Method and system for displaying changes of source code

Abstract

Methods and systems consistent with the present invention provide an improved software development tool which displays versions of source code with the indications of the edits in a graphical representation, wherein the graphical representation of the source code is not merely a text representation on a user interface. Each version reflects an instance in an edit history, i.e., reflects the changes made to the source code.

Description

FIELD OF THE INVENTION

The present invention relates to a method and system for developing software. More particularly, the invention relates to a method and system for tracking changes made to source code, and displaying the source code with these changes.

BACKGROUND OF THE INVENTION

Computer instructions are written in source code. Although a skilled programmer can understand source code to determine what the code is designed to accomplish, with highly complex software systems, a graphical representation or model of the source code is helpful to organize and visualize the structure and components of the system. Using models, the complex systems are easily identified, and the structural and behavioral patterns can be visualized and documented.

The well-known Unified Modeling Language (UML) is a general-purpose notational language for visualizing, specifying, constructing, and documenting complex software systems. UML is used to model systems ranging from business information systems to Web-based distributed systems, to real-time embedded systems. UML formalizes the notion that real-world objects are best modeled as self-contained entities that contain both data and functionality. UML is more clearly described in the following references, which are incorporated herein by reference: (1) Martin Fowler, UML Distilled Second Edition: Applying the Standard Object Modeling Language, Addison-Wesley (1999); (2) Booch, Rumbaugh, and Jacobson, The Unified Modeling Language User Guide, Addison-Wesley (1998); (3) Peter Coad, Jeff DeLuca, and Eric Lefebvre, Java Modeling in Color with UML: Enterprise Components and Process, Prentice Hall (1999); and (4) Peter Coad, Mark Mayfield, and Jonathan Kern, Java Design: Building Better Apps & Applets (2nd Ed.), Prentice Hall (1998).

As shown in FIG. 1, conventional software development tools 100 allow a programmer to view UML 102 while viewing source code 104. The source code 104 is stored in a file, and a reverse engineering module 106 converts the source code 104 into a representation of the software project in a database or repository 108. The software project comprises source code 104 in at least one file which, when compiled, forms a sequence of instructions to be run by the data processing system. The repository 108 generates the UML 102. If any changes are made to the UML 102, they are automatically reflected in the repository 108, and a code generator 110 converts the representation in the repository 108 into source code 104. Such software development tools 100, however, do not synchronize the displays of the UML 102 and the source code 104. Rather, the repository 108 stores the representation of the software project while the file stores the source code 104. A modification in the UML 102 does not appear in the source code 104 unless the code generator 110 re-generates the source code 104 from the data in the repository 108. When this occurs, the entire source code 104 is rewritten. Similarly, any modifications made to the source code 104 do not appear in the UML 102 unless the reverse engineering module 106 updates the repository 108. As a result, redundant information is stored in the repository 108 and the source code 104. In addition, rather than making incremental changes to the source code 104, conventional software development tools 100 rewrite the overall source code 104 when modifications are made to the UML 102, resulting in wasted processing time. This type of manual, large-grained synchronization requires either human intervention, or a “batch” style process to try to keep the two views (the UML 102 and the source code 104) in sync. Unfortunately, this approach, adopted by many tools, leads to many undesirable side-effects; such as desired changes to the source code being overwritten by the tool. A further disadvantage with conventional software development tools 100 is that they are designed to only work in a single programming language. Thus, a tool 100 that is designed for Java™ programs cannot be utilized to develop a program in C++. Moreover, it is not possible to track the changes made to the source code using conventional software development tools. Accordingly, unless the developer maintains detailed notes regarding the development of the source code, it is difficult to determine what modifications to the source code were attempted during its development. There is a need in the art for a tool that avoids the limitations of these conventional software development tools.

SUMMARY OF THE INVENTION

Methods and systems consistent with the present invention provide an improved software development tool which overcomes the limitations of conventional software development tools. The improved software development tool of the present invention allows a developer to track changes made to source code, and display the source code with these changes. Accordingly, the developer can recollect the modifications that were made to the source code during the development of the source code.

In accordance with methods consistent with the present invention, a method is provided in a data processing system for displaying versions of source code. Each version reflects an instance in an edit history. The method comprises the steps of storing indications of the edits to the source code, and displaying the versions of the source code with the indications of the edits.

In accordance with articles of manufacture consistent with the present invention, a computer-readable medium is provided. The computer-readable medium contains instructions for controlling a data processing system to perform a method. The data processing system has versions of source code. Each version reflects an instance in an edit history. The method comprises the steps of storing indications of the edits to the source code, and displaying the versions of the source code with the indications of the edits.

Other systems, methods, features and advantages of the invention will be or will become apparent to one with skill in the art upon examination of the following figures and detailed description. It is intended that all such additional systems, methods, features and advantages be included within this description, be within the scope of the invention, and be protected by the accompanying claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate an implementation of the invention and, together with the description, serve to explain the advantages and principles of the invention. In the drawings,

FIG. 1 depicts a conventional software development tool;

FIG. 2 depicts an overview of a software development tool in accordance with the present invention;

FIG. 3 depicts a data structure of the language-neutral representation created by the software development tool of FIG. 2;

FIG. 4 depicts representative source code;

FIG. 5 depicts the data structure of the language-neutral representation of the source code of FIG. 4;

FIG. 6 depicts a data processing system suitable for practicing the present invention;

FIG. 7 depicts an architectural overview of the software development tool of FIG. 2;

FIG. 8A depicts a user interface displayed by the software development tool depicted in FIG. 2, where the user interface displays a list of predefined criteria which the software development tool checks in the source code;

FIG. 8B depicts a user interface displayed by the software development tool depicted in FIG. 2, where the user interface displays the definition of the criteria which the software development tool checks in the source code, and an example of source code which does not conform to the criteria;

FIG. 8C depicts a user interface displayed by the software development tool depicted in FIG. 2, where the user interface displays an example of source code which conforms to the criteria which the software development tool checks in the source code;

FIG. 9 depicts a flow diagram of the steps performed by the software development tool depicted in FIG. 2;

FIGS. 10A and 10B depict a flow diagram illustrating the update model step of FIG. 9;

FIG. 11 depicts a flow diagram of the steps performed by the software development tool in FIG. 2 when creating a class;

