Is there an existing issue for this?

• I have searched the existing issues

Description of the Issue

I've been thinking about a feature that could enhance the user experience in Notepad++: displaying the temporary name as the first line in untitled documents.

Many modern editors such as VS Code and Sublime Text implement a similar feature, and I find it quite helpful. It gives users a quick context of which untitled tab they're working in, especially when multiple are open.

I came across issue #3994, which touched on a related topic.

Although that issue was closed with an alternative solution that works well, I believe this specific feature still has merit and could be useful to some users.

I’m suggesting it as an optional setting, so users who prefer a cleaner untitled document can keep the current behavior, while others who find value in the temporary name display can enable it.

Thanks for considering this!

Describe the solution you'd like.

1. Add an option in Preferences > New Document (which is disabled by default).

2. If the option is enabled and the document is untitled (displayed as "new #"), use the first line as the temporary name for it.
3. If the user updates the first line, the temporary name will be updated as well.
4. If the first line is empty, use the original name ("new #").
5. Restrict length and remove invalid characters to make a valid file name (VS Code doesn't have this).
6. Auto-detect language based on temporary file name

   Example: If the first line is "// sample.cpp", the temporary name will be sample.cpp and file will automatically be detected as C++ language

Debug Information

Notepad++ v8.8.1   (64-bit)
Build time : May 23 2025 - 10:54:53
Scintilla/Lexilla included : 5.5.6/5.4.4
Boost Regex included : 1_85
Path : C:\Program Files\Notepad++\notepad++.exe
Command Line : 
Admin mode : ON
Local Conf mode : OFF
Cloud Config : OFF
Periodic Backup : ON
Placeholders : OFF
Scintilla Rendering Mode : SC_TECHNOLOGY_DEFAULT (0)
Multi-instance Mode : monoInst
File Status Auto-Detection : cdEnabledNew (for current file/tab only)
Dark Mode : OFF
Display Info : 
    primary monitor: 1920x1080, scaling 112%
    visible monitors count: 1
    installed Display Class adapters: 
        0001: Description - Intel(R) UHD Graphics 630
        0001: DriverVersion - 31.0.101.2111
        0002: Description - NVIDIA GeForce GTX 1050 Ti
        0002: DriverVersion - 32.0.15.7652
    - warning, search has been limited to maximum number of adapter records: 4
OS Name : Windows 11 Pro (64-bit)
OS Version : 24H2
OS Build : 26100.3775
Current ANSI codepage : 1252
Plugins : 
    mimeTools (3.1)
    NppConverter (4.6)
    NppExport (0.4)

Anything else?

No response