About ABAP Objects

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Category: ABAP

Published on Wednesday, 09 January 2008 11:51

Written by Henrik Frank

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Public attributes

Public attributes are defined in the PUBLIC section and can be viewed and changed from outside the class. There is direct access to public attributes. As a general rule, as few public attributes should be defined as possible.

PUBLIC SECTION.

  DATA: Counter type i.

 Private attributes

Private attributes are defined in the PRIVATE section. The can only be viewes and changed from within the class. There is no direct access from outside the class.

PRIVATE SECTION.

    DATA: name(25) TYPE c,

          planetype LIKE saplane-planetyp,

Instance attributes

There exist one instance attribute for each instance of the class, thus they exist seperately for each object. Instance attributes are declared with the DATA keyword.

Static attributes

Static attributes exist only once for each class. The data are the same for all instances of the class, and can be used e.g. for instance counters. Static attributes are defined with the keyword CLASS-DATA.

PRIVATE SECTION.

  CLASS-DATA: counter type i,  

Public methods

Can called from outside the class

PUBLIC SECTION.

  METHODS:  set_attributes IMPORTING p_name(25) TYPE c,

                                                            p_planetype LIKE saplane-planetyp,

Private methods

Can only be called from inside the class. They are placed in the PRIVATE section of the class.

 Constructor method

Implicitly, each class has an instance constructor method with the reserved name constructor and a static constructor method with the reserved name class_constructor.

The instance constructor is executed each time you create an object (instance) with the CREATE OBJECT statement, while the class constructor is executed exactly once before you first access a class.

The constructors are always present. However, to implement a constructor you must declare it explicitly with the METHODS or CLASS-METHODS statements. An instance constructor can have IMPORTING parameters and exceptions. You must pass all non-optional parameters when creating an object. Static constructors have no parameters.

Static constructor

The static constructor is always called CLASS_CONSTRUCTER, and is called autmatically before the clas is first accessed, that is before any of the following actions are executed:

• Creating an instance using CREATE_OBJECT
• Adressing a static attribute using <classname>-><attrbute>
• Calling a ststic attribute using CALL METHOD
• Registering a static event handler
• Registering an evetm handler method for a static event

The static constructor cannot be called explicitly.

Protected components

When we are talking subclassing and enheritance there is one more component than Public and Private, the Protected component. Protected components can be used by the superclass and all of the subclasses. Note that Subclasses cannot access Private components.

Polymorphism

Polymorphism: When the same method is implemented differently in different classes. This can be done using enheritance, by redefining a method from the superclass in subclasses and implement it differently.

 

Template for making a class

Delete the parts that should not be used

******************************************

* Definition part

******************************************

CLASS xxx DEFINITION.

 

*------------------------------

* Public section

*------------------------------

  PUBLIC SECTION.

    TYPES:

    DATA:

*   Static data

    CLASS-DATA:

*   Methods

    METHODS:

*     Using the constructor to initialize parameters

       constructor    IMPORTING xxx type yyy,

                               

*     Method with parameters

      mm1 IMPORTING iii   TYPE ttt.

*     Method without parameters

      mm2.

*   Static methods

    CLASS-METHODS: 

                    

*---------------------------------------------------*

* Protected section. Also accessable by subclasses

*---------------------------------------------------

  PROTECTED SECTION.

*---------------------------------------------------

* Private section. Not accessable by subclasses

*---------------------------------------------------

  PRIVATE SECTION.

ENDCLASS.

 

******************************************

* Implementation part

******************************************

CLASS lcl_airplane IMPLEMENTATION.

  METHOD constructor.

  ENDMETHOD.

 

  METHOD mm1.

  ENDMETHOD.

 

  METHOD mm2.

  ENDMETHOD.

 

ENDCLASS.

 

Template for calling a class

* Create reference to class lcl_airplane

DATA: airplane1 TYPE REF TO lcl_airplane.

 

START-OF-SELECTION.

* Create instance using parameters in the cosntructor method

  CREATE OBJECT airplane1 exporting im_name = 'Hansemand'

                                    im_planetype = 'Boing 747'.

*  Calling a method with parameters

  CALL METHOD: airplane1->display_n_o_airplanes,

               airplane1->display_attributes.

Subclass

CLASS xxx DEFINITION INHERITING FROM yyy.

Using af class as a parameter for a method

The class LCL_AIRPLANE is used as a parameter for method add_a_new_airplane:

METHODS:

  add_a_new_airplane importing im_airplane TYPE REF to lcl_airplane.

Interfaces

In ABAP interfaces are implemented in addition to, and independently of classes. An interface only has a declaration part, and do not have visibillity sections. Components (Attributes, methods, constants, types) can be defined the same way as in classes.

·                Interfaces are listed in the definition part lof the class, and must always be in the PUBLIC SECTION.

·                Operations defined in the interface atre impemented as methods of the class. All methods of the interface must be present in the

·                implementation part of the class.

·                Attributes, events, constants and types defined in the interface are automatically available to the class carying out the implementation.

·                Interface components are adresse in the class by <interface name>~<component name>

 

Example of how to implement an interface:

INTERFACE lif_document

  DATA:          author type ref to lcl_author.

  METHODS:  print,

                     display.

ENDINTERFACE.

CLASS lcl_text_document DEFINITION.

   PUBLIC SECTION.

      INTERFACES lif_document.

      METHODS     display.

ENDCLASS.

CLASS lcl_text_document IMPLEMENTTION.

  METHOD lif_document~print.

  ENDMETHOD.

  METHOD lif_document~display

  ENDMETHOD.

  METHOD display.

  ENDMETHOD.

ENDCLASS.

REPORT zzz.

  DATA: text_doc TYPE REF TO lcl_document.

  Start-of-selection.

    CREATE OBJECT text_doc.

    CALL METHOD text_doc->lif_document~print.

    CALL METHOD text_doc->lif_document~display.

    CALL METHOD text_doc->display.

Events

For events of controls, refer to How to use controls.

·                Events can only have EXPORTING parameters

·                When an event is triggerede, only those events handlers that have registred themselves using SET HANDLER by this point of runtime are

·                executed. You can register an event using ACTIVATION 'X' and derigert it by using ACTIVATION 'SPACE'.

Defining events:

CLASS <classname> DEFINITION.

  EVENTS: <event> EXPORTING VALUE (<ex_par>) TYPE type.

CLASS <classname> IMPLEMENTATION.

  METHOD <m>:

    RAISE EVENT <event> EXPORTING <ex_par> = <act_par>.

Handling events:

CLASS <classname> DEFINITION.

  METHODS: <on_event> FOR <event> OF <classname> ! <interface> IMPORTING <imp_par1>...<imp_parN> SENDER.

Setting handler 

SET HANDLER <ref_handle> <on_event> FOR <ref_sender> ! FOR ALL INSTANCES

                             [ACTIVATION <var>]

 Define, implement and use simple class

***INCLUDE ZBC404_HF_LCL_AIRPLANE .

  

******************************************

* Definition part

******************************************

CLASS lcl_airplane DEFINITION.

 

*------------------------------

* Public section

*------------------------------

  PUBLIC SECTION.

    TYPES: t_name(25) TYPE c.

 

    METHODS:

      constructor,

      set_attributes IMPORTING p_name       TYPE t_name

                               p_planetype  TYPE saplane-planetype,

      display_attributes,

      display_n_o_airplanes.

  

*------------------------------

* Private section

*------------------------------

  PRIVATE SECTION.

*   Private attributes

    DATA: name(25) TYPE c,

          planetype TYPE saplane-planetype.

*   Private static attribute

    CLASS-DATA n_o_airplanes TYPE i.

 ENDCLASS.

 ******************************************

* Implementation part

******************************************

CLASS lcl_airplane IMPLEMENTATION.

  METHOD constructor.

*   Counts number of instances

    n_o_airplanes = n_o_airplanes + 1.

  ENDMETHOD.

 

  METHOD set_attributes.

    name      = p_name.

    planetype = p_planetype.

  ENDMETHOD.

 

  METHOD display_attributes.

    WRITE:/ 'Name:', name, 'Planetype:', planetype.

  ENDMETHOD.

 

  METHOD display_n_o_airplanes.

    WRITE: / 'No. planes:', n_o_airplanes.

  ENDMETHOD.

 

ENDCLASS.

REPORT zbc404_hf_maintain_airplanes .

 

INCLUDE zbc404_hf_lcl_airplane.

 

* Create reference to class lcl_airplane

DATA: airplane1 TYPE REF TO lcl_airplane,

      airplane2 TYPE REF TO lcl_airplane.

 

START-OF-SELECTION.

 

* Create instance

  CREATE OBJECT airplane1.

  CALL METHOD: airplane1->display_n_o_airplanes.

 

  CREATE OBJECT airplane2.

 

 

* Setting attributes using a method with parameters

  CALL METHOD airplane1->set_attributes EXPORTING p_name      = 'Kurt'

                                                  p_planetype = 'MD80'.

 

 

END-OF-SELECTION.

 

* Using methods

  CALL METHOD: airplane1->display_n_o_airplanes,

               airplane1->display_attributes. 

  

 

The resulting report:

Maintain airplanes                                    

                                                       

No. planes:          1                                

No. planes:          2                                

Name: Kurt                      Planetype: MD80       

Use constructor to create an object with parameters

 

CLASS lcl_airplane DEFINITION.

  PUBLIC SECTION.

    TYPES: t_name(25) TYPE c.

 

    METHODS:

      constructor    importing p2_name      type t_name

                               p2_planetype  TYPE saplane-planetype,

..... more code .......

CLASS lcl_airplane IMPLEMENTATION.

  METHOD constructor.

    name      = p2_name.

    planetype = p2_planetype.

..... more code .......

 

START-OF-SELECTION.

  CREATE OBJECT airplane1 exporting p2_name = 'Hansemand'

                                    p2_planetype = 'Boing 747'.

                                                    

Subclassing

This example uses a superclass LCL_AIRPLANE and subclasses it into LCL_PASSENGER_AIRPLANE and LCL_CARGO_PLANE.

LCL_AIRPLANE has a method display_n_o_airplanes that displays the number of object instances.

LCL_PASSENGER_AIRPLANE has the private instance attribute n_o_seats, and redefines the superclass method display_attributes, so it also displays n_o_seats.

LCL_CARGO_PLANE has the private instance attribute cargomax, and redefines the superclass method display_attributes, so it also displays cargomax.

All instance attributes are provided by the cunstructor method.

Superclass LCL_AIRPLANE

***INCLUDE ZBC404_HF_LCL_AIRPLANE .

 

******************************************

* Definition part

******************************************

CLASS lcl_airplane DEFINITION.

 

*------------------------------

* Public section

*------------------------------

  PUBLIC SECTION.

    TYPES: t_name(25) TYPE c.

 

    METHODS:

      constructor    IMPORTING im_name      TYPE t_name

                               im_planetype  TYPE saplane-planetype,

      display_attributes.

 

*   Static methods

    CLASS-METHODS:

      display_n_o_airplanes.

 

*------------------------------

* Protected section

*------------------------------

  PROTECTED SECTION.

*   Private attributes

    DATA: name(25) TYPE c,

          planetype TYPE saplane-planetype.

*   Private static attribute

    CLASS-DATA n_o_airplanes TYPE i.

 

 

ENDCLASS.

 

******************************************

* Implementation part

******************************************

CLASS lcl_airplane IMPLEMENTATION.

  METHOD constructor.

    name      = im_name.

    planetype = im_planetype.

 

*   Counts number of instances

    n_o_airplanes = n_o_airplanes + 1.

  ENDMETHOD.