FIG. 12 depicts a user interface displayed by the software development tool depicted in FIG. 2, where the user interface displays a use case diagram of source code;

FIG. 13 depicts a user interface displayed by the software development tool depicted in FIG. 2, where the user interface displays both a class diagram and a textual view of source code;

FIG. 14 depicts a user interface displayed by the software development tool depicted in FIG. 2, where the user interface displays a sequence diagram of source code;

FIG. 15 depicts a user interface displayed by the software development tool depicted in FIG. 2, where the user interface displays a collaboration diagram of source code;

FIG. 16 depicts a user interface displayed by the software development tool depicted in FIG. 2, where the user interface displays a statechart diagram of source code;

FIG. 17 depicts a user interface displayed by the software development tool depicted in FIG. 2, where the user interface displays an activity diagram of source code;

FIG. 18 depicts a user interface displayed by the software development tool depicted in FIG. 2, where the user interface displays a component diagram of source code;

FIG. 19 depicts a user interface displayed by the software development tool depicted in FIG. 2, where the user interface displays a deployment diagram of source code;

FIG. 20 depicts a flow diagram of the steps performed by the software development tool depicted in FIG. 2 to store the edit history of source code, in accordance with the present invention; and

FIGS. 21A–C depict a flow diagram of the steps performed by the software development tool depicted in FIG. 2 to sequentially displaying the source code with the indications of the edit history, in accordance with the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Methods and systems consistent with the present invention provide an improved software development tool which displays versions of source code. Each version reflects an instance in an edit history, i.e., reflects the changes made to the source code.

As depicted in FIG. 2, source code 202 is being displayed in both a graphical form 204 and a textual form 206. In accordance with methods and systems consistent with the present invention, the improved software development tool generates a transient meta model (TMM) 200 which stores a language-neutral representation of the source code 202. The graphical 204 and textual 206 representations of the source code 202 are generated from the language-neutral representation in the TMM 200. Although modifications made on the displays 204 and 206 may appear to modify the displays 204 and 206, in actuality all modifications are made directly to the source code 202 via an incremental code editor (ICE) 208, and the TMM 200 is used to generate the modifications in both the graphical 204 and the textual 206 views from the modifications to the source code 202.

The improved software development tool provides simultaneous round-trip engineering, i.e., the graphical representation 204 is synchronized with the textual representation 206. Thus, if a change is made to the source code 202 via the graphical representation 204, the textual representation 206 is updated automatically. Similarly, if a change is made to the source code 202 via the textual representation 206, the graphical representation 204 is updated to remain synchronized. There is no repository, no batch code generation, and no risk of losing code.

The data structure 300 of the language-neutral representation is depicted in FIG. 3. The data structure 300 comprises a Source Code Interface (SCI) model 302, an SCI package 304, an SCI class 306, and an SCI member 308. The SCI model 302 is the source code organized into packages. The SCI model 302 corresponds to a directory for a software project being developed by the user, and the SCI package 304 corresponds to a subdirectory. The software project comprises the source code in at least one file that is compiled to form a sequence of instructions to be run by a data processing system. The data processing system is discussed in detail below. As is well known in object-oriented programming, the class 306 is a category of objects which describes a group of objects with similar properties (attributes), common behavior (operations or methods), common relationships to other objects, and common semantics. The members 308 comprise attributes and/or operations.

For example, the data structure 500 for the source code 400 depicted in FIG. 4 is depicted in FIG. 5. UserInterface 402 is defined as a package 404. Accordingly, UserInterface 402 is contained in SCI package 502. Similarly, Bank 406, which is defined as a class 408, is contained in SCI class 504, and Name 410 and Assets 412, which are defined as attributes (strings 414), are contained in SCI members 506. Since these elements are in the same project, all are linked. The data structure 500 also identifies the language in which the source code is written 508, e.g., the Java™ language.

FIG. 6 depicts a data processing system 600 suitable for practicing methods and systems consistent with the present invention. Data processing system 600 comprises a memory 602, a secondary storage device 604, an I/O device 606, and a processor 608. Memory 602 includes the improved software development tool 610. The software development tool 610 is used to develop a software project 612, and create the TMM 200 in the memory 602. The project 612 is stored in the secondary storage device 604 of the data processing system 600. One skilled in the art will recognize that data processing system 600 may contain additional or different components.

Although aspects of the present invention are described as being stored in memory, one skilled in the art will appreciate that these aspects can also be stored on or read from other types of computer-readable media, such as secondary storage devices, like hard disks, floppy disks or CD-ROM; or other forms of RAM or ROM either currently known or later developed.

FIG. 7 illustrates an architectural overview of the improved software development tool 610. The tool 610 comprises a core 700, an open application program interface (API) 702, and modules 704. The core 700 includes a parser 706 and an ICE 208. The parser 706 converts the source code into the language-neutral representation in the TMM, and the ICE 208 converts the text from the displays into source code. There are three main packages composing the API 702: Integrated Development Environment (IDE) 708; Read-Write Interface (RWI) 710; and Source Code Interface (SCI) 712. Each package includes corresponding subpackages. As is well known in the art, a package is a collection of attributes, notifications, operations, or behaviors that are treated as a single module or program unit.

IDE 708 is the API 702 needed to generate custom outputs based on information contained in a model. It is a read-only interface, i.e., the user can extract information from the model, but not change the model. IDE 708 provides the functionality related to the model's representation in IDE 708 and interaction with the user. Each package composing the IDE group has a description highlighting the areas of applicability of this concrete package.

RWI 710 enables the user to go deeper into the architecture. Using RWI 710, information can be extracted from and written to the models. RWI not only represents packages, classes and members, but it may also represent different diagrams (class diagrams, use case diagrams, sequence diagrams and others), links, notes, use cases, actors, states, etc.

SCI 712 is at the source code level, and allows the user to work with the source code almost independently of the language being used.

There are a variety of modules 704 in the software development tool 610 of the present invention. Some of the modules 704 access information to generate graphical and code documentation in custom formats, export to different file formats, or develop patterns. The software development tool also includes a quality assurance (QA) module which monitors the modifications to the source code and calculates the complexity metrics, i.e., the measurement of the program's performance or efficiency, to support quality assurance. The types of metrics calculated by the software development tool include basic metrics, cohesion metrics, complexity metrics, coupling metrics, Halstead metrics, inheritance metrics, maximum metrics, polymorphism metrics, and ratio metrics. Examples of these metrics with their respective definitions are identified in Tables 1–9 below.

