Chapter 1. The various actions

Each object in a form has its own programmable actions. General actions are

Let's write a 'hello world' program. Create a new form and add a button. Select the button and click on the 'On click'-actionbutton in the property editor. Now add the following program into the program editor

Example 1-1. Hello world-program

   1 hk_this.show_warningmessage("Hello world")
   2 

Now close the window and change to viewmode. When you push the button you will see a dialog window with "Hello world".

The global variable hk_this is set from hk_classes and represents the current object, in this case the button. show_warningmessage() is a method of this object, that allows you to display a string in a GUI independent way (as knoda is a KDE application it will be displayed as a KDE window but if you start it within a command line program it will be displayed on the standard output).

Important

Other GUI-independent ways for user interaction are

  • show_warningmessage(message); displays 'message'

  • bool show_yesnodialog(message, bool default_value); displays 'message' and returns true if you answer 'yes'. The parameter 'default_value' is used for conevience to preselect 'yes' or 'no' in dialog boxes

  • hk_string show_stringvaluedialog(text); displays 'text' as a question and returns your response