If you want to receive and handle the events of a GUI control in your program, you must identify the events that the object can trigger. The associated class for representative objects of the control can provide you with this information.

 

For information about the representative classes, see the online documentation for the respective controls.

 

 

Searches for ALV Grid Events

The ALV grid control has more than 25 events.

 

The Most Important Events of the ALV Grid

• DOUBLE_CLICK
  This event is triggered after a double-click with the mouse.
• PRINT_TOP_OF_LIST, PRINT_TOP_OF_PAGE, PRINT_END_OF_PAGE, PRINT_END_OF_LIST
  These events are triggered at various points during output of the print list.
• TOOLBAR
  This event is triggered when the ALV grid control is created or refreshed, but can also be triggered  explicitly with a method. It allows you to change the composition of the toolbar.
• USER_COMMAND
  This event is triggered when user-defined function codes are chosen. These codes are assigned to your own buttons in the toolbar or entries in the context menu. This event allows you to implement your own functions.

 

 

Event Handlers

Every event has an implicit parameter, called sender, which you can also receive by listing it in the IMPORTING addition. This parameter allows handlers of instance events to access the instance that triggered the event, for example, to call its methods.

 

A static handler method is declared with CLASS-METHODS .... You do not have to instantiate the class to use static handler methods.

 

The definition of an event handler method in a class means that the instances of the class and the class itself are, in principle, capable of handling the event in question.

 

 

ALV Grid Control Events Through Mouse Operations

If the user double-clicks the data area, the double_click event is triggered in the calling program.

 

The export parameters contain information about the data table. Both of these parameters are structures.

 

The export parameters are as follows:

• ES_ROW_NO
  You can find the number of the double-clicked row in the row_id This corresponds to the correct row number in the internal table.
• E_COLUMN
  You can find the name of the double-clicked column in the FIELDNAME This corresponds to the correct column name in the internal table.

 

If a column has been identified as a hotspot, and the user presses the mouse button in the hotspot column of the data area, the hotspot_click event is triggered in the calling program. The export parameters are filled in the same way as for the double_click event.

 

 

Syntax Example – Handlers as Static Methods

A handler method can be a static method, for example, of a local class, or an instance method of an object.

 

In case of a static method, the local class can be compared with a repository that stores the methods. The difference in the class method compared with the instance method is that you do not need to instantiate an object for the local class to use the method.

 

To create a handler method for an event, first define a local class. The local class requires a public method (in the PUBLIC SECTION) that is defined as a handler method for a particular event of a certain class. You can use the CLASS-METHODS statement for this process.

 

After defining the method, you need to implement it.

 

The method receives the information provided by the event about the mouse position at the double-click and generates an information message that displays the row and field of the mouse click.

 

 

Syntax Example – Handlers as Instance Methods

To generate an instance method, use the METHODS statement when defining the class.

 

Implement the method in the same way as the class method and then create a reference variable with a reference to your local class. Finally, create a corresponding object.