Geany is very lightweight thanks to the smaller offering of features.

Geany is a cross platform editor, very similar to Notepad++ in Windows.

Which usually means it will remain free of charge.

Hence it is capable of showing the methods and inner classes of, e.g., a Java source file.

For example, there is an easy way to change the font and theme in the View menu. No need to search through several syntax styles like in Notepad++ just to be able to change the used font.

Geany has a built-in plugin manager which can be used to install plugins and add new powerful features to the editor.

Press F5 and code will run without the need to switch between windows.