• in Java applications generated with WINDEV.
• in Android applications generated with WINDEV Mobile.

Writing a global procedure in Java

1. Create a new global procedure (via "New global procedure" in the context menu of sets of procedures in the "Project explorer" pane). Specify the name of this procedure.
2. The procedure is created in the code editor.
3. In the header of the procedure, click "WL" to change the type of code.
   
4. In the list that opens, select "Java".
5. The header becomes purple and "Java" appears to the left of the procedure name. The existing code is commented out.
   
6. Write the Java code directly in the code editor in WINDEV and/or WINDEV Mobile.

Important notes

• In Java procedures, parameters are automatically passed by value.
• The parameters of procedures written in Java must be of a primitive type (integer, real, string, etc.).
  Caution: The float type is not supported, it can be replaced with the double type.
• The return values of methods must be of a primitive type (integer, real, string, etc.).
  Caution: The float type is not supported, it can be replaced with the double type.
• Caution: you need to import the classes used in the native Java code with the "Import" keyword. It is recommended to import these elements before declaring the method.
• Only comments and imported elements are taken in into account in the lines of code before the prototype of the Java function. Any other code will be ignored and may trigger an error (especially missing parenthesis).
• Java is case-sensitive: make sure you always use the same lowercase and uppercase characters in the function names.

Android specific features:

• If the Java code entered requires specific permissions, they must be explicitly defined when generating the application. For more details, see Generating an Android application.
• The classes and methods of Android SDK often handle a reference on a "Context" object. In an Android project, when writing native code, you can retrieve a "Context" object by referencing the current activity or the application context via the following methods (these methods can be directly called in the code of the procedure):
  
  // Get the current activity
  getCurrentActivity()
  
  // Get the current "Context"
  getApplicationContext()
• To retrieve the View object corresponding to the main control component, you must use the getView method while passing the control name.
  Example: The following code returns the instance of the "Button" class used by the control:
  
  getView("BTN_Button1")

Generating the application

• The Java classes used in the native Java code must be specified in the Android application generation wizard:
  • "Integrate libraries" step for classes included in ".jar" or ".aar" libraries.
  • "Integrate Maven dependencies" step for Maven dependencies.
    Remark: These classes cannot be tested via the GO option. The application must be generated and launched.
• The Java classes used in the native Java code must be specified in the Java application generation wizard ("Other archive files" step).
  Remark: These classes cannot be tested via the GO option. The application must be generated and launched.
• Automatically take into account external classes: To automatically take external Java classes into account when generating the application:
  • Add the files to the "Other" folder of the "Project explorer" pane (via the "Add elements" option of the context menu).
    Caution: Java files must be encoded in UTF-8.
  • If the Java class belongs to a package, this package must be declared in the first line of the file. If the package is not specified, the file will be located in <Package_AppName>.wdgen with the other generated ".java" files.