TABLE 1
Basics Metrics
Basic Metrics        Description
Lines Of Code        Counts the number of code lines.
Number Of Attributes Counts the number of attributes. If a class has
                     a high number of attributes, it may be
                     appropriate to divide it into subclasses.
Number Of Classes    Counts the number of classes.
Number Of Import     Counts the number of imported packages/
Statements           classes. This measure can highlight excessive
                     importing, and also can be used as a measure of
                     coupling.
Number Of Members    Counts the number of members, i.e., attributes
                     and operations. If a class has a high number of
                     members, it may be appropriate to divide it into
                     subclasses.
Number Of Operations Counts the number of operations. If a class
                     has a high number of operations, it may be
                     appropriate to divide it into subclasses.

TABLE 2
Cohesion Metrics
Cohesion Metrics    Description
Lack Of Cohesion Of Takes each pair of methods in the class and
Methods 1           determines the set of fields they each access. A
                    low value indicates high coupling between
                    methods, which indicates potentially low
                    reusability and increased testing because many
                    methods can affect the same attributes.
Lack Of Cohesion Of Counts the percentage of methods that do not
Methods 2           access a specific attribute averaged over all
                    attributes in the class. A high value of cohesion
                    (a low lack of cohesion) implies that the class
                    is well designed.
Lack Of Cohesion Of Measures the dissimilarity of methods in a class
Methods 3           by attributes. A low value indicates good
                    class subdivision, implying simplicity and
                    high reusability. A high lack of cohesion
                    increases complexity, thereby increasing the
                    likelihood of errors during the development
                    process.

TABLE 3
Complexity Metrics
Complexity
Metrics    Description
Attribute  Defined as the sum of each attribute's value in the class.
Complexity
Cyclomatic Represents the cognitive complexity of the class. It counts
Complexity the number of possible paths through an algorithm by
           counting the number of distinct regions on a flowgraph, i.e.,
           the number of ‘if,’ ‘for’ and ‘while’ statements in the
           operation's body.
Number     Processes all of the methods and constructors, and counts
Of         the number of different remote methods called. A remote
Remote     method is defined as a method which is not declared in
Methods    either the class itself or its ancestors.
Response   Calculated as ‘Number of Local Methods’ + ‘Number of
For        Remote Methods.’ A class which provides a larger response
Class      set is considered to be more complex and requires more
           testing than one with a smaller overall design complexity.
Weighted   The sum of the complexity of all methods for a class, where
Methods    each method is weighted by its cyclomatic complexity. The
Per        number of methods and the complexity of the methods
Class 1    involved is a predictor of how much time and effort is
           required to develop and maintain the class.
Weighted   Measures the complexity of a class, assuming that a class
Methods    with more methods than another is more complex, and that
Per        a method with more parameters than another is also likely
Class 2    to be more complex.

TABLE 4
Coupling Metrics
Coupling
Metrics     Description
Coupling    Represents the number of other classes to which a class is
Between     coupled. Counts the number of reference types that are used
Objects     in attribute declarations, formal parameters, return types,
            throws declarations and local variables, and types from
            which attribute and method selections are made.
            Excessive coupling between objects is detrimental to
            modular design and prevents reuse. The more independent a
            class is, the easier it is to reuse it in another application. In
            order to improve modularity and promote encapsulation,
            inter-object class couples should be kept to a minimum. The
            larger the number of couples, the higher the sensitivity to
            changes in other parts of the design, and therefore
            maintenance is more difficult. A measure of coupling is
            useful to determine how complex the testing of various
            parts of a design is likely to be. The higher the inter-object
            class coupling, the more rigorous the testing needs to be.
Data        Counts the number of reference types used in the attribute
Abstraction declarations.
Coupling
FanOut      Counts the number of reference types that are used in
            attribute declarations, formal parameters, return types,
            throws declarations and local variables.

TABLE 5
Halstead Metrics
Halstead
Metrics    Description
Halstead   This measure is one of the Halstead Software Science
Difficulty metrics. It is calculated as (‘Number of Unique Operators’/
           ‘Number of Unique Operands’) * (‘Number of Operands’/
           ‘Number of Unique Operands’).
Halstead   This measure is one of the Halstead Software Science
Effort     metrics. It is calculated as ‘Halstead Difficulty’ * ‘Halstead
           Program Volume.’
Halstead   This measure is one of the Halstead Software Science
Program    metrics. It is calculated as ‘Number of Operators’ +
Length     ‘Number of Operands.’
Halstead   This measure is one of the Halstead Software Science
Program    metrics. It is calculated as ‘Number of Unique Operators’ +
Vocabulary ‘Number of Unique Operands.’
Halstead   This measure is one of the Halstead Software Science
Program    metrics. It is calculated as ‘Halstead Program Length’ *
Volume     Log2(‘Halstead Program Vocabulary’).
Number Of  This measure is used as an input to the Halstead Software
Operands   Science metrics. It counts the number of operands used in a
           class.
Number Of  This measure is used as an input to the Halstead Software
Operators  Science metrics. It counts the number of operators used in a
           class.
Number Of  This measure is used as an input to the Halstead Software
Unique     Science metrics. It counts the number of unique operands
Operands   used in a class.
Number Of  This measure is used as an input to the Halstead Software
Unique     Science metrics. It counts the number of unique operators
Operators  used in a class.

TABLE 6
Inheritance Metrics
Inheritance
Metrics     Description
Depth Of    Counts how far down the inheritance hierarchy a class or
Inheritance interface is declared. High values imply that a class is quite
Hierarchy   specialized.
Number Of   Counts the number of classes which inherit from a
Child       particular class, i.e., the number of classes in the
Classes     inheritance tree down from a class. Non-zero value
            indicates that the particular class is being re-used. The
            abstraction of the class may be poor if there are too many
            child classes. It should also be stated that a high value of
            this measure points to the definite amount of testing
            required for each child class.