 

  METHOD display_attributes.

    WRITE:/ 'Name:', name, 'Planetype:', planetype.

  ENDMETHOD.

 

  METHOD display_n_o_airplanes.

    WRITE: / 'No. planes:', n_o_airplanes.

  ENDMETHOD.

 

ENDCLASS.

Sub class LCL_PASSENGER_AIRPLANE

***INCLUDE ZBC404_HF_LCL_PASSENGER_PLANE .

 

**********************************************

* This is a subclass of class lcl_airplane

**********************************************

CLASS lcl_passenger_airplane DEFINITION INHERITING FROM lcl_airplane.

  PUBLIC SECTION.

 

*   The constructor contains the parameters from the superclass

*   plus the parameters from the subclass

    METHODS:

      constructor IMPORTING im_name      TYPE t_name

                            im_planetype TYPE saplane-planetype

                            im_n_o_seats TYPE sflight-seatsmax,

*     Redefinition of superclass method display_attributes

      display_attributes REDEFINITION.

 

  PRIVATE SECTION.

    DATA: n_o_seats TYPE sflight-seatsmax.

ENDCLASS.

 

CLASS lcl_passenger_airplane IMPLEMENTATION.

  METHOD constructor.

*   The constructor method of the superclass MUST be called withing the

*   construtor

    CALL METHOD super->constructor

                          EXPORTING im_name      = im_name

                                    im_planetype = im_planetype.

    n_o_seats = im_n_o_seats.

 

  ENDMETHOD.

*   The redefined  display_attributes method

  METHOD display_attributes.

    CALL METHOD super->display_attributes.

    WRITE: / 'No. seats:', n_o_seats.

  ENDMETHOD.

 

ENDCLASS.

Sub class LCL_CARGO_PLANE

***INCLUDE ZBC404_HF_LCL_CARGO_PLANE .

*******************************************

* This is a subclass of class lcl_airplane

*******************************************

CLASS lcl_cargo_plane DEFINITION INHERITING FROM lcl_airplane.

  PUBLIC SECTION.

    METHODS:

*     The constructor contains the parameters from the superclass

*     plus the parameters from the subclass

      constructor IMPORTING im_name      TYPE t_name

                            im_planetype TYPE saplane-planetype

                            im_cargomax  type scplane-cargomax,

*     Redefinition of superclass method display_attributes

      display_attributes REDEFINITION.

  PRIVATE SECTION.

    DATA:cargomax TYPE scplane-cargomax.

ENDCLASS.

CLASS lcl_cargo_plane IMPLEMENTATION.

  METHOD constructor.

*   The constructor method of the superclass MUST be called withing the

*   constructor

    CALL METHOD super->constructor

                          EXPORTING im_name      = im_name

                                    im_planetype = im_planetype.

    cargomax = im_cargomax.

  ENDMETHOD.

  METHOD display_attributes.

*   The redefined  display_attributes method

    CALL METHOD super->display_attributes.

    WRITE: / 'Cargo max:', cargomax.

  ENDMETHOD.

 

 

ENDCLASS.

 

The Main program that uses the classes

REPORT zbc404_hf_main .

* Super class

INCLUDE zbc404_hf_lcl_airplane.

* Sub classes

INCLUDE zbc404_hf_lcl_passenger_plane.

INCLUDE zbc404_hf_lcl_cargo_plane.

DATA:

* Type ref to sub classes. Note: It is not necesssary to make typeref to the superclass

  o_passenger_airplane TYPE REF TO lcl_passenger_airplane,

  o_cargo_plane        TYPE REF TO lcl_cargo_plane.

START-OF-SELECTION.

* Display initial number of instances = 0

  CALL METHOD  lcl_airplane=>display_n_o_airplanes.

* Create objects

  CREATE OBJECT o_passenger_airplane

    EXPORTING

      im_name      = 'LH505'

      im_planetype = 'Boing 747'

      im_n_o_seats = 350.

  CREATE OBJECT o_cargo_plane

    EXPORTING

      im_name      = 'AR13'

      im_planetype = 'DC 3'

      im_cargomax = 35.

* Display attributes

  CALL METHOD o_passenger_airplane->display_attributes.

  CALL METHOD o_cargo_plane->display_attributes.

* Call static method display_n_o_airplanes

* Note: The syntax for calling a superclass method, differs from the syntax when calling a subclass method.

* When calling a superclass => must be used instead of ->

  CALL METHOD  lcl_airplane=>display_n_o_airplanes.

Result:

No. planes: 0
Name: LH505 Planetype: Boing 747
No. seats: 350
Name: AR13 Planetype: DC 3
Cargo max: 35,0000
No. planes: 2

 

 

Polymorphism

Polymorphism: When the same method is implemented differently in different classes. This can be done using enheritance, by redefining a method from the superclass in subclasses and implement it differently.

Classes:

• lcl_airplane Superclass
• lcl_cargo_airplane Subclass
• lcl_passenger_airplane Subclass

The method estimate_fuel_consumption is implemented differently in the 3 classes, as it depends on the airplane type.

Object from different classes are stored in an internal table (plane_list) consisting of references to the superclass, and the processed

identically for all the classes.

What coding for the estimate_fuel_consumption method taht is actually executed, depends on the dynamic type of the plane reference variable,

 that is, depends on which object plane points to.

DATA: cargo_plane            TYPE REF to lcl_cargo_airplane,

          passenger_plane    TYPE REF to lcl_passenger_airplane,

          plane_list                  TYPE TABLE OF REF TO lcl_airplane.

* Creating the list of references

CREATE OBJECT cargo_plane.

APPEND cargo_plane to plane_list.

CREATE OBJECT passenger_plane

APPEND passenger_plane to plane list.

* Generic method for calucalting required fuel

METHOD calculate required_fuel.

  DATA: plane TYPE REF TO lcl_airplane.

  LOOP AT plane_list INTO plane.

    re_fuel = re_fuel + plane->estimate_fuel_consumption( distance ).

  ENDLOOP.

ENDMETHOD.

Working example:

This example assumes that the classes lcl_airplane,  lcl_passnger_airplane and lcl_cargo plane (Se Subcallsing)  exists.

Create objects of type lcl_cargo_plane and lcl_passenger_airplane, adds them to a list in lcl_carrier, and displays the list. 

*&------------------------------------------------

*& Include  ZBC404_HF_LCL_CARRIER               

*&                                             

*&------------------------------------------------

*       CLASS lcl_carrier DEFINITION             

*-------------------------------------------------

CLASS lcl_carrier DEFINITION.

  PUBLIC SECTION.

    TYPES: BEGIN OF flight_list_type,

              connid   TYPE sflight-connid,

              fldate   TYPE sflight-fldate,

              airplane TYPE REF TO lcl_airplane,

              seatsocc TYPE sflight-seatsocc,

              cargo(5) TYPE p DECIMALS 3,

           END OF flight_list_type.

    METHODS: constructor IMPORTING im_name TYPE string,

             get_name RETURNING value(ex_name) TYPE string,

             add_a_new_airplane IMPORTING

                                   im_airplane TYPE REF TO lcl_airplane,

    create_a_new_flight importing

                          im_connid   type sflight-connid

                          im_fldate   type sflight-fldate

                          im_airplane type ref to lcl_airplane

                          im_seatsocc type sflight-seatsocc

                                    optional

                        im_cargo    type p optional,

     display_airplanes.

  PRIVATE SECTION.

    DATA: name              TYPE string,

          list_of_airplanes TYPE TABLE OF REF TO lcl_airplane,

          list_of_flights   TYPE TABLE OF flight_list_type.

ENDCLASS.

*---------------------------------------------

*       CLASS lcl_carrier IMPLEMENTATION

*---------------------------------------------

CLASS lcl_carrier IMPLEMENTATION.

  METHOD constructor.

    name = im_name.

  ENDMETHOD.

  METHOD get_name.

    ex_name = name.

  ENDMETHOD.

  METHOD create_a_new_flight.

    DATA: wa_list_of_flights TYPE flight_list_type.

    wa_list_of_flights-connid   = im_connid.

    wa_list_of_flights-fldate   = im_fldate.

    wa_list_of_flights-airplane = im_airplane.

    IF im_seatsocc IS INITIAL.

      wa_list_of_flights-cargo = im_cargo.

    ELSE.

      wa_list_of_flights-seatsocc = im_seatsocc.

    ENDIF.

    APPEND wa_list_of_flights TO list_of_flights.

  ENDMETHOD.

  METHOD add_a_new_airplane.

    APPEND im_airplane TO list_of_airplanes.

  ENDMETHOD.

  METHOD display_airplanes.

    DATA: l_airplane TYPE REF TO lcl_airplane.

    LOOP AT list_of_airplanes INTO l_airplane.

      CALL METHOD l_airplane->display_attributes.

    ENDLOOP.

  ENDMETHOD.

ENDCLASS.

 

REPORT zbc404_hf_main .

****************************************

*  This reprort uses class LCL_AIRPLNAE and subclasses

*  LCL_CARGO_PLANE and LCL_PASSENGER_AIRPLANE and class LCL_CARRIER

****************************************

* Super class for airplanes

INCLUDE zbc404_hf_lcl_airplane.

* Sub classes for airplanes

INCLUDE zbc404_hf_lcl_passenger_plane.

INCLUDE zbc404_hf_lcl_cargo_plane.

* Carrier class

INCLUDE zbc404_hf_lcl_carrier.

DATA:

* Type ref to classes

  o_passenger_airplane  TYPE REF TO lcl_passenger_airplane,

  o_passenger_airplane2 TYPE REF TO lcl_passenger_airplane,

  o_cargo_plane         TYPE REF TO lcl_cargo_plane,

  o_cargo_plane2        TYPE REF TO lcl_cargo_plane,

  o_carrier             TYPE REF TO lcl_carrier.

START-OF-SELECTION.

* Create objects

  CREATE OBJECT o_passenger_airplane

    EXPORTING

      im_name      = 'LH505'

      im_planetype = 'Boing 747'

      im_n_o_seats = 350.

  CREATE OBJECT o_passenger_airplane2

    EXPORTING

      im_name      = 'SK333'

      im_planetype = 'MD80'

      im_n_o_seats = 110.

  CREATE OBJECT o_cargo_plane

    EXPORTING

      im_name      = 'AR13'

      im_planetype = 'DC 3'

      im_cargomax = 35.

  CREATE OBJECT o_cargo_plane2

    EXPORTING

      im_name      = 'AFL124'

      im_planetype = 'Iljutsin 2'

      im_cargomax = 35000.

  CREATE OBJECT o_carrier

    EXPORTING im_name = 'Spritisch Airways'.

* Add passenger and cargo planes to the list of airplanes

  CALL METHOD o_carrier->add_a_new_airplane

     EXPORTING im_airplane = o_passenger_airplane.

  CALL METHOD o_carrier->add_a_new_airplane

     EXPORTING im_airplane = o_passenger_airplane2.

  CALL METHOD o_carrier->add_a_new_airplane

     EXPORTING im_airplane = o_cargo_plane.

  CALL METHOD o_carrier->add_a_new_airplane

     EXPORTING im_airplane = o_cargo_plane2.

* Display list of airplanes

  call method o_carrier->display_airplanes.

Result:

Name: LH505                     Planetype: Boing 747        

No. seats:       350                                        

Name: SK333                     Planetype: MD80             

No. seats:       110                                        

Name: AR13                      Planetype: DC 3              

Cargo max:             35,0000                              

Name: AFL124                    Planetype: Iljutsin 2       

Cargo max:         35.000,0000                              

Events

Below is a simple example of how to implement an event.

REPORT zbc404_hf_events_5.

