JP2000132384A - Method for constructing class library - Google Patents

Abstract

PROBLEM TO BE SOLVED: To construct the class libraries of plural hierarchies, thus allowing the respective class libraries to be independently used with an application program. SOLUTION: In the class library of graphic plotting, an abstract basic layer, a basic graphic layer, a composite graphic layer and an application graphic operation layer are made into hierarchies and the respective hierarchies can independently construct an application. The respective hierarchies realize differential programming by permitting the succeeded low-order class to call the similar function of a high-order class so as to transmit it. The respective hierarchies output objects in a block unit and read them in the block unit, generate the corresponding object and read data into the generated object itself.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a method of constructing a class library in object-oriented programming, and more particularly to a method of inputting and outputting a file.

[0002]

2. Description of the Related Art At present, computer software programs (hereinafter referred to as programs) are being described by a new programming method, object-oriented programming.

In conventional structured programming, data is read from and written to a secondary storage (hereinafter referred to as a file) by a function of a program.

In object-oriented programming, data is contained in one class, and a class exists as an instance object (hereinafter, object) during execution of a program, and data is saved and read by inputting and outputting an object to and from a file. it can.

[0005]

In the object-oriented programming, in addition to the above-mentioned functions, the hierarchical development of classes using the concept of inheritance enables differential development of programs. In the object orientation, there is a case where a single library is prepared as a class library in which classes are put together.

[0006] When all functions are satisfied by one class library, no problem occurs, but when there is a major change in which a new function is added, the class library must be largely changed. This is because the current class library is not implemented as a multi-layered class library layer. Here, only the file input / output problem is dealt with, but the same can be said for the layering of drawing and the layering of other functions.

Since the class library is not multi-layered, input / output of data contained in an object to / from a file cannot be realized well. The problem is that classes in each layer cannot input / output their own data. This is because the file size, output order, and output format are undefined.

At present, when each application is used independently using each layer of the class library,
Each class library must be able to independently have file I / O.

It is an object of the present invention to provide a method of constructing a class library in which a plurality of class libraries are constructed and each class library can be used independently by an application program.

[0010]

According to the present invention, in an object-oriented programming, a class library is realized as a plurality of layers, each of the layers independently builds an application, and each of the layers has an inherited lower class. Differential programming is enabled by calling and propagating the same function of the upper class, and each layer outputs objects in block units, reads out objects in block units,
A corresponding object is generated, and data is read into the generated object itself.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present embodiment, a class library having a plurality of layers is constructed, and each class library is used as an input / output method of a file which can be used independently by an application program. Hereinafter, the output method and the input method of the file will be described in detail.

(1) Method of Outputting Files at Multiple Hierarchies As shown in FIG. 1, a class library layer of graphics, a plurality of class libraries such as an abstract basic layer, a basic graphic layer, a composite graphic layer, and an application graphic operation layer By constructing the layers, the file input / output function is satisfied, and the application program can use each layer to realize a difference program.

FIG. 2 shows an example in which graphic information in the basic graphic class library layer is output. FIG. 3 shows an example in which connection information of a figure in the composite figure class library layer is output.
FIG. 4 shows a class hierarchy specifically showing an example of file input / output based on FIG.

FIG. 5 shows an example of the function of the class library hierarchy. The basic graphic layer has a basic graphic drawing and operation function.
The composite figure layer has a basic figure, connection information, and connected information.

FIG. 3 shows an example in which, for example, the graphic shown in FIG. 6 is output to a file by such a configuration of the class library layer.

Further, in order to realize the differential programming, for example, only the information possessed for each hierarchy at which the graphic shown in FIG. 6 is written is output, and the member functions of the upper hierarchy are called. FIG. 7 shows a specific example. In FIG. 7, three connected figures shown in FIG. 6 are output. This graphic is represented using the composite graphic class library layer. In the complex figure hierarchy, drawing and manipulating the figure (moving, transforming,
Other attribute changes (color, line type, line thickness, etc.) are added with the function of connecting figures, and the connected figure retains the connection information even if one figure deformation is moved.
Other figures also move and deform.