TABLE 7
Maximum Metrics
Maximum
Metrics    Description
Maximum    Counts the maximum depth of ‘if,’ ‘for’ and ‘while’
Number Of  branches in the bodies of methods. Logical units with a
Levels     large number of nested levels may need implementation
           simplification and process improvement because groups that
           contain more than seven pieces of information are
           increasingly harder for people to understand in problem
           solving.
Maximum    Displays the maximum number of parameters among all
Number Of  class operations. Methods with many parameters tend to be
Parameters more specialized and, thus, are less likely to be reusable.
Maximum    Counts the maximum size of the operations for a class.
Size Of    Method size is determined in terms of cyclomatic
Operation  complexity, i.e., the number of ‘if,’ ‘for’ and ‘while’
           statements in the operation's body.

TABLE 8
Polymorphism Metrics
Polymorphism
Metrics    Description
Number Of  Counts the number of operations added by a class. A
Added      large value of this measure indicates that the functionality
Methods    of the given class becomes increasingly distinct from that
           of the parent classes. In this case, it should be considered
           whether this class genuinely should be inheriting from
           the parent, or if it could be broken down into several
           smaller classes.
Number Of  Counts the number of inherited operations which a class
Overridden overrides. Classes without parents are not processed.
Methods    High values tend to indicate design problems, i.e.,
           subclasses should generally add to and extend the
           functionality of the parent classes rather than overriding
           them.

TABLE 9
Ratio Metrics
Ratio
Metrics    Description
Comment    Counts the ratio of comments to total lines of code
Ratio      including comments.
Percentage Counts the percentage of package members in a class.
Of Package
Members
Percentage Counts the percentage of private members in a class.
Of Private
Members
Percentage Counts the percentage of protected members in a class.
Of Protected
Members
Percentage Counts the proportion of vulnerable members in a class. A
Of Public  large proportion of such members means that the class has
Members    high potential to be affected by external classes and means
           that increased efforts will be needed to test such a class
           thoroughly.
True       Counts the ratio of comments to total lines of code
Comment    excluding comments.
Ratio

The QA module also provides audits, i.e., the module checks for conformance to predefined or user-defined styles. The types of audits provided by the module include coding style, critical errors, declaration style, documentation, naming style, performance, possible errors and superfluous content. Examples of these audits with their respective definitions are identified in Tables 10–17 below.

TABLE 10
Coding Style Audits
Coding Style
Audits        Description
Access Of     Static members should be referenced through class names
Static        rather than through objects.
Members
Through
Objects
Assignment    Formal parameters should not be assigned.
To Formal
Parameters
Complex       Checks for the occurrence of multiple assignments and
Assignment    assignments to variables within the same expression.
              Complex assignments should be avoided since they
              decrease program readability.
Don't Use     The negation operator slows down the readability of the
the Negation  program. Thus, it is recommended that it not be used
Operator      frequently.
Frequently
Operator ‘?:’ The operator ‘?:’ makes the code harder to read than the
May Not Be    alternative form with an if-statement.
Used
Provide       Checks if the third argument of the ‘for’-statement is
Incremental   missing.
In For-
Statement or
use while-
statement
Replacement   Demand import-declarations must be replaced by a list of
For Demand    single import-declarations that are actually imported into
Imports       the compilation unit. In other words, import-statements
              may not end with an asterisk.
Use           Use the abbreviated assignment operator in order to write
Abbreviated   programs more rapidly. Also some compilers run faster
Assignment    with the abbreviated assignment operator.
Operator
Use ‘this’    Tries to make the developer use ‘this’ explicitly when
Explicitly To trying to access class members. Using the same class
Access Class  member names with parameter names often makes what the
Members       developer is referring to unclear.

TABLE 11
Critical Errors Audits
Critical Errors
Audits         Description
Avoid Hiding   Detects when attributes declared in child classes hide
Inherited      inherited attributes.
Attributes
Avoid Hiding   Detects when inherited static operations are hidden by
Inherited      child classes.
Static Methods
Command        Prevents methods that return a value from a modifying
Query          state. The methods used to query the state of an object
Separation     must be different from the methods used to perform
               commands (change the state of the object).
Hiding Of      Declarations of names should not hide other declarations
Names          of the same name.
Inaccessible   Overload resolution only considers constructors and
Constructor Or methods that are visible at the point of the call. If,
Method         however, all the constructors and methods were
Matches        considered, there may be more matches. This rule is
               violated in this case.
               Imagine that ClassB is in a different package than
               ClassA. Then the allocation of ClassB violates this rule
               since the second constructor is not visible at the point of
               the allocation, but it still matches the allocation (based
               on signature). Also the call to open in ClassB violates
               this rule since the second and the third declarations of
               open are not visible at the point of the call, but it still
               matches the call (based on signature).
Multiple       Multiple declarations with the same name must not be
Visible        simultaneously visible except for overloaded methods.
Declarations
With Same
Name
Overriding a   Checks for abstract methods overriding non-abstract
Non-Abstract   methods in a subclass.
Method With
an Abstract
Method
Overriding a   A subclass should not contain a method with the same
Private Method name and signature as in a superclass if these methods
               are declared to be private.
Overloading    A superclass method may not be overloaded within a
Within a       subclass unless all overloading in the superclass are also
Subclass       overridden in the subclass. It is very unusual for a
               subclass to be overloading methods in its superclass
               without also overriding the methods it is overloading.
               More frequently this happens due to inconsistent changes
               between the superclass and subclass - i.e., the intention
               of the user is to override the method in the superclass,
               but due to the error, the subclass method ends up
               overloading the superclass method.
Use of Static  Non-final static attributes should not be used in
Attribute for  initializations of attributes.
Initialization

TABLE 12
Declaration Style Audits
Declaration
Style Audits Description
Badly        Array declarators must be placed next to the type descriptor
Located      of their component type.
Array
Declarators
Constant     Private attributes that never get their values changed must
Private      be declared final. By explicitly declaring them in such a
Attributes   way, a reader of the source code get some information of
Must Be      how the attribute is supposed to be used.
Final
Constant     Local variables that never get their values changed must be
Variables    declared final. By explicitly declaring them in such a way, a
Must Be      reader of the source code obtains information about how the
Final        variable is supposed to be used.
Declare      Several variables (attributes and local variables) should not
Variables In be declared in the same statement.
One
Statement
Each
Instantiated This rule recommends making all instantiated classes final.
Classes      It checks classes which are present in the object model.
Should Be    Classes from search/classpath are ignored.
Final
List All     Enforces a standard to improve readability. Methods/data in
Public And   your class should be ordered properly.
Package
Members
First
Order Of     Checks for correct ordering of modifiers. For classes, this
Appearance   includes visibility (public, protected or private), abstract,
Of Modifiers static, final. For attributes, this includes visibility (public,
             protected or private), static, final, transient, volatile. For
             operations, this includes visibility (public, protected or
             private), abstract, static, final, synchronized, native.
Put the Main Tries to make the program comply with various coding
Function     standards regarding the form of the class definitions.
Last