*--------------------------------------------------

*       CLASS lcl_dog DEFINITION

*--------------------------------------------------

CLASS lcl_dog DEFINITION.

  PUBLIC SECTION.

*   Declare events

    EVENTS:

      dog_is_hungry

        EXPORTING value(ex_time_since_last_meal) TYPE i.

    METHODS:

      constructor

          IMPORTING im_name TYPE string,

      set_time_since_last_meal

          IMPORTING im_time TYPE i,

      on_dog_is_hungry FOR EVENT dog_is_hungry OF lcl_dog

          IMPORTING ex_time_since_last_meal.

ENDCLASS.

*---------------------------------------------

*       CLASS lcl_dog IMPLEMENTATION

*---------------------------------------------

CLASS lcl_dog IMPLEMENTATION.

  METHOD constructor.

    WRITE: / 'I am a dog and my name is', im_name.

  ENDMETHOD.

  METHOD set_time_since_last_meal.

    IF im_time < 4.

      SKIP 1.

      WRITE: / 'You fool, I am not hungry yet'.

    ELSE.

*    Subsrcribe for event:

*    set handler <Event handler method>

*    FOR <ref_sender>!FOR ALL INSTANCES [ACTIVATION <var>]

      SET HANDLER on_dog_is_hungry FOR ALL INSTANCES ACTIVATION 'X'.

*    Raise event

      RAISE EVENT dog_is_hungry

        EXPORTING ex_time_since_last_meal = im_time.

    ENDIF.

  ENDMETHOD.

  METHOD on_dog_is_hungry.

*   Event method, called when the event dog_is_hungry is raised

    SKIP 1.

    WRITE: /  'You son of a bitch. I have not eaten for more than',

              ex_time_since_last_meal, ' hours'.

    WRITE: / 'Give me something to eat NOW!'.

  ENDMETHOD.

ENDCLASS.

*-------------------------------------------

*       R E P O R T

*-------------------------------------------

DATA: o_dog1 TYPE REF TO lcl_dog.

START-OF-SELECTION.

  CREATE OBJECT o_dog1 EXPORTING im_name = 'Beefeater'.

  CALL METHOD o_dog1->set_time_since_last_meal

    EXPORTING im_time = 2.

* This method call will raise the event dog_is_hungy

* because time > 3

  CALL METHOD o_dog1->set_time_since_last_meal

    EXPORTING im_time = 5.

Result:

I am a dog and my name is Beefeater

You fool, I am not hungry yet

You son of a bitch. I have not eaten for more than 5 hours
Give me something to eat NOW!

 

 

1. Simple class

This example shows how to create a simple employee class. The constructor method is used to initialize number and name of thje employee when the object is created. A display_employee method can be called to show the attributes of the employee, and CLASS-METHOD dosplay_no_of_employees can be called to show the total number of employees (Number of instances of the employee class).

 

REPORT zbc404_hf_events_1.

**********************************************

* L C L _ E M P L O Y E E

**********************************************

*---- LCL Employee - Definition

CLASS lcl_employee DEFINITION.

  PUBLIC SECTION.

*-------------------------------------------

* The public section is accesible from outside  

*-------------------------------------------

    TYPES:

      BEGIN OF t_employee,

        no  TYPE i,

        name TYPE string,

     END OF t_employee.

    METHODS:

      constructor

        IMPORTING im_employee_no TYPE i

                  im_employee_name TYPE string,

      display_employee.

*   Class methods are global for all instances      

    CLASS-METHODS: display_no_of_employees.

  PROTECTED SECTION.

*--------------------------------------------------------------------

* The protecetd section is accesible from the class and its subclasses 

*--------------------------------------------------------------------

*   Class data are global for all instances      

    CLASS-DATA: g_no_of_employees TYPE i.

  PRIVATE SECTION.

*--------------------------------------------------------------------

* The private section is only accesible from within the classs 

*-------------------------------------------------------------------- 

    DATA: g_employee TYPE t_employee.

ENDCLASS.

*--- LCL Employee - Implementation

CLASS lcl_employee IMPLEMENTATION.

  METHOD constructor.

    g_employee-no = im_employee_no.

    g_employee-name = im_employee_name.

    g_no_of_employees = g_no_of_employees + 1.

  ENDMETHOD.

  METHOD display_employee.

    WRITE:/ 'Employee', g_employee-no, g_employee-name.

  ENDMETHOD.

  METHOD display_no_of_employees.

    WRITE: / 'Number of employees is:', g_no_of_employees.

  ENDMETHOD.

ENDCLASS.

************************************************************************

* R E P O R T

*********************************************************************

DATA: g_employee1 TYPE REF TO lcl_employee,

      g_employee2 TYPE REF TO lcl_employee.

START-OF-SELECTION.

  CREATE OBJECT g_employee1

    EXPORTING im_employee_no = 1

              im_employee_name = 'John Jones'.

  CREATE OBJECT g_employee2

    EXPORTING im_employee_no = 2

              im_employee_name = 'Sally Summer'.

  CALL METHOD g_employee1->display_employee.

  CALL METHOD g_employee2->display_employee.

  CALL METHOD g_employee2->display_no_of_employees.

 

2. Inheritance and polymorphism

This example uses a superclass lcl_company_employees and two subclasses lcl_bluecollar_employee and lcl_whitecollar_employee to add employees to a list and then display a list of employees and there wages. The wages are calcukated in the method add_employee, but as the wages are calculated differently for blue collar employees and white collar emplyees, the superclass method add_employee is redeifined in the subclasses.

Principles:

Create super class LCL_CompanyEmployees.

The class has the methods:

• Constructor
• Add_Employee - Adds a new employee to the list of employees
• Display_Employee_List - Displays all employees and there wage
• Display_no_of_employees - Displays total number of employees

Note the use of CLASS-DATA to keep the list of employees and number of employees the same from instance to instance.

Create subclasses lcl_bluecollar_employee and lcl_whitecollar_employee. The calsses are identical, except for the redifinition of the add_employee method, where the caclculation of wage is different.

Methodes:

• Constructor. The constructor is used to initialize the attributes of the employee. Note that the constructor in the supclasss has to be called from within the constructor of the subclass.
• Add_Employee. This is a redinition of the same method in the superclass. In the redefined class the wage is calcuated, and the superclass method is called to add the employees to the emploee list.:

The program

 

REPORT zbc404_hf_events_2 .

*******************************************************

* Super class LCL_CompanyEmployees

*******************************************************

CLASS lcl_company_employees DEFINITION.

  PUBLIC SECTION.

    TYPES:

      BEGIN OF t_employee,

        no  TYPE i,

        name TYPE string,

        wage TYPE i,

     END OF t_employee.

    METHODS:

      constructor,

      add_employee

        IMPORTING im_no   TYPE i

                  im_name TYPE string

                  im_wage TYPE i,

      display_employee_list,

      display_no_of_employees.

 

  PRIVATE SECTION.

    CLASS-DATA: i_employee_list TYPE TABLE OF t_employee,

                no_of_employees TYPE i.

ENDCLASS.

*-- CLASS LCL_CompanyEmployees IMPLEMENTATION

CLASS lcl_company_employees IMPLEMENTATION.

  METHOD constructor.

    no_of_employees = no_of_employees + 1.

  ENDMETHOD.

  METHOD add_employee.

*   Adds a new employee to the list of employees

    DATA: l_employee TYPE t_employee.

    l_employee-no = im_no.

    l_employee-name = im_name.

    l_employee-wage = im_wage.

    APPEND l_employee TO i_employee_list.

  ENDMETHOD.

  METHOD display_employee_list.

*   Displays all employees and there wage

    DATA: l_employee TYPE t_employee.

    WRITE: / 'List of Employees'.

    LOOP AT i_employee_list INTO l_employee.

      WRITE: / l_employee-no, l_employee-name, l_employee-wage.

    ENDLOOP.

  ENDMETHOD.

  METHOD display_no_of_employees.

*   Displays total number of employees

    SKIP 3.

    WRITE: / 'Total number of employees:', no_of_employees.

  ENDMETHOD.

ENDCLASS.

 

*******************************************************

* Sub class LCL_BlueCollar_Employee

*******************************************************

CLASS lcl_bluecollar_employee DEFINITION

          INHERITING FROM lcl_company_employees.

  PUBLIC SECTION.

    METHODS:

        constructor

          IMPORTING im_no             TYPE i

                    im_name           TYPE string

                    im_hours          TYPE i

                    im_hourly_payment TYPE i,

         add_employee REDEFINITION.

  PRIVATE SECTION.

    DATA:no             TYPE i,

         name           TYPE string,

         hours          TYPE i,

         hourly_payment TYPE i.

 

ENDCLASS.

*---- CLASS LCL_BlueCollar_Employee IMPLEMENTATION

CLASS lcl_bluecollar_employee IMPLEMENTATION.

  METHOD constructor.

*   The superclass constructor method must be called from the subclass

*   constructor method

    CALL METHOD super->constructor.

    no = im_no.

    name = im_name.

    hours = im_hours.

    hourly_payment = im_hourly_payment.

  ENDMETHOD.

  METHOD add_employee.

*   Calculate wage an call the superclass method add_employee to add

*   the employee to the employee list

    DATA: l_wage TYPE i.

    l_wage = hours * hourly_payment.

    CALL METHOD super->add_employee

      EXPORTING im_no = no

                im_name = name

                im_wage = l_wage.

  ENDMETHOD.

ENDCLASS.

*******************************************************

* Sub class LCL_WhiteCollar_Employee

*******************************************************

CLASS lcl_whitecollar_employee DEFINITION

    INHERITING FROM lcl_company_employees.

  PUBLIC SECTION.

    METHODS:

        constructor

          IMPORTING im_no                 TYPE i

                    im_name               TYPE string

                    im_monthly_salary     TYPE i

                    im_monthly_deductions TYPE i,

         add_employee REDEFINITION.

  PRIVATE SECTION.

    DATA:

      no                    TYPE i,

      name                  TYPE string,

      monthly_salary        TYPE i,

      monthly_deductions    TYPE i.

ENDCLASS.

*---- CLASS LCL_WhiteCollar_Employee IMPLEMENTATION

CLASS lcl_whitecollar_employee IMPLEMENTATION.

  METHOD constructor.

*   The superclass constructor method must be called from the subclass

*   constructor method

    CALL METHOD super->constructor.

    no = im_no.

    name = im_name.

    monthly_salary = im_monthly_salary.

    monthly_deductions = im_monthly_deductions.

  ENDMETHOD.

  METHOD add_employee.

*   Calculate wage an call the superclass method add_employee to add

*   the employee to the employee list

    DATA: l_wage TYPE i.

    l_wage = monthly_salary - monthly_deductions.

    CALL METHOD super->add_employee

      EXPORTING im_no = no

                im_name = name

                im_wage = l_wage.

  ENDMETHOD.

ENDCLASS.

*******************************************************

* R E P O R T

*******************************************************

DATA:

* Object references

  o_bluecollar_employee1  TYPE REF TO lcl_bluecollar_employee,

  o_whitecollar_employee1 TYPE REF TO lcl_whitecollar_employee.

START-OF-SELECTION.

* Create bluecollar employee obeject

  CREATE OBJECT o_bluecollar_employee1

      EXPORTING im_no  = 1

                im_name  = 'Gylle Karen'

                im_hours = 38

                im_hourly_payment = 75.

* Add bluecollar employee to employee list

  CALL METHOD o_bluecollar_employee1->add_employee

      EXPORTING im_no  = 1

                im_name  = 'Gylle Karen'

                im_wage = 0.

