce<-objects_freed) Total amount of living objects (i.e. objects created and not yet freed).

  Tool name: statistics

  Bugs:

  It appears this tools uses for misterious reasons a little bit of memory each time it is updated.

  See also

  - pce<-objects_undecided
  - pce<-objects_freed
  - pce<-objects_allocated
  - pce<-core_wasted
  - pce<-core_usage
  - pce->garbage_collect
  - topic Creating Objects
  - topic Removing Objects
  - topic Garbage collection

7.1.30 Summary List

List of card summaries

Most of the manual tools provide means to find cards, giving some starting point. For example, the Class browser allows you to find cards from a PCE class; the Keyword Browser; allows you to find cards from some keyword.

These tools display a list of card-summaries in a browser window, normally positioned somewhere at the right side of the tool. This browser window displays the cards line-by-line. The first character indicates the type of the card:

B	Browser (manual) tool
C	PCE Class
E	Example
K	Keyword entry
M	Method of a class
O	Global PCE object (@prolog, @pce, ...)
P	(Prolog) predicate
T	Topic
!	Error object
~	Description of a change to PCE

The next field provides the name of the card. When there is enough space, a third field is added that provides a 40 character summary string of the contents of the card.

When the summary field is tagged with _(+)_, the description field is not empty. A double click will show the description field in the card viewer.

User interface:

A summary browser indicates the selected card by inverting it. It has the follwing user interface behaviour:

A LEFT-CLICK on a line sets the global selection of the manual to this card. This implies the Card Viewer will display the contents of the card. If the Card Viewer is not open, DOUBLE-LEFT-CLICK will open it.

A RIGTH-DOWN on a card invokes a popup menu with the following options:

SELECT		Equivalent to LEFT-CLICK
FOCUS		Set global focus.  Currently only useful on
                _Class cards_ to set the current class of the
                _Class Browser_.
=====================================================
SOURCE		Display the source-code related to the
                card (Classes, methods, variables and
                resources).
SPY		If the object is a method, put a Prolog
                spy-point on the implementing predicate.
=====================================================
TRACE		When the object is a method, put a PCE
                trace point on it.  See also Method->trace
=====================================================
RELATE		Relate this card to the selection
UNRELATE	Destroy relation to the selection

See also

- Manual Tools
- method-summary
- PCE Changes
- PCE Manual
- Predicate Browser
- Object Browser
- Example Browser
- ClassBrowser
- Card Viewer

7.1.31 Topic Browser

Hierarchical overview of the manual

The Topic Browser displays a hierarchical overview of the manual. Unlike the class hierarchy, which shape has a technical motivation, the topic hierarchy is not constrained by any technical issues and contains subjects that are not directly related to a class.

Representing a tree, the interface is similar to that of the‘Class Hierarchy’browser. Some more options are available to allow for editing the topic hierarchy.

The contents of a topic are shown by the Card Viewer, which is automatically started when a topic is selected by a LEFT-CLICK or by the SELECT option from the POPUP-MENU associated with each topic (under the right mouse-button).

User interface:

A LEFT-CLICK on a node displayed the contents in the Card Viewer. If the Card Viewer is not yet opened, DOUBLE-CLICK will do so.

Each node (topic) in the tree has a popup-menu associated with the follwing options:

SELECT		Make topic the selection (view contents)
=====================================================
EXPAND		Expand 1 level of sub-topics
EXPAND TREE	Expand all the way down
COLLAPSE NODE	Destroy all subnodes
=====================================================
RELATE		Relate topic to selection
RENAME		Change the name to the NAME field
=====================================================
MOVE BELOW	Reorder: move just below selection or to be first
MAKE DAUGHTER	Make this node a daughther of the selection
REMOVE DAUGHTER	Remove link to selected parent
=====================================================
DELETE CARD	Destroy the entire topic card

A new topic card is CREATED (when the manual is in edit-mode) by:

• Selecting the super-topic
• Typing the name in the NAME field
• Typing a summary in the SUMMARY field
• Typing RETURN or Pressing CREATE Tool name: topic_browser

  See also

  - Card Viewer
  - Class Hierarchy
  - PCE Manual

7.1.32 Visual Hierarchy

Overview consists hierarchy of visuals

The Visual Hierarchy tool can be used to overview the consists_of hierarchy of visual objects. It is commonly used to find the PCE reference for visual objects from the screen or to examine the structure of a tool (in terms of the visual objects it is built from).

The tool consists of a graphical window for displaying the hierarchy and a dialog. The graphical window displays the hierarchy. The root of the hierarchy is the PCE predefined object @display_manager and is always present.

User interface:

Any XPCE graphical object from the screen may be added to the tree by positioning the pointer (mouse) on the object and pressing META-SHIFT-CONTROL-V. Mnemonic: V for Visual and all modifiers to avoid conflict with applications.

Each node of the hierarchy has a menu associated with the right button. This menu has the following entries:

FLASH			Send ->flash to the represented graphical
=============================================
EXPAND			Expand the next level of the hierarchy
EXPAND TREE		Expand as many levels as possible
COLLAPSE		Remove all subtrees
DELETE			Remove this node and anything below
=============================================
SOURCE			View source of class of object
INSPECT			Start _Inspector_ on object
TILE HIERARCHY	Frames: analyse the tile structure
CLASS BROWSER	Start _ClassBrowser_  on class of object..
=============================================
FREE			Send ->free to the object
POSTSCRIPT 		Genererate a PostScript description

The following button bindings are defined:

LEFT

->Flash the object and print the output of portray_object/1 in the dialog. The reference of the object is put on the X-display clipboard for pasting in another application (typically the Prolog window for further analysis of the object).

DOUBLE - LEFT

Expand the next level of the hierarchy.

Tool name: visual_hierarchy

Bugs:

The functionality of this tool is still experimental.

The tool does not automatically update for changes in the PCE world. Only destroyed visuals that are displayed by this tool will be removed from it.

See also

- ClassBrowser
- Inspector
- class visual