In this window the currently active file will be shown. A program (or a class) can consist of several files, which are listed in the Explorer:.
The keywords of the source file are marked by different colors. Comments are also shown in s special color. You can also have the line numbers shown at the left side or the column numbers on the top. The source files can be modified in the editor. On modification the color changes to gray for to discern them form the original source. On pressing the save button the source becomes analyzed again and its syntactical structuire is checked.
Automatic code completion is invoked by simultaneously clicking Ctrl and Space:
The simple formatting of the source code is invoked by pressing the 
button.
If you doubleclick on a file name (without path), it will be opened, if it is found via the libraries specified in the options dialogue.
If you doubleclick on the grey area above the source, it will become maximized within the window.In the search and replace dialog it is possible to use simple regular expressions consisting of:
| ^ | beginning of a line |
| $ | end of a line |
| [a-z] | is a character between a and z |
| \] | is the character ] |
| . | stands for every character |
| [a] | exactly the character a |
| \0 | is the text found in the replace field |
Examples:
| ^...... | finds the first 6 characters of a line |
| [a-z][0-9] | finds pairs of characters like a1, b2, c5 etc. |