* Create whitecollar employee obeject

  CREATE OBJECT o_whitecollar_employee1

      EXPORTING im_no  = 2

                im_name  = 'John Dickens'

                im_monthly_salary = 10000

                im_monthly_deductions = 2500.

* Add bluecollar employee to employee list

  CALL METHOD o_whitecollar_employee1->add_employee

      EXPORTING im_no  = 1

                im_name  = 'Karen Johnson'

                im_wage = 0.

* Display employee list and number of employees. Note that the result

* will be the same when called from o_whitecollar_employee1 or

* o_bluecolarcollar_employee1, because the methods are defined

* as static (CLASS-METHODS)

  CALL METHOD o_whitecollar_employee1->display_employee_list.

  CALL METHOD o_whitecollar_employee1->display_no_of_employees.

The resulting report

List of Employees
1 Karen Johnson 2.850
2 John Dickens 7.500


Total number of employees: 2

3. Interfaces

This example is similiar to th eprevious example, however an interface is implemented with the method add_employee. Note that the interface is only implemented in the superclass ( The INTERFACE stament), but also used in the subclasses.

The interface in the example only contains a method, but an iterface can also contain attrbutes, constants, types and alias names.

The output from example 3 is similiar to the output in example 2.

All changes in the program compared to example 2 are marked with red.

REPORT zbc404_hf_events_3 .

*---------------------------------------------------------------------*

*       INTERFACE lif_employee

*---------------------------------------------------------------------*

INTERFACE lif_employee.

  METHODS:

    add_employee

       IMPORTING im_no   TYPE i

                  im_name TYPE string

                  im_wage TYPE i.

ENDINTERFACE.

*******************************************************

* Super class LCL_CompanyEmployees

*******************************************************

CLASS lcl_company_employees DEFINITION.

  PUBLIC SECTION.

    INTERFACES lif_employee.

    TYPES:

      BEGIN OF t_employee,

        no  TYPE i,

        name TYPE string,

        wage TYPE i,

     END OF t_employee.

    METHODS:

      constructor,

*      add_employee      "Removed

        IMPORTING im_no   TYPE i

                  im_name TYPE string

                  im_wage TYPE i,

      display_employee_list,

      display_no_of_employees.

 

  PRIVATE SECTION.

    CLASS-DATA: i_employee_list TYPE TABLE OF t_employee,

                no_of_employees TYPE i.

ENDCLASS.

*-- CLASS LCL_CompanyEmployees IMPLEMENTATION

CLASS lcl_company_employees IMPLEMENTATION.

  METHOD constructor.

    no_of_employees = no_of_employees + 1.

  ENDMETHOD.

  METHOD lif_employee~add_employee.

*   Adds a new employee to the list of employees

    DATA: l_employee TYPE t_employee.

    l_employee-no = im_no.

    l_employee-name = im_name.

    l_employee-wage = im_wage.

    APPEND l_employee TO i_employee_list.

  ENDMETHOD.

  METHOD display_employee_list.

*   Displays all employees and there wage

    DATA: l_employee TYPE t_employee.

    WRITE: / 'List of Employees'.

    LOOP AT i_employee_list INTO l_employee.

      WRITE: / l_employee-no, l_employee-name, l_employee-wage.

    ENDLOOP.

  ENDMETHOD.

  METHOD display_no_of_employees.

*   Displays total number of employees

    SKIP 3.

    WRITE: / 'Total number of employees:', no_of_employees.

  ENDMETHOD.

ENDCLASS.

 

*******************************************************

* Sub class LCL_BlueCollar_Employee

*******************************************************

CLASS lcl_bluecollar_employee DEFINITION

          INHERITING FROM lcl_company_employees.

  PUBLIC SECTION.

    METHODS:

        constructor

          IMPORTING im_no             TYPE i

                    im_name           TYPE string

                    im_hours          TYPE i

                    im_hourly_payment TYPE i,

         lif_employee~add_employee REDEFINITION..

  PRIVATE SECTION.

    DATA:no             TYPE i,

         name           TYPE string,

         hours          TYPE i,

         hourly_payment TYPE i.

 

ENDCLASS.

*---- CLASS LCL_BlueCollar_Employee IMPLEMENTATION

CLASS lcl_bluecollar_employee IMPLEMENTATION.

  METHOD constructor.

*   The superclass constructor method must be called from the subclass

*   constructor method

    CALL METHOD super->constructor.

    no = im_no.

    name = im_name.

    hours = im_hours.

    hourly_payment = im_hourly_payment.

  ENDMETHOD.

  METHOD lif_employee~add_employee.

*   Calculate wage an call the superclass method add_employee to add

*   the employee to the employee list

    DATA: l_wage TYPE i.

    l_wage = hours * hourly_payment.

    CALL METHOD super->lif_employee~add_employee

      EXPORTING im_no = no

                im_name = name

                im_wage = l_wage.

  ENDMETHOD.

ENDCLASS.

*******************************************************

* Sub class LCL_WhiteCollar_Employee

*******************************************************

CLASS lcl_whitecollar_employee DEFINITION

    INHERITING FROM lcl_company_employees.

  PUBLIC SECTION.

    METHODS:

        constructor

          IMPORTING im_no                 TYPE i

                    im_name               TYPE string

                    im_monthly_salary     TYPE i

                    im_monthly_deductions TYPE i,

         lif_employee~add_employee REDEFINITION.

  PRIVATE SECTION.

    DATA:

      no                    TYPE i,

      name                  TYPE string,

      monthly_salary        TYPE i,

      monthly_deductions    TYPE i.

ENDCLASS.

*---- CLASS LCL_WhiteCollar_Employee IMPLEMENTATION

CLASS lcl_whitecollar_employee IMPLEMENTATION.

  METHOD constructor.

*   The superclass constructor method must be called from the subclass

*   constructor method

    CALL METHOD super->constructor.

    no = im_no.

    name = im_name.

    monthly_salary = im_monthly_salary.

    monthly_deductions = im_monthly_deductions.

  ENDMETHOD.

  METHOD lif_employee~add_employee.

*   Calculate wage an call the superclass method add_employee to add

*   the employee to the employee list

    DATA: l_wage TYPE i.

    l_wage = monthly_salary - monthly_deductions.

    CALL METHOD super->lif_employee~add_employee

      EXPORTING im_no = no

                im_name = name

                im_wage = l_wage.

  ENDMETHOD.

ENDCLASS.

*******************************************************

* R E P O R T

*******************************************************

DATA:

* Object references

  o_bluecollar_employee1  TYPE REF TO lcl_bluecollar_employee,

  o_whitecollar_employee1 TYPE REF TO lcl_whitecollar_employee.

START-OF-SELECTION.

* Create bluecollar employee obeject

  CREATE OBJECT o_bluecollar_employee1

      EXPORTING im_no  = 1

                im_name  = 'Gylle Karen'

                im_hours = 38

                im_hourly_payment = 75.

* Add bluecollar employee to employee list

  CALL METHOD o_bluecollar_employee1->lif_employee~add_employee

      EXPORTING im_no  = 1

                im_name  = 'Karen Johnson'

                im_wage = 0.

* Create whitecollar employee obeject

  CREATE OBJECT o_whitecollar_employee1

      EXPORTING im_no  = 2

                im_name  = 'John Dickens'

                im_monthly_salary = 10000

                im_monthly_deductions = 2500.

* Add bluecollar employee to employee list

  CALL METHOD o_whitecollar_employee1->lif_employee~add_employee

      EXPORTING im_no  = 1

                im_name  = 'Gylle Karen'

                im_wage = 0.

* Display employee list and number of employees. Note that the result

* will be the same when called from o_whitecollar_employee1 or

* o_bluecolarcollar_employee1, because the methods are defined

* as static (CLASS-METHODS)

  CALL METHOD o_whitecollar_employee1->display_employee_list.

  CALL METHOD o_whitecollar_employee1->display_no_of_employees.

 

4. Events

This is the same example as example 4. All changes are marked with red. There have been no canges to the subclasses, only to the superclass and the report, sp the code for th esubclasses is not shown.

For a simple example refer to Events in Examples.

REPORT zbc404_hf_events_4 .

*---------------------------------------------------------------------*

*       INTERFACE lif_employee

*---------------------------------------------------------------------*

INTERFACE lif_employee.

  METHODS:

    add_employee

       IMPORTING im_no   TYPE i

                  im_name TYPE string

                  im_wage TYPE i.

ENDINTERFACE.

*******************************************************

* Super class LCL_CompanyEmployees

*******************************************************

CLASS lcl_company_employees DEFINITION.

  PUBLIC SECTION.

    TYPES:

    BEGIN OF t_employee,

      no  TYPE i,

      name TYPE string,

      wage TYPE i,

   END OF t_employee.

*   Declare event. Note that declaration could also be placed in the

*   interface

    EVENTS: employee_added_to_list

        EXPORTING value(ex_employee_name) TYPE string.

*  CLASS-EVENTS: Events can also be defined as class-events

    INTERFACES lif_employee.

    METHODS:

      constructor,

      display_employee_list,

      display_no_of_employees,

*     Declare event method

      on_employee_added_to_list FOR EVENT employee_added_to_list OF lcl_company_employees

         IMPORTING ex_employee_name sender.

  PRIVATE SECTION.

    CLASS-DATA:

      i_employee_list TYPE TABLE OF t_employee,

      no_of_employees TYPE i.

ENDCLASS.

*-- CLASS LCL_CompanyEmployees IMPLEMENTATION

CLASS lcl_company_employees IMPLEMENTATION.

  METHOD constructor.

    no_of_employees = no_of_employees + 1.

  ENDMETHOD.

  METHOD lif_employee~add_employee.

*   Adds a new employee to the list of employees

    DATA: l_employee TYPE t_employee.

    l_employee-no = im_no.

    l_employee-name = im_name.

    l_employee-wage = im_wage.

    APPEND l_employee TO i_employee_list.

*   Raise event employee_added_to_list

    RAISE EVENT employee_added_to_list

       EXPORTING ex_employee_name =  l_employee-name.

  ENDMETHOD.

  METHOD display_employee_list.

*   Displays all employees and there wage

    DATA: l_employee TYPE t_employee.

    WRITE: / 'List of Employees'.

    LOOP AT i_employee_list INTO l_employee.

      WRITE: / l_employee-no, l_employee-name, l_employee-wage.

    ENDLOOP.

  ENDMETHOD.

  METHOD display_no_of_employees.

*   Displays total number of employees

    SKIP 3.

    WRITE: / 'Total number of employees:', no_of_employees.

  ENDMETHOD.

  METHOD on_employee_added_to_list.

*   Event method

    WRITE: / 'Employee added to list', ex_employee_name.

  ENDMETHOD.

ENDCLASS.

*******************************************************

* Sub class LCL_BlueCollar_Employee

*******************************************************

CLASS lcl_bluecollar_employee DEFINITION

          INHERITING FROM lcl_company_employees.

 See code in example 3...

ENDCLASS.

CLASS lcl_bluecollar_employee IMPLEMENTATION.

 See code in example 3...

ENDCLASS.

*******************************************************

* Sub class LCL_WhiteCollar_Employee

*******************************************************

CLASS lcl_whitecollar_employee DEFINITION

 See code in example 3...

ENDCLASS.

CLASS lcl_whitecollar_employee IMPLEMENTATION.

 See code in example 3...

ENDCLASS.

*******************************************************

* R E P O R T

*******************************************************

DATA:

* Object references

  o_bluecollar_employee1  TYPE REF TO lcl_bluecollar_employee,

  o_whitecollar_employee1 TYPE REF TO lcl_whitecollar_employee.

START-OF-SELECTION.

