A few general tips

KDE application names generally start with the letter K followed by a name suggesting what the program does. For example, KMail is very simple and tells the user that this is indeed a KDE application and about email. A good practice is to choose an english name for the name that follows the K. Of course, this is just an indication and you are free to do what you want. But a good name can help to get your program known quicker.

Comments should be in English as it is really easier if someone else has a look at your code.

Class names usually are also in English and the names must indicate what the class does. Good examples: TopLevel, CursorInterface, TaskManager. Note the upper case letters and remember that C++ is case-sensitive.

Function names usually begin with a lower case letter and here are examples of good names:

void activateRaiseOrIconify();
void toDesktop(int);
void windowAdded(WId);

Code indentation can be whatever you like as long as the code is lisible for other developers. Always keep in mind that other people will have a look in your code and try to make it easy to read.