Currently, when selecting a text editor in the engine settings, you can only pick between Visual Studio, VS Code, and the jetbrains one. Why is this, and why can’t I choose to use a IDE or text editor that isn’t one of those?
Unreal Engine knows how to generate project files and open up source files in those editors, and each editor/IDE requires custom code inside the engine.
If you look at the source code of UnrealBuildTool, you can see that they support the following project file generators:
C:\UnrealEngine\UE_4.26\Engine\Source\Programs\UnrealBuildTool\ProjectFiles> dir
Directory: C:\UnrealEngine\UE_4.26\Engine\Source\Programs\UnrealBuildTool\ProjectFiles
Mode LastWriteTime Length Name
---- ------------- ------ ----
d---- 12/3/20 11:00 CLion
d---- 12/3/20 11:00 CMake
d---- 12/3/20 11:00 CodeLite
d---- 12/3/20 11:00 Eddie
d---- 12/3/20 11:00 KDevelop
d---- 12/3/20 11:00 Make
d---- 12/3/20 11:00 QMake
d---- 4/30/21 8:43 Rider
d---- 4/30/21 8:43 VisualStudio
d---- 4/30/21 8:43 VisualStudioCode
d---- 12/3/20 11:00 VisualStudioMac
d---- 4/30/21 8:43 Xcode
--r-- 2/3/21 8:55 14236 PlatformProjectGenerator.cs
--r-- 12/3/20 10:55 5176 PlatformProjectGeneratorCollection.cs
--r-- 12/3/20 10:55 20801 Project.cs
--r-- 2/3/21 8:55 127018 ProjectFileGenerator.cs
That said, you’re free to use any editor you want. I use Vim myself, though it doesn’t have built in support. My Vim setup allows me to switch between headers and source files, jump to definitions, do basic autocomplete (though not nearly as sophisticated as Visual Studio). The main thing my setup doesn’t support is the UE4 Editor integration for creating new C++ classes from the Editor or for jumping to source code from the Editor.