* Create bluecollar employee obeject

  CREATE OBJECT o_bluecollar_employee1

      EXPORTING im_no  = 1

                im_name  = 'Karen Johnson'

                im_hours = 38

                im_hourly_payment = 75.

* Register event for o_bluecollar_employee1

  SET HANDLER o_bluecollar_employee1->on_employee_added_to_list

     FOR o_bluecollar_employee1.

* Add bluecollar employee to employee list

  CALL METHOD o_bluecollar_employee1->lif_employee~add_employee

      EXPORTING im_no  = 1

                im_name  = 'Gylle Karen'

                im_wage = 0.

* Create whitecollar employee obeject

  CREATE OBJECT o_whitecollar_employee1

      EXPORTING im_no  = 2

                im_name  = 'John Dickens'

                im_monthly_salary = 10000

                im_monthly_deductions = 2500.

* Register event for o_whitecollar_employee1

  SET HANDLER o_whitecollar_employee1->on_employee_added_to_list

     FOR o_whitecollar_employee1.´

 

* Add bluecollar employee to employee list

  CALL METHOD o_whitecollar_employee1->lif_employee~add_employee

      EXPORTING im_no  = 1

                im_name  = 'Gylle Karen'

                im_wage = 0.

* Display employee list and number of employees. Note that the result

* will be the same when called from o_whitecollar_employee1 or

* o_bluecolarcollar_employee1, because the methods are defined

* as static (CLASS-METHODS)

  CALL METHOD o_whitecollar_employee1->display_employee_list.

  CALL METHOD o_whitecollar_employee1->display_no_of_employees.

Result:

Employee added to list Karen Johnson
Employee added to list John Dickens
List of Employees
1 Karen Johnson 2.850
2 John Dickens 7.500


Total number of employees: 2

 

 

General

Control Framework and enheritance hierarchy

The control framework consists of 2 parts:

• CL_GUI_CFW contains methods that provide services for communication with the frontend, and can be used both by control wrapper calsses and by control progtrammers
• The CL_GUI_OBJECT encapsulates ActiveX or JavaBeans methods, while CL_GUI_CONTROL is responsible for displaying the control on the screen.

CL_GUI_OBJECT -> CL_GUI_CONTROL -> CL_GUI_* (Wrapper class)

These classes contains methods that are enherited by subsequent classes in the enheritance tree.

Synchronization/Flush

RFC calls is used to synchronize the front and backend. This synchronization takes palce at some predifined points in the program flow. However you should not rely entirely on automatic synchronization, but force synchronization with the Flush method when necessary.

Bear in mind that the synchronization/RFC calls represenmts a bottleneck, so you should keep the not use the Flush method to a minimum.

Syntax:

CALL METHOD cl_gui_cfw=>FLUSH

 

Set up event handling for controls

There are two types of events:

Application events. T

The flow logic of the screen is processed after the event (The PAI module is processed).

In the events table the event must be registred as an application event by setting then field appl_event to 'X':

wa_events-eventid = cl_gui_textedit=>event_double_click.
wa_events-appl_event = 'X'.
append wa_events to i_events.

Important: The dispatch method of cl_gui_cfw must be called in the PAI module:

CALL METHOD cl_gui_cfw=>dispatch.

System events.

For system events the flow-logic of the screen is not executed. That means that the PAI and PBO modules are not processed.

In the events table the the field appl_event must be set to SAPCE:

wa_events-eventid = cl_gui_textedit=>event_double_click.
wa_events-appl_event = space.
append wa_events to i_events.

The dispatch method of cl_gui_cfw must NOT be called.

Example

It is presumed that a SAP toolbar control named go_toolbar of class cl_gui_toolbar has been defined. To see a complete example of how to handle events, refer to The SAP toolbar control.

Data:

* 1.  Define and instance of the eventhandler class.

*      If the event handler class is defined after the data decalaration

*      the class must be declared as DEFERRED in the top of the program:  CLASS cls_event_handler DEFINITION DEFERRED.

  go_event_handler TYPE REF TO cls_event_handler,

* 2. Define table for registration of events.

*     Note that a TYPE REF   to cls_event_handler must be created before you can

*     reference types cntl_simple_events and cntl_simple_event

  gi_events TYPE cntl_simple_events,

* Workspace for table gi_events

  g_event TYPE cntl_simple_event.

* 3. Define and implement eventhandler class

CLASS cls_event_handler DEFINITION.

  PUBLIC SECTION.

    METHODS:

*     Syntax:

*     <method name> FOR EVENT <event of control - see the control documentation>

*         OF <class of object> <importing parameters l - see the control documentation>

      on_function_selected

        FOR EVENT function_selected OF cl_gui_toolbar

          IMPORTING fcode,

ENDCLASS.

CLASS cls_event_handler IMPLEMENTATION.

   METHOD on_function_selected.

*     Do something when the event is raised

  ENDMETHOD.

ENDCLASS.

* 4. Append events to the events table

*     The Event Id  can be found in the control documentation. Note that The event below is registred as an application event

 g_event-eventid         = go_toolbar->m_id_function_selected.

 g_event-appl_event   = 'X'.    "This is an application event

APPEND g_event TO gi_events.

.... append more events i necessary...

* 5. Use the events table to register events for the control

    CALL METHOD go_toolbar->set_registered_events

        EXPORTING

           events = gi_events.

* 6. Create event handler

CREATE OBJECT   go_event_handler.

* Syntax:

* SET HANDLER <event handler class> -> <Event handler method>

*   FOR <control>

SET HANDLER go_event_handler->on_function_selected

      FOR go_toolbar.

 

 

Declare a reference variable before the class has been defined

Scenario:

DATA: o_my_class TYPE REF TO lcl_myclass.

CLASS lcl_myclass.....
ENDCLASS.

This will cause an error because the definition of class lcl_myclass is after the declaration.

Solution:

Define the class in the beginning of the program with DEFINITION DEFERRED:

CLASS lcl_myclass DEFINITION DEFERRED.

DATA: o_my_class TYPE REF TO lcl_myclass.

CLASS lcl_myclass.....
ENDCLASS.

 

Set focus to a control

Set the focus to a control named go_grid:

CALL METHOD cl_gui_control=>set_focus

  EXPORTING control = go_grid.

 

 

To Use BADI - Business Add In you need to Understand ABAP OO Interface Concept

Content Author:  Jayanta Narayan Choudhuri
Author Email:      This email address is being protected from spambots. You need JavaScript enabled to view it. '; document.write(''); document.write(addy_text71113); document.write('<\/a>'); //-->\n This email address is being protected from spambots. You need JavaScript enabled to view it.
Author Website:  http://www.geocities.com/ojnc

* For Rajat's OO ans BAdI Education

Report Z_CTRY.

 

* A Shape Interface "Like a shape" "Behaves like a Shape" 

Adverb/Adjective

 

Interface IShape.

Methods:  getArea Returning Value(area) Type F,

          getCircumference Returning Value(circumference) Type F.

Endinterface.

 

* A Circle Class that behaves like a Shape

Class CCircle Definition.

 

    Public Section.

 

        Interfaces IShape.

 

        Aliases:   getArea For IShape~getArea,

                   getCircumference For IShape~getCircumference.

 

        Methods:   Constructor Importing pRadius Type F,

                   setRadius   Importing pRadius Type F,

                   getRadius   Returning Value(pRadius) Type F.

 

    Private Section.

        Data radius Type F.

        Constants PI Type F Value '3.141592365359'.

EndClass.

 

Class CCircle Implementation.

 

    Method Constructor.

        radius = pRadius.

    EndMethod.

 

    Method setRadius.

        radius = pRadius.

    EndMethod.

 

    Method getRadius.

        pRadius = radius.

    EndMethod.

 

    Method IShape~getArea.

        Compute area = 2 * PI * radius.

    EndMethod.

 

    Method IShape~getCircumference.

        Compute circumference = PI * radius * radius.

    EndMethod.

 

EndClass.

 

* A Square Class

Class CSquare Definition.

 

    Public Section.

 

        Interfaces IShape.

 

        Aliases:   getArea For IShape~getArea,

                   getCircumference For IShape~getCircumference.

 

        Methods:   Constructor Importing pSide Type F.

 

    Private Section.

        Data side Type F.

EndClass.

 

Class CSquare Implementation.

 

    Method Constructor.

        side = pSide.

    EndMethod.

 

    Method IShape~getArea.

        Compute area = side * side.

    EndMethod.

 

    Method IShape~getCircumference.

        Compute circumference = 4 * side.

    EndMethod.

 

EndClass.

 

* A Rectangle Class

Class CRectangle Definition.

 

    Public Section.

 

        Interfaces IShape.

 

        Aliases:   getArea For IShape~getArea,

                   getCircumference For IShape~getCircumference.

 

        Methods:   Constructor Importing pHeight Type F

                                         pLength Type F.

 

    Private Section.

        Data: height Type F,

              length Type F.

EndClass.

 

Class CRectangle Implementation.

 

    Method Constructor.

        height = pHeight.

        length = pLength.

    EndMethod.

 

    Method IShape~getArea.

        Compute area = height * length.

    EndMethod.

 

    Method IShape~getCircumference.

        Compute circumference = 2 * ( height + length ).

    EndMethod.

 

EndClass.

 

* START of PROGRAM

 

* Array of Shapes

Data:  OneShape   Type Ref To IShape,             " One Object with 

Shape Behaviour

       ShapeTable Type Table Of Ref To IShape.    " Array of Objects 

with Shape Behaviour

 

* Concrete Objects with IShape Behaviour!

Data:  C1 Type Ref To CCircle,

       S1 Type Ref To CSquare,

       R1 Type Ref To CRectangle,

       C2 Type Ref To CCircle,

       S2 Type Ref To CSquare,

       R2 Type Ref To CRectangle.

 

 

Data:  descr_ref  TYPE ref to CL_ABAP_TYPEDESCR,

       ClassName  Type String,

       Serial     Type I.

 

Data:  myArea          Type F,

       myCircumference Type F.

 

START-OF-SELECTION.

    Create Object C1 Exporting pRadius = '2.5'.

    Create Object C2 Exporting pRadius = '5.0'.

 

    Create Object S1 Exporting pSide = '3.5'.

    Create Object S2 Exporting pSide = '6.0'.

 

    Create Object R1 Exporting pHeight = '2.8' pLength = '3.4'.

    Create Object R2 Exporting pHeight = '1.7' pLength = '6.3'.

 

* Append in any order!

    Append S1  to ShapeTable.

    Append R2  to ShapeTable.

    Append R1  to ShapeTable.

    Append C2  to ShapeTable.

    Append C1  to ShapeTable.

    Append S2  to ShapeTable.

 

    Serial = 0.

 

    Loop At ShapeTable into OneShape.

       Call Method OneShape->getArea

                             Receiving area = myArea.

       Call Method OneShape->getCircumference

                             Receiving circumference = myCircumference.

 

       descr_ref = CL_ABAP_TYPEDESCR=>Describe_By_Object_Ref( OneShape 

).

       Call Method descr_ref->get_relative_name

                   Receiving P_RELATIVE_NAME = ClassName.

 

       Add 1 to Serial.

 

       Write: / Serial,  ClassName.

       Write: / 'Area          ',  myArea          Decimals 4 Exponent 

0.

       Write: / 'Circumference ',  myCircumference Decimals 4 Exponent 

0.

       Write: /.

 

    EndLoop.