Referring to FIGS. 7 and 4, the output example of FIG. 6 will be described. When the user requests to save to a file, CComp
The instruction is sent to the object4 of the siteComponent. Since CCompositeComponent has no file-specific operations, the upper-layer CBase
Request file output to Component. CBas
eComponent is also CGenericCom
request to the applicant. CGenericCompo
The “nent” manages all figures and requests all objects to output to a file. The file output is requested to the object 1, the object 2, and the object in the order of (1), (2), and (3) in FIG.

First, the object 1 is composed of the upper layer CRe.
ctFigure is requested to output a file so as to output higher-order data. After that, the generation class CCom
Only connection information is output by the file output member function of postSymbol. Requested CRec
Figure is the CBaseFigure of the upper layer similarly.
Requesting a file output to the server and outputting information on the size and position of the figure. The requested CBaseFigure similarly requests the upper layer CGeneric Figure to output a file, and outputs data specific to the CBaseFigure (though there is no data to be output in this example). CGe
NericFigure operates in the same manner as CBaseFigure. It ends here because there is no upper layer. In exactly the same manner, the output of the object 2 and the object 3 is performed.

(2) Method of Inputting Files in Multiple Hierarchies A plurality of class library layers as shown in FIG. 1 satisfy the file input / output function, and an application program can use each hierarchy to realize a difference program. .

In the data output of the object by the above-described file output method, each object outputs data individually. However, in the case of file input, the object becomes one file and the object is not stored. Therefore, in the procedure for generating a figure from a file shown in FIG. 8, a file output in blocks is cut out, a target object is generated,
Take the method of requesting the object to enter data.

In the same manner as the file output method, the file input method enables differential programming.
As shown in FIG. 8, the object 4 propagates the request of the user to the upper layer.

In FIG. 8, CGeneric FIG.
re has a function of separating blocks, determines the type of the separated blocks, generates an object of a class corresponding to the object 4, and requests the object to set data. CCompositeSymbo
When creating an object of l, Cgeneric,
The request is propagated to the CBaseFigure and the CorrectFigure, the graphic information is read by the CorrectFigure, and the graphic information is set to itself. Further CCpomp
Request to siteSymbol, CComositeS
The symbol reads connection information and sets the connection information to itself.

[0023]

As described above, according to the present invention, a new class library can be constructed without changing the upper class library. Further, a plurality of class libraries derived from the upper class library can be constructed.

In the file output method, the function of outputting the data of the object to the class to which it belongs is provided, and the inherited class need only be requested to a higher class, so that differential programming can be realized. As a result, the amount of program code can be significantly reduced in the lower-layer class library. In addition, it is possible to reduce debugging and testing of the functions of the upper class.

In the file input method, the file format is set in object blocks, the management class divides the object into blocks, generates an object of the corresponding class, analyzes the block in the object again, and sets data in the object. Is performed. By using this method, the function of outputting the data of the object to the class to which it belongs is provided in the same manner as in the file output method, and the inherited class need only be requested to a higher class, and differential programming can be realized.

[Brief description of the drawings]

FIG. 1 shows a class library layer and an application program according to an embodiment of the present invention.

FIG. 2 is an example of file output in a basic graphic class library layer according to the embodiment.

FIG. 3 is an example of file output in a composite graphic class library layer according to the embodiment.

FIG. 4 is a class library hierarchy diagram in the embodiment.

FIG. 5 is an exemplary function of a class library hierarchy according to the embodiment;

FIG. 6 is an example of a graphic output in the embodiment.

FIG. 7 shows a graphic output procedure in the embodiment.

FIG. 8 is an exemplary procedure for generating a figure from a file in the embodiment.

Claims (1)

[Claims] In an object-oriented programming, a class library is realized as a plurality of layers, each of the layers independently builds an application, and each of the layers inherits a lower class which calls and propagates the same function of a higher class. To enable differential programming,
A method for constructing a class library, wherein each layer outputs objects in block units, reads out objects in block units, generates corresponding objects, and reads data into the generated objects themselves.