TABLE 13
Documentation Audits
Documentation
Audits      Description
Bad Tag In  This rule verifies code against accidental use of improper
JavaDoc     JavaDoc tags.
Comments
Distinguish Checks whether the JavaDoc comments in your program
Between     ends with ‘**/’ and ordinary C-style ones with ‘*/.’
JavaDoc And
Ordinary
Comments

TABLE 14
Naming Style Audits
Naming Style
Audits       Description
Class Name   Checks whether top level classes or interfaces have the
Must Match   same name as the file in which they reside.
Its File Name
Group        Enforces standard to improve readability.
Operations
With Same
Name Together
Naming       Takes a regular expression and item name and reports all
Conventions  occurrences where the pattern does not match the
             declaration.
Names Of     Names of classes which inherit from Exception should
Exception    end with Exception.
Classes
Use          One-character local variable or parameter names should
Conventional be avoided, except for temporary and looping variables,
Variable     or where a variable holds an undistinguished value of a
Names        type.

TABLE 15
Performance Audits
Performance
Audits    Description
Avoid     This rule recommends declaring local variables outside the
Declaring loops since declaring variables inside the loop is less
Variables efficient.
Inside Loops
Append To Performance enhancements can be obtained by replacing
String    String operations with StringBuffer operations if a String
Within a  object is appended within a loop.
Loop
Complex   Avoid using complex expressions as repeat conditions
Loop      within loops.
Expressions

TABLE 16
Possible Error Audits
Possible
Error Audits      Description
Avoid Public      Declare the attributes either private or protected, and
And Package       provide operations to access or change them.
Attributes
Avoid             Avoid statements with empty body.
Statements
With Empty
Body
Assignment        ‘For’-loop variables should not be assigned.
To For-Loop
Variables
Don't Compare     Avoid testing for equality of floating point numbers since
Floating          floating-point numbers that should be equal are not
Point Types       always equal due to rounding problems.
Enclosing         The statement of a loop must always be a block. The
Body Within       ‘then’ and ‘else’ parts of ‘if’-statements must always be
a Block           blocks. This makes it easier to add statements without
                  accidentally introducing bugs in case the developer
                  forgets to add braces.
Explicitly        Explicitly initialize all variables. The only reason not to
Initialize All    initialize a variable is where it's declared is if the initial
Variables         value depends on some computation occurring first.
Method            Calling of super.finalize() from finalize() is good practice
finalize()        of programming, even if the base class doesn't define the
Doesn't Call      finalize() method. This makes class implementations less
super.finalize()  dependent on each other.
Mixing Logical    An expression containing multiple logical operators
Operators         should be parenthesized properly.
Without
Parentheses
No                Use of assignment within conditions makes the source
Assignments In    code hard to understand.
Conditional
Expressions
Use ‘equals’      The ‘==’ operator used on strings checks if two string
Instead Of ‘==’   objects are two identical objects. In most situations,
                  however, one likes to simply check if two strings have
                  the same value. In these cases, the ‘equals’ method
                  should be used.
Use ‘L’ Instead   It is better to use uppercase ‘L’ to distinguish the letter
Of ‘l’ at the end ‘l’ from the number ‘1.’
of integer
constant
Use Of the        The ‘synchronized’ modifier on methods can sometimes
‘synchronized’    cause confusion during maintenance as well as during
Modifier          debugging. This rule therefore recommends against using
                  this modifier, and instead recommends using
                  ‘synchronized’ statements as replacements.

TABLE 17
Superfluous Content Audits
Superfluous
Content Audits  Description
Duplicate       There should be at most one import declaration that
Import          imports a particular class/package.
Declarations
Don't Import    No classes or interfaces need to be imported from the
the Package the package to which the source code file belongs.
Source File     Everything in that package is available without explicit
Belongs To      import statements.
Explicit Import Explicit import of classes from the package ‘java.lang’
Of the          should not be performed.
java.lang
Classes
Equality        Avoid performing equality operations on Boolean
Operations On   operands. ‘True’ and ‘false’ literals should not be used
Boolean         in conditional clauses.
Arguments
Imported Items  It is not legal to import a class or an interface and never
Must Be Used    use it. This rule checks classes and interfaces that are
                explicitly imported with their names - that is not with
                import of a complete package, using an asterisk. If
                unused class and interface imports are omitted, the
                amount of meaningless source code is reduced - thus the
                amount of code to be understood by a reader is
                minimized.
Unnecessary     Checks for the use of type casts that are not necessary.
Casts
Unnecessary     Verifies that the runtime type of the left-hand side
‘instanceof’    expression is the same as the one specified on the
Evaluations     right-hand side.
Unused Local    Local variables and formal parameter declarations must
Variables And   be used.
Formal
Parameters
Use Of          The modifier ‘abstract’ is considered obsolete and should
Obsolete        not be used.
Interface
Modifier
Use Of          All interface operations are implicitly public and abstract.
Unnecessary     All interface attributes are implicitly public, final and
Interface       static.
Member
Modifiers
Unused Private  An unused class member might indicate a logical flaw in
Class Member    the program. The class declaration has to be reconsidered
                in order to determine the need of the unused member(s).

If the QA module determines that the source code does not conform, an error message is provided to the developer. For example, as depicted in FIG. 8A, the software development tool checks for a variety of coding styles 800. If the software development tool were to check for “Access Of Static Members Through Objects” 802, it would verify whether static members are referenced through class names rather than through objects 804. Further, as depicted in FIG. 8B, if the software development tool were to check for “Complex Assignment” 806, the software development tool would check for the occurrence of multiple assignments and assignments to variables within the same expression to avoid complex assignments since these decrease program readability 808. An example of source code having a complex assignment 810 and source code having a non-complex assignment 812 are depicted in FIGS. 8B and 8C, respectively. The QA module of the software development tool monitors the source code for other syntax errors well known in the art, as described above, and provides an error message if any such errors are detected.