 

** Results    

*           1  CSQUARE                        

*  Area                            12.2500    

*  Circumference                   14.0000    

*                                             

*           2  CRECTANGLE                     

*  Area                            10.7100    

*  Circumference                   16.0000    

*                                             

*           3  CRECTANGLE                     

*  Area                             9.5200    

*  Circumference                   12.4000    

*                                             

*           4  CCIRCLE                        

*  Area                            31.4159    

*  Circumference                   78.5398    

*                                             

*           5  CCIRCLE                        

*  Area                            15.7080    

*  Circumference                   19.6350    

*                                             

*           6  CSQUARE                        

*  Area                            36.0000    

*  Circumference                   24.0000

 

 

Example 1: Creating the TextEdit control

This is a simple example of how to implement a text edit control.

Steps

1. Create a report
2. In the start of selection event add: SET SCREEN '100'.
3. Create screen 100
4. Place a custom control on the screen by choosing the custom control icon which can be recognized by the letter 'C', and give it the name MYCONTAINER1.
5. To be able to exit the program, add a pushbutton with the function code EXIT.
6. In the elements list enter the name OK_CODE for the element of type OK.

The code

REPORT sapmz_hf_controls1 .

CONSTANTS:

  line_length TYPE i VALUE 254.

DATA: ok_code LIKE sy-ucomm.

DATA:

* Create reference to the custom container

  custom_container TYPE REF TO cl_gui_custom_container,

* Create reference to the TextEdit control

  editor TYPE REF TO cl_gui_textedit,

  repid LIKE sy-repid.

START-OF-SELECTION.

  SET SCREEN '100'.

*---------------------------------------------------------------------*

*       MODULE USER_COMMAND_0100 INPUT                                *

*---------------------------------------------------------------------*

MODULE user_command_0100 INPUT.

  CASE ok_code.

    WHEN 'EXIT'.

      LEAVE TO SCREEN 0.

  ENDCASE.

ENDMODULE.                 " USER_COMMAND_0100  INPUT

*&---------------------------------------------------------------------*

*&      Module  STATUS_0100  OUTPUT

*&---------------------------------------------------------------------*

MODULE status_0100 OUTPUT.

* The TextEdit control shoul only be initialized the first time the

* PBO module executes

  IF editor IS INITIAL.

    repid = sy-repid.

*   Create obejct for custom container

    CREATE OBJECT custom_container

      EXPORTING

        container_name              = 'MYCONTAINER1'

      EXCEPTIONS

        cntl_error                  = 1

        cntl_system_error           = 2

        create_error                = 3

        lifetime_error              = 4

        lifetime_dynpro_dynpro_link = 5

        others                      = 6

        .

    IF sy-subrc <> 0.

      MESSAGE ID sy-msgid TYPE 'I' NUMBER sy-msgno

                 WITH sy-msgv1 sy-msgv2 sy-msgv3 sy-msgv4.

    ENDIF.

*   Create obejct for the TextEditor control

    CREATE OBJECT editor

      EXPORTING

         wordwrap_mode          =

                cl_gui_textedit=>wordwrap_at_fixed_position

         wordwrap_position      = line_length

         wordwrap_to_linebreak_mode = cl_gui_textedit=>true

        parent                  = custom_container

      EXCEPTIONS

        error_cntl_create      = 1

        error_cntl_init        = 2

        error_cntl_link        = 3

        error_dp_create        = 4

        gui_type_not_supported = 5

        others                 = 6

        .

    IF sy-subrc <> 0.

      MESSAGE ID sy-msgid TYPE 'I' NUMBER sy-msgno

                 WITH sy-msgv1 sy-msgv2 sy-msgv3 sy-msgv4.

    ENDIF.

  ENDIF.

ENDMODULE.                 " STATUS_0100  OUTPUT

The result

 

 

Example 2: Event handling - Application event

There are 2 types of events:

• System events. These events are triggerede irrespective of the screen flow-logic.
• Application events. The PAI module is processed after an event. The method CL_GUI_CFW=>DISPATCH must be called to initiate event handling

In this example an application event is added to the program in example 1. New code is marked with red.

Steps:

1. Create an input/output field on screen 100, where the event type can be output. Name it EVENT_TYPE

The code:

 

REPORT sapmz_hf_controls1 .

CONSTANTS:

  line_length TYPE i VALUE 254.

DATA: ok_code LIKE sy-ucomm.

DATA:

* Create reference to the custom container

  custom_container TYPE REF TO cl_gui_custom_container,

* Create reference to the TextEdit control

  editor TYPE REF TO cl_gui_textedit,

  repid LIKE sy-repid.

**********************************************************************

* Impmenting events

**********************************************************************

DATA:

  event_type(20) TYPE c,

* Internal table for events that should be registred

  i_events TYPE cntl_simple_events,

* Structure for oneline of the table

  wa_events TYPE cntl_simple_event.

*---------------------------------------------------------------------*

*       CLASS lcl_event_handler DEFINITION

*---------------------------------------------------------------------*

CLASS lcl_event_handler DEFINITION.

  PUBLIC SECTION.

    CLASS-METHODS:

      catch_dblclick FOR EVENT dblclick

         OF cl_gui_textedit IMPORTING sender.

ENDCLASS.

CLASS lcl_event_handler IMPLEMENTATION.

  METHOD catch_dblclick.

    event_type = 'Event DBLCLICK raised'.

  ENDMETHOD.

ENDCLASS.

 

START-OF-SELECTION.

  CLEAR wa_events. refresh i_events.

  SET SCREEN '100'.

 

*---------------------------------------------------------------------*

*       MODULE USER_COMMAND_0100 INPUT                                *

*---------------------------------------------------------------------*

MODULE user_command_0100 INPUT.

  CASE ok_code.

    WHEN 'EXIT'.

      LEAVE TO SCREEN 0.

    WHEN OTHERS.

*   Call the Dispacth method to initiate application event handling

    call method cl_gui_cfw=>Dispatch.

 

  ENDCASE.

ENDMODULE.                 " USER_COMMAND_0100  INPUT

*&---------------------------------------------------------------------*

*&      Module  STATUS_0100  OUTPUT

*&---------------------------------------------------------------------*

MODULE status_0100 OUTPUT.

* The TextEdit control shoul only be initialized the first time the

* PBO module executes

  IF editor IS INITIAL.

    repid = sy-repid.

*   Create obejct for custom container

    CREATE OBJECT custom_container

      EXPORTING

        container_name              = 'MYCONTAINER1'

      EXCEPTIONS

        cntl_error                  = 1

        cntl_system_error           = 2

        create_error                = 3

        lifetime_error              = 4

        lifetime_dynpro_dynpro_link = 5

        others                      = 6

        .

    IF sy-subrc <> 0.

      MESSAGE ID sy-msgid TYPE 'I' NUMBER sy-msgno

                 WITH sy-msgv1 sy-msgv2 sy-msgv3 sy-msgv4.

    ENDIF.

*   Create obejct for the TextEditor control

    CREATE OBJECT editor

      EXPORTING

         wordwrap_mode          =

                cl_gui_textedit=>wordwrap_at_fixed_position

         wordwrap_position      = line_length

         wordwrap_to_linebreak_mode = cl_gui_textedit=>true

        parent                  = custom_container

      EXCEPTIONS

        error_cntl_create      = 1

        error_cntl_init        = 2

        error_cntl_link        = 3

        error_dp_create        = 4

        gui_type_not_supported = 5

        others                 = 6

        .

    IF sy-subrc <> 0.

      MESSAGE ID sy-msgid TYPE 'I' NUMBER sy-msgno

                 WITH sy-msgv1 sy-msgv2 sy-msgv3 sy-msgv4.

    ENDIF.

*   Link the event handler method to the event and the

*   TextEdit control

    SET HANDLER lcl_event_handler=>catch_dblclick FOR editor.

*   Register the event in the internal table i_events

    wa_events-eventid = cl_gui_textedit=>event_double_click.

    wa_events-appl_event = 'X'. "This is an application event

    append wa_events to i_events.

*   Pass the table to the TextEdit control using method

*   set_registred_events

    call method editor->set_registered_events

       exporting events = i_events.

  ENDIF.

ENDMODULE.                 " STATUS_0100  OUTPUT

Result:

When you double click on the TextEdit control, the input/ouput field should show the text: Event DBLCLICK

Example 3: Event handling - System event

System events are passed irrespective of the flow-logic of the screen. To implement a system event change the code from example 2 as follows:

Code:

CLASS lcl_event_handler IMPLEMENTATION.

  METHOD catch_dblclick.

*---  event_type = 'Event DBLCLICK raised'.

* Reacting to the system event

  call method cl_gui_cfw=>set_new_ok_code

    exporting new_code = 'SHOW'.

 

 

MODULE user_command_0100 INPUT.

  CASE ok_code.

   code.........

    WHEN 'SHOW'.

      event_type = 'System dblclick'.

    WHEN OTHERS.

*----    call method cl_gui_cfw=>Dispatch.

  ENDCASE.

ENDMODULE.                 " USER_COMMAND_0100  INPUT

 

MODULE status_0100 OUTPUT.

 Code ................

*---    wa_events-appl_event = 'X'. "This is an application event

    wa_events-appl_event = space. "This is a system event

  ENDIF.

ENDMODULE.                 " STATUS_0100  OUTPUT

Result:

When you double clicks on the TextEdit control nothing happens, since the flow-logic of the screen an dthe fielde transport is ignore.

Example 4: Calling methods of the control

In this exercise a function that loads the texts of an internal table into the text window, is implemented.

Steps:

Define anoterh pushbutton on the screen, that activates the method that fills the TextEdit control. Give itname PUSHBUTTON_IMPORT and function code IMP.

Define a form CREATE_TEXTS that carries out the text import.

Only changes to the code in example 2 is show.

Code:

MODULE user_command_0100 INPUT.

  CASE ok_code.

   code.........

    WHEN 'IMP'.

      perform load_texts.

  ENDCASE.

ENDMODULE.                 " USER_COMMAND_0100  INPUT

*&---------------------------------------------------------------------*

*&      Form  load_texts

*&---------------------------------------------------------------------*

* This form creates an internal table with texts. The the contents of

* the table is instered into the TextEdit control using method

* set_text_as_r3table

*----------------------------------------------------------------------*

FORM load_texts.

  TYPES:

   BEGIN OF t_texttable,

     line(line_length) TYPE c,

   END OF t_texttable.

  DATA

    i_texttable TYPE TABLE OF t_texttable.

* Create internal table with texts

  APPEND 'This a method that fills the TextEdit control' TO i_texttable.

  APPEND 'with a text.' TO i_texttable.

  DO 10 TIMES.

    APPEND 'hallo world !' TO i_texttable.

  ENDDO.

* Load TextEdit control with texts

  CALL METHOD editor->set_text_as_r3table

    EXPORTING table = i_texttable.

  IF sy-subrc > 0.

*   Display an error message

    EXIT.

  ENDIF.

* All methods that operates on controls are transferred to the frontend

* by a RFC calls. the method FLUSH is used to determine when this is done.

  CALL METHOD cl_gui_cfw=>flush.

  IF sy-subrc > 0.

*   Display an error message

  ENDIF.

ENDFORM.                    " create_texts

 

Example 5: Responding to an event

When you double click on a text line in the TextEdit control, you want it to be prefixed with a '*'.

The line number of the TextEdit control that is double clicked, is retreived using method GET_SELECTION_POS. The internal text table is reloaded froim the TextEdit control with method GET_TEXT_AS_R3TABLE. The position of the double click in the TextEdit control is used to find the entry in the table, and the entry is prefixed with '*' and loaded into the TextEdit control again.

The program should be changed so that the internal table i_texttable is global, and a global flag g_loaded added. The load of the table should be moved to the PBO module. The changes in thje code are marked with red. The whole program now looks like this:

Code

REPORT sapmz_hf_controls1 .

CONSTANTS:

  line_length TYPE i VALUE 254.

DATA: ok_code LIKE sy-ucomm.

DATA:

* Create reference to the custom container

  custom_container TYPE REF TO cl_gui_custom_container,

* Create reference to the TextEdit control

  editor TYPE REF TO cl_gui_textedit,

  repid LIKE sy-repid.

**********************************************************************

* Utillity table to load texts

**********************************************************************

TYPES:

   BEGIN OF t_texttable,

     line(line_length) TYPE c,

   END OF t_texttable.

DATA:

  i_texttable TYPE TABLE OF t_texttable,

  g_loaded(1) TYPE c.

 

**********************************************************************

* Impmenting events

**********************************************************************

DATA:

  event_type(20) TYPE c,

* Internal table for events that should be registred

  i_events TYPE cntl_simple_events,

* Structure for oneline of the table

  wa_events TYPE cntl_simple_event.

*---------------------------------------------------------------------*

*       CLASS lcl_event_handler DEFINITION

*---------------------------------------------------------------------*

CLASS lcl_event_handler DEFINITION.

  PUBLIC SECTION.

    CLASS-METHODS:

      catch_dblclick FOR EVENT dblclick

         OF cl_gui_textedit IMPORTING sender.

ENDCLASS.

CLASS lcl_event_handler IMPLEMENTATION.

  METHOD catch_dblclick.

    DATA:

      from_line TYPE i,

      from_pos  TYPE i,

      to_line TYPE i,

      to_pos TYPE i,

      wa_texttable TYPE t_texttable.

* Used for the sytem event

  call method cl_gui_cfw=>set_new_ok_code

    exporting new_code = 'SHOW'.

* Read the position of the double click

    CALL METHOD sender->get_selection_pos

      IMPORTING

         from_line = from_line

         from_pos  = from_pos

         to_line   = to_line

         to_pos    = to_pos.

*   Texts in the TextEdit control can have been changed, so

*   first reload text from the control into the internal

*   table that contains text

    IF NOT g_loaded IS INITIAL.

      CALL METHOD sender->get_text_as_r3table

           IMPORTING table = i_texttable.

*   Read the line of the internal table that was clicked

      READ TABLE i_texttable INDEX from_line INTO wa_texttable.

      IF sy-subrc <> 0.

        EXIT.

      ENDIF.

      IF wa_texttable+0(1) CS '*'.

        SHIFT wa_texttable.

      ELSEIF wa_texttable+0(1) NS '*'.

        SHIFT wa_texttable RIGHT.

        wa_texttable+0(1) = '*'.

      ENDIF.

      modify i_texttable from wa_texttable index from_line.

*     Reload texts from h einternal table

      perform load_texts.

    ENDIF.

  ENDMETHOD.

ENDCLASS.

 

START-OF-SELECTION.

  CLEAR wa_events.

  REFRESH: i_events.

  SET SCREEN '100'.

*---------------------------------------------------------------------*

*       MODULE USER_COMMAND_0100 INPUT                                *

*---------------------------------------------------------------------*

MODULE user_command_0100 INPUT.

  CASE ok_code.

    WHEN 'EXIT'.

      LEAVE TO SCREEN 0.

    WHEN 'SHOW'.

      event_type = 'System dblclick'.

    WHEN 'IMP'.

      PERFORM Load_texts.

    WHEN OTHERS.

*    CALL METHOD cl_gui_cfw=>dispatch. "Not used for system events

  ENDCASE.

ENDMODULE.                 " USER_COMMAND_0100  INPUT

*&---------------------------------------------------------------------*

*&      Module  STATUS_0100  OUTPUT

*&---------------------------------------------------------------------*

MODULE status_0100 OUTPUT.

* The TextEdit control shoul only be initialized the first time the

* PBO module executes

  IF editor IS INITIAL.

    repid = sy-repid.

*   Create object for custom container

    CREATE OBJECT custom_container

      EXPORTING

        container_name              = 'MYCONTAINER1'

      EXCEPTIONS

        cntl_error                  = 1

        cntl_system_error           = 2

        create_error                = 3

        lifetime_error              = 4

        lifetime_dynpro_dynpro_link = 5

        others                      = 6

        .

    IF sy-subrc <> 0.

      MESSAGE ID sy-msgid TYPE 'I' NUMBER sy-msgno

                 WITH sy-msgv1 sy-msgv2 sy-msgv3 sy-msgv4.

    ENDIF.

*   Create obejct for the TextEditor control

    CREATE OBJECT editor

      EXPORTING

         wordwrap_mode          =

                cl_gui_textedit=>wordwrap_at_fixed_position

         wordwrap_position      = line_length

         wordwrap_to_linebreak_mode = cl_gui_textedit=>true

        parent                  = custom_container

      EXCEPTIONS

        error_cntl_create      = 1

        error_cntl_init        = 2

        error_cntl_link        = 3

        error_dp_create        = 4

        gui_type_not_supported = 5

        others                 = 6

        .

    IF sy-subrc <> 0.

      MESSAGE ID sy-msgid TYPE 'I' NUMBER sy-msgno

                 WITH sy-msgv1 sy-msgv2 sy-msgv3 sy-msgv4.

    ENDIF.

*   Link the event handler method to the event and the

*   TextEdit control

    SET HANDLER lcl_event_handler=>catch_dblclick FOR editor.

*   Register the event in the internal table i_events

    wa_events-eventid = cl_gui_textedit=>event_double_click.

*    wa_events-appl_event = 'X'. "This is an application event

    wa_events-appl_event = space. "This is a system event

    APPEND wa_events TO i_events.

*   Pass the table to the TextEdit control uding method

*   set_registred_events

    CALL METHOD editor->set_registered_events

       EXPORTING events = i_events.

* Create internal table with texts taht can be uploaded to

* the TextEdit control

  APPEND 'This a method that fills the TextEdit control' TO i_texttable.

    APPEND 'with a text.' TO i_texttable.

    DO 10 TIMES.

      APPEND 'hallo world !' TO i_texttable.

    ENDDO.

 

  ENDIF.

ENDMODULE.                 " STATUS_0100  OUTPUT

*&---------------------------------------------------------------------*

*&      Form Load_texts

*&---------------------------------------------------------------------*

* This form loads the lines of the internal table i_texttable into

* the TextEdit control

*----------------------------------------------------------------------*

FORM Load_texts.

* Load TextEdit control with texts

  CALL METHOD editor->set_text_as_r3table

    EXPORTING table = i_texttable.

  IF sy-subrc > 0.

*   Display an error message

    EXIT.

  ENDIF.

* All methods that operates on controls are transferred to the frontend

* by a RFC calls. the method FLUSH is used to determine when this is

* done.

  CALL METHOD cl_gui_cfw=>flush.

  IF sy-subrc > 0.

*   Display an error message

  ENDIF.

  g_loaded = 'X'.

ENDFORM.                    " create_texts

Example 6: Protect a line in the TextEdit control and the importance of FLUSH

All methods that operates on controls are transfered to the fronend by RFC calls. The FLUSH method is used to synchronize control execution and the frontend. This is very important when working e.g. with export parameters from a method, as the parmeters will not be correct before the FLUSH method has been called.

The example below portects selected lines in the TextEdit and uses FLUSH to ensure that the correct parameters are returned from method GET_SELECTION_POS.

Note: Instead of using method PROTECT_LINES, the method PROTECT_SELECTION could be used. This method does not need line numbers or a FLUSH statement

Steps

• Add a new pushbutton to the screen with the function code PROTECT.

Code

Add the following code to the example:

* Global variables

DATA:

   from_idx TYPE i,

   to_idx TYPE i,

   index TYPE i.

MODULE user_command_0100 INPUT.

  CASE ok_code.

    code.......................

    WHEN 'PROTECT'.

      PERFORM protect.

 

.    .......................

  ENDCASE.

*&---------------------------------------------------------------------*

*&      Form  protect

*&---------------------------------------------------------------------*

* Protects marked lines in a TextEdit control

*----------------------------------------------------------------------*

FORM protect.

* Determine the area selected by the user

  CALL METHOD editor->get_selection_pos

     IMPORTING

       from_line = from_idx

       to_line   = to_idx

     EXCEPTIONS

       error_cntl_call_method = 1.

* Synchronize execution in the control with the ABAP program.

* Without this synchronization the variables from_idx and

* to_idx will have obsolutete values (The initial value for

* both, are 0)

  CALL METHOD cl_gui_cfw=>flush.

  IF sy-subrc > 0.

* Errormessage: Error in flush

  ENDIF.

* Protect the selected lines

  IF to_idx > from_idx.

    to_idx = to_idx - 1.

  ENDIF.

  CALL METHOD editor->protect_lines

    EXPORTING

      from_line = from_idx

      to_line   = to_idx.

* The PROTECT_SELECTION method could be used instead, eliminating the

* need of line numbers and the last FLUSH

 

* call method editor->protect_selection.

* Flush again to protect immidiately

  CALL METHOD cl_gui_cfw=>flush.

  IF sy-subrc > 0.

* Errormessage: Error in flush

  ENDIF.

 

ENDFORM.                    " protect

 Example 7: Using multiple controls

In this example a second TextEdit control will be added to the screen. The new TextEdit control will be designed to act as a clipboard for short texts.

Steps:

• Add a new container to the screen and name it MYCONTAINER2.

 Code:

Insert global datadeclaration:

**********************************************************************

* Implementing a second Scratch TextEdit control

**********************************************************************

DATA:

  scratch            TYPE REF TO cl_gui_textedit,

  custom_container2  TYPE REF TO cl_gui_custom_container.

Insert the following code in the PBO module:

*------------------------------------------------------

* The SCRATCH TextEdit control

*------------------------------------------------------

  IF scratch IS INITIAL.

*   Create obejct for custom container2

    CREATE OBJECT custom_container2

      EXPORTING

        container_name              = 'MYCONTAINER2'

      EXCEPTIONS

        cntl_error                  = 1

        cntl_system_error           = 2

        create_error                = 3

        lifetime_error              = 4

        lifetime_dynpro_dynpro_link = 5

        others                      = 6

        .

    IF sy-subrc <> 0.

      MESSAGE ID sy-msgid TYPE 'I' NUMBER sy-msgno

                 WITH sy-msgv1 sy-msgv2 sy-msgv3 sy-msgv4.

    ENDIF.

*   Create obejct for the SCRATCH TextEditor control

    CREATE OBJECT scratch

      EXPORTING

         parent         = custom_container2

         wordwrap_mode  =

                cl_gui_textedit=>wordwrap_at_windowborder

        wordwrap_to_linebreak_mode = cl_gui_textedit=>true.

*   Remove the staus bar

    CALL METHOD scratch->set_statusbar_mode

      EXPORTING statusbar_mode = cl_gui_textedit=>false.

  ENDIF.

Result:

 1  REPORT sapmz_hf_controls1 .

      2 

      3  CONSTANTS:

      4    line_length TYPE i VALUE 254.

      5 

      6  DATA: ok_code LIKE sy-ucomm.

      7 

      8  DATA:

      9  * Create reference to the custom container

     10    custom_container TYPE REF TO cl_gui_custom_container,

     11  * Create reference to the TextEdit control

     12    editor TYPE REF TO cl_gui_textedit,

     13    repid LIKE sy-repid.

     14 

     15  **********************************************************************

     16  * Utillity table to load texts

     17  **********************************************************************

     18  TYPES:

     19     BEGIN OF t_texttable,

     20       line(line_length) TYPE c,

     21     END OF t_texttable.

     22 

     23  DATA:

     24    i_texttable TYPE TABLE OF t_texttable,

     25    wa_texttable TYPE t_texttable,

     26    g_loaded(1) TYPE c.