The improved software development tool of the present invention is used to develop source code in a project. The project comprises a plurality of files and the source code of one of the plurality of files is written in a given language. The software development tool determines the language of the source code of the file, converts the source code from the language into a language-neutral representation, uses the language-neutral representation to textually display the source code of the file in the language, and uses the language-neutral representation to display a graphical representation of at least a portion of the project. The source code and the graphical representation are displayed simultaneously.

The improved software development tool of the present invention is also used to develop source code. The software development tool receives an indication of a selected language for the source code, creates a file to store the source code in the selected language, converts the source code from the selected language into a language-neutral representation, uses the language-neutral representation to display the source code of the file, and uses the language-neutral representation to display a graphical representation of the file. Again, the source code and the graphical representation are displayed simultaneously.

Moreover, if the source code in the file is modified, the modified source code and a graphical representation of at least a portion of the modified source code are displayed simultaneously. The QA module of the software development tool provides an error message if the modification does not conform to predefined or user-defined styles, as described above. The modification to the source code may be received from the display of the source code, the display of the graphical representation of the project, or via some other independent software to modify the code. The graphical representation of the project may be in Unified Modeling Language; however, one skilled in the art will recognize that other graphical representations of the source code may be displayed. Further, although the present invention is described and shown using the various views of the UML, one of ordinary skill in the art will recognize that other views may be displayed.

FIG. 9 depicts a flow diagram of the steps performed by the software development tool to develop a project in accordance with the present invention. As previously stated, the project comprises a plurality of files. The developer either uses the software development tool to open a file which contains existing source code, or to create a file in which the source code will be developed. If the software development tool is used to open the file, determined in step 900, the software development tool initially determines the programming language in which the code is written (step 902). The language is identified by the extension of the file, e.g., “java” identifies source code written in the Java™ language, while “.cpp” identifies source code written in C++. The software development tool then obtains a template for the current programming language, i.e., a collection of generalized definitions for the particular language that can be used to build the data structure (step 904). For example, the definition of a new Java™ class contains a default name, e.g., “Class1,” and the default code, “public class Class1 { }.” Such templates are well known in the art. For example, the “Microsoft Foundation Class Library” and the “Microsoft Word Template For Business Use Case Modeling” are examples of standard template libraries from which programmers can choose individual template classes. The software development tool uses the template to parse the source code (step 906), and create the data structure (step 908). After creating the data structure or if there is no existing code, the software development tool awaits an event, i.e., a modification or addition to the source code by the developer (step 910). If an event is received and the event is to close the file (step 912), the file is saved (step 914) and closed (step 916). Otherwise, the software development tool performs the event (step 918), i.e., the tool makes the modification. The software development tool then updates the TMM or model (step 920), as discussed in detail below, and updates both the graphical and the textual views (step 922).

FIGS. 10A and 10B depict a flow diagram illustrating the update model step of FIG. 9. The software development tool selects a file from the project (step 1000), and determines whether the file is new (step 1002), whether the file has been updated (step 1004), or whether the file has been deleted (step 1006). If the file is new, the software development tool adds the additional symbols from the file to the TMM (step 1008). To add the symbol to the TMM, the software development tool uses the template to parse the symbol to the TMM. If the file has been updated, the software development tool updates the symbols in the TMM (step 1010). Similar to the addition of a symbol to the TMM, the software development tool uses the template to parse the symbol to the TMM. If the file has been deleted, the software development tool deletes the symbols in the TMM (step 1012). The software development tool continues this analysis for all files in the project. After all files are analyzed (step 1014), any obsolete symbols in the TMM (step 1016) are deleted (step 1018).

FIG. 11 depicts a flow diagram illustrating the performance of an event, specifically the creation of a class, in accordance with the present invention. After identifying the programming language (step 1100), the software development tool obtains a template for the language (step 1102), creates a source code file in the project directory (step 1104), and pastes the template onto the TMM (step 1106). The project directory corresponds to the SCI model 302 of FIG. 3. Additional events which a developer may perform using the software development tool include the creation, modification or deletion of packages, projects, attributes, interfaces, links, operations, and the closing of a file.

The software development tool is collectively broken into three views of the application: the static view, the dynamic view, and the functional view. The static view is modeled using the use-case and class diagrams. A use case diagram 1200, depicted in FIG. 12, shows the relationship among actors 1202 and use cases 1204 within the system 1206. A class diagram 1300, depicted in FIG. 13 with its associated source code 1302, on the other hand, includes classes 1304, interfaces, packages and their relationships connected as a graph to each other and to their contents.

The dynamic view is modeled using the sequence, collaboration and statechart diagrams. As depicted in FIG. 14, a sequence diagram 1400 represents an interaction, which is a set of messages 1402 exchanged among objects 1404 within a collaboration to effect a desired operation or result. In a sequence diagram 1400, the vertical dimension represents time and the horizontal dimension represents different objects. A collaboration diagram 1500, depicted in FIG. 15, is also an interaction with messages 1502 exchanged among objects 1504, but it is also a collaboration, which is a set of objects 1504 related in a particular context. Contrary to sequence diagrams 1400 (FIG. 14), which emphasize the time ordering of messages along the vertical axis, collaboration diagrams 1500 (FIG. 15) emphasize the structural organization of objects.

A statechart diagram 1600 is depicted in FIG. 16. The statechart diagram 1600 includes the sequences of states 1602 that an object or interaction goes through during its life in response to stimuli, together with its responses and actions. It uses a graphic notation that shows states of an object, the events that cause a transition from one state to another, and the actions that result from the transition.

The functional view can be represented by activity diagrams 1700 and more traditional descriptive narratives such as pseudocode and minispecifications. An activity diagram 1700 is depicted in FIG. 17, and is a special case of a state diagram where most, if not all, of the states are action states 1702 and where most, if not all, of the transitions are triggered by completion of the actions in the source states. Activity diagrams 1700 are used in situations where all or most of the events represent the completion of internally generated actions.

There is also a fourth view mingled with the static view called the architectural view. This view is modeled using package, component and deployment diagrams. Package diagrams show packages of classes and the dependencies among them. Component diagrams 1800, depicted in FIG. 18, are graphical representations of a system or its component parts. Component diagrams 1800 show the dependencies among software components, including source code components, binary code components and executable components. As depicted in FIG. 19, Deployment diagrams 1900 are used to show the distribution strategy for a distributed object system. Deployment diagrams 1900 show the configuration of run-time processing elements and the software components, processes and objects that live on them.

Although discussed in terms of class diagrams, one skilled in the art will recognize that the software development tool of the present invention may support these and other graphical views.

The improved software development tool of the present invention is used to display versions of source code. Each version is an instance in an edit history. The software development tool determines a language of the source code, stores indications of the edits to the source code, converts the source code with the indications of the edits from the language into a language-neutral representation, uses the language-neutral representation to display the source code in the language with the indications of the edits, and uses the language-neutral representation to display the corresponding graphical representation of the source code with the indications of the edits. The rate at which the source code with the indications of the edits is displayed is adjustable. Moreover, the source code with the indications of the edits may be displayed sequentially or in reverse order.

FIG. 20 depicts a flow diagram of the steps performed by the software development tool to store the edit history of source code. After the source code has been modified (step 2000), the software development tool saves the edits to the source code into the secondary storage (step 2002). After all edits have been made (step 2004), the software development tool saves the source code into the secondary storage (step 2006).

The steps performed by the software development tool to sequentially display the source code with the edit history is depicted in FIGS. 21A–C. The software development tool retrieves the source code (step 2100), identifies the programming language of the source code (step 2102), and obtains the template for the current programming language (step 2104). The software development tool then parses the source code (step 2106) and creates the data structure (step 2108). The software development tool retrieves the edit history, i.e., all of the edits which were stored for the source code (step 2110), and the user chooses a rate of displaying the source code (step 2112), thus setting the time period (step 2114). The user chooses whether to display the source code in the forward mode or in the reverse mode (step 2116).

In the forward mode shown in FIG. 21B, the software development tool removes all edits to the source code (step 2118) and updates the model (step 2120). The software development tool pauses for the time period determined by the rate at which the source code is displayed (step 2122), and for each edit (step 2124), the software development tool applies the edit to the source code (step 2126) before updating the model (step 2128). If the user chooses to adjust the rate of the display (step 2130), the time period is adjusted accordingly (step 2132). The process then continues with the next edit (step 2134).

In the reverse mode depicted in FIG. 21C, the software development tool pauses for the time period (step 2136), and for each edit (step 2138), the software development tool removes the edit from the source code (step 2140) before updating the model (step 2142). If the user chooses to adjust the rate of the display (step 2144), the software development tool adjusts the time period accordingly (step 2146). The process then continues with the next edit (step 2148).

While various embodiments of the application have been described, it will be apparent to those of ordinary skill in the art that many more embodiments and implementations are possible that are within the scope of this invention. Accordingly, the invention is not to be restricted except in light of the attached claims and their equivalents.

Claims

1. A method in a data processing system for displaying versions of a source code, each version reflecting an instance in an edit history, the method comprising the steps of: determining the language of the source code;storing indications of the edits to the source code;converting the source code with the indications of the edits from the language into a language-neutral representation that includes a data structure having a source code interface (SCI) model, an SCI package, an SCI class, and an SCI member; andusing language-neutral representation to simultaneously display a text representation and a corresponding graphical representation of the converted source code with the indications of the edits, showing visual differences of the source code through time, wherein the graphical representation of the converted source code displays a diagrammatic representation of the source code to demonstrate relationships between elements of the source code, andwherein the graphical representation of the source code is not an alpha-numeric display and is not merely a text representation on a user interface, and calculating metrics selected from a group consisting of basic metrics, cohesion metrics, complexity metrics, coupling metrics, Halstead metrics, inheritance metrics, maximum metrics, polymorphism metrics, and maximum metrics by way of a quality assurance module, which monitors the modifications to the source code.

2. The method of claim 1, wherein the source code and the corresponding graphical representation of the converted source code are displayed sequentially.

3. The method of claim 1, wherein a rate at which the source code with the indications of the edits is displayed is adjustable.

4. The method of claim 1, wherein the source code with the indications of the edits is displayed in reverse order.

5. The method of claim 1, wherein the graphical representation is one from a group consisting of a use case diagram, a sequence diagram, a collaboration diagram, a state transition diagram, an activity diagram, a package diagram, a component diagram and a deployment diagram.

6. A method in a data processing system for displaying versions of a source code, the method comprising the steps of: storing an edit to the source code; anddisplaying simultaneously a text representation and acorresponding language-neutral graphical representation of the source code that includes a data structure having a source code interface (SCI) model, an SCI package, an SCI class, and an SCI member with an indication of the edit,wherein the language-neutral graphical representation of the source code displays a diagrammatic representation of the source code demonstrating relationships between elements of the source code, andwherein the language-neutral graphical representation of the source code is not an alpha-numeric numeric display and is not merely a text representation on a user interface, andcalculating metrics selected from a group consisting of basic metrics, cohesion metrics, complexity metrics, coupling metrics, Halstead metrics, inheritance metrics, maximum metrics, polymorphism metrics, and maximum metrics by way of a quality assurance module, which monitors the modifications to the source code.

7. The method of claim 5, wherein the step of displaying the source code comprises the steps of: determining a language of the source code;converting the source code from the language into the language-neutral graphical representation that includes a data structure having a source code interface (SCI) model, an SCI package, an SCI class, and an SCI member; andusing the language-neutral graphical representation to simultaneously display a text representation and a graphical representation of the converted source code with an indication of the source code edit.

8. The method of claim 7, wherein the source code is displayed after the converted source code with an indication of the edit is displayed.

9. A computer-readable medium containing instructions for controlling a data processing system to perform a method, the data processing system having versions of a source code, each version reflecting an instance in an edit history, the method comprising the steps of: determining a language of the source code;storing indications of the edits to the source code;converting the source code with the indications of the edits from the language into a language-neutral representation that includes a data structure having a source code interface (SCI) model, an SCI package, an SCI class, and an SCI member; andusing the language-neutral representation to simultaneously display a text representation and a corresponding graphical representation of the source code with indications of all the edits; wherein the graphical representation of the source code displays a diagrammatic representation of the source code demonstrating relationships between elements of the source code, andwherein the graphical representation of the source code is not an alpha-numeric display and is not merely a text representation on a user interface, andcalculating metrics selected from a group consisting of basic metrics, cohesion metrics, complexity metrics, coupling metrics, Halstead metrics, inheritance metrics, maximum metrics, polymorphism metrics, and maximum metrics by way of a quality assurance module, which monitors the modifications to the source code.

10. The computer-readable medium of claim 9, wherein the source code and the corresponding graphical representation of the source code are displayed sequentially.

11. The computer-readable medium of claim 9, wherein a rate at which the source code with the indications of the edits is displayed is adjustable.

12. The computer-readable medium of claim 9, wherein the source code with the indications of the edits is displayed in reverse order.

13. The computer-readable medium of claim 9, wherein the graphical representation is one from a group consisting of a class diagram, a use case diagram, a sequence diagram, a collaboration diagram, a state transition diagram, an activity diagram, a package diagram, a component diagram and a deployment diagram.

14. A computer-readable medium containing instructions for controlling a data processing system to perform a method, the data processing system having versions of a source code, each version reflecting an instance in an edit history, the method comprising the steps of: storing indications of the edits to the source code; anddisplaying simultaneously a text representation and a language-neutral graphical representation of the source code that includes a data structure having a source code interface (SCI) model, an SCI package, an SCI class, and an SCI member with indications of all the edits, wherein the language-neutral graphical representation of the source code of the source code displays a diagrammatic representation of the source code to demonstrate relationships between elements of the source code, andwherein the language-neutral graphical representation of the source code is not analpha-numeric display and is not merely a text representation on a user interface, andcalculating metrics selected from a group consisting of basic metrics, cohesion metrics, complexity metrics, coupling metrics, Halstead metrics, inheritance metrics, maximum metrics, polymorphism metrics, and maximum metrics by way of a quality assurance module, which monitors the modifications to the source code.

15. The computer-readable medium of claim 14, wherein the versions of the source code are displayed sequentially.

16. The computer-readable medium of claim 14, wherein a rate at which the source code with the indications of the edits is displayed is adjustable.

17. The computer-readable medium of claim 14, wherein the source code with the indications of the edits is displayed in reverse order.

18. The computer-readable medium of claim 14, wherein the language-neutral graphical representation is one from a group consisting of a class diagram, a use diagram, a sequence diagram, a collaboration diagram, a state transition diagram, an activity diagram, a package diagram, a component diagram and a deployment diagram.

19. A computer-readable medium containing instructions for controlling a data processing system to perform a method, the data processing system having a source code, the method comprising the steps of: storing an edit to the source code;displaying simultaneously a text representation and a language-neutral graphical representation of the source code that includes a data structure having a source code interface (SCI) model, an SCI package, an SCI class, and an SCI member with indications of all the edits, wherein the language-neutral graphical representation of the source code displays a diagrammatic representation of the source code to demonstrate relationships between elements of the source code, andwherein the language-neutral graphical representation of the source code is not an alpha-numeric display and is not merely a text representation on a user interface, andcalculating metrics selected from a group consisting of cohesion metrics, complexity metrics, coupling metrics, Halstead metrics, inheritance metrics, maximum metrics, polymorphism metrics, and maximum metrics by way of a quality assurance module, which monitors the modifications to the source code.

20. The computer-readable medium of claim 19, wherein the step of displaying the source code comprises the steps of: determining a language of the source code;converting the source code from the language into the language-neutral representation; andusing the language-neutral representation to simultaneously display a text representation and a corresponding graphical representation of the converted source code with an indication of the edit.

21. The computer-readable medium of claim 19, wherein the step of displaying the source code with the edit comprises the steps of: converting the source code with an indication of the edit from the language into the language-neutral graphical representation; andusing the language-neutral representation of the converted source code with an indication of the edit to display the graphical representation of the source code with the edit.

22. The computer-readable medium of claim 19, wherein the source code is displayed after the source code with the edit is displayed.

23. A data processing system comprising: a secondary storage including a source code;a memory device including:a program that stores indications of edits to the source code into the memory device, and that simultaneously displays a text representation and a corresponding language-neutral graphical representation of the source code that includes a data structure having a source code interface (SCI) model, an SCI package, an SCI class, and an SCI member with indications of all edits, wherein the language-neutral graphical representation of the source code displays a diagrammatic representation of the source code to demonstrate relationships between elements of the source code, andwherein the language-neutral graphical representation of the source code is not an alpha-numeric display and is not merely a text representation on a user interface of the source code with the indications of the edits;a quality assurance module which monitors the modifications to the source code and calculates metrics selected from a group consisting of basic metrics, cohesion metrics, complexity metrics, coupling metrics, Halstead metrics, inheritance metrics, maximum metrics polymorphism metrics, and maximum metrics; anda processor for running the program.

24. The data processing system of claim 23, wherein the source code with the indications of the edits are displayed sequentially.

25. The data processing system of claim 23, wherein a rate at which the source codes with the indications of the edits is displayed is adjustable.

26. The data processing system of claim 23, wherein the source code with the indications of the edits is displayed in reverse order.

27. The data processing system of claim 23, wherein the program further determines the language of the source code,converts the source code with the indications of the edits from the language into the language-neutral graphical representation, anduses the language-neutral graphical representation to simultaneously display a text representation and a corresponding graphical representation of the source code with indications of all the edits.

28. The data processing system of claim 27, wherein the memory device further comprises a transient meta model, wherein said transient meta model stores the language neutral graphical representation of the source code.

29. The data processing system of claim 23, wherein the graphical representation is one from a group consisting of a class diagram, a use case diagram, a sequence diagram, a collaboration diagram, a state transition diagram, an activity diagram, a package diagram, a component diagram and a deployment diagram.

30. A system for displaying versions of a source code, each version reflecting an instance in an edit history, the system comprising: means for storing indications of the edits to the source code; andmeans for simultaneously displaying a text representation and a language-neutral graphical representation of the source code that includes a data structure having a source code interface (SCI) model, an SCI package, an SCI class, and an SCI member with the indications of all the edits,wherein the graphical representation of the source code displays a diagrammatic representation of the source code to demonstraterelationships between elements of the source code, andwherein the graphical representation of the source code is not an alpha-numeric display and is not merely a text representation on a user interface, anda means for calculating metrics selected from a group consisting of basic metrics, cohesion metrics, complexity metrics, coupling metrics, Halstead metrics, inheritance metrics, maximum metrics, polymorphism metrics, and maximum metrics.