     27 

     28  **********************************************************************

     29  * Data for the protection example

     30  **********************************************************************

     31  DATA:

     32    from_idx TYPE i,

     33    to_idx   TYPE i,

     34    index    TYPE i.

     35 

     36  **********************************************************************

     37  * Implementing a second Scratch TextEdit control

     38  **********************************************************************

     39  DATA:

     40    scratch            TYPE REF TO cl_gui_textedit,

     41    custom_container2  TYPE REF TO cl_gui_custom_container.

     42 

     43 

     44  **********************************************************************

     45  * Implementing events

     46  **********************************************************************

     47  DATA:

     48    event_type(20) TYPE c,

     49  * Internal table for events that should be registred

     50    i_events TYPE cntl_simple_events,

     51  * Structure for oneline of the table

     52    wa_events TYPE cntl_simple_event.

     53 

     54  *---------------------------------------------------------------------*

     55  *       CLASS lcl_event_handler DEFINITION

     56  *---------------------------------------------------------------------*

     57  *       ........                                                      *

     58  *---------------------------------------------------------------------*

     59  CLASS lcl_event_handler DEFINITION.

     60    PUBLIC SECTION.

     61      CLASS-METHODS:

     62        catch_dblclick FOR EVENT dblclick

     63           OF cl_gui_textedit IMPORTING sender.

     64 

     65  ENDCLASS.

     66 

     67  *---------------------------------------------------------------------*

     68  *       CLASS lcl_event_handler IMPLEMENTATION

     69  *---------------------------------------------------------------------*

     70  *       ........                                                      *

     71  *---------------------------------------------------------------------*

     72  CLASS lcl_event_handler IMPLEMENTATION.

     73    METHOD catch_dblclick.

     74      DATA:

     75        from_line TYPE i,

     76        from_pos  TYPE i,

     77        to_line TYPE i,

     78        to_pos TYPE i.

     79 

     80 

     81  * Used for the sytem event

     82      CALL METHOD cl_gui_cfw=>set_new_ok_code

     83        EXPORTING new_code = 'SHOW'.

     84 

     85 

     86  * Read the position of the double click

     87      CALL METHOD sender->get_selection_pos

     88        IMPORTING

     89           from_line = from_line

     90           from_pos  = from_pos

     91           to_line   = to_line

     92           to_pos    = to_pos.

     93 

     94  *   Texts in the TextEdit control can have been changed, so

     95  *   first reload text from the control into the internal

     96  *   table that contains text

     97      IF NOT g_loaded IS INITIAL.

     98        CALL METHOD sender->get_text_as_r3table

     99             IMPORTING table = i_texttable.

    100  *   Read the line of the internal table that was clicked

    101        READ TABLE i_texttable INDEX from_line INTO wa_texttable.

    102        IF sy-subrc <> 0.

    103          EXIT.

    104        ENDIF.

    105 

    106        IF wa_texttable+0(1) CS '*'.

    107          SHIFT wa_texttable.

    108        ELSEIF wa_texttable+0(1) NS '*'.

    109          SHIFT wa_texttable RIGHT.

    110          wa_texttable+0(1) = '*'.

    111        ENDIF.

    112        MODIFY i_texttable FROM wa_texttable INDEX from_line.

    113  *     Reload texts from h einternal table

    114        PERFORM load_texts.

    115 

    116 

    117      ENDIF.

    118 

    119 

    120    ENDMETHOD.

    121  ENDCLASS.

    122 

    123 

    124 

    125  START-OF-SELECTION.

    126    CLEAR wa_events.

    127    REFRESH: i_events.

    128 

    129    SET SCREEN '100'.

    130 

    131 

    132 

    133  *---------------------------------------------------------------------*

    134  *       MODULE USER_COMMAND_0100 INPUT                                *

    135  *---------------------------------------------------------------------*

    136  MODULE user_command_0100 INPUT.

    137 

    138    CASE ok_code.

    139      WHEN 'EXIT'.

    140        LEAVE TO SCREEN 0.

    141      WHEN 'SHOW'.

    142        event_type = 'System dblclick'.

    143      WHEN 'IMP'.

    144        PERFORM load_texts.

    145      WHEN 'PROTECT'.

    146        PERFORM protect.

    147 

    148      WHEN OTHERS.

    149  *    CALL METHOD cl_gui_cfw=>dispatch. "Not used for system events

    150    ENDCASE.

    151 

    152 

    153  ENDMODULE.                 " USER_COMMAND_0100  INPUT

    154  *&---------------------------------------------------------------------*

    155  *&      Module  STATUS_0100  OUTPUT

    156  *&---------------------------------------------------------------------*

    157  MODULE status_0100 OUTPUT.

    158  * The TextEdit control shoul only be initialized the first time the

    159  * PBO module executes

    160    IF editor IS INITIAL.

    161      repid = sy-repid.

    162  *   Create obejct for custom container

    163      CREATE OBJECT custom_container

    164        EXPORTING

    165          container_name              = 'MYCONTAINER1'

    166        EXCEPTIONS

    167          cntl_error                  = 1

    168          cntl_system_error           = 2

    169          create_error                = 3

    170          lifetime_error              = 4

    171          lifetime_dynpro_dynpro_link = 5

    172          others                      = 6

    173          .

    174      IF sy-subrc <> 0.

    175        MESSAGE ID sy-msgid TYPE 'I' NUMBER sy-msgno

    176                   WITH sy-msgv1 sy-msgv2 sy-msgv3 sy-msgv4.

    177      ENDIF.

    178 

    179  *   Create obejct for the TextEditor control

    180      CREATE OBJECT editor

    181        EXPORTING

    182 

    183           wordwrap_mode          =

    184                  cl_gui_textedit=>wordwrap_at_fixed_position

    185           wordwrap_position      = line_length

    186           wordwrap_to_linebreak_mode = cl_gui_textedit=>true

    187          parent                  = custom_container

    188        EXCEPTIONS

    189          error_cntl_create      = 1

    190          error_cntl_init        = 2

    191          error_cntl_link        = 3

    192          error_dp_create        = 4

    193          gui_type_not_supported = 5

    194          others                 = 6

    195          .

    196      IF sy-subrc <> 0.

    197        MESSAGE ID sy-msgid TYPE 'I' NUMBER sy-msgno

    198                   WITH sy-msgv1 sy-msgv2 sy-msgv3 sy-msgv4.

    199      ENDIF.

    200 

    201  *   Link the event handler method to the event and the

    202  *   TextEdit control

    203      SET HANDLER lcl_event_handler=>catch_dblclick FOR editor.

    204 

    205  *   Register the event in the internal table i_events

    206      wa_events-eventid = cl_gui_textedit=>event_double_click.

    207 

    208  *    wa_events-appl_event = 'X'. "This is an application event

    209      wa_events-appl_event = space. "This is a system event

    210 

    211 

    212      APPEND wa_events TO i_events.

    213  *   Pass the table to the TextEdit control uding method

    214  *   set_registred_events

    215      CALL METHOD editor->set_registered_events

    216         EXPORTING events = i_events.

    217 

    218  * Create internal table with texts taht can be uploaded to

    219  * the TextEdit control

    220    APPEND 'This a method that fills the TextEdit control' TO i_texttable.

    221      APPEND 'with a text.' TO i_texttable.

    222      DO 10 TIMES.

    223        APPEND 'hallo world !' TO i_texttable.

    224      ENDDO.

    225    ENDIF.

    226 

    227  *------------------------------------------------------

    228  * The SCRATCH TextEdit control

    229  *------------------------------------------------------

    230    IF scratch IS INITIAL.

    231  *   Create obejct for custom container2

    232      CREATE OBJECT custom_container2

    233        EXPORTING

    234          container_name              = 'MYCONTAINER2'

    235        EXCEPTIONS

    236          cntl_error                  = 1

    237          cntl_system_error           = 2

    238          create_error                = 3

    239          lifetime_error              = 4

    240          lifetime_dynpro_dynpro_link = 5

    241          others                      = 6

    242          .

    243      IF sy-subrc <> 0.

    244        MESSAGE ID sy-msgid TYPE 'I' NUMBER sy-msgno

    245                   WITH sy-msgv1 sy-msgv2 sy-msgv3 sy-msgv4.

    246      ENDIF.

    247 

    248  *   Create obejct for the SCRATCH TextEditor control

    249      CREATE OBJECT scratch

    250        EXPORTING

    251           parent         = custom_container2

    252           wordwrap_mode  =

    253                  cl_gui_textedit=>wordwrap_at_windowborder

    254          wordwrap_to_linebreak_mode = cl_gui_textedit=>true.

    255 

    256  *   Remove the staus bar

    257      CALL METHOD scratch->set_statusbar_mode

    258        EXPORTING statusbar_mode = cl_gui_textedit=>false.

    259 

    260    ENDIF.

    261 

    262 

    263  ENDMODULE.                 " STATUS_0100  OUTPUT

    264 

    265  *&---------------------------------------------------------------------*

    266  *&      Form Load_texts

    267  *&---------------------------------------------------------------------*

    268  * This form loads the lines of the internal table i_texttable into

    269  * the TextEdit control

    270  *----------------------------------------------------------------------*

    271  FORM load_texts.

    272 

    273  * Load TextEdit control with texts

    274    CALL METHOD editor->set_text_as_r3table

    275      EXPORTING table = i_texttable.

    276    IF sy-subrc > 0.

    277  *   Display an error message

    278      EXIT.

    279    ENDIF.

    280 

    281  * All methods that operates on controls are transferred to the frontend

    282  * by a RFC calls. the method FLUSH is used to determine when this is

    283  * done.

    284    CALL METHOD cl_gui_cfw=>flush.

    285    IF sy-subrc > 0.

    286  *   Display an error message

    287    ENDIF.

    288    g_loaded = 'X'.

    289  ENDFORM.                    " create_texts

    290  *&---------------------------------------------------------------------*

    291  *&      Form  protect

    292  *&---------------------------------------------------------------------*

    293  * Protects marked lines in a TextEdit control

    294  *----------------------------------------------------------------------*

    295  FORM protect.

    296  * Determine the area selected by the user

    297    CALL METHOD editor->get_selection_pos

    298       IMPORTING

    299         from_line = from_idx

    300         to_line   = to_idx

    301       EXCEPTIONS

    302         error_cntl_call_method = 1.

    303 

    304  * Synchronize execution in the control with the ABAP program.

    305  * Without this synchronization the variables from_idx and

    306  * to_idx will have obsolutete values (The initial value for

    307  * both, are 0)

    308    CALL METHOD cl_gui_cfw=>flush.

    309    IF sy-subrc > 0.

    310  * Errormessage: Error in flush

    311    ENDIF.

    312 

    313  * Protect the lines selected

    314    IF to_idx > from_idx.

    315      to_idx = to_idx - 1.

    316    ENDIF.

    317    CALL METHOD editor->protect_lines

    318      EXPORTING

    319        from_line = from_idx

    320        to_line   = to_idx.

    321 

    322 

    323  * The PROTECT_SELECTION method could be used instead, eliminating the

    324  * need of line numbers and the last FLUSH

    325 

    326  * call method editor->protect_selection.

    327 

    328 

    329  * Flush again to protect immidately

    330    CALL METHOD cl_gui_cfw=>flush.

    331    IF sy-subrc > 0.

    332  * Errormessage: Error in flush

    333    ENDIF.

    334 

    335 

    336 

    337  ENDFORM.                    